1
|
Vigneau J, Martinho C, Godfroy O, Zheng M, Haas FB, Borg M, Coelho SM. Interactions between U and V sex chromosomes during the life cycle of Ectocarpus. Development 2024; 151:dev202677. [PMID: 38512707 PMCID: PMC11057875 DOI: 10.1242/dev.202677] [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: 01/04/2024] [Accepted: 03/01/2024] [Indexed: 03/23/2024]
Abstract
In many animals and flowering plants, sex determination occurs in the diploid phase of the life cycle with XX/XY or ZW/ZZ sex chromosomes. However, in early diverging plants and most macroalgae, sex is determined by female (U) or male (V) sex chromosomes in a haploid phase called the gametophyte. Once the U and V chromosomes unite at fertilization to produce a diploid sporophyte, sex determination no longer occurs, raising key questions about the fate of the U and V sex chromosomes in the sporophyte phase. Here, we investigate genetic and molecular interactions of the UV sex chromosomes in both the haploid and diploid phases of the brown alga Ectocarpus. We reveal extensive developmental regulation of sex chromosome genes across its life cycle and implicate the TALE-HD transcription factor OUROBOROS in suppressing sex determination in the diploid phase. Small RNAs may also play a role in the repression of a female sex-linked gene, and transition to the diploid sporophyte coincides with major reconfiguration of histone H3K79me2, suggesting a more intricate role for this histone mark in Ectocarpus development than previously appreciated.
Collapse
Affiliation(s)
| | | | - Olivier Godfroy
- Roscoff Biological Station, CNRS-Sorbonne University, Place Georges Teissier, Roscoff 29680, France
| | - Min Zheng
- Max Planck Institute for Biology, 72076 Tübingen, Germany
| | - Fabian B. Haas
- Max Planck Institute for Biology, 72076 Tübingen, Germany
| | - Michael Borg
- Max Planck Institute for Biology, 72076 Tübingen, Germany
| | | |
Collapse
|
2
|
Hoshino M, Cossard G, Haas FB, Kane EI, Kogame K, Jomori T, Wakimoto T, Glemin S, Coelho SM. Parallel loss of sexual reproduction in field populations of a brown alga sheds light on the mechanisms underlying the emergence of asexuality. Nat Ecol Evol 2024:10.1038/s41559-024-02490-w. [PMID: 39152327 DOI: 10.1038/s41559-024-02490-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2024] [Accepted: 06/18/2024] [Indexed: 08/19/2024]
Abstract
Sexual reproduction is widespread, but asexual lineages have repeatedly arisen from sexual ancestors across a wide range of eukaryotic taxa. The molecular changes underpinning the switch to asexuality remain elusive, particularly in organisms with haploid sexual systems. Here we explore independent events of loss of sex in the brown alga Scytosiphon, examine the proximate and evolutionary mechanisms involved, and test the importance of sexual conflict on gene expression changes following loss of sex. We find that asexual females ('Amazons') lose ability to produce sex pheromone and, consequently, are incapable of attracting males, whereas they gain rapid parthenogenic development from large, unfertilized eggs. These phenotypic changes are accompanied by convergent changes in gene expression. Decay of female functions, rather than relaxation of sexual antagonism, may be a dominant force at play during the emergence of asexuality in haploid sexual systems. Moreover, we show that haploid purifying selection plays a key role in limiting the accumulation of deleterious alleles in Amazons, and we identify an autosomal locus associated with the Amazon phenotype. The sex chromosome, together with this autosomal locus, may underlie the switch to obligate asexuality in the Amazon populations.
Collapse
Affiliation(s)
- Masakazu Hoshino
- Department of Algal Development and Evolution, Max Planck Institute for Biology Tübingen, Tübingen, Germany
- Research Center for Inland Seas, Kobe University, Rokkodai 1-1, Nadaku, Kobe, Japan
| | - Guillaume Cossard
- Department of Algal Development and Evolution, Max Planck Institute for Biology Tübingen, Tübingen, Germany
| | - Fabian B Haas
- Department of Algal Development and Evolution, Max Planck Institute for Biology Tübingen, Tübingen, Germany
| | - Emma I Kane
- Department of Algal Development and Evolution, Max Planck Institute for Biology Tübingen, Tübingen, Germany
| | - Kazuhiro Kogame
- Department of Biological Sciences, Faculty of Science, Hokkaido University, Sapporo, Japan
| | - Takahiro Jomori
- Faculty of Pharmaceutical Sciences, Hokkaido University, Sapporo, Japan
| | | | - Sylvain Glemin
- Laboratoire ECOBIO (Ecosystèmes, biodiversité, évolution), UMR 6553, CNRS, Université de Rennes, Rennes, France
- Department of Ecology and Genetics, Evolutionary Biology Centre, Uppsala University, Uppsala, Sweden
| | - Susana M Coelho
- Department of Algal Development and Evolution, Max Planck Institute for Biology Tübingen, Tübingen, Germany.
| |
Collapse
|
3
|
Geng Y, Xie C, Yan A, Yang X, Lai DN, Liu X, Zhou Y. A conserved GRAS-domain transcriptional regulator links meristem indeterminacy to sex determination in Ceratopteris gametophytes. Curr Biol 2024; 34:3454-3472.e7. [PMID: 39059395 DOI: 10.1016/j.cub.2024.06.064] [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: 09/15/2023] [Revised: 05/16/2024] [Accepted: 06/25/2024] [Indexed: 07/28/2024]
Abstract
Most land plants alternate between generations of sexual gametophytes and asexual sporophytes. Unlike seed plants, fern gametophytes are free living and grow independently of their sporophytes. In homosporous ferns such as Ceratopteris, gametophytes derived from genetically identical spores exhibit sexual dimorphism, developing as either males or hermaphrodites. Males lack meristems and promote cell differentiation into sperm-producing antheridia. In contrast, hermaphrodites initiate multicellular meristems that stay undifferentiated, sustain cell division and prothallus expansion, and drive the formation of egg-producing archegonia. Once initiating the meristem, hermaphrodites secrete the pheromone antheridiogen, which triggers neighboring slower-growing gametophytes to develop as males, while the hermaphrodites themselves remain insensitive to antheridiogen. This strategy promotes outcrossing and prevents all individuals in the colony from becoming males. This study reveals that an evolutionarily conserved GRAS-domain transcriptional regulator (CrHAM), directly repressed by Ceratopteris microRNA171 (CrmiR171), promotes meristem development in Ceratopteris gametophytes and determines the male-to-hermaphrodite ratio in the colony. CrHAM preferentially accumulates within the meristems of hermaphrodites but is excluded from differentiated antheridia. CrHAM sustains meristem proliferation and cell division through conserved hormone pathways. In the meantime, CrHAM inhibits the antheridiogen-induced conversion of hermaphrodites to males by suppressing the male program expression and preventing meristem cells from differentiating into sperm-producing antheridia. This finding establishes a connection between meristem indeterminacy and sex determination in ferns, suggesting both conserved and diversified roles of meristem regulators in land plants.
Collapse
Affiliation(s)
- Yuan Geng
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA; Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Chong Xie
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA; Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - An Yan
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, CA 91125, USA; Howard Hughes Medical Institute, California Institute of Technology, Pasadena, CA 91125, USA
| | - Xi Yang
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA; Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Dinh Nhan Lai
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA; Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Xing Liu
- Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA; Department of Biochemistry, Purdue University, West Lafayette, IN 47907, USA
| | - Yun Zhou
- Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN 47907, USA; Purdue Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA.
| |
Collapse
|
4
|
Castel J, Pradillon F, Cueff V, Leger G, Daguin-Thiébaut C, Ruault S, Mary J, Hourdez S, Jollivet D, Broquet T. Genetic sex determination in three closely related hydrothermal vent gastropods, including one species with intersex individuals. J Evol Biol 2024; 37:779-794. [PMID: 38699972 DOI: 10.1093/jeb/voae051] [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: 02/14/2024] [Revised: 03/27/2024] [Accepted: 05/02/2024] [Indexed: 05/05/2024]
Abstract
Molluscs have undergone many transitions between separate sexes and hermaphroditism, which is of interest in studying the evolution of sex determination and differentiation. Here, we combined multi-locus genotypes obtained from restriction site-associated DNA (RAD) sequencing with anatomical observations of the gonads of three deep-sea hydrothermal vent gastropods of the genus Alviniconcha living in the southwest Pacific. We found that all three species (Alviniconcha boucheti, Alviniconcha strummeri, and Alviniconcha kojimai) share the same male-heterogametic XY sex-determination system but that the gonads of XX A. kojimai individuals are invaded by a variable proportion of male reproductive tissue. The identification of Y-specific RAD loci (found only in A. boucheti) and the phylogenetic analysis of three sex-linked loci shared by all species suggested that X-Y recombination has evolved differently within each species. This situation of three species showing variation in gonadal development around a common sex-determination system provides new insights into the reproductive mode of poorly known deep-sea species and opens up an opportunity to study the evolution of recombination suppression on sex chromosomes and its association with mixed or transitory sexual systems.
Collapse
Affiliation(s)
- Jade Castel
- UMR 7144 AD2M CNRS-Sorbonne Université, Station Biologique de Roscoff, Roscoff, France
| | - Florence Pradillon
- Univ Brest, CNRS, Ifremer, UMR6197 Biologie et Ecologie des Ecosystèmes marins Profonds, Plouzané, France
| | - Valérie Cueff
- Univ Brest, CNRS, Ifremer, UMR6197 Biologie et Ecologie des Ecosystèmes marins Profonds, Plouzané, France
| | - Guillaume Leger
- Univ Brest, CNRS, Ifremer, UMR6197 Biologie et Ecologie des Ecosystèmes marins Profonds, Plouzané, France
| | | | - Stéphanie Ruault
- UMR 7144 AD2M CNRS-Sorbonne Université, Station Biologique de Roscoff, Roscoff, France
| | - Jean Mary
- UMR 7144 AD2M CNRS-Sorbonne Université, Station Biologique de Roscoff, Roscoff, France
| | - Stéphane Hourdez
- UMR 8222 LECOB CNRS-Sorbonne Université, Observatoire Océanologique de Banyuls, Banyuls-sur-Mer, France
| | - Didier Jollivet
- UMR 7144 AD2M CNRS-Sorbonne Université, Station Biologique de Roscoff, Roscoff, France
| | - Thomas Broquet
- UMR 7144 AD2M CNRS-Sorbonne Université, Station Biologique de Roscoff, Roscoff, France
| |
Collapse
|
5
|
Krueger-Hadfield SA. Let's talk about sex: Why reproductive systems matter for understanding algae. JOURNAL OF PHYCOLOGY 2024; 60:581-597. [PMID: 38743848 DOI: 10.1111/jpy.13462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/23/2024] [Accepted: 04/24/2024] [Indexed: 05/16/2024]
Abstract
Sex is a crucial process that has molecular, genetic, cellular, organismal, and population-level consequences for eukaryotic evolution. Eukaryotic life cycles are composed of alternating haploid and diploid phases but are constrained by the need to accommodate the phenotypes of these different phases. Critical gaps in our understanding of evolutionary drivers of the diversity in algae life cycles include how selection acts to stabilize and change features of the life cycle. Moreover, most eukaryotes are partially clonal, engaging in both sexual and asexual reproduction. Yet, our understanding of the variation in their reproductive systems is largely based on sexual reproduction in animals or angiosperms. The relative balance of sexual versus asexual reproduction not only controls but also is in turn controlled by standing genetic variability, thereby shaping evolutionary trajectories. Thus, we must quantitatively assess the consequences of the variation in life cycles on reproductive systems. Algae are a polyphyletic group spread across many of the major eukaryotic lineages, providing powerful models by which to resolve this knowledge gap. There is, however, an alarming lack of data about the population genetics of most algae and, therefore, the relative frequency of sexual versus asexual processes. For many algae, the occurrence of sexual reproduction is unknown, observations have been lost in overlooked papers, or data on population genetics do not yet exist. This greatly restricts our ability to forecast the consequences of climate change on algal populations inhabiting terrestrial, aquatic, and marine ecosystems. This perspective summarizes our extant knowledge and provides some future directions to pursue broadly across micro- and macroalgal species.
Collapse
|
6
|
Borg M, Krueger-Hadfield SA, Destombe C, Collén J, Lipinska A, Coelho SM. Red macroalgae in the genomic era. THE NEW PHYTOLOGIST 2023; 240:471-488. [PMID: 37649301 DOI: 10.1111/nph.19211] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 07/24/2023] [Indexed: 09/01/2023]
Abstract
Rhodophyta (or red algae) are a diverse and species-rich group that forms one of three major lineages in the Archaeplastida, a eukaryotic supergroup whose plastids arose from a single primary endosymbiosis. Red algae are united by several features, such as relatively small intron-poor genomes and a lack of cytoskeletal structures associated with motility like flagella and centrioles, as well as a highly efficient photosynthetic capacity. Multicellular red algae (or macroalgae) are one of the earliest diverging eukaryotic lineages to have evolved complex multicellularity, yet despite their ecological, evolutionary, and commercial importance, they have remained a largely understudied group of organisms. Considering the increasing availability of red algal genome sequences, we present a broad overview of fundamental aspects of red macroalgal biology and posit on how this is expected to accelerate research in many domains of red algal biology in the coming years.
Collapse
Affiliation(s)
- Michael Borg
- Department of Algal Development and Evolution, Max Planck Institute for Biology, 72076, Tübingen, Germany
| | - Stacy A Krueger-Hadfield
- Department of Biology, The University of Alabama at Birmingham, Birmingham, AL, 35294, USA
- Virginia Institute of Marine Science Eastern Shore Laboratory, Wachapreague, VA, 23480, USA
| | - Christophe Destombe
- International Research Laboratory 3614 (IRL3614) - Evolutionary Biology and Ecology of Algae, Centre National de la Recherche Scientifique (CNRS), Sorbonne Université, Pontificia Universidad Católica de Chile, Universidad Austral de Chile, Roscoff, 29680, France
| | - Jonas Collén
- CNRS, Integrative Biology of Marine Models (LBI2M, UMR8227), Station Biologique de Roscoff, Sorbonne Université, Roscoff, 29680, France
| | - Agnieszka Lipinska
- Department of Algal Development and Evolution, Max Planck Institute for Biology, 72076, Tübingen, Germany
| | - Susana M Coelho
- Department of Algal Development and Evolution, Max Planck Institute for Biology, 72076, Tübingen, Germany
| |
Collapse
|
7
|
Pinello JF, Clark TG. HAP2-Mediated Gamete Fusion: Lessons From the World of Unicellular Eukaryotes. Front Cell Dev Biol 2022; 9:807313. [PMID: 35071241 PMCID: PMC8777248 DOI: 10.3389/fcell.2021.807313] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 11/15/2021] [Indexed: 01/29/2023] Open
Abstract
Most, if not all the cellular requirements for fertilization and sexual reproduction arose early in evolution and are retained in extant lineages of single-celled organisms including a number of important model organism species. In recent years, work in two such species, the green alga, Chlamydomonas reinhardtii, and the free-living ciliate, Tetrahymena thermophila, have lent important new insights into the role of HAP2/GCS1 as a catalyst for gamete fusion in organisms ranging from protists to flowering plants and insects. Here we summarize the current state of knowledge around how mating types from these algal and ciliate systems recognize, adhere and fuse to one another, current gaps in our understanding of HAP2-mediated gamete fusion, and opportunities for applying what we know in practical terms, especially for the control of protozoan parasites.
Collapse
Affiliation(s)
- Jennifer F. Pinello
- Department of Cell Biology and Molecular Genetics, University of Maryland, College Park, MD, United States
| | - Theodore G. Clark
- Department of Microbiology and Immunology, Cornell University, Ithaca, NY, United States
| |
Collapse
|