1
|
Lizano AMD, Kim KM, Juinio-Meñez MA, Ravago-Gotanco R. Pseudocryptic diversity and species boundaries in the sea cucumber Stichopus cf. horrens (Echinodermata: Stichopodidae) revealed by mitochondrial and microsatellite markers. Sci Rep 2024; 14:4886. [PMID: 38418859 PMCID: PMC10901784 DOI: 10.1038/s41598-024-54987-w] [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: 10/12/2023] [Accepted: 02/19/2024] [Indexed: 03/02/2024] Open
Abstract
Morphologically cryptic and pseudo-cryptic species pose a challenge to taxonomic identification and assessments of species diversity and distributions. Such is the case for the sea cucumber Stichopus horrens, commonly confused with Stichopus monotuberculatus. Here, we used mitochondrial cytochrome oxidase subunit I (COI) and microsatellite markers to examine genetic diversity in Stichopus cf. horrens throughout the Philippine archipelago, to aid species identification and clarify species boundaries. Phylogenetic analysis reveals two recently diverged COI lineages (Clade A and Clade B; c. 1.35-2.54 Mya) corresponding to sequence records for specimens identified as S. monotuberculatus and S. horrens, respectively. Microsatellite markers reveal two significantly differentiated genotype clusters broadly concordant with COI lineages (Cluster 1, Cluster 2). A small proportion of individuals were identified as later-generation hybrids indicating limited contemporary gene flow between genotype clusters, thus confirming species boundaries. Morphological differences in papillae distribution and form are observed for the two species, however tack-like spicules from the dorsal papillae are not a reliable diagnostic character. An additional putative cryptic species was detected within Clade B-Cluster 2 specimens warranting further examination. We propose that these lineages revealed by COI and genotype data be referred to as Stichopus cf. horrens species complex.
Collapse
Affiliation(s)
- Apollo Marco D Lizano
- Faculty of Biosciences & Aquaculture, Nord University, Bodø, Norway.
- Marine Science Institute, University of the Philippines, 1101, Diliman Quezon City, Philippines.
| | - Kenneth M Kim
- Department of Ecology and Evolution, University of Lausanne, Lausanne, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, Switzerland
- Marine Science Institute, University of the Philippines, 1101, Diliman Quezon City, Philippines
| | | | - Rachel Ravago-Gotanco
- Marine Science Institute, University of the Philippines, 1101, Diliman Quezon City, Philippines
| |
Collapse
|
2
|
Kustra M, Carrier TJ. On the spread of microbes that manipulate reproduction in marine invertebrates. Am Nat 2022; 200:217-235. [DOI: 10.1086/720282] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
3
|
Hernández-Hernández T, Miller EC, Román-Palacios C, Wiens JJ. Speciation across the Tree of Life. Biol Rev Camb Philos Soc 2021; 96:1205-1242. [PMID: 33768723 DOI: 10.1111/brv.12698] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 02/13/2021] [Accepted: 02/16/2021] [Indexed: 01/04/2023]
Abstract
Much of what we know about speciation comes from detailed studies of well-known model systems. Although there have been several important syntheses on speciation, few (if any) have explicitly compared speciation among major groups across the Tree of Life. Here, we synthesize and compare what is known about key aspects of speciation across taxa, including bacteria, protists, fungi, plants, and major animal groups. We focus on three main questions. Is allopatric speciation predominant across groups? How common is ecological divergence of sister species (a requirement for ecological speciation), and on what niche axes do species diverge in each group? What are the reproductive isolating barriers in each group? Our review suggests the following patterns. (i) Based on our survey and projected species numbers, the most frequent speciation process across the Tree of Life may be co-speciation between endosymbiotic bacteria and their insect hosts. (ii) Allopatric speciation appears to be present in all major groups, and may be the most common mode in both animals and plants, based on non-overlapping ranges of sister species. (iii) Full sympatry of sister species is also widespread, and may be more common in fungi than allopatry. (iv) Full sympatry of sister species is more common in some marine animals than in terrestrial and freshwater ones. (v) Ecological divergence of sister species is widespread in all groups, including ~70% of surveyed species pairs of plants and insects. (vi) Major axes of ecological divergence involve species interactions (e.g. host-switching) and habitat divergence. (vii) Prezygotic isolation appears to be generally more widespread and important than postzygotic isolation. (viii) Rates of diversification (and presumably speciation) are strikingly different across groups, with the fastest rates in plants, and successively slower rates in animals, fungi, and protists, with the slowest rates in prokaryotes. Overall, our study represents an initial step towards understanding general patterns in speciation across all organisms.
Collapse
Affiliation(s)
- Tania Hernández-Hernández
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721-0088, U.S.A.,Catedrática CONACYT asignada a LANGEBIO-UGA Cinvestav, Libramiento Norte Carretera León Km 9.6, 36821, Irapuato, Guanajuato, Mexico
| | - Elizabeth C Miller
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721-0088, U.S.A
| | - Cristian Román-Palacios
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721-0088, U.S.A
| | - John J Wiens
- Department of Ecology and Evolutionary Biology, University of Arizona, Tucson, AZ, 85721-0088, U.S.A
| |
Collapse
|
4
|
Geyer LB, Zigler KS, Tiozzo S, Lessios HA. Slow evolution under purifying selection in the gamete recognition protein bindin of the sea urchin Diadema. Sci Rep 2020; 10:9834. [PMID: 32555217 PMCID: PMC7299941 DOI: 10.1038/s41598-020-66390-2] [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: 03/10/2020] [Accepted: 05/06/2020] [Indexed: 01/22/2023] Open
Abstract
Bindin is a sperm protein that mediates attachment and membrane fusion of gametes. The mode of bindin evolution varies across sea urchin genera studied to date. In three genera it evolves under positive selection, in four under mostly purifying selection, and in one, results have been mixed. We studied bindin evolution in the pantropical sea urchin Diadema, which split from other studied genera 250 million years ago. We found that Diadema bindin is structurally similar to that of other genera, but much longer (418 amino acids). In seven species of Diadema, bindin evolves under purifying selection, more slowly than in any other sea urchin genus. Only bindin of the recently rediscovered D. clarki shows evidence of positive selection. As D. clarki is sympatric with D. setosum and D. savignyi, positive selection could arise from avoidance of maladaptive hybridization. However, D. setosum and D. savignyi overlap in the Indo-West Pacific, yet their bindins show no evidence of positive selection, possibly because the two species spawn at different times. Bindin in the East Pacific D. mexicanum, the West Atlantic D. antillarum, the East Atlantic D. africanum, and the Indo-Pacific D. paucispinum also evolves slowly under purifying selection.
Collapse
Affiliation(s)
- L B Geyer
- Smithsonian Tropical Research Institute, Apartado Postal 0843-03092, Balboa, Ancon, Panama.
| | - K S Zigler
- Department of Biology, Sewanee: University of the South, 735 University Ave., Sewanee, TN, 37383, United States
| | - S Tiozzo
- Sorbonne Universite, CNRS, Laboratoire de Biologie du Developpement de Villefranche-sur-mer (LBDV), 06230, Paris, France
| | - H A Lessios
- Smithsonian Tropical Research Institute, Apartado Postal 0843-03092, Balboa, Ancon, Panama
| |
Collapse
|
5
|
Balakirev ES, Anisimova M, Pavlyuchkov VA, Ayala FJ. DNA polymorphism and selection at the bindin locus in three Strongylocentrotus sp. (Echinoidea). BMC Genet 2016; 17:66. [PMID: 27176219 PMCID: PMC4866015 DOI: 10.1186/s12863-016-0374-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2015] [Accepted: 05/02/2016] [Indexed: 02/04/2023] Open
Abstract
BACKGROUND The sperm gene bindin encodes a gamete recognition protein, which plays an important role in conspecific fertilization and reproductive isolation of sea urchins. Molecular evolution of the gene has been extensively investigated with the attention focused on the protein coding regions. Intron evolution has been investigated to a much lesser extent. We have studied nucleotide variability in the complete bindin locus, including two exons and one intron, in the sea urchin Strongylocentrotus intermedius represented by two morphological forms. We have also analyzed all available bindin sequences for two other sea urchin species, S. pallidus and S. droebachiensis. RESULTS The results show that the bindin sequences from the two forms of S. intermedius are intermingled with no evidence of genetic divergence; however, the forms exhibit slightly different patterns in bindin variability. The level of the bindin nucleotide diversity is close for S. intermedius and S. droebachiensis, but noticeably higher for S. pallidus. The distribution of variability is non-uniform along the gene; however there are striking similarities among the species, indicating similar evolutionary trends in this gene engaged in reproductive function. The patterns of nucleotide variability and divergence are radically different in the bindin coding and intron regions. Positive selection is detected in the bindin coding region. The neutrality tests as well as the maximum likelihood approaches suggest the action of diversifying selection in the bindin intron. CONCLUSIONS Significant deviation from neutrality has been detected in the bindin coding region and suggested in the intron, indicating the possible functional importance of the bindin intron variability. To clarify the question concerning possible involvement of diversifying selection in the bindin intron evolution more data combining population genetic and functional approaches are necessary.
Collapse
Affiliation(s)
- Evgeniy S Balakirev
- A. V. Zhirmunsky Institute of Marine Biology, Far Eastern Branch of the Russian Academy of Science, Vladivostok, 690041, Russia.
- Department of Ecology and Evolutionary Biology, University of California, 321 Steinhaus Hall, Irvine, CA, 92697-2525, USA.
- Far Eastern Federal University, Vladivostok, 690950, Russia.
| | - Maria Anisimova
- Institute of Applied Simulation, School of Life Sciences and Facility Management, Zürich University of Applied Sciences, Wädenswil, 8820, Switzerland
- Swiss Institute of Bioinformatics, Lausanne, 1015, Switzerland
| | | | - Francisco J Ayala
- Department of Ecology and Evolutionary Biology, University of California, 321 Steinhaus Hall, Irvine, CA, 92697-2525, USA
| |
Collapse
|
6
|
Demographic history and asynchronous spawning shape genetic differentiation among populations of the hard coral Acropora tenuis in Western Australia. Mol Phylogenet Evol 2016; 98:89-96. [PMID: 26876640 DOI: 10.1016/j.ympev.2016.02.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2015] [Revised: 12/31/2015] [Accepted: 02/04/2016] [Indexed: 11/23/2022]
Abstract
Genetic subdivision within populations can ultimately lead to the evolution of new species, and in populations of broadcast-spawners a potential facilitator of genetic subdivision is asynchronous reproduction. However, the factors that shape genetic variation in marine systems are complex and ambiguous, and ecological genetic structure may be influenced by the overriding signature of past demographic events. Here, the relative roles of the timing of reproduction and historical geography on the partitioning of genetic variation were examined in seven populations of the broadcast-spawning coral Acropora tenuis over 12° of latitude. The analysis of multiple loci (mitochondrial control region, two nuclear introns and six microsatellites) revealed significant genetic division between the most northern reef and all other reefs, suggesting that WA reefs were re-colonized from two different sources after the Pleistocene glaciation. Accompanying this pattern was significant genetic differentiation associated with different breeding seasons (spring and autumn), which was greatest in PaxC, in which there were two divergent lineages (ΦST=0.98). This is the second study to find divergent clades of PaxC associated with spring and autumn spawners, strengthening the suggestion of some selective connection to timing of reproduction in corals. This study reiterates the need to incorporate reproductive timing into population genetic studies of corals because it facilitates genetic differentiation; however, careful analysis of population genetic data is required to separate ecological and evolutionary processes.
Collapse
|
7
|
Rosser NL. Asynchronous spawning in sympatric populations of a hard coral reveals cryptic species and ancient genetic lineages. Mol Ecol 2015; 24:5006-19. [DOI: 10.1111/mec.13372] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2014] [Revised: 08/27/2015] [Accepted: 09/01/2015] [Indexed: 12/24/2022]
Affiliation(s)
- Natalie L. Rosser
- School of Animal Biology (M092); University of Western Australia; Crawley WA 6009 Australia
| |
Collapse
|
8
|
Evans JP, Sherman CDH. Sexual selection and the evolution of egg-sperm interactions in broadcast-spawning invertebrates. THE BIOLOGICAL BULLETIN 2013; 224:166-183. [PMID: 23995741 DOI: 10.1086/bblv224n3p166] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Many marine invertebrate taxa are broadcast spawners, where multiple individuals release their gametes into the water for external fertilization, often in the presence of gametes from heterospecifics. Consequently, sperm encounter the considerable challenges of locating and fertilizing eggs from conspecific females. To overcome these challenges, many taxa exhibit species-specific attraction of sperm toward eggs through chemical signals released from eggs (sperm chemotaxis) and species-specific gamete recognition proteins (GRPs) that mediate compatibility of gametes at fertilization. In this prospective review, we highlight these selective forces, but also emphasize the role that sexual selection, manifested through sperm competition, cryptic female choice, and evolutionary conflicts of interest between the sexes (sexual conflict), can also play in mediating the action of egg chemoattractants and GRPs, and thus individual reproductive fitness. Furthermore, we explore patterns of selection at the level of gametes (sperm phenotype, gamete plasticity, and egg traits) to identify putative traits targeted by sexual selection in these species. We conclude by emphasizing the excellent, but relatively untapped, potential of broadcast-spawning marine invertebrates as model systems to illuminate several areas of research in post-mating sexual selection.
Collapse
Affiliation(s)
- Jonathan P Evans
- Centre for Evolutionary Biology, School of Animal Biology, University of Western Australia, Crawley, Australia.
| | | |
Collapse
|
9
|
Sunday JM, Hart MW. Sea star populations diverge by positive selection at a sperm-egg compatibility locus. Ecol Evol 2013; 3:640-54. [PMID: 23532786 PMCID: PMC3605852 DOI: 10.1002/ece3.487] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2012] [Accepted: 12/24/2012] [Indexed: 11/27/2022] Open
Abstract
Fertilization proteins of marine broadcast spawning species often show signals of positive selection. Among geographically isolated populations, positive selection within populations can lead to differences between them, and may result in reproductive isolation upon secondary contact. Here, we test for positive selection in the reproductive compatibility locus, bindin, in two populations of a sea star on either side of a phylogeographic break. We find evidence for positive selection at codon sites in both populations, which are under neutral or purifying selection in the reciprocal population. The signal of positive selection is stronger and more robust in the population where effective population size is larger and bindin diversity is greater. In addition, we find high variation in coding sequence length caused by large indels at two repetitive domains within the gene, with greater length diversity in the larger population. These findings provide evidence of population-divergent positive selection in a fertilization compatibility locus, and suggest that sexual selection can lead to reproductive divergence between conspecific marine populations.
Collapse
Affiliation(s)
- Jennifer M Sunday
- Department of Biological Sciences, Simon Fraser University Burnaby, British Columbia, Canada
| | | |
Collapse
|
10
|
Liu M, Lin L, Gao T, Yanagimoto T, Sakurai Y, Grant WS. What maintains the central North Pacific genetic discontinuity in Pacific herring? PLoS One 2012; 7:e50340. [PMID: 23300525 PMCID: PMC3532504 DOI: 10.1371/journal.pone.0050340] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2012] [Accepted: 10/17/2012] [Indexed: 11/18/2022] Open
Abstract
Pacific herring show an abrupt genetic discontinuity in the central North Pacific that represents secondary contact between refuge populations previously isolated during Pleistocene glaciations. Paradoxically, high levels of gene flow produce genetic homogeneity among ocean-type populations within each group. Here, we surveyed variability in mtDNA control-region sequences (463 bp) and nine microsatellite loci in Pacific herring from sites across the North Pacific to further explore the nature of the genetic discontinuity around the Alaska Peninsula. Consistent with previous studies, little divergence (Φ(ST) = 0.011) was detected between ocean-type populations of Pacific herring in the North West Pacific, except for a population in the Yellow Sea (Φ(ST) = 0.065). A moderate reduction in genetic diversity for both mtDNA and microsatellites in the Yellow Sea likely reflects founder effects during the last colonization of this sea. Reciprocal monophyly between divergent mtDNA lineages (Φ(ST) = 0.391) across the Alaska Peninsula defines the discontinuity across the North Pacific. However, microsatellites did not show a strong break, as eastern Bering Sea (EBS) herring were more closely related to NE Pacific than to NW Pacific herring. This discordance between mtDNA and microsatellites may be due to microsatellite allelic convergence or to sex-biased dispersal across the secondary contact zone. The sharp discontinuity between Pacific herring populations may be maintained by high-density blocking, competitive exclusion or hybrid inferiority.
Collapse
Affiliation(s)
- Ming Liu
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, Shandong, China
| | - Longshan Lin
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, Shandong, China
| | - Tianxiang Gao
- Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, Shandong, China
| | - Takashi Yanagimoto
- National Research Institute of Fisheries Science, Fisheries Research Agency, Yokohama, Kanagawa, Japan
| | - Yasunori Sakurai
- Graduate School of Fisheries Science, Hokkaido University, Hakodate, Hokkaido, Japan
| | - W. Stewart Grant
- Alaska Department of Fish and Game, Anchorage, Alaska, United States of America
| |
Collapse
|