1
|
Lindsey CR, Knoll AH, Herron MD, Rosenzweig F. Fossil-calibrated molecular clock data enable reconstruction of steps leading to differentiated multicellularity and anisogamy in the Volvocine algae. BMC Biol 2024; 22:79. [PMID: 38600528 PMCID: PMC11007952 DOI: 10.1186/s12915-024-01878-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 04/03/2024] [Indexed: 04/12/2024] Open
Abstract
BACKGROUND Throughout its nearly four-billion-year history, life has undergone evolutionary transitions in which simpler subunits have become integrated to form a more complex whole. Many of these transitions opened the door to innovations that resulted in increased biodiversity and/or organismal efficiency. The evolution of multicellularity from unicellular forms represents one such transition, one that paved the way for cellular differentiation, including differentiation of male and female gametes. A useful model for studying the evolution of multicellularity and cellular differentiation is the volvocine algae, a clade of freshwater green algae whose members range from unicellular to colonial, from undifferentiated to completely differentiated, and whose gamete types can be isogamous, anisogamous, or oogamous. To better understand how multicellularity, differentiation, and gametes evolved in this group, we used comparative genomics and fossil data to establish a geologically calibrated roadmap of when these innovations occurred. RESULTS Our ancestral-state reconstructions, show that multicellularity arose independently twice in the volvocine algae. Our chronograms indicate multicellularity evolved during the Carboniferous-Triassic periods in Goniaceae + Volvocaceae, and possibly as early as the Cretaceous in Tetrabaenaceae. Using divergence time estimates we inferred when, and in what order, specific developmental changes occurred that led to differentiated multicellularity and oogamy. We find that in the volvocine algae the temporal sequence of developmental changes leading to differentiated multicellularity is much as proposed by David Kirk, and that multicellularity is correlated with the acquisition of anisogamy and oogamy. Lastly, morphological, molecular, and divergence time data suggest the possibility of cryptic species in Tetrabaenaceae. CONCLUSIONS Large molecular datasets and robust phylogenetic methods are bringing the evolutionary history of the volvocine algae more sharply into focus. Mounting evidence suggests that extant species in this group are the result of two independent origins of multicellularity and multiple independent origins of cell differentiation. Also, the origin of the Tetrabaenaceae-Goniaceae-Volvocaceae clade may be much older than previously thought. Finally, the possibility of cryptic species in the Tetrabaenaceae provides an exciting opportunity to study the recent divergence of lineages adapted to live in very different thermal environments.
Collapse
Affiliation(s)
- Charles Ross Lindsey
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Andrew H Knoll
- Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford St., Cambridge, MA, 02138, USA
| | - Matthew D Herron
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Frank Rosenzweig
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
- Parker H. Petit Institute for Bioengineering and Biosciences, Atlanta, GA, 30332, USA.
| |
Collapse
|
2
|
Ma X, Shi X, Wang Q, Zhao M, Zhang Z, Zhong B. A Reinvestigation of Multiple Independent Evolution and Triassic-Jurassic Origins of Multicellular Volvocine Algae. Genome Biol Evol 2023; 15:evad142. [PMID: 37498572 PMCID: PMC10410301 DOI: 10.1093/gbe/evad142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 07/09/2023] [Accepted: 07/22/2023] [Indexed: 07/28/2023] Open
Abstract
The evolution of multicellular organisms is considered to be a major evolutionary transition, profoundly affecting the ecology and evolution of nearly all life on earth. The volvocine algae, a unique clade of chlorophytes with diverse cell morphology, provide an appealing model for investigating the evolution of multicellularity and development. However, the phylogenetic relationship and timescale of the volvocine algae are not fully resolved. Here, we use extensive taxon and gene sampling to reconstruct the phylogeny of the volvocine algae. Our results support that the colonial volvocine algae are not monophyletic group and multicellularity independently evolve at least twice in the volvocine algae, once in Tetrabaenaceae and another in the Goniaceae + Volvocaceae. The simulation analyses suggest that incomplete lineage sorting is a major factor for the tree topology discrepancy, which imply that the multispecies coalescent model better fits the data used in this study. The coalescent-based species tree supports that the Goniaceae is monophyletic and Crucicarteria is the earliest diverging lineage, followed by Hafniomonas and Radicarteria within the Volvocales. By considering the multiple uncertainties in divergence time estimation, the dating analyses indicate that the volvocine algae occurred during the Cryogenian to Ediacaran (696.6-551.1 Ma) and multicellularity in the volvocine algae originated from the Triassic to Jurassic. Our phylogeny and timeline provide an evolutionary framework for studying the evolution of key traits and the origin of multicellularity in the volvocine algae.
Collapse
Affiliation(s)
- Xiaoya Ma
- College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Xuan Shi
- College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Qiuping Wang
- College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Mengru Zhao
- College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Zhenhua Zhang
- College of Life Sciences, Nanjing Normal University, Nanjing, China
| | - Bojian Zhong
- College of Life Sciences, Nanjing Normal University, Nanjing, China
| |
Collapse
|
3
|
Grochau-Wright ZI, Nedelcu AM, Michod RE. The Genetics of Fitness Reorganization during the Transition to Multicellularity: The Volvocine regA-like Family as a Model. Genes (Basel) 2023; 14:genes14040941. [PMID: 37107699 PMCID: PMC10137558 DOI: 10.3390/genes14040941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 04/06/2023] [Accepted: 04/13/2023] [Indexed: 04/29/2023] Open
Abstract
The evolutionary transition from single-celled to multicellular individuality requires organismal fitness to shift from the cell level to a cell group. This reorganization of fitness occurs by re-allocating the two components of fitness, survival and reproduction, between two specialized cell types in the multicellular group: soma and germ, respectively. How does the genetic basis for such fitness reorganization evolve? One possible mechanism is the co-option of life history genes present in the unicellular ancestors of a multicellular lineage. For instance, single-celled organisms must regulate their investment in survival and reproduction in response to environmental changes, particularly decreasing reproduction to ensure survival under stress. Such stress response life history genes can provide the genetic basis for the evolution of cellular differentiation in multicellular lineages. The regA-like gene family in the volvocine green algal lineage provides an excellent model system to study how this co-option can occur. We discuss the origin and evolution of the volvocine regA-like gene family, including regA-the gene that controls somatic cell development in the model organism Volvox carteri. We hypothesize that the co-option of life history trade-off genes is a general mechanism involved in the transition to multicellular individuality, making volvocine algae and the regA-like family a useful template for similar investigations in other lineages.
Collapse
Affiliation(s)
| | - Aurora M Nedelcu
- Biology Department, University of New Brunswick, Fredericton, NB E3B 5A3, Canada
| | - Richard E Michod
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA
| |
Collapse
|
4
|
Jiménez-Marín B, Rakijas JB, Tyagi A, Pandey A, Hanschen ER, Anderson J, Heffel MG, Platt TG, Olson BJSC. Gene loss during a transition to multicellularity. Sci Rep 2023; 13:5268. [PMID: 37002250 PMCID: PMC10066295 DOI: 10.1038/s41598-023-29742-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 02/09/2023] [Indexed: 04/03/2023] Open
Abstract
Multicellular evolution is a major transition associated with momentous diversification of multiple lineages and increased developmental complexity. The volvocine algae comprise a valuable system for the study of this transition, as they span from unicellular to undifferentiated and differentiated multicellular morphologies despite their genomes being similar, suggesting multicellular evolution requires few genetic changes to undergo dramatic shifts in developmental complexity. Here, the evolutionary dynamics of six volvocine genomes were examined, where a gradual loss of genes was observed in parallel to the co-option of a few key genes. Protein complexes in the six species exhibited novel interactions, suggesting that gene loss could play a role in evolutionary novelty. This finding was supported by gene network modeling, where gene loss outpaces gene gain in generating novel stable network states. These results suggest gene loss, in addition to gene gain and co-option, may be important for the evolution developmental complexity.
Collapse
Affiliation(s)
- Berenice Jiménez-Marín
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
- Interdepartmental Genetics Graduate Program, Kansas State University, Manhattan, KS, 66506, USA
| | - Jessica B Rakijas
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| | - Antariksh Tyagi
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| | - Aakash Pandey
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| | | | - Jaden Anderson
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| | - Matthew G Heffel
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
- Interdepartmental Genetics Graduate Program, Kansas State University, Manhattan, KS, 66506, USA
| | - Thomas G Platt
- Division of Biology, Kansas State University, Manhattan, KS, 66506, USA
| | | |
Collapse
|
5
|
Nozaki H, Mori F, Tanaka Y, Matsuzaki R, Yamashita S, Yamaguchi H, Kawachi M. Cryopreservation of two species of the multicellular volvocine green algal genus Astrephomene. BMC Microbiol 2023; 23:16. [PMID: 36650459 PMCID: PMC9847204 DOI: 10.1186/s12866-023-02767-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 01/10/2023] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Astrephomene is an interesting green algal genus that, together with Volvox, shows convergent evolution of spheroidal multicellular bodies with somatic cells of the colonial or multicellular volvocine lineage. A recent whole-genome analysis of A. gubernaculifera resolved the molecular-genetic basis of such convergent evolution, and two species of Astrephomene were described. However, maintenance of culture strains of Astrephomene requires rapid inoculation of living cultures, and cryopreserved culture strains have not been established in public culture collections. RESULTS To establish cryopreserved culture strains of two species of Astrephomene, conditions for cryopreservation of the two species were investigated using immature and mature vegetative colonies and two cryoprotectants: N,N-dimethylformamide (DMF) and hydroxyacetone (HA). Rates of cell survival of the A. gubernaculifera or A. perforata strain after two-step cooling and freezing in liquid nitrogen were compared between different concentrations (3 and 6%) of DMF and HA and two types of colonies: immature colonies (small colonies newly released from the parent) and mature colonies (large colonies just before daughter colony formation). The highest rate of survival [11 ± 13% (0.36-33%) by the most probable number (MPN) method] of A. gubernaculifera strain NIES-4017 (established in 2014) was obtained when culture samples of immature colonies were subjected to cryogenic treatment with 6% DMF. In contrast, culture samples of mature colonies subjected to 3% HA cryogenic treatment showed the highest "MPN survival" [5.5 ± 5.9% (0.12-12%)] in A. perforata. Using the optimized cryopreservation conditions for each species, survival after freezing in liquid nitrogen was examined for six other strains of A. gubernaculifera (established from 1962 to 1981) and another A. perforata strain maintained in the Microbial Culture Collection at the National Institute for Environmental Studies (MCC-NIES). We obtained ≥0.1% MPN survival of the A. perforata strain. However, only two of the six strains of A. gubernaculifera showed ≥0.1% MPN survival. By using the optimal cryopreserved conditions obtained for each species, five cryopreserved strains of two species of Astrephomene were established and deposited in the MCC-NIES. CONCLUSIONS The optimal cryopreservation conditions differed between the two species of Astrephomene. Cryopreservation of long-term-maintained strains of A. gubernaculifera may be difficult; further studies of cryopreservation of these strains are needed.
Collapse
Affiliation(s)
- Hisayoshi Nozaki
- grid.140139.e0000 0001 0746 5933Biodiversity Division, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506 Japan ,grid.26999.3d0000 0001 2151 536XDepartment of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033 Japan
| | - Fumi Mori
- grid.140139.e0000 0001 0746 5933Biodiversity Division, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506 Japan
| | - Yoko Tanaka
- grid.140139.e0000 0001 0746 5933Biodiversity Division, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506 Japan
| | - Ryo Matsuzaki
- grid.140139.e0000 0001 0746 5933Biodiversity Division, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506 Japan
| | - Shota Yamashita
- grid.26999.3d0000 0001 2151 536XDepartment of Biological Sciences, Graduate School of Science, The University of Tokyo, Bunkyo-ku, Tokyo, 113-0033 Japan ,grid.288127.60000 0004 0466 9350Present Address: Department of Gene Function and Phenomics, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540 Japan
| | - Haruyo Yamaguchi
- grid.140139.e0000 0001 0746 5933Biodiversity Division, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506 Japan
| | - Masanobu Kawachi
- grid.140139.e0000 0001 0746 5933Biodiversity Division, National Institute for Environmental Studies, Tsukuba, Ibaraki 305-8506 Japan
| |
Collapse
|
6
|
Grochau-Wright ZI, Ferris PJ, Tumberger J, Jiménez-Marin B, Olson BJSC, Michod RE. Characterization and Transformation of reg Cluster Genes in Volvox powersii Enable Investigation of Convergent Evolution of Cellular Differentiation in Volvox. Protist 2021; 172:125834. [PMID: 34695730 DOI: 10.1016/j.protis.2021.125834] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 09/07/2021] [Accepted: 09/09/2021] [Indexed: 10/20/2022]
Abstract
The evolution of germ-soma cellular differentiation represents a key step in the evolution of multicellular individuality. Volvox carteri and its relatives, the volvocine green algae, provide a model system for studying the evolution of cellular differentiation. In V. carteri, the regA gene controls somatic cell differentiation and is found in a group of paralogs called the reg cluster, along with rlsA, rlsB, and rlsC. However, the developmental program of V. carteri is derived compared to other volvocine algae. Here we examine Volvox powersii which possesses an ancestral developmental program and independent evolution of the Volvox body plan. We sequenced the reg cluster from V. powersii wild-type and a mutant with fewer cells and altered germ-soma ratio. We found that the mutant strain's rlsB gene has a deletion predicted to cause a truncated protein product. We developed a genetic transformation procedure to insert wild-type rlsB into the mutant strain. Transformation did not result in phenotypic rescue, suggesting the rlsB mutation is insufficient for generating the mutant phenotype. The transformation techniques and sequences described here provide essential tools to study V. powersii, a species well suited for studying the evolution of cellular differentiation and convergent evolution of Volvox morphology.
Collapse
Affiliation(s)
| | | | - John Tumberger
- Division of Biology, Kansas State University, Manhattan, KS 66506, USA
| | | | | | - Richard E Michod
- Ecology & Evolutionary Biology, University of Arizona, Tucson, AZ 85721, USA
| |
Collapse
|
7
|
Lindsey CR, Rosenzweig F, Herron MD. Phylotranscriptomics points to multiple independent origins of multicellularity and cellular differentiation in the volvocine algae. BMC Biol 2021; 19:182. [PMID: 34465312 PMCID: PMC8408923 DOI: 10.1186/s12915-021-01087-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 07/08/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The volvocine algae, which include the single-celled species Chlamydomonas reinhardtii and the colonial species Volvox carteri, serve as a model in which to study the evolution of multicellularity and cellular differentiation. Studies reconstructing the history of this group have by and large relied on datasets of one to a few genes for phylogenetic inference and ancestral character state reconstruction. As a result, volvocine phylogenies lack concordance depending on the number and/or type of genes (i.e., chloroplast vs nuclear) chosen for phylogenetic inference. While multiple studies suggest that multicellularity evolved only once in the volvocine algae, that each of its three colonial families is monophyletic, and that there have been at least three independent origins of cellular differentiation in the group, other studies call into question one or more of these conclusions. An accurate assessment of the evolutionary history of the volvocine algae requires inference of a more robust phylogeny. RESULTS We performed RNA sequencing (RNA-seq) on 55 strains representing 47 volvocine algal species and obtained similar data from curated databases on 13 additional strains. We then compiled a dataset consisting of transcripts for 40 single-copy, protein-coding, nuclear genes and subjected the predicted amino acid sequences of these genes to maximum likelihood, Bayesian inference, and coalescent-based analyses. These analyses show that multicellularity independently evolved at least twice in the volvocine algae and that the colonial family Goniaceae is not monophyletic. Our data further indicate that cellular differentiation arose independently at least four, and possibly as many as six times, within the volvocine algae. CONCLUSIONS Altogether, our results demonstrate that multicellularity and cellular differentiation are evolutionarily labile in the volvocine algae, affirming the importance of this group as a model system for the study of major transitions in the history of life.
Collapse
Affiliation(s)
- Charles Ross Lindsey
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Frank Rosenzweig
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA
- Parker H. Petit Institute for Bioengineering and Biosciences, Atlanta, USA
| | - Matthew D Herron
- School of Biological Sciences, Georgia Institute of Technology, Atlanta, GA, 30332, USA.
| |
Collapse
|
8
|
Preuss M, Verbruggen H, West JA, Zuccarello GC. Divergence times and plastid phylogenomics within the intron-rich order Erythropeltales (Compsopogonophyceae, Rhodophyta). JOURNAL OF PHYCOLOGY 2021; 57:1035-1044. [PMID: 33657649 DOI: 10.1111/jpy.13159] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 01/25/2021] [Accepted: 02/04/2021] [Indexed: 06/12/2023]
Abstract
The advent of high-throughput sequencing (HTS) has allowed for the use of large numbers of coding regions to produce robust phylogenies. These phylogenies have been used to highlight relationships at ancient diversifications (subphyla, class) and highlight the evolution of plastid genome structure. The Erythropeltales are an order in the Compsopogonophyceae, a group with unusual plastid genomes but with low taxon sampling. We use HTS to produce near complete plastid genomes of all genera, and multiple species within some genera, to produce robust phylogenies to investigate character evolution, dating of divergence in the group, and plastid organization, including intron patterns. Our results produce a fully supported phylogeny of the genera in the Erythropeltales and suggest that morphologies (upright versus crustose) have evolved multiple times. Our dated phylogeny also indicates that the order is very old (~800 Ma), with diversification occurring after the ice ages of the Cryogenian period (750-635 Ma). Plastid gene order is congruent with phylogenetic relationships and suggests that genome architecture does not change often. Our data also highlight the abundance of introns in the plastid genomes of this order. We also produce a nearly complete plastid genome of Tsunamia transpacifica (Stylonematophyceae) to add to the taxon sampling of genomes of this class. The use of plastid genomes clearly produces robust phylogenetic relationships that can be used to infer evolutionary events, and increased taxon sampling, especially in less well-known red algal groups, will provide additional insights into their evolution.
Collapse
Affiliation(s)
- Maren Preuss
- School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand
| | - Heroen Verbruggen
- School of BioSciences, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - John A West
- School of BioSciences, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Giuseppe C Zuccarello
- School of Biological Sciences, Victoria University of Wellington, PO Box 600, Wellington, 6140, New Zealand
| |
Collapse
|
9
|
Hu Y, Xing W, Hu Z, Liu G. Phylogenetic Analysis and Substitution Rate Estimation of Colonial Volvocine Algae Based on Mitochondrial Genomes. Genes (Basel) 2020; 11:genes11010115. [PMID: 31968709 PMCID: PMC7016891 DOI: 10.3390/genes11010115] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 01/13/2020] [Accepted: 01/15/2020] [Indexed: 01/30/2023] Open
Abstract
We sequenced the mitochondrial genome of six colonial volvocine algae, namely: Pandorina morum, Pandorina colemaniae, Volvulina compacta, Colemanosphaera angeleri, Colemanosphaera charkowiensi, and Yamagishiella unicocca. Previous studies have typically reconstructed the phylogenetic relationship between colonial volvocine algae based on chloroplast or nuclear genes. Here, we explore the validity of phylogenetic analysis based on mitochondrial protein-coding genes. We found phylogenetic incongruence of the genera Yamagishiella and Colemanosphaera. In Yamagishiella, the stochastic error and linkage group formed by the mitochondrial protein-coding genes prevent phylogenetic analyses from reflecting the true relationship. In Colemanosphaera, a different reconstruction approach revealed a different phylogenetic relationship. This incongruence may be because of the influence of biological factors, such as incomplete lineage sorting or horizontal gene transfer. We also analyzed the substitution rates in the mitochondrial and chloroplast genomes between colonial volvocine algae. Our results showed that all volvocine species showed significantly higher substitution rates for the mitochondrial genome compared with the chloroplast genome. The nonsynonymous substitution (dN)/synonymous substitution (dS) ratio is similar in the genomes of both organelles in most volvocine species, suggesting that the two counterparts are under a similar selection pressure. We also identified a few chloroplast protein-coding genes that showed high dN/dS ratios in some species, resulting in a significant dN/dS ratio difference between the mitochondrial and chloroplast genomes.
Collapse
Affiliation(s)
- Yuxin Hu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- School of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Weiyue Xing
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- School of Life Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhengyu Hu
- State Key Laboratory of Freshwater Ecology and Biotechnology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
| | - Guoxiang Liu
- Key Laboratory of Algal Biology, Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan 430072, China
- Correspondence: ; Tel.: +86-027-6878-0576
| |
Collapse
|
10
|
Morphology, phylogeny, and taxonomy of two species of colonial volvocine green algae from Lake Victoria, Tanzania. PLoS One 2019; 14:e0224269. [PMID: 31710621 PMCID: PMC6844456 DOI: 10.1371/journal.pone.0224269] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2019] [Accepted: 10/09/2019] [Indexed: 11/19/2022] Open
Abstract
The biodiversity and taxonomy of colonial volvocine green algae are important in ancient lakes in tropical regions. However, few taxonomic studies of these algae have been conducted in African ancient lakes. Here, we describe two species of colonial volvocine green algae in cultures originating from water samples from Lake Victoria, an ancient lake in Africa. One was identified as an undescribed morphological species of Eudorina; E. compacta sp. nov. This new species can be distinguished from other Eudorina species by its compactly arranged vegetative cells that form a hollow ellipsoidal colony. The other was identified as Colemanosphaera charkowiensis. The genus Colemanosphaera is new to Africa.
Collapse
|
11
|
Abstract
Algae are photosynthetic eukaryotes whose taxonomic breadth covers a range of life histories, degrees of cellular and developmental complexity, and diverse patterns of sexual reproduction. These patterns include haploid- and diploid-phase sex determination, isogamous mating systems, and dimorphic sexes. Despite the ubiquity of sexual reproduction in algae, their mating-type-determination and sex-determination mechanisms have been investigated in only a limited number of representatives. These include volvocine green algae, where sexual cycles and sex-determining mechanisms have shed light on the transition from mating types to sexes, and brown algae, which are a model for UV sex chromosome evolution in the context of a complex haplodiplontic life cycle. Recent advances in genomics have aided progress in understanding sexual cycles in less-studied taxa including ulvophyte, charophyte, and prasinophyte green algae, as well as in diatoms.
Collapse
Affiliation(s)
- James Umen
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132, USA;
| | - Susana Coelho
- Algal Genetics Group, Integrative Biology of Marine Models, Station Biologique de Roscoff, Sorbonne Université, UPMC Université Paris 06, CNRS, CS 90074, F-29688 Roscoff, France;
| |
Collapse
|
12
|
Embryogenesis of flattened colonies implies the innovation required for the evolution of spheroidal colonies in volvocine green algae. BMC Evol Biol 2019; 19:120. [PMID: 31185890 PMCID: PMC6560780 DOI: 10.1186/s12862-019-1452-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2019] [Accepted: 05/31/2019] [Indexed: 12/27/2022] Open
Abstract
Background Volvocine algae provide a suitable model for investigation of the evolution of multicellular organisms. Within this group, evolution of the body plan from flattened to spheroidal colonies is thought to have occurred independently in two different lineages, Volvocaceae and Astrephomene. Volvocacean species undergo inversion to form a spheroidal cell layer following successive cell divisions during embryogenesis. During inversion, the daughter protoplasts change their shape and develop acute chloroplast ends (opposite to basal bodies). By contrast, Astrephomene does not undergo inversion; rather, its daughter protoplasts rotate during successive cell divisions to form a spheroidal colony. However, the evolutionary pathways of these cellular events involved in the two tactics for formation of spheroidal colony are unclear, since the embryogenesis of extant volvocine genera with ancestral flattened colonies, such as Gonium and Tetrabaena, has not previously been investigated in detail. Results We conducted time-lapse imaging by light microscopy and indirect immunofluorescence microscopy with staining of basal bodies, nuclei, and microtubules to observe embryogenesis in G. pectorale and T. socialis, which form 16-celled or 4-celled flattened colonies, respectively. In G. pectorale, a cup-shaped cell layer of the 16-celled embryo underwent gradual expansion after successive cell divisions, with the apical ends (position of basal bodies) of the square embryo’s peripheral protoplasts separated from each other. In T. socialis, on the other hand, there was no apparent expansion of the daughter protoplasts in 4-celled embryos after successive cell divisions, however the two pairs of diagonally opposed daughter protoplasts shifted slightly and flattened after hatching. Neither of these two species exhibited rotation of daughter protoplasts during successive cell divisions as in Astrephomene or the formation of acute chloroplast ends of daughter protoplasts as in volvocacean inversion. Conclusions The present results indicate that the ancestor of Astrephomene might have newly acquired the rotation of daughter protoplasts after it diverged from the ancestor of Gonium, while the ancestor of Volvocaceae might have newly acquired the formation of acute chloroplast ends to complete inversion after divergence from the ancestor of Goniaceae (Gonium and Astrephomene). Electronic supplementary material The online version of this article (10.1186/s12862-019-1452-x) contains supplementary material, which is available to authorized users.
Collapse
|
13
|
Featherston J, Arakaki Y, Hanschen ER, Ferris PJ, Michod RE, Olson BJSC, Nozaki H, Durand PM. The 4-Celled Tetrabaena socialis Nuclear Genome Reveals the Essential Components for Genetic Control of Cell Number at the Origin of Multicellularity in the Volvocine Lineage. Mol Biol Evol 2019; 35:855-870. [PMID: 29294063 DOI: 10.1093/molbev/msx332] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Multicellularity is the premier example of a major evolutionary transition in individuality and was a foundational event in the evolution of macroscopic biodiversity. The volvocine chlorophyte lineage is well suited for studying this process. Extant members span unicellular, simple colonial, and obligate multicellular taxa with germ-soma differentiation. Here, we report the nuclear genome sequence of one of the most morphologically simple organisms in this lineage-the 4-celled colonial Tetrabaena socialis and compare this to the three other complete volvocine nuclear genomes. Using conservative estimates of gene family expansions a minimal set of expanded gene families was identified that associate with the origin of multicellularity. These families are rich in genes related to developmental processes. A subset of these families is lineage specific, which suggests that at a genomic level the evolution of multicellularity also includes lineage-specific molecular developments. Multiple points of evidence associate modifications to the ubiquitin proteasomal pathway (UPP) with the beginning of coloniality. Genes undergoing positive or accelerating selection in the multicellular volvocines were found to be enriched in components of the UPP and gene families gained at the origin of multicellularity include components of the UPP. A defining feature of colonial/multicellular life cycles is the genetic control of cell number. The genomic data presented here, which includes diversification of cell cycle genes and modifications to the UPP, align the genetic components with the evolution of this trait.
Collapse
Affiliation(s)
- Jonathan Featherston
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa.,Agricultural Research Council, Biotechnology Platform, Pretoria, South Africa
| | - Yoko Arakaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo, Hongo, Japan
| | - Erik R Hanschen
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ
| | - Patrick J Ferris
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ
| | - Richard E Michod
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ
| | | | - Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo, Hongo, Japan
| | - Pierre M Durand
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa
| |
Collapse
|
14
|
Abstract
The reproductive adaptations of land plants have played a key role in their terrestrial colonization and radiation. This encompasses mechanisms used for the production, dispersal and union of gametes to support sexual reproduction. The production of small motile male gametes and larger immotile female gametes (oogamy) in specialized multicellular gametangia evolved in the charophyte algae, the closest extant relatives of land plants. Reliance on water and motile male gametes for sexual reproduction was retained by bryophytes and basal vascular plants, but was overcome in seed plants by the dispersal of pollen and the guided delivery of non-motile sperm to the female gametes. Here we discuss the evolutionary history of male gametogenesis in streptophytes (green plants) and the underlying developmental biology, including recent advances in bryophyte and angiosperm models. We conclude with a perspective on research trends that promise to deliver a deeper understanding of the evolutionary and developmental mechanisms of male gametogenesis in plants.
Collapse
Affiliation(s)
- Dieter Hackenberg
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom.
| | - David Twell
- Department of Genetics and Genome Biology, University of Leicester, Leicester, United Kingdom.
| |
Collapse
|
15
|
Improved taxon sampling and multigene phylogeny of unicellular chlamydomonads closely related to the colonial volvocalean lineage Tetrabaenaceae-Goniaceae-Volvocaceae (Volvocales, Chlorophyceae). Mol Phylogenet Evol 2018; 130:1-8. [PMID: 30266459 DOI: 10.1016/j.ympev.2018.09.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Revised: 09/13/2018] [Accepted: 09/21/2018] [Indexed: 11/23/2022]
Abstract
In the green algal order Volvocales (Chlorophyceae), flagellate colonial forms have evolved at least four times. One of these colonial lineages, Tetrabaenaceae-Goniaceae-Volvocaceae (TGV), which belongs to the clade Reinhardtinia, is closely related to several unicellular chlamydomonads in the genera Chlamydomonas and Vitreochlamys. However, the unicellular sister of TGV has not been specified. Here, the largest ever 18S rRNA phylogenetic tree of Reinhardtinia was constructed including several newly isolated chlamydomonads, and a clade (core-Reinhardtinia) including 32 unicellular lineages and three colonial families were recognized. Interrelationships within core-Reinhardtinia were barely resolved in the tree, and therefore combined 18S-atpB-psaA-psaB-psbC-rbcL gene phylogenetic analyses were performed with selected representatives of 29 of the 32 unicellular lineages and three colonial families. The 29 unicellular lineages were clustered into five metaclades and an unassigned lineage; the metaclade that includes Chlamydomonas pila was resolved, with moderate support, as the sister clade to TGV. To examine possible biases from specific gene(s), long-branch taxa, and the heterogeneous base composition, phylogenetic analyses using several smaller data sets were also performed. Light microscopy of C. pila and its relatives indicated that any early steps towards colony evolution appeared after divergence of TGV from the C. pila lineage.
Collapse
|
16
|
Van den Wyngaert S, Rojas-Jimenez K, Seto K, Kagami M, Grossart HP. Diversity and Hidden Host Specificity of Chytrids Infecting Colonial Volvocacean Algae. J Eukaryot Microbiol 2018; 65:870-881. [PMID: 29752884 DOI: 10.1111/jeu.12632] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2018] [Revised: 04/27/2018] [Accepted: 05/02/2018] [Indexed: 01/18/2023]
Abstract
Chytrids are zoosporic fungi that play an important, but yet understudied, ecological role in aquatic ecosystems. Many chytrid species have been morphologically described as parasites on phytoplankton. However, the majority of them have rarely been isolated and lack DNA sequence data. In this study we isolated and cultivated three parasitic chytrids, infecting a common volvocacean host species, Yamagishiella unicocca. To identify the chytrids, we characterized morphology and life cycle, and analyzed phylogenetic relationships based on 18S and 28S rDNA genes. Host range and specificity of the chytrids was determined by cross-infection assays with host strains, characterized by rbcL and ITS markers. We were able to confirm the identity of two chytrid strains as Endocoenobium eudorinae Ingold and Dangeardia mamillata Schröder and described the third chytrid strain as Algomyces stechlinensis gen. et sp. nov. The three chytrids were assigned to novel and phylogenetically distant clades within the phylum Chytridiomycota, each exhibiting different host specificities. By integrating morphological and molecular data of both the parasitic chytrids and their respective host species, we unveiled cryptic host-parasite associations. This study highlights that a high prevalence of (pseudo)cryptic diversity requires molecular characterization of both phytoplankton host and parasitic chytrid to accurately identify and compare host range and specificity, and to study phytoplankton-chytrid interactions in general.
Collapse
Affiliation(s)
- Silke Van den Wyngaert
- Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Alte Fischerhuette 2, D-16775, Stechlin, Germany
| | - Keilor Rojas-Jimenez
- Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Alte Fischerhuette 2, D-16775, Stechlin, Germany.,Universidad Latina de Costa Rica, Campus San Pedro, Apdo, 10138-1000, San Jose, Costa Rica
| | - Kensuke Seto
- Department of Environmental Sciences, Faculty of Science, Toho University, Funabashi, Chiba, Japan
| | - Maiko Kagami
- Department of Environmental Sciences, Faculty of Science, Toho University, Funabashi, Chiba, Japan
| | - Hans-Peter Grossart
- Department of Experimental Limnology, Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Alte Fischerhuette 2, D-16775, Stechlin, Germany.,Institute of Biochemistry and Biology, Potsdam University, Maulbeerallee 2, 14476, Potsdam, Germany
| |
Collapse
|
17
|
Geng S, Miyagi A, Umen JG. Evolutionary divergence of the sex-determining gene MID uncoupled from the transition to anisogamy in volvocine algae. Development 2018; 145:dev.162537. [PMID: 29549112 DOI: 10.1242/dev.162537] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2017] [Accepted: 03/13/2018] [Indexed: 12/28/2022]
Abstract
Volvocine algae constitute a unique comparative model for investigating the evolution of oogamy from isogamous mating types. The sex- or mating type-determining gene MID encodes a conserved RWP-RK transcription factor found in either the MT- or male mating locus of dioecious volvocine species. We previously found that MID from the isogamous species Chlamydomonas reinhardtii (CrMID) could not induce ectopic spermatogenesis when expressed heterologously in Volvox carteri females, suggesting coevolution of Mid function with gamete dimorphism. Here we found that ectopic expression of MID from the anisogamous species Pleodorina starrii (PsMID) could efficiently induce spermatogenesis when expressed in V. carteri females and, unexpectedly, that GpMID from the isogamous species Gonium pectorale was also able to induce V. carteri spermatogenesis. Neither VcMID nor GpMID could complement a C. reinhardtii mid mutant, at least partly owing to instability of heterologous Mid proteins. Our data show that Mid divergence was not a major contributor to the transition between isogamy and anisogamy/oogamy in volvocine algae, and instead implicate changes in cis-regulatory interactions and/or trans-acting factors of the Mid network in the evolution of sexual dimorphism.
Collapse
Affiliation(s)
- Sa Geng
- Donald Danforth Plant Science Center, 975 N. Warson Rd., St. Louis, MO 63132, USA
| | - Ayano Miyagi
- Donald Danforth Plant Science Center, 975 N. Warson Rd., St. Louis, MO 63132, USA
| | - James G Umen
- Donald Danforth Plant Science Center, 975 N. Warson Rd., St. Louis, MO 63132, USA
| |
Collapse
|
18
|
Nozaki H, Ueki N, Takusagawa M, Yamashita S, Misumi O, Matsuzaki R, Kawachi M, Chiang YR, Wu JT. Morphology, taxonomy and mating-type loci in natural populations of Volvox carteri in Taiwan. BOTANICAL STUDIES 2018; 59:10. [PMID: 29616358 PMCID: PMC5882469 DOI: 10.1186/s40529-018-0227-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 03/29/2018] [Indexed: 06/08/2023]
Abstract
BACKGROUND Volvox carteri f. nagariensis is a model taxon that has been studied extensively at the cellular and molecular level. The most distinctive morphological attribute of V. carteri f. nagariensis within V. carteri is the production of sexual male spheroids with only a 1:1 ratio of somatic cells to sperm packets or androgonidia (sperm packet initials). However, the morphology of male spheroids of V. carteri f. nagariensis has been examined only in Japanese strains. In addition, V. carteri f. nagariensis has heterothallic sexuality; male and female sexes are determined by the sex-determining chromosomal region or mating-type locus composed of a > 1 Mbp linear chromosome. Fifteen sex-specific genes and many sex-based divergent shared genes (gametologs) are present within this region. Thus far, such genes have not been identified in natural populations of this species. RESULTS During a recent fieldwork in Taiwan, we encountered natural populations of V. carteri that had not previously been recorded from Taiwan. In total, 33 strains of this species were established from water samples collected in Northern Taiwan. Based on sequences of the internal transcribed spacer 2 region of nuclear ribosomal DNA and the presence of asexual spheroids with up to 16 gonidia, the species was clearly identified as V. carteri f. nagariensis. However, the sexual male spheroids of the Taiwanese strains generally exhibited a 1:1 to > 50:1 ratio of somatic cells to androgonidia. We also investigated the presence or absence of several sex-specific genes and the sex-based divergent genes MAT3m, MAT3f and LEU1Sm. We did not identify recombination or deletion of such genes between the male and female mating-type locus haplotypes in 32 of the 33 strains. In one putative female strain, the female-specific gene HMG1f was not amplified by genomic polymerase chain reaction. When sexually induced, apparently normal female sexual spheroids developed in this strain. CONCLUSIONS Male spheroids are actually variable within V. carteri f. nagariensis. Therefore, the minimum ratio of somatic cells to androgonidia in male spheroids and the maximum number of gonidia in asexual spheroids may be diagnostic for V. carteri f. nagariensis. HMG1f may not be directly related to the formation of female spheroids in this taxon.
Collapse
Affiliation(s)
- Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan
| | - Noriko Ueki
- Department of Biology, Brooklyn College, City University of New York, Brooklyn, NY 11210 USA
| | - Mari Takusagawa
- Department of Botany, Graduate School of Science, Kyoto University, Sakyo-ku, Kyoto, 606-8502 Japan
| | - Shota Yamashita
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo, 113-0033 Japan
| | - Osami Misumi
- Department of Biological Science and Chemistry, Faculty of Science, Graduate School of Medicine, Yamaguchi University, Yoshida, Yamaguchi, 753-8512 Japan
| | - Ryo Matsuzaki
- Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Onogawa, Tsukuba, Ibaraki 305-8506 Japan
| | - Masanobu Kawachi
- Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Onogawa, Tsukuba, Ibaraki 305-8506 Japan
| | - Yin-Ru Chiang
- Biodiversity Research Center, Academia Sinica, Nankang, Taipei, 11529 Taiwan
| | - Jiunn-Tzong Wu
- Biodiversity Research Center, Academia Sinica, Nankang, Taipei, 11529 Taiwan
| |
Collapse
|
19
|
Cell-Type Transcriptomes of the Multicellular Green Alga Volvox carteri Yield Insights into the Evolutionary Origins of Germ and Somatic Differentiation Programs. G3-GENES GENOMES GENETICS 2018; 8:531-550. [PMID: 29208647 PMCID: PMC5919742 DOI: 10.1534/g3.117.300253] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Germ-soma differentiation is a hallmark of complex multicellular organisms, yet its origins are not well understood. Volvox carteri is a simple multicellular green alga that has recently evolved a simple germ-soma dichotomy with only two cell-types: large germ cells called gonidia and small terminally differentiated somatic cells. Here, we provide a comprehensive characterization of the gonidial and somatic transcriptomes of V. carteri to uncover fundamental differences between the molecular and metabolic programming of these cell-types. We found extensive transcriptome differentiation between cell-types, with somatic cells expressing a more specialized program overrepresented in younger, lineage-specific genes, and gonidial cells expressing a more generalist program overrepresented in more ancient genes that shared striking overlap with stem cell-specific genes from animals and land plants. Directed analyses of different pathways revealed a strong dichotomy between cell-types with gonidial cells expressing growth-related genes and somatic cells expressing an altruistic metabolic program geared toward the assembly of flagella, which support organismal motility, and the conversion of storage carbon to sugars, which act as donors for production of extracellular matrix (ECM) glycoproteins whose secretion enables massive organismal expansion. V. carteri orthologs of diurnally controlled genes from C. reinhardtii, a single-celled relative, were analyzed for cell-type distribution and found to be strongly partitioned, with expression of dark-phase genes overrepresented in somatic cells and light-phase genes overrepresented in gonidial cells- a result that is consistent with cell-type programs in V. carteri arising by cooption of temporal regulons in a unicellular ancestor. Together, our findings reveal fundamental molecular, metabolic, and evolutionary mechanisms that underlie the origins of germ-soma differentiation in V. carteri and provide a template for understanding the acquisition of germ-soma differentiation in other multicellular lineages.
Collapse
|
20
|
Arakaki Y, Fujiwara T, Kawai-Toyooka H, Kawafune K, Featherston J, Durand PM, Miyagishima SY, Nozaki H. Evolution of cytokinesis-related protein localization during the emergence of multicellularity in volvocine green algae. BMC Evol Biol 2017; 17:243. [PMID: 29212441 PMCID: PMC5717801 DOI: 10.1186/s12862-017-1091-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2017] [Accepted: 11/24/2017] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND The volvocine lineage, containing unicellular Chlamydomonas reinhardtii and differentiated multicellular Volvox carteri, is a powerful model for comparative studies aiming at understanding emergence of multicellularity. Tetrabaena socialis is the simplest multicellular volvocine alga and belongs to the family Tetrabaenaceae that is sister to more complex multicellular volvocine families, Goniaceae and Volvocaceae. Thus, T. socialis is a key species to elucidate the initial steps in the evolution of multicellularity. In the asexual life cycle of C. reinhardtii and multicellular volvocine species, reproductive cells form daughter cells/colonies by multiple fission. In embryogenesis of the multicellular species, daughter protoplasts are connected to one another by cytoplasmic bridges formed by incomplete cytokinesis during multiple fission. These bridges are important for arranging the daughter protoplasts in appropriate positions such that species-specific integrated multicellular individuals are shaped. Detailed comparative studies of cytokinesis between unicellular and simple multicellular volvocine species will help to elucidate the emergence of multicellularity from the unicellular ancestor. However, the cytokinesis-related genes between closely related unicellular and multicellular species have not been subjected to a comparative analysis. RESULTS Here we focused on dynamin-related protein 1 (DRP1), which is known for its role in cytokinesis in land plants. Immunofluorescence microscopy using an antibody against T. socialis DRP1 revealed that volvocine DRP1 was localized to division planes during cytokinesis in unicellular C. reinhardtii and two simple multicellular volvocine species T. socialis and Gonium pectorale. DRP1 signals were mainly observed in the newly formed division planes of unicellular C. reinhardtii during multiple fission, whereas in multicellular T. socialis and G. pectorale, DRP1 signals were observed in all division planes during embryogenesis. CONCLUSIONS These results indicate that the molecular mechanisms of cytokinesis may be different in unicellular and multicellular volvocine algae. The localization of DRP1 during multiple fission might have been modified in the common ancestor of multicellular volvocine algae. This modification may have been essential for the re-orientation of cells and shaping colonies during the emergence of multicellularity in this lineage.
Collapse
Affiliation(s)
- Yoko Arakaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Takayuki Fujiwara
- Department of Cell Genetics, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
| | - Hiroko Kawai-Toyooka
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Kaoru Kawafune
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.,Department of Life Science and Technology, School of Life Science and Technology, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo, 152-8550, Japan
| | - Jonathan Featherston
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, 2000, South Africa.,Agricultural Research Council, Biotechnology Platform, Pretoria, 0040, South Africa
| | - Pierre M Durand
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, 2000, South Africa.,Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721, USA
| | - Shin-Ya Miyagishima
- Department of Cell Genetics, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka, 411-8540, Japan
| | - Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
| |
Collapse
|
21
|
Nakada T, Tomita M. Morphology and phylogeny of a new wall-less freshwater volvocalean flagellate, Hapalochloris nozakii gen. et sp. nov. (Volvocales, Chlorophyceae). JOURNAL OF PHYCOLOGY 2017; 53:108-117. [PMID: 27767210 DOI: 10.1111/jpy.12484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2016] [Accepted: 09/13/2016] [Indexed: 06/06/2023]
Abstract
New strains of a wall-less unicellular volvocalean flagellate were isolated from a freshwater environment in Japan. Observations of the alga, described here as Hapalochloris nozakii Nakada, gen. et sp. nov., were made using light, fluorescence, and electron microscopy. Each vegetative cell had two flagella, four contractile vacuoles, and a spirally furrowed cup-shaped chloroplast with an axial pyrenoid, and mitochondria located in the furrows. Based on the morphology, H. nozakii was distinguished from other known wall-less volvocalean flagellates. Under electron microscopy, fibrous material, instead of a cell wall and dense cortical microtubules, was observed outside and inside the cell membrane, respectively. Based on the phylogenetic analyses of 18S rRNA gene sequences, H. nozakii was found to be closely related to Asterococcus, Oogamochlamys, Rhysamphichloris, and "Dunaliella" lateralis and was separated from other known wall-less flagellate volvocaleans, indicating independent secondary loss of the cell wall in H. nozakii. In the combined 18S rRNA and chloroplast gene tree, H. nozakii was sister to Lobochlamys.
Collapse
Affiliation(s)
- Takashi Nakada
- Institute for Advanced Biosciences, Keio University, Kakuganji, Tsuruoka 997-0052, Japan
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Fujisawa 252-0882, Japan
| | - Masaru Tomita
- Institute for Advanced Biosciences, Keio University, Kakuganji, Tsuruoka 997-0052, Japan
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Fujisawa 252-0882, Japan
| |
Collapse
|
22
|
Nozaki H, Mahakham W, Athibai S, Yamamoto K, Takusagawa M, Misumi O, Herron MD, Rosenzweig F, Kawachi M. Rediscovery of the species of 'ancestral Volvox': morphology and phylogenetic position of Pleodorina sphaerica (Volvocales, Chlorophyceae) from Thailand. PHYCOLOGIA 2017; 56:469-475. [PMID: 29375162 PMCID: PMC5785936 DOI: 10.2216/17-3.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Pleodorina sphaerica Iyengar was considered to be a phylogenetic link between Volvox and the type species Pleodorina californica Shaw because it has small somatic cells distributed from the anterior to posterior poles in 64- or 128-celled vegetative colonies. However, cultural studies and molecular and ultrastructural data are lacking in P. sphaerica, and this species has not been recorded since 1951. Here, we performed light and electron microscopy and molecular phylogeny of P. sphaerica based on newly established culture strains originating from Thailand. Morphological features of the present Thai species agreed well with those of the previous studies of the Indian material of P. sphaerica and with those of the current concept of the advanced members of the Volvocaceae. The present P. sphaerica strains exhibited homothallic sexuality; male and facultative female colonies developed within a single clonal culture. Chloroplast multigene phylogeny demonstrated that P. sphaerica was sister to two other species of Pleodorina (P. californica and Pleodorina japonica Nozaki) without posterior somatic cells, and these three species of Pleodorina formed a robust clade, which was positioned distally in the large monophyletic group including nine taxa of Volvox sect. Merrillosphaera and Volvox (sect. Janetosphaera) aureus Ehrenberg. Based on the present phylogenetic results, evolutionary losses of posterior somatic cells might have occurred in the ancestor of P. californica and P. japonica. Thus, P. sphaerica might represent an ancestral morphology of Pleodorina, rather than of Volvox.
Collapse
Affiliation(s)
- Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
- Corresponding author ()
| | - Wuttipong Mahakham
- Applied Taxonomic Research Center, Department of Biology, Faculty of Science, Khon Kaen University, Nai-Muang, Muang District, Khon Kaen 40002, Thailand
| | - Sujeephon Athibai
- Applied Taxonomic Research Center, Department of Biology, Faculty of Science, Khon Kaen University, Nai-Muang, Muang District, Khon Kaen 40002, Thailand
| | - Kayoko Yamamoto
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Mari Takusagawa
- Department of Biological Science and Chemistry, Faculty of Science, Graduate School of Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8512, Japan
| | - Osami Misumi
- Department of Biological Science and Chemistry, Faculty of Science, Graduate School of Medicine, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8512, Japan
| | - Matthew D. Herron
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Frank Rosenzweig
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Masanobu Kawachi
- Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Onogawa 16-2, Tsukuba-shi, Ibaraki 305-8506, Japan
| |
Collapse
|
23
|
Nozaki H, Ueki N, Isaka N, Saigo T, Yamamoto K, Matsuzaki R, Takahashi F, Wakabayashi KI, Kawachi M. A New Morphological Type of Volvox from Japanese Large Lakes and Recent Divergence of this Type and V. ferrisii in Two Different Freshwater Habitats. PLoS One 2016; 11:e0167148. [PMID: 27880842 PMCID: PMC5120847 DOI: 10.1371/journal.pone.0167148] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2016] [Accepted: 11/09/2016] [Indexed: 11/26/2022] Open
Abstract
Volvox sect. Volvox is characterized by having unique morphological characteristics, such as thick cytoplasmic bridges between adult somatic cells in the spheroids and spiny zygote walls. Species of this section are found from various freshwater habitats. Recently, three species of Volvox sect. Volvox originating from rice paddies and a marsh were studied taxonomically based on molecular and morphological data of cultured materials. However, taxonomic studies have not been performed on cultured materials of this section originating from large lake water bodies. We studied a new morphological type of Volvox sect. Volvox (“Volvox sp. Sagami”), using cultured materials originating from two large lakes and a pond in Japan. Volvox sp. Sagami produced monoecious sexual spheroids and may represent a new morphological species; it could be clearly distinguished from all previously described monoecious species of Volvox sect. Volvox by its small number of eggs or zygotes (5–25) in sexual spheroids, with short acute spines (up to 3 μm long) on the zygote walls and elongated anterior somatic cells in asexual spheroids. Based on sequences of internal transcribed spacer (ITS) regions of nuclear ribosomal DNA (rDNA; ITS-1, 5.8S rDNA and ITS-2) and plastid genes, however, the Volvox sp. Sagami lineage and its sister lineage (the monoecious species V. ferrisii) showed very small genetic differences, which correspond to the variation within a single biological species in other volvocalean algae. Since V. ferrisii was different from Volvox sp. Sagami, by having approximately 100–200 zygotes in the sexual spheroids and long spines (6–8.5 μm long) on the zygote walls, as well as growing in Japanese rice paddies, these two morphologically distinct lineages might have diverged rapidly in the two different freshwater habitats. In addition, the swimming velocity during phototaxis of Volvox sp. Sagami spheroids originating from large lakes was significantly higher than that of V. ferrisii originating from rice paddies, suggesting adaptation of Volvox sp. Sagami to large water bodies.
Collapse
Affiliation(s)
- Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113–0033, Japan
- * E-mail:
| | - Noriko Ueki
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226–8503, Japan
| | - Nanako Isaka
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113–0033, Japan
| | - Tokiko Saigo
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113–0033, Japan
| | - Kayoko Yamamoto
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo, 113–0033, Japan
| | - Ryo Matsuzaki
- Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Onogawa 16–2, Tsukuba-shi, Ibaraki, 305–8506, Japan
| | - Fumio Takahashi
- College of Life Sciences, Ritsumeikan University, Nojihigashi 1-1-1, Kusatsu-shi, Shiga, 525–8577, Japan
| | - Ken-ichi Wakabayashi
- Laboratory for Chemistry and Life Science, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, 226–8503, Japan
| | - Masanobu Kawachi
- Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Onogawa 16–2, Tsukuba-shi, Ibaraki, 305–8506, Japan
| |
Collapse
|
24
|
Yamashita S, Arakaki Y, Kawai-Toyooka H, Noga A, Hirono M, Nozaki H. Alternative evolution of a spheroidal colony in volvocine algae: developmental analysis of embryogenesis in Astrephomene (Volvocales, Chlorophyta). BMC Evol Biol 2016; 16:243. [PMID: 27829356 PMCID: PMC5103382 DOI: 10.1186/s12862-016-0794-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 10/07/2016] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Volvocine algae, which range from the unicellular Chlamydomonas to the multicellular Volvox with a germ-soma division of labor, are a model for the evolution of multicellularity. Within this group, the spheroidal colony might have evolved in two independent lineages: Volvocaceae and the goniacean Astrephomene. Astrephomene produces spheroidal colonies with posterior somatic cells. The feature that distinguishes Astrephomene from the volvocacean algae is lack of inversion during embryogenesis; the volvocacean embryo undergoes inversion after successive divisions to orient flagella toward the outside. The mechanisms of inversion at the molecular and cellular levels in volvocacean algae have been assessed in detail, particularly in Volvox carteri. However, embryogenesis in Astrephomene has not been subjected to such investigations. RESULTS This study relied on light microscopy time-lapse imaging using an actively growing culture of a newly established strain to conduct a developmental analysis of Astrephomene as well as to perform a comparison with the similar spheroidal volvocacean Eudorina. During the successive divisions involved in Astrephomene embryogenesis, gradual rotation of daughter protoplasts resulted in movement of their apical portions toward the embryonic posterior, forming a convex-to-spheroidal cell sheet with the apical ends of protoplasts on the outside. Differentiation of the posterior somatic cells from the embryo periphery was traced based on cell lineages during embryogenesis. In contrast, in Eudorina, the rotation of daughter protoplasts did not occur during successive cell divisions; however, inversion occurred after such divisions, and a spheroidal embryo was formed. Indirect immunofluorescence microscopy of basal bodies and nuclei verified this difference between Astrephomene and Eudorina in the movement of embryonic protoplasts. CONCLUSIONS These results suggest different tactics for spheroidal colony formation between the two lineages: rotation of daughter protoplasts during successive cell divisions in Astrephomene, and inversion after cell divisions in Eudorina. This study will facilitate further research into the molecular and genetic mechanisms of the parallel evolution of the spheroidal colony in volvocine algae.
Collapse
Affiliation(s)
- Shota Yamashita
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Yoko Arakaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Hiroko Kawai-Toyooka
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Akira Noga
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Masafumi Hirono
- Department of Frontier Bioscience, Faculty of Bioscience and Applied Chemistry, Hosei University, 3-7-2 Kajino-cho, Koganei-shi, Tokyo, 184-8584, Japan
| | - Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan.
| |
Collapse
|
25
|
Matt G, Umen J. Volvox: A simple algal model for embryogenesis, morphogenesis and cellular differentiation. Dev Biol 2016; 419:99-113. [PMID: 27451296 PMCID: PMC5101179 DOI: 10.1016/j.ydbio.2016.07.014] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Revised: 07/15/2016] [Accepted: 07/15/2016] [Indexed: 11/20/2022]
Abstract
Patterning of a multicellular body plan involves a coordinated set of developmental processes that includes cell division, morphogenesis, and cellular differentiation. These processes have been most intensively studied in animals and land plants; however, deep insight can also be gained by studying development in simpler multicellular organisms. The multicellular green alga Volvox carteri (Volvox) is an excellent model for the investigation of developmental mechanisms and their evolutionary origins. Volvox has a streamlined body plan that contains only a few thousand cells and two distinct cell types: reproductive germ cells and terminally differentiated somatic cells. Patterning of the Volvox body plan is achieved through a stereotyped developmental program that includes embryonic cleavage with asymmetric cell division, morphogenesis, and cell-type differentiation. In this review we provide an overview of how these three developmental processes give rise to the adult form in Volvox and how developmental mutants have provided insights into the mechanisms behind these events. We highlight the accessibility and tractability of Volvox and its relatives that provide a unique opportunity for studying development.
Collapse
Affiliation(s)
- Gavriel Matt
- Donald Danforth Plant Science Center, 975 N Warson Rd, St. Louis, MO 63132, USA; Washington University in St. Louis, Division of Biology & Biomedical Science, Campus Box 8226, 660 South Euclid Ave, St. Louis, MO 63110, USA.
| | - James Umen
- Donald Danforth Plant Science Center, 975 N Warson Rd, St. Louis, MO 63132, USA.
| |
Collapse
|
26
|
Delineation of six species of the primitive algal genus Glaucocystis based on in situ ultrastructural characteristics. Sci Rep 2016; 6:29209. [PMID: 27383831 PMCID: PMC4935853 DOI: 10.1038/srep29209] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2016] [Accepted: 06/13/2016] [Indexed: 12/31/2022] Open
Abstract
The field of microbiology was established in the 17th century upon the discovery of microorganisms by Antonie van Leeuwenhoek using a single-lens microscope. Now, the detailed ultrastructures of microorganisms can be elucidated in situ using three-dimensional electron microscopy. Since the availability of electron microscopy, the taxonomy of microscopic organisms has entered a new era. Here, we established a new taxonomic system of the primitive algal genus Glaucocystis (Glaucophyta) using a new-generation electron microscopic methodology: ultra-high-voltage electron microscopy (UHVEM) and field-emission scanning electron microscopy (FE-SEM). Various globally distributed Glaucocystis strains were delineated into six species, based on differences in in situ ultrastructural features of the protoplast periphery under UHVEM tomography and in the mother cell wall by FE-SEM, as well as differences in the light microscopic characteristics and molecular phylogenetic results. The present work on Glaucocystis provides a model case of new-generation taxonomy.
Collapse
|
27
|
Olson BJ, Nedelcu AM. Co-option during the evolution of multicellular and developmental complexity in the volvocine green algae. Curr Opin Genet Dev 2016; 39:107-115. [PMID: 27379901 DOI: 10.1016/j.gde.2016.06.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 06/02/2016] [Accepted: 06/07/2016] [Indexed: 11/19/2022]
Abstract
Despite its major impact on the evolution of Life on Earth, the transition to multicellularity remains poorly understood, especially in terms of its genetic basis. The volvocine algae are a group of closely related species that range in morphology from unicellular individuals (Chlamydomonas) to undifferentiated multicellular forms (Gonium) and complex organisms with distinct developmental programs and one (Pleodorina) or two (Volvox) specialized cell types. Modern genetic approaches, complemented by the recent sequencing of genomes from several key species, revealed that co-option of existing genes and pathways is the primary driving force for the evolution of multicellularity in this lineage. The initial transition to undifferentiated multicellularity, as typified by the extant Gonium, was driven primarily by the co-option of cell cycle regulation. Further morphological and developmental innovations in the lineage leading to Volvox resulted from additional co-option events involving genes important for embryonic inversion, asymmetric cell division, somatic and germ cell differentiation and the structure and function of the extracellular matrix. Because of their relatively low but variable levels of morphological and developmental complexity, simple underlying genetics and recent evolutionary history, the volvocine algae are providing significant insight into our understanding of the genetics and evolution of major developmental and morphological traits.
Collapse
Affiliation(s)
| | - Aurora M Nedelcu
- Department of Biology, University of New Brunswick, Fredericton, NB, Canada
| |
Collapse
|
28
|
Characterization of salt stress-induced palmelloids in the green alga, Chlamydomonas reinhardtii. ALGAL RES 2016. [DOI: 10.1016/j.algal.2016.03.035] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
29
|
Sequence of the Gonium pectorale Mating Locus Reveals a Complex and Dynamic History of Changes in Volvocine Algal Mating Haplotypes. G3-GENES GENOMES GENETICS 2016; 6:1179-89. [PMID: 26921294 PMCID: PMC4856071 DOI: 10.1534/g3.115.026229] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Sex-determining regions (SDRs) or mating-type (MT) loci in two sequenced volvocine algal species, Chlamydomonas reinhardtii and Volvox carteri, exhibit major differences in size, structure, gene content, and gametolog differentiation. Understanding the origin of these differences requires investigation of MT loci from related species. Here, we determined the sequences of the minus and plus MT haplotypes of the isogamous 16-celled volvocine alga, Gonium pectorale, which is more closely related to the multicellular V. carteri than to C. reinhardtii. Compared to C. reinhardtii MT, G. pectorale MT is moderately larger in size, and has a less complex structure, with only two major syntenic blocs of collinear gametologs. However, the gametolog content of G. pectorale MT has more overlap with that of V. carteri MT than with C. reinhardtii MT, while the allelic divergence between gametologs in G. pectorale is even lower than that in C. reinhardtii. Three key sex-related genes are conserved in G. pectorale MT: GpMID and GpMTD1 in MT–, and GpFUS1 in MT+. GpFUS1 protein exhibited specific localization at the plus-gametic mating structure, indicating a conserved function in fertilization. Our results suggest that the G. pectorale–V. carteri common ancestral MT experienced at least one major reformation after the split from C. reinhardtii, and that the V. carteri ancestral MT underwent a subsequent expansion and loss of recombination after the divergence from G. pectorale. These data begin to polarize important changes that occurred in volvocine MT loci, and highlight the potential for discontinuous and dynamic evolution in SDRs.
Collapse
|
30
|
Nakada T, Tomita M, Wu JT, Nozaki H. Taxonomic revision of Chlamydomonas subg. Amphichloris (Volvocales, Chlorophyceae), with resurrection of the genus Dangeardinia and descriptions of Ixipapillifera gen. nov. and Rhysamphichloris gen. nov. JOURNAL OF PHYCOLOGY 2016; 52:283-304. [PMID: 27037593 DOI: 10.1111/jpy.12397] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2015] [Accepted: 12/17/2015] [Indexed: 06/05/2023]
Abstract
Chlamydomonas (Cd.) is one of the largest but most polyphyletic genera of freshwater unicellular green algae. It consists of 400-600 morphological species and requires taxonomic revision. Toward reclassification, each morphologically defined classical subgenus (or subgroup) should be examined using culture strains. Chlamydomonas subg. Amphichloris is characterized by a central nucleus between two axial pyrenoids, however, the phylogenetic structure of this subgenus has yet to be examined using molecular data. Here, we examined 12 strains including six newly isolated strains, morphologically identified as Chlamydomonas subg. Amphichloris, using 18S rRNA gene phylogeny, light microscopy, and mitochondria fluorescent microscopy. Molecular phylogenetic analyses revealed three independent lineages of the subgenus, separated from the type species of Chlamydomonas, Cd. reinhardtii. These three lineages were further distinguished from each other by light and fluorescent microscopy-in particular by the morphology of the papillae, chloroplast surface, stigmata, and mitochondria-and are here assigned to three genera: Dangeardinia emend., Ixipapillifera gen. nov., and Rhysamphichloris gen. nov. Based on the molecular and morphological data, two to three species were recognized in each genus, including one new species, I. pauromitos. In addition, Cd. deasonii, which was previously assigned to subgroup "Pleiochloris," was included in the genus Ixipapillifera as I. deasonii comb. nov.
Collapse
Affiliation(s)
- Takashi Nakada
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Fujisawa, 252-0882, Japan
- Institute for Advanced Biosciences, Keio University, Kakuganji, Tsuruoka, 997-0052, Japan
| | - Masaru Tomita
- Systems Biology Program, Graduate School of Media and Governance, Keio University, Fujisawa, 252-0882, Japan
- Institute for Advanced Biosciences, Keio University, Kakuganji, Tsuruoka, 997-0052, Japan
| | - Jiunn-Tzong Wu
- Biodiversity Research Center, Academia Sinica, Nankang, Taipei, 11529, Taiwan
| | - Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bukyo-ku, Tokyo, 113-0033, Japan
| |
Collapse
|
31
|
Herron MD. Origins of multicellular complexity: Volvox and the volvocine algae. Mol Ecol 2016; 25:1213-23. [PMID: 26822195 DOI: 10.1111/mec.13551] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 12/21/2015] [Accepted: 12/26/2015] [Indexed: 11/28/2022]
Abstract
The collection of evolutionary transformations known as the 'major transitions' or 'transitions in individuality' resulted in changes in the units of evolution and in the hierarchical structure of cellular life. Volvox and related algae have become an important model system for the major transition from unicellular to multicellular life, which touches on several fundamental questions in evolutionary biology. The Third International Volvox Conference was held at the University of Cambridge in August 2015 to discuss recent advances in the biology and evolution of this group of algae. Here, I highlight the benefits of integrating phylogenetic comparative methods and experimental evolution with detailed studies of developmental genetics in a model system with substantial genetic and genomic resources. I summarize recent research on Volvox and its relatives and comment on its implications for the genomic changes underlying major evolutionary transitions, evolution and development of complex traits, evolution of sex and sexes, evolution of cellular differentiation and the biophysics of motility. Finally, I outline challenges and suggest future directions for research into the biology and evolution of the volvocine algae.
Collapse
Affiliation(s)
- Matthew D Herron
- Division of Biological Sciences, University of Montana, 32 Campus Dr., Missoula, MT, 59812, USA
| |
Collapse
|
32
|
Abstract
The evolution of multicellular animals has been attributed to many kinds of selective advantage; here I suggest that the evolution of somatic cells to feed and protect the germline was central to the appearance of animals. This would have been driven by selection for extreme anisogamy--the evolution of sperm and egg. Evidence is adduced from the germline stem cells of simple animals (defining germline as any cell that normally produces the next generation via the sexual process) and from the control circuitry ubiquitous in animal germlines. With the soma and its elaboration came animal development, as we understand it.
Collapse
Affiliation(s)
- Hugh R Woodland
- School of Life Sciences, University of Warwick, Coventry, United Kingdom.
| |
Collapse
|
33
|
Munakata H, Nakada T, Nakahigashi K, Nozaki H, Tomita M. Phylogenetic Position and Molecular Chronology of a Colonial Green Flagellate, Stephanosphaera pluvialis
(Volvocales, Chlorophyceae), among Unicellular Algae. J Eukaryot Microbiol 2015; 63:340-8. [DOI: 10.1111/jeu.12283] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Revised: 11/10/2015] [Accepted: 11/13/2015] [Indexed: 11/28/2022]
Affiliation(s)
- Hidehito Munakata
- Systems Biology Program; Graduate School of Media and Governance; Keio University; Fujisawa 252-0882 Japan
- Institute for Advanced Biosciences; Keio University; Kakuganji Tsuruoka 997-0052 Japan
| | - Takashi Nakada
- Systems Biology Program; Graduate School of Media and Governance; Keio University; Fujisawa 252-0882 Japan
- Institute for Advanced Biosciences; Keio University; Kakuganji Tsuruoka 997-0052 Japan
| | - Kenji Nakahigashi
- Systems Biology Program; Graduate School of Media and Governance; Keio University; Fujisawa 252-0882 Japan
- Institute for Advanced Biosciences; Keio University; Kakuganji Tsuruoka 997-0052 Japan
| | - Hisayoshi Nozaki
- Department of Biological Sciences; Graduate School of Science; University of Tokyo; 7-3-1 Hongo, Bunkyo Tokyo 113-0033 Japan
| | - Masaru Tomita
- Systems Biology Program; Graduate School of Media and Governance; Keio University; Fujisawa 252-0882 Japan
- Institute for Advanced Biosciences; Keio University; Kakuganji Tsuruoka 997-0052 Japan
| |
Collapse
|
34
|
Nozaki H, Matsuzaki R, Yamamoto K, Kawachi M, Takahashi F. Delineating a New Heterothallic Species of Volvox (Volvocaceae, Chlorophyceae) Using New Strains of "Volvox africanus". PLoS One 2015; 10:e0142632. [PMID: 26562165 PMCID: PMC4643018 DOI: 10.1371/journal.pone.0142632] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Accepted: 10/23/2015] [Indexed: 11/18/2022] Open
Abstract
The volvocine algae represent an excellent model lineage in which to study evolution of female and male genders based on comparative analyses of related species. Among these species, Volvox carteri has been extensively studied as a model of an oogamous and complex organism. However, it may have unique derived features that are not present in other species of Volvox. Therefore, information regarding the characteristics of sexual reproduction of other species of Volvox is also important. In 1971, Starr studied four types of sexuality in several global strains identified as Volvox africanus; however, further taxonomic studies of these strains have been lacking, and strains of three of the four sexual types are not available. Here, we studied the morphology, sexual reproduction, and taxonomy of two V. africanus-like species isolated recently from Lake Biwa, Japan. These two species were very similar to two sexual types described by Starr in 1971: one producing dioecious sexual spheroids in heterothallic strains and the other forming both male spheroids and monoecious spheroids in a single strain. The former species produced zygotes with a reticulate cell wall, whereas a smooth zygote wall was observed in the latter species as in V. africanus previously reported from various localities around the world. Our multigene phylogenetic analysis demonstrated that these are sister species to each other. However, the presence of a compensatory base change in the most conserved region of the secondary structure of nuclear ribosomal DNA internal transcribed spacer-2, hybrid inviability demonstrated by intercrossing experiments, and morphological differences in the density of abutment between the gelatinous material of adjacent cells (individual sheaths) in the spheroid supported the recognition of the two species, V. africanus having a smooth zygote wall and V. reticuliferus Nozaki sp. nov. having a reticulate zygote wall.
Collapse
Affiliation(s)
- Hisayoshi Nozaki
- Department of Biological Sciences, Graduate school of Science, University of Tokyo, Tokyo, Japan
- * E-mail:
| | - Ryo Matsuzaki
- Department of Biological Sciences, Graduate school of Science, University of Tokyo, Tokyo, Japan
| | - Kayoko Yamamoto
- Department of Biological Sciences, Graduate school of Science, University of Tokyo, Tokyo, Japan
| | - Masanobu Kawachi
- Center for Environmental Biology and Ecosystem Studies, National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan
| | - Fumio Takahashi
- Ritsumeikan University, College of Life Sciences, Kusatsu, Shiga, Japan
| |
Collapse
|
35
|
Mori T, Kawai-Toyooka H, Igawa T, Nozaki H. Gamete Dialogs in Green Lineages. MOLECULAR PLANT 2015; 8:1442-54. [PMID: 26145252 DOI: 10.1016/j.molp.2015.06.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 06/15/2015] [Accepted: 06/28/2015] [Indexed: 05/20/2023]
Abstract
Gamete fusion is a core process of sexual reproduction and, in both plants and animals, different sex gametes fuse within species. Although most of the molecular factors involved in gamete interaction are still unknown in various sex-possessing eukaryotes, reports of such factors in algae and land plants have been increasing in the past decade. In particular, knowledge of gamete interaction in flowering plants and green algae has increased since the identification of the conserved gamete fusion factor generative cell specific 1/hapless 2 (GCS1/HAP2). GCS1 was first identified as a pollen generative cell-specific transmembrane protein in the lily (Lilium longiflorum), and was then shown to function not only in flowering plant gamete fusion but also in various eukaryotes, including unicellular protists and metazoans. In addition, although initially restricted to Chlamydomonas, knowledge of gamete attachment in flowering plants was also acquired. This review focuses on recent progress in the study of gamete interaction in volvocine green algae and flowering plants and discusses conserved mechanisms of gamete recognition, attachment, and fusion leading to zygote formation.
Collapse
Affiliation(s)
- Toshiyuki Mori
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
| | - Hiroko Kawai-Toyooka
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Tomoko Igawa
- Graduate School of Horticulture, Chiba University, 648 Matsudo, Matsudo, Chiba 271-8510, Japan
| | - Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
| |
Collapse
|
36
|
Takahashi T, Sato M, Toyooka K, Matsuzaki R, Kawafune K, Kawamura M, Okuda K, Nozaki H. Five Cyanophora (Cyanophorales, Glaucophyta) species delineated based on morphological and molecular data. JOURNAL OF PHYCOLOGY 2014; 50:1058-1069. [PMID: 26988787 DOI: 10.1111/jpy.12236] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 08/19/2014] [Indexed: 06/05/2023]
Abstract
Cyanophora is an important glaucophyte genus of unicellular biflagellates that may have retained ancestral features of photosynthetic eukaryotes. The nuclear genome of Cyanophora was recently sequenced, but taxonomic studies of more than two strains are lacking for this genus. Furthermore, no study has used molecular methods to taxonomically delineate Cyanophora species. Here, we delimited the species of Cyanophora using light and electron microscopy, combined with molecular data from several globally distributed strains, including one newly established. Using a light microscope, we identified two distinct morphological groups: one with ovoid to ellipsoidal vegetative cells and another with dorsoventrally flattened or broad, bean-shaped vegetative cells containing duplicated plastids. Our light and scanning electron microscopy clearly distinguished three species with ovoid to ellipsoidal cells (C. paradoxa Korshikov, C. cuspidata Tos.Takah. & Nozaki sp. nov., and C. kugrensii Tos.Takah. & Nozaki sp. nov.) and two species with broad, bean-shaped cells (C. biloba Kugrens, B.L.Clay, C.J.Mey. & R.E.Lee and C. sudae Tos.Takah. & Nozaki sp. nov.) based on differences in cell shape and surface ornamentations of the vegetative cells under the field-emission scanning electron microscope. Molecular phylogenetic analyses of P700 chl a apoprotein A2 (psaB) genes and internal transcribed spacer (ITS) regions of nuclear ribosomal DNA (rDNA), as well as a comparison of secondary structures of nuclear rDNA ITS-2 and genetic distances of psaB genes, supported the delineation of five morphological species of Cyanophora.
Collapse
Affiliation(s)
- Toshiyuki Takahashi
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Mayuko Sato
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa, 230-0045, Japan
| | - Kiminori Toyooka
- RIKEN Center for Sustainable Resource Science, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama-shi, Kanagawa, 230-0045, Japan
| | - Ryo Matsuzaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Kaoru Kawafune
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| | - Mai Kawamura
- Department of Natural Science, Faculty of Science, Kochi University, 2-5-1 Akebono-cho, Kochi-shi, 780-8520, Japan
| | - Kazuo Okuda
- Graduate School of Integrated Arts and Sciences, Doctoral Course, Kuroshio Science, Kochi University, 2-5-1 Akebono-cho, Kochi-shi, 780-8520, Japan
| | - Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-0033, Japan
| |
Collapse
|
37
|
Abstract
The green lineage of chlorophyte algae and streptophytes form a large and diverse clade with multiple independent transitions to produce multicellular and/or macroscopically complex organization. In this review, I focus on two of the best-studied multicellular groups of green algae: charophytes and volvocines. Charophyte algae are the closest relatives of land plants and encompass the transition from unicellularity to simple multicellularity. Many of the innovations present in land plants have their roots in the cell and developmental biology of charophyte algae. Volvocine algae evolved an independent route to multicellularity that is captured by a graded series of increasing cell-type specialization and developmental complexity. The study of volvocine algae has provided unprecedented insights into the innovations required to achieve multicellularity.
Collapse
Affiliation(s)
- James G Umen
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132
| |
Collapse
|
38
|
Sex-specific posttranslational regulation of the gamete fusogen GCS1 in the isogamous volvocine alga Gonium pectorale. EUKARYOTIC CELL 2014; 13:648-56. [PMID: 24632243 DOI: 10.1128/ec.00330-13] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Male and female, generally defined based on differences in gamete size and motility, likely have multiple independent origins, appearing to have evolved from isogamous organisms in various eukaryotic lineages. Recent studies of the gamete fusogen GCS1/HAP2 indicate that this protein is deeply conserved across eukaryotes, and its exclusive and/or functional expression generally resides in males or in male homologues. However, little is known regarding the conserved or primitive molecular traits of males and females within eukaryotes. Here, using morphologically indistinguishable isogametes of the colonial volvocine Gonium pectorale, we demonstrated that GCS1 is differently regulated between the sexes. G. pectorale GCS1 molecules in one sex (homologous to male) are transported from the gamete cytoplasm to the protruded fusion site, whereas those of the other sex (females) are quickly degraded within the cytoplasm upon gamete activation. This molecular trait difference might be conserved across various eukaryotic lineages and may represent male and female prototypes originating from a common eukaryotic ancestor.
Collapse
|
39
|
Nozaki H, Yamada TK, Takahashi F, Matsuzaki R, Nakada T. New "missing link" genus of the colonial volvocine green algae gives insights into the evolution of oogamy. BMC Evol Biol 2014; 14:37. [PMID: 24589311 PMCID: PMC4015742 DOI: 10.1186/1471-2148-14-37] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 02/25/2014] [Indexed: 11/17/2022] Open
Abstract
Background The evolution of oogamy from isogamy, an important biological event, can be summarized as follows: morphologically similar gametes (isogametes) differentiated into small “male” and large “female” motile gametes during anisogamy, from which immotile female gametes (eggs) evolved. The volvocine green algae represent a model lineage to study this type of sex evolution and show two types of gametic unions: conjugation between isogametes outside the parental colonies (external fertilization during isogamy) and fertilization between small motile gametes (sperm) and large gametes (eggs) inside the female colony (internal fertilization during anisogamy and oogamy). Although recent cultural studies on volvocine algae revealed morphological diversity and molecular genetic data of sexual reproduction, an intermediate type of union between these two gametic unions has not been identified. Results We identified a novel colonial volvocine genus, Colemanosphaera, which produces bundles of spindle-shaped male gametes through successive divisions of colonial cells. Obligately anisogamous conjugation between male and female motile gametes occurred outside the female colony (external fertilization during anisogamy). This new genus contains 16- or 32-celled spheroidal colonies similar to those of the volvocine genera Yamagishiella and Eudorina. However, Colemanosphaera can be clearly distinguished from these two genera based on its sister phylogenetic position to the enigmatic flattened colonial volvocine Platydorina and external fertilization during anisogamy. Two species of Colemanosphaera were found in a Japanese lake; these species are also distributed in European freshwaters based on a published sequence of an Austrian strain and the original description of Pandorina charkowiensis from Ukraine. Conclusions Based on phylogeny and morphological data, this novel genus exhibits a missing link between Platydorina and the typical spheroidal colonial volvocine members such as Pandorina or Yamagishiella. Considering the external obligate anisogamy, oogamy evolution may have been preceded by the transition from external to internal fertilization during anisogamy within the volvocine green algae.
Collapse
Affiliation(s)
- Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, 7-3-1 Hongo, Bunkyo, Tokyo 113-0033, Japan.
| | | | | | | | | |
Collapse
|
40
|
Arakaki Y, Kawai-Toyooka H, Hamamura Y, Higashiyama T, Noga A, Hirono M, Olson BJSC, Nozaki H. The simplest integrated multicellular organism unveiled. PLoS One 2013; 8:e81641. [PMID: 24349103 PMCID: PMC3859500 DOI: 10.1371/journal.pone.0081641] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 10/15/2013] [Indexed: 11/18/2022] Open
Abstract
Volvocine green algae represent the "evolutionary time machine" model lineage for studying multicellularity, because they encompass the whole range of evolutionary transition of multicellularity from unicellular Chlamydomonas to >500-celled Volvox. Multicellular volvocalean species including Gonium pectorale and Volvox carteri generally have several common morphological features to survive as integrated multicellular organisms such as "rotational asymmetry of cells" so that the cells become components of the individual and "cytoplasmic bridges between protoplasts in developing embryos" to maintain the species-specific form of the multicellular individual before secretion of new extracellular matrix (ECM). However, these morphological features have not been studied in the four-celled colonial volvocine species Tetrabaena socialis that is positioned in the most basal lineage within the colonial or multicellular volvocine greens. Here we established synchronous cultures of T. socialis and carried out immunofluorescence microscopic and ultrastructural observations to elucidate these two morphological attributes. Based on immunofluorescence microscopy, four cells of the mature T. socialis colony were identical in morphology but had rotational asymmetry in arrangement of microtubular rootlets and separation of basal bodies like G. pectorale and V. carteri. Ultrastructural observations clearly confirmed the presence of cytoplasmic bridges between protoplasts in developing embryos of T. socialis even after the formation of new flagella in each daughter protoplast within the parental ECM. Therefore, these two morphological attributes might have evolved in the common four-celled ancestor of the colonial volvocine algae and contributed to the further increase in cell number and complexity of the multicellular individuals of this model lineage. T. socialis is one of the simplest integrated multicellular organisms in which four identical cells constitute the individual.
Collapse
Affiliation(s)
- Yoko Arakaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Hiroko Kawai-Toyooka
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Yuki Hamamura
- Division of Biological Science, Graduate School of Science, Nagoya University, Nagoya, Aichi, Japan
| | - Tetsuya Higashiyama
- Institute of Transformative Bio-Molecules (WPI-ITbM), Nagoya University, Nagoya, Aichi, Japan
- JST ERATO Higashiyama Live-Holonics Project, Nagoya University, Nagoya, Aichi, Japan
| | - Akira Noga
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Masafumi Hirono
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo, Japan
| | - Bradley J. S. C. Olson
- Division of Biology, Kansas State University, Chalmers, Manhattan, Kansas, United States of America
| | - Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Bunkyo-ku, Tokyo, Japan
- * E-mail:
| |
Collapse
|
41
|
Species and population level molecular profiling reveals cryptic recombination and emergent asymmetry in the dimorphic mating locus of C. reinhardtii. PLoS Genet 2013; 9:e1003724. [PMID: 24009520 PMCID: PMC3757049 DOI: 10.1371/journal.pgen.1003724] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2013] [Accepted: 06/28/2013] [Indexed: 12/12/2022] Open
Abstract
Heteromorphic sex-determining regions or mating-type loci can contain large regions of non-recombining sequence where selection operates under different constraints than in freely recombining autosomal regions. Detailed studies of these non-recombining regions can provide insights into how genes are gained and lost, and how genetic isolation is maintained between mating haplotypes or sex chromosomes. The Chlamydomonas reinhardtii mating-type locus (MT) is a complex polygenic region characterized by sequence rearrangements and suppressed recombination between its two haplotypes, MT+ and MT−. We used new sequence information to redefine the genetic contents of MT and found repeated translocations from autosomes as well as sexually controlled expression patterns for several newly identified genes. We examined sequence diversity of MT genes from wild isolates of C. reinhardtii to investigate the impacts of recombination suppression. Our population data revealed two previously unreported types of genetic exchange in Chlamydomonas MT—gene conversion in the rearranged domains, and crossover exchanges in flanking domains—both of which contribute to maintenance of genetic homogeneity between haplotypes. To investigate the cause of blocked recombination in MT we assessed recombination rates in crosses where the parents were homozygous at MT. While normal recombination was restored in MT+×MT+ crosses, it was still suppressed in MT−×MT− crosses. These data revealed an underlying asymmetry in the two MT haplotypes and suggest that sequence rearrangements are insufficient to fully account for recombination suppression. Together our findings reveal new evolutionary dynamics for mating loci and have implications for the evolution of heteromorphic sex chromosomes and other non-recombining genomic regions. Sex chromosomes and mating-type loci are often atypical in their structure and evolutionary dynamics. One distinguishing feature is the absence of recombination that results in genetic isolation and promotes rapid evolution and sometimes degeneration. We investigated gene content, sex-regulated expression, and recombination of mating locus (MT) genes in the unicellular alga Chlamydomonas reinhardtii. Despite the lack of observable recombination in and around Chlamydomonas MT, genes from its two mating types are far more similar to each other than expected for a non-recombining region. This discrepancy is explained by our finding evidence of genetic exchange between the two mating types within wild populations. In addition, we observed an unexpected asymmetry in the recombination behavior of the two mating types that may have contributed to the preferential expansion of one MT haplotype over the other through insertion of new genes. Our data suggest a mechanism to explain the emergence of heteromorphic sex chromosomes in haploid organisms by asymmetric expansion rather than by loss or degeneration as occurs in some Y or W chromosomes from diploid organisms. Our observations support a revised view of recombination in sex-determining regions as a quantitative phenomenon that can significantly affect rates of evolution and sex-linked genetic diversification.
Collapse
|
42
|
Tao W, Mayden RL, He S. Remarkable phylogenetic resolution of the most complex clade of Cyprinidae (Teleostei: Cypriniformes): A proof of concept of homology assessment and partitioning sequence data integrated with mixed model Bayesian analyses. Mol Phylogenet Evol 2013; 66:603-16. [DOI: 10.1016/j.ympev.2012.09.024] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 09/18/2012] [Accepted: 09/21/2012] [Indexed: 11/16/2022]
|
43
|
Hamaji T, Smith DR, Noguchi H, Toyoda A, Suzuki M, Kawai-Toyooka H, Fujiyama A, Nishii I, Marriage T, Olson BJSC, Nozaki H. Mitochondrial and plastid genomes of the colonial green alga Gonium pectorale give insights into the origins of organelle DNA architecture within the volvocales. PLoS One 2013; 8:e57177. [PMID: 23468928 PMCID: PMC3582580 DOI: 10.1371/journal.pone.0057177] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 01/18/2013] [Indexed: 02/07/2023] Open
Abstract
Volvocalean green algae have among the most diverse mitochondrial and plastid DNAs (mtDNAs and ptDNAs) from the eukaryotic domain. However, nearly all of the organelle genome data from this group are restricted to unicellular species, like Chlamydomonas reinhardtii, and presently only one multicellular species, the ∼4,000-celled Volvox carteri, has had its organelle DNAs sequenced. The V. carteri organelle genomes are repeat rich, and the ptDNA is the largest plastome ever sequenced. Here, we present the complete mtDNA and ptDNA of the colonial volvocalean Gonium pectorale, which is comprised of ∼16 cells and occupies a phylogenetic position closer to that of V. carteri than C. reinhardtii within the volvocine line. The mtDNA and ptDNA of G. pectorale are circular-mapping AT-rich molecules with respective lengths and coding densities of 16 and 222.6 kilobases and 73 and 44%. They share some features with the organelle DNAs of V. carteri, including palindromic repeats within the plastid compartment, but show more similarities with those of C. reinhardtii, such as a compact mtDNA architecture and relatively low organelle DNA intron contents. Overall, the G. pectorale organelle genomes raise several interesting questions about the origin of linear mitochondrial chromosomes within the Volvocales and the relationship between multicellularity and organelle genome expansion.
Collapse
Affiliation(s)
- Takashi Hamaji
- Department of Botany, Graduate School of Science, Kyoto University, Oiwake-cho, Kita-shirakawa, Sakyo-ku, Kyoto, Japan
| | - David R. Smith
- Canadian Institute for Advanced Research, Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada
| | - Hideki Noguchi
- Center for Advanced Genomics, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Atsushi Toyoda
- Center for Advanced Genomics, National Institute of Genetics, Mishima, Shizuoka, Japan
- Center for Information Biology, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Masahiro Suzuki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
| | - Hiroko Kawai-Toyooka
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
| | - Asao Fujiyama
- Center for Advanced Genomics, National Institute of Genetics, Mishima, Shizuoka, Japan
- Center for Information Biology, National Institute of Genetics, Mishima, Shizuoka, Japan
| | - Ichiro Nishii
- Temasek Life Sciences Laboratory, The National University of Singapore, Singapore, Singapore
| | - Tara Marriage
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
| | - Bradley J. S. C. Olson
- Division of Biology, Kansas State University, Manhattan, Kansas, United States of America
| | - Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
- * E-mail:
| |
Collapse
|
44
|
Lerche K, Hallmann A. Stable nuclear transformation of Eudorina elegans. BMC Biotechnol 2013; 13:11. [PMID: 23402598 PMCID: PMC3576287 DOI: 10.1186/1472-6750-13-11] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2012] [Accepted: 02/08/2013] [Indexed: 05/16/2023] Open
Abstract
Background A fundamental step in evolution was the transition from unicellular to differentiated, multicellular organisms. Volvocine algae have been used for several decades as a model lineage to investigate the evolutionary aspects of multicellularity and cellular differentiation. There are two well-studied volvocine species, a unicellular alga (Chlamydomonas reinhardtii) and a multicellular alga with differentiated cell types (Volvox carteri). Species with intermediate characteristics also exist, which blur the boundaries between unicellularity and differentiated multicellularity. These species include the globular alga Eudorina elegans, which is composed of 16–32 cells. However, detailed molecular analyses of E. elegans require genetic manipulation. Unfortunately, genetic engineering has not yet been established for Eudorina, and only limited DNA and/or protein sequence information is available. Results Here, we describe the stable nuclear transformation of E. elegans by particle bombardment using both a chimeric selectable marker and reporter genes from different heterologous sources. Transgenic algae resistant to paromomycin were achieved using the aminoglycoside 3′-phosphotransferase VIII (aphVIII) gene of Streptomyces rimosus, an actinobacterium, under the control of an artificial promoter consisting of two V. carteri promoters in tandem. Transformants exhibited an increase in resistance to paromomycin by up to 333-fold. Co-transformation with non-selectable plasmids was achieved with a rate of 50 - 100%. The luciferase (gluc) gene from the marine copepod Gaussia princeps, which previously was engineered to match the codon usage of C. reinhardtii, was used as a reporter gene. The expression of gluc was mediated by promoters from C. reinhardtii and V. carteri. Heterologous heat shock promoters induced an increase in luciferase activity (up to 600-fold) at elevated temperatures. Long-term stability and both constitutive and inducible expression of the co-bombarded gluc gene was demonstrated by transcription analysis and bioluminescence assays. Conclusions Heterologous flanking sequences, including promoters, work in E. elegans and permit both constitutive and inducible expression of heterologous genes. Stable nuclear transformation of E. elegans is now routine. Thus, we show that genetic engineering of a species is possible even without the resources of endogenous genes and promoters.
Collapse
Affiliation(s)
- Kai Lerche
- Department of Cellular and Developmental Biology of Plants, University of Bielefeld, Bielefeld, Germany
| | | |
Collapse
|
45
|
Herron MD. Many from one: Lessons from the volvocine algae on the evolution of multicellularity. Commun Integr Biol 2013; 2:368-70. [PMID: 19721894 DOI: 10.4161/cib.2.4.8611] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Accepted: 04/01/2009] [Indexed: 11/19/2022] Open
Abstract
The volvocine green algae are a model system for the evolution of multicellularity and cellular differentiation. A combination of molecular genetic and phylogenetic comparative approaches has resulted in a detailed picture of the transition from single cells to differentiated, multicellular organisms in this group. To be useful as a model system, the volvocine algae should provide information that is relevant to other groups. Here I discuss recent advances in understanding the origins of multicellularity and cellular differentiation in the volvocine algae and consider the implications for such transitions in general. Several general principles emerge that are relevant to the origins of major multicellular groups, such as animals, plants, fungi, red and brown algae. First, if the lessons learned from the volvocine algae can be generalized to other origins of multicellularity, we should expect these transitions to be understandable as a series of small changes, each potentially adaptive in itself. In addition, cooperation, conflict and mediation of conflicts among cells are likely to have played central roles. Finally, we should expect the histories of these transitions to include parallel evolution of some traits, periods of relatively rapid change interspersed with long periods of stasis, and simpler forms coexisting with more complex forms for long periods of time as in the evolution of the volvocine algae.
Collapse
Affiliation(s)
- Matthew D Herron
- Department of Ecology and Evolutionary Biology; University of Arizona; Tucson, AZ USA
| |
Collapse
|
46
|
Smith DR, Hamaji T, Olson BJSC, Durand PM, Ferris P, Michod RE, Featherston J, Nozaki H, Keeling PJ. Organelle genome complexity scales positively with organism size in volvocine green algae. Mol Biol Evol 2013; 30:793-7. [PMID: 23300255 DOI: 10.1093/molbev/mst002] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
It has been argued that for certain lineages, noncoding DNA expansion is a consequence of the increased random genetic drift associated with long-term escalations in organism size. But a lack of data has prevented the investigation of this hypothesis in most plastid-bearing protists. Here, using newly sequenced mitochondrial and plastid genomes, we explore the relationship between organelle DNA noncoding content and organism size within volvocine green algae. By looking at unicellular, colonial, and differentiated multicellular algae, we show that organelle DNA complexity scales positively with species size and cell number across the volvocine lineage. Moreover, silent-site genetic diversity data suggest that the volvocine species with the largest cell numbers and most bloated organelle genomes have the smallest effective population sizes. Together, these findings support the view that nonadaptive processes, like random genetic drift, promote the expansion of noncoding regions in organelle genomes.
Collapse
Affiliation(s)
- David Roy Smith
- Canadian Institute for Advanced Research, Department of Botany, University of British Columbia, Vancouver, British Columbia, Canada.
| | | | | | | | | | | | | | | | | |
Collapse
|
47
|
Nozaki H, Yang Y, Maruyama S, Suzaki T. A case study for effects of operational taxonomic units from intracellular endoparasites and ciliates on the eukaryotic phylogeny: phylogenetic position of the haptophyta in analyses of multiple slowly evolving genes. PLoS One 2012; 7:e50827. [PMID: 23226396 PMCID: PMC3511332 DOI: 10.1371/journal.pone.0050827] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2012] [Accepted: 10/25/2012] [Indexed: 01/09/2023] Open
Abstract
Recent multigene phylogenetic analyses have contributed much to our understanding of eukaryotic phylogeny. However, the phylogenetic positions of various lineages within the eukaryotes have remained unresolved or in conflict between different phylogenetic studies. These phylogenetic ambiguities might have resulted from mixtures or integration from various factors including limited taxon sampling, missing data in the alignment, saturations of rapidly evolving genes, mixed analyses of short- and long-branched operational taxonomic units (OTUs), intracellular endoparasite and ciliate OTUs with unusual substitution etc. In order to evaluate the effects from intracellular endoparasite and ciliate OTUs co-analyzed on the eukaryotic phylogeny and simplify the results, we here used two different sets of data matrices of multiple slowly evolving genes with small amounts of missing data and examined the phylogenetic position of the secondary photosynthetic chromalveolates Haptophyta, one of the most abundant groups of oceanic phytoplankton and significant primary producers. In both sets, a robust sister relationship between Haptophyta and SAR (stramenopiles, alveolates, rhizarians, or SA [stramenopiles and alveolates]) was resolved when intracellular endoparasite/ciliate OTUs were excluded, but not in their presence. Based on comparisons of character optimizations on a fixed tree (with a clade composed of haptophytes and SAR or SA), disruption of the monophyly between haptophytes and SAR (or SA) in the presence of intracellular endoparasite/ciliate OTUs can be considered to be a result of multiple evolutionary reversals of character positions that supported the synapomorphy of the haptophyte and SAR (or SA) clade in the absence of intracellular endoparasite/ciliate OTUs.
Collapse
Affiliation(s)
- Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo, Japan.
| | | | | | | |
Collapse
|
48
|
Isaka N, Kawai-Toyooka H, Matsuzaki R, Nakada T, Nozaki H. DESCRIPTION OF TWO NEW MONOECIOUS SPECIES OF VOLVOX SECT. VOLVOX (VOLVOCACEAE, CHLOROPHYCEAE), BASED ON COMPARATIVE MORPHOLOGY AND MOLECULAR PHYLOGENY OF CULTURED MATERIAL(1). JOURNAL OF PHYCOLOGY 2012; 48:759-767. [PMID: 27011093 DOI: 10.1111/j.1529-8817.2012.01142.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Species of Volvox sect. Volvox (Volvocaceae, Chlorophyceae) are unique because they have thick cytoplasmic bridges between somatic cells and spiny-walled zygotes. This section is taxonomically important because the genus Volvox is polyphyletic. However, taxonomic studies of species in Volvox sect. Volvox have not been carried out on cultured material. Here, we performed a taxonomic study of monoecious species of Volvox sect. Volvox based on the comparative morphology and molecular phylogeny of chloroplast genes and the internal transcribed spacer (ITS) regions of nuclear rDNA using various strains originating from Japan and two preserved strains from the USA. The strains were clearly divided into four species, V. globator L., V. barberi W. Shaw, V. kirkiorum sp. nov., and V. ferrisii sp. nov., on the basis of differences in numbers of zygotes (eggs) in the sexual spheroids, form of zygote wall, and somatic cell shape. Sequences for ITS of nuclear rDNA resolved that the two new species have phylogenetic positions separated from V. globator, V. barberi, V. capensis F. Rich et Pocock, and V. rousseletii G. S. West UTEX 1862 within Volvox sect. Volvox.
Collapse
Affiliation(s)
- Nanako Isaka
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, JapanInstitute for Advanced Biosciences, Keio University, 246-2 Mizukami, Kakuganji, Tsuruoka, Yamagata, 997-0052, JapanDepartment of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hiroko Kawai-Toyooka
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, JapanInstitute for Advanced Biosciences, Keio University, 246-2 Mizukami, Kakuganji, Tsuruoka, Yamagata, 997-0052, JapanDepartment of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Ryo Matsuzaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, JapanInstitute for Advanced Biosciences, Keio University, 246-2 Mizukami, Kakuganji, Tsuruoka, Yamagata, 997-0052, JapanDepartment of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takashi Nakada
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, JapanInstitute for Advanced Biosciences, Keio University, 246-2 Mizukami, Kakuganji, Tsuruoka, Yamagata, 997-0052, JapanDepartment of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, JapanInstitute for Advanced Biosciences, Keio University, 246-2 Mizukami, Kakuganji, Tsuruoka, Yamagata, 997-0052, JapanDepartment of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| |
Collapse
|
49
|
Mogi Y, Hamaji T, Suzuki M, Ferris P, Mori T, Kabeya Y, Miyagishima SY, Nozaki H. EVIDENCE FOR TUBULAR MATING STRUCTURES INDUCED IN EACH MATING TYPE OF HETEROTHALLIC GONIUM PECTORALE (VOLVOCALES, CHLOROPHYTA)(1). JOURNAL OF PHYCOLOGY 2012; 48:670-4. [PMID: 27011083 DOI: 10.1111/j.1529-8817.2012.01149.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Gametes were induced separately in cultures of each mating type of the heterothallic, isogamous colonial volvocalean Gonium pectorale O. F. Müll. to examine the tubular mating structure (TMS) of both mating types plus and minus (plus and minus), referred to as "bilateral mating papillae." Addition of dibutyryl cyclic adenosine monophosphate (DcAMP or db-cAMP) and 3-isobutyl-1-methylxanthine (IBMX) to approximately 3-week-old cultures of each mating type induced immediate release of naked gametes from the cell walls. Both plus and minus gametes formed a TMS in the anterior region of the protoplasts. Accumulation of actin was visualized by antibody staining in the TMS of both mating types as occurs in the TMS (fertilization tubule) of the plus gametes of the unicellular volvocalean Chlamydomonas reinhardtii P. A. Dang. Induction of naked gametes with a TMS in each mating type will be useful for future cell biological and evolutionary studies of the isogametes of colonial volvocalean algae.
Collapse
Affiliation(s)
- Yuko Mogi
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, JapanDepartment of Botany, Laboratory of Plant Molecular Genetics, Kyoto University, Oiwake-cho, Kita-shirakawa, Sakyo-ku, Kyoto 606-8502, JapanDepartment of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, JapanDepartment of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USAWaseda Institute for Advanced Study (WIAS), Waseda University, 1-6-1 Nishiwaseda, Shinjuku-ku, Tokyo 169-8050, JapanCenter for Frontier Research, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, JapanDepartment of Biological Sciences, Graduate school of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Takashi Hamaji
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, JapanDepartment of Botany, Laboratory of Plant Molecular Genetics, Kyoto University, Oiwake-cho, Kita-shirakawa, Sakyo-ku, Kyoto 606-8502, JapanDepartment of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, JapanDepartment of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USAWaseda Institute for Advanced Study (WIAS), Waseda University, 1-6-1 Nishiwaseda, Shinjuku-ku, Tokyo 169-8050, JapanCenter for Frontier Research, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, JapanDepartment of Biological Sciences, Graduate school of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Masahiro Suzuki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, JapanDepartment of Botany, Laboratory of Plant Molecular Genetics, Kyoto University, Oiwake-cho, Kita-shirakawa, Sakyo-ku, Kyoto 606-8502, JapanDepartment of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, JapanDepartment of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USAWaseda Institute for Advanced Study (WIAS), Waseda University, 1-6-1 Nishiwaseda, Shinjuku-ku, Tokyo 169-8050, JapanCenter for Frontier Research, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, JapanDepartment of Biological Sciences, Graduate school of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Patrick Ferris
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, JapanDepartment of Botany, Laboratory of Plant Molecular Genetics, Kyoto University, Oiwake-cho, Kita-shirakawa, Sakyo-ku, Kyoto 606-8502, JapanDepartment of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, JapanDepartment of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USAWaseda Institute for Advanced Study (WIAS), Waseda University, 1-6-1 Nishiwaseda, Shinjuku-ku, Tokyo 169-8050, JapanCenter for Frontier Research, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, JapanDepartment of Biological Sciences, Graduate school of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Toshiyuki Mori
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, JapanDepartment of Botany, Laboratory of Plant Molecular Genetics, Kyoto University, Oiwake-cho, Kita-shirakawa, Sakyo-ku, Kyoto 606-8502, JapanDepartment of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, JapanDepartment of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USAWaseda Institute for Advanced Study (WIAS), Waseda University, 1-6-1 Nishiwaseda, Shinjuku-ku, Tokyo 169-8050, JapanCenter for Frontier Research, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, JapanDepartment of Biological Sciences, Graduate school of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Yukihiro Kabeya
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, JapanDepartment of Botany, Laboratory of Plant Molecular Genetics, Kyoto University, Oiwake-cho, Kita-shirakawa, Sakyo-ku, Kyoto 606-8502, JapanDepartment of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, JapanDepartment of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USAWaseda Institute for Advanced Study (WIAS), Waseda University, 1-6-1 Nishiwaseda, Shinjuku-ku, Tokyo 169-8050, JapanCenter for Frontier Research, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, JapanDepartment of Biological Sciences, Graduate school of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Shin-Ya Miyagishima
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, JapanDepartment of Botany, Laboratory of Plant Molecular Genetics, Kyoto University, Oiwake-cho, Kita-shirakawa, Sakyo-ku, Kyoto 606-8502, JapanDepartment of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, JapanDepartment of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USAWaseda Institute for Advanced Study (WIAS), Waseda University, 1-6-1 Nishiwaseda, Shinjuku-ku, Tokyo 169-8050, JapanCenter for Frontier Research, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, JapanDepartment of Biological Sciences, Graduate school of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Hisayoshi Nozaki
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, JapanDepartment of Botany, Laboratory of Plant Molecular Genetics, Kyoto University, Oiwake-cho, Kita-shirakawa, Sakyo-ku, Kyoto 606-8502, JapanDepartment of Biological Sciences, Graduate School of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, JapanDepartment of Ecology and Evolutionary Biology, University of Arizona, Tucson, Arizona 85721, USAWaseda Institute for Advanced Study (WIAS), Waseda University, 1-6-1 Nishiwaseda, Shinjuku-ku, Tokyo 169-8050, JapanCenter for Frontier Research, National Institute of Genetics, 1111 Yata, Mishima, Shizuoka 411-8540, JapanDepartment of Biological Sciences, Graduate school of Science, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
| |
Collapse
|
50
|
Abstract
Volvocine algae are a group of chlorophytes that together comprise a unique model for evolutionary and developmental biology. The species Chlamydomonas reinhardtii and Volvox carteri represent extremes in morphological diversity within the Volvocine clade. Chlamydomonas is unicellular and reflects the ancestral state of the group, while Volvox is multicellular and has evolved numerous innovations including germ-soma differentiation, sexual dimorphism, and complex morphogenetic patterning. The Chlamydomonas genome sequence has shed light on several areas of eukaryotic cell biology, metabolism and evolution, while the Volvox genome sequence has enabled a comparison with Chlamydomonas that reveals some of the underlying changes that enabled its transition to multicellularity, but also underscores the subtlety of this transition. Many of the tools and resources are in place to further develop Volvocine algae as a model for evolutionary genomics.
Collapse
Affiliation(s)
- James G Umen
- Donald Danforth Plant Science Center, 975 North Warson Rd., St. Louis, MO 63132 USA
| | - Bradley J S C Olson
- Molecular Cellular and Developmental Biology, Ecological Genomics Institute, Division of Biology, Kansas State University, Manhattan, KS 66506 USA
| |
Collapse
|