Extensive hybridization and past introgression between divergent lineages in a quasi‐clonal hermaphroditic fish: Ramifications for species concepts and taxonomy
| Autor: | John C. Avise, William P. Davis, D. Scott Taylor, Ryan L. Earley, Andrey Tatarenkov |
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| Rok vydání: | 2020 |
| Předmět: |
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0106 biological sciences 0301 basic medicine Bahamas Allopatric speciation Introgression Self-Fertilization Genetic Introgression 010603 evolutionary biology 01 natural sciences 03 medical and health sciences Fundulidae Animals Hermaphroditic Organisms Mangrove rivulus Clade Ecology Evolution Behavior and Systematics Hybrid biology Haplotype biology.organism_classification Phylogeography Sympatry 030104 developmental biology Sympatric speciation Evolutionary biology Female Inbreeding |
| Zdroj: | Journal of Evolutionary Biology. 34:49-59 |
| ISSN: | 1420-9101 1010-061X |
| Popis: | Extreme inbreeding is expected to reduce the incidence of hybridization, serving as a prezygotic barrier. Mangrove rivulus is a small killifish that reproduces predominantly by self-fertilization, producing highly homozygous lines throughout its geographic range. The Bahamas and Caribbean are inhabited by two highly diverged phylogeographic lineages of mangrove rivulus, Kryptolebias marmoratus and a 'Central clade' closely related to K. hermaphroditus from Brazil. The two lineages are largely allopatric, but recently were found in syntopy on San Salvador, Bahamas, where a single hybrid was reported. To better characterize the degree of hybridization and the possibility of secondary introgression, here we conducted a detailed genetic analysis of the contact zone on San Salvador. Two mixed populations were identified, one of which contained sexually mature hybrids. The distribution of heterozygosity at diagnostic microsatellite loci in hybrids showed that one of these hybrids was an immediate offspring from the K. marmoratus x Central clade cross, whereas the remaining five hybrids were products of reproduction by self-fertilization for 1-3 generations following the initial cross. Two hybrids had mitochondrial haplotypes of K. marmoratus and the remaining four hybrids had a haplotype of the Central clade, indicating that crosses go in both directions. In hybrids, alleles of parental lineages were represented in equal proportions suggesting lack of recent backcrossing to either of the parental lineages. However, sympatric populations of two lineages were less diverged than allopatric populations, consistent with introgression. Results are discussed in terms of applicability of the biological species concept for isogenic, effectively clonal, organisms. |
| Databáze: | OpenAIRE |
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