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Pierrat J, Magalon H, Libaud N, Oury N. Isolation and characterization of 21 microsatellite loci for the sea cucumber Holothuria (Halodeima) atra (Echinodermata, Holothuroidea) reveal low asexual propagation through time in Reunion Island (southwestern Indian Ocean). Mol Biol Rep 2023; 50:1953-1960. [PMID: 36454431 DOI: 10.1007/s11033-022-08127-0] [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: 05/31/2022] [Accepted: 11/15/2022] [Indexed: 12/04/2022]
Abstract
BACKGROUND Holothuria (Halodeima) atra Jaeger, 1833 is a tropical sea cucumber usually harvested for the "bêche-de-mer" trade market. It has been reported to reproduce both sexually, through gamete spawning, or asexually, through fission. To date, no study has ever investigated clonality, nor genetic connectivity, among its populations, using microsatellite markers. METHODS AND RESULTS We isolated the first 21 microsatellite loci specific for H. atra, which were then used to investigate clonal diversity, genetic structure and diversity among 44 H. atra individuals sampled in Reunion Island (southwestern Indian Ocean), over two seasons. All 21 loci were polymorphic, with number of alleles per locus ranging from 2 to 10. No repetitive multi-locus genotype (MLG) and few clonal lineages (MLL) were found. Observed heterozygosities per locus and season ranged from 0.000 to 0.909, while expected heterozygosities ranged from 0.290 to 0.882. Four loci were at Hardy-Weinberg equilibrium for both seasons, all others presenting a deficit of heterozygotes in one or both seasons. Meanwhile, no genetic differentiation was detected between seasons, according to assignment tests and global FST. CONCLUSIONS These results suggest low asexual propagation in this population. These loci represent useful tools to better understand reproductive strategies and population connectivity of H. atra, and thus provide relevant knowledge for efficient management.
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Affiliation(s)
- Joséphine Pierrat
- UMR ENTROPIE (Université de La Réunion, Université de Nouvelle-Calédonie, IRD, CNRS, IFREMER), Faculté Des Sciences Et Technologies, Université de La Réunion, 15 Bd René Cassin, CS 92003, 97744, St Denis Cedex 09, La Réunion, France
| | - Hélène Magalon
- UMR ENTROPIE (Université de La Réunion, Université de Nouvelle-Calédonie, IRD, CNRS, IFREMER), Faculté Des Sciences Et Technologies, Université de La Réunion, 15 Bd René Cassin, CS 92003, 97744, St Denis Cedex 09, La Réunion, France.,Laboratoire Cogitamus, Paris, France.,Laboratoire d'Excellence Corail, Perpignan, France
| | - Noa Libaud
- UMR ENTROPIE (Université de La Réunion, Université de Nouvelle-Calédonie, IRD, CNRS, IFREMER), Faculté Des Sciences Et Technologies, Université de La Réunion, 15 Bd René Cassin, CS 92003, 97744, St Denis Cedex 09, La Réunion, France
| | - Nicolas Oury
- UMR ENTROPIE (Université de La Réunion, Université de Nouvelle-Calédonie, IRD, CNRS, IFREMER), Faculté Des Sciences Et Technologies, Université de La Réunion, 15 Bd René Cassin, CS 92003, 97744, St Denis Cedex 09, La Réunion, France. .,Laboratoire Cogitamus, Paris, France.
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Pirog A, Gélin P, Bédier A, Bianchetti G, Georget S, Frouin P, Magalon H. Clonal structure through space and time: High stability in the holothurian Stichopus chloronotus (Echinodermata). Ecol Evol 2017; 7:7534-7547. [PMID: 28944037 PMCID: PMC5606904 DOI: 10.1002/ece3.3285] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Revised: 06/24/2017] [Accepted: 06/30/2017] [Indexed: 11/24/2022] Open
Abstract
Sea cucumbers are increasingly exploited for human consumption and for their curative properties, and many wild populations are now depleted or in danger of extinction. While aquaculture is seen as an alternative to fisheries and as a mean to restore wild populations, more knowledge is needed on their reproductive strategies to render this practice efficient, notably for fissiparous holothurians, which are some of the mobile animals able of asexual reproduction by transverse fission. Little information is available on their population genetic diversity and structure. Here, the clonal structure of populations of the fissiparous sea cucumber Stichopus chloronotus has been investigated using nine microsatellite loci and a random sampling, at different spatial (intra‐reef and inter‐reef) and temporal (inter‐season and inter‐year) scales. Our findings highlight the importance of asexual reproduction in maintaining these populations, and the prevalence of the “initial seedling recruitment” strategy (ISR), leading to a high stability of clonal composition over seasons and years. It also seemed that clonal propagation was limited to the reef scale (<10 km) while reefs were connected by sexual dispersal. This is the first time that clonal structure in sea cucumbers has been studied at such a fine scale, with a specific sampling strategy. It provides key findings on the genetic diversity and structure of fissiparous sea cucumbers, which will be useful for the management of wild populations and aquaculture.
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Affiliation(s)
- Agathe Pirog
- UMR ENTROPIE (Université de La Réunion, IRD, CNRS) Saint Denis, La Réunion France
| | - Pauline Gélin
- UMR ENTROPIE (Université de La Réunion, IRD, CNRS) Saint Denis, La Réunion France.,Laboratory of Excellence CORAIL Perpignan France
| | - Alexandre Bédier
- UMR ENTROPIE (Université de La Réunion, IRD, CNRS) Saint Denis, La Réunion France
| | - Grégoire Bianchetti
- UMR ENTROPIE (Université de La Réunion, IRD, CNRS) Saint Denis, La Réunion France
| | - Stéphane Georget
- UMR ENTROPIE (Université de La Réunion, IRD, CNRS) Saint Denis, La Réunion France
| | - Patrick Frouin
- UMR ENTROPIE (Université de La Réunion, IRD, CNRS) Saint Denis, La Réunion France.,Laboratory of Excellence CORAIL Perpignan France
| | - Hélène Magalon
- UMR ENTROPIE (Université de La Réunion, IRD, CNRS) Saint Denis, La Réunion France.,Laboratory of Excellence CORAIL Perpignan France
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