Travelling in time with networks: Revealing present day hybridization versus ancestral polymorphism between two species of brown algae, Fucus vesiculosus and F. spiralis. | - CCMAR -

Journal Article

TítuloTravelling in time with networks: Revealing present day hybridization versus ancestral polymorphism between two species of brown algae, Fucus vesiculosus and F. spiralis.
Publication TypeJournal Article
AuthorsMoalic, Y, Arnaud-Haond, S, Perrin, C, Pearson, GA, Serrão, EA
Year of Publication2011
JournalBMC Evol Biol
Volume11
Date Published2011 Jan 31
Pagination33
ISSN1471-2148
Palavras-chaveEvolution, Molecular, Fucus, Genotype, Hybridization, Genetic, Microsatellite Repeats, Polymorphism, Genetic
Abstract

BACKGROUND: Hybridization or divergence between sympatric sister species provides a natural laboratory to study speciation processes. The shared polymorphism in sister species may either be ancestral or derive from hybridization, and the accuracy of analytic methods used thus far to derive convincing evidence for the occurrence of present day hybridization is largely debated.RESULTS: Here we propose the application of network analysis to test for the occurrence of present day hybridization between the two species of brown algae Fucus spiralis and F. vesiculosus. Individual-centered networks were analyzed on the basis of microsatellite genotypes from North Africa to the Pacific American coast, through the North Atlantic. Two genetic distances integrating different time steps were used, the Rozenfeld (RD; based on alleles divergence) and the Shared Allele (SAD; based on alleles identity) distances. A diagnostic level of genotype divergence and clustering of individuals from each species was obtained through RD while screening for exchanges through putative hybridization was facilitated using SAD. Intermediate individuals linking both clusters on the RD network were those sampled at the limits of the sympatric zone in Northwest Iberia.CONCLUSION: These results suggesting rare hybridization were confirmed by simulation of hybrids and F2 with directed backcrosses. Comparison with the Bayesian method STRUCTURE confirmed the usefulness of both approaches and emphasized the reliability of network analysis to unravel and study hybridization.

DOI10.1186/1471-2148-11-33
Sapientia

http://www.ncbi.nlm.nih.gov/pubmed/21281515?dopt=Abstract

Alternate JournalBMC Evol. Biol.
PubMed ID21281515
PubMed Central IDPMC3040711