| Autor: |
Kemppainen, Petri, Li, Zitong, Rastas, Pasi, Löytynoja, Ari, Fang, Bohao, Guo, Baocheng, Shikano, Takahito, Yang, Jing, Merilä, Juha |
| Jazyk: |
angličtina |
| Rok vydání: |
2020 |
| DOI: |
10.1101/2020.01.17.908970 |
| Popis: |
Repeated and independent evolution of the same phenotypes in similar environments is common, but less is known about the repeatability of the underlying genetic mechanisms, particularly in species with small effective population sizes and strong population structuring. We identified genomic regions responsible for the repeated reduction of pelvic spines and girdles in three crosses between pond (reduced pelvic apparatus) and marine (full apparatus) nine-spined sticklebacks ( Pungitius pungitius ) using quantitative trait locus (QTL) mapping. In one cross both traits mapped to linkage group 7 (LG7), where the gene Pituitary homeobox transcription factor 1 ( Pitx1 ) is known to be associated with pelvic reduction. In the other two crosses, pelvic reduction was polygenic and the nine out of the ten novel QTL (explaining 3-10% of the total phenotypic variation) were all unique to one of the three crosses. We further screened whole genomes from 27 different populations for the presence of deletions in Pitx1 regulatory element ( Pel ) which, in the related Gasterosteus aculeatus , is associated with a repeated pelvic reduction. No deletions were found in any other locations, except in the population where pelvic reduction mapped to LG7, including ponds where phenotypic data suggested fixation of large effect loci causing complete pelvic reduction. These results, which are backed up by simulations, are consistent with the notion that in small populations where founder events and strong genetic drift prevail, parallel phenotypic evolution can be expected to be highly non-parallel at the genetic level. The results contribute to our understanding of genetic architecture of adaptation highlighting the fact that a diversity of genetic architectures may underline expression of similar phenotypes in species characterised by high degree of population structuring. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
|
