Microsatellite genotypes and associated data for: Tetrasporophyte bias coupled with heterozygote deficiency in Antarctic Plocamium sp. (Rhodophyta)

Author ORCID

Sabrina Heiser 0000-0003-3307-3233

Charles D. Amsler 0000-0002-4843-3759

Solenn Stoeckel 0000-0001-6064-5941

James B. McClintock 0000-0002-6295-5094

Bill J. Baker 0000-0003-3033-5779

Stacy A. Krueger-Hadfield 0000-0002-7324-7448

Publication Date

11-22-2022

Abstract

Meiosis and syngamy generate an alternation between two ploidy stages, but the timing of these two processes varies widely across taxa, thereby generating life cycle diversity. One hypothesis suggests that life cycles with long-lived haploid stages are correlated with selfing, asexual reproduction, or both. Though mostly studied in angiosperms, selfing and asexual reproduction are often associated with marginal habitats. Yet, in haploid-diploid macroalgae, these two reproductive modes have subtle, but unique consequences whereby predictions from angiosperms may not apply. Along the western Antarctic Peninsula, there is a thriving macroalgal community, providing an opportunity to explore reproductive system variation in haploid-diploid macroalgae at high latitudes where endemism is common. Plocamium sp. is a widespread and abundant red macroalga found within this ecosystem. We sampled twelve sites during 2017 and 2018 field seasons and used ten microsatellite loci to describe the reproductive system. Overall genotypic richness and evenness were high, suggesting sexual reproduction. Eight sites were dominated by tetrasporophytes, but there was strong heterozygote deficiency, suggesting intergametophytic selfing. We found slight differences in the prevailing reproductive mode among sites, possibly due to local conditions (e.g., disturbance) that may contribute to site-specific variation. It remains to be determined whether high levels of selfing are characteristic of macroalgae more generally at high latitudes or due to the haploid-diploid life cycle. Further investigations of algal life cycles will likely reveal the processes underlying the maintenance of sexual reproduction more broadly across eukaryotes, but more studies of natural populations are required.

Keywords

gametophytes, homozygote excess, mating system, seaweed, rates of clonality

Repository

Zenodo

Distribution License

Creative Commons Attribution 4.0 International License
This work is licensed under a Creative Commons Attribution 4.0 International License.

Funder

Funder: National Science Foundation
Funder DOI: 10.13039/100000001
Collaborative Research: The Chemical Ecology of Shallow-water Marine Macroalgae and Invertebrates on the Antarctic Peninsula
1341333

Funder: National Science Foundation
Funder DOI: 10.13039/100000001
Collaborative Research: The Chemical Ecology of Shallow-water Marine Macroalgae and Invertebrates on the Antarctic Peninsula
1341339

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