Temporal genetic dynamics among mosquitofish (Gambusia holbrooki) populations in invaded watersheds

Abstract

SummaryThe temporal components of genetic diversity and geographical structure of invasive mosquitofish populations are poorly known. Through the genetic monitoring of four consecutive cohorts of Gambusia holbrooki from three different river basins we aimed to determine temporal patterns of regional genetic variation and dispersal rates within invasive populations. Despite showing evidence of strong population size fluctuations, genetic diversity levels were maintained among local cohorts. We only detected temporal allele frequency changes associated with seasonal flooding that did not modify major trends on population structure among cohorts. Downstream gene flow coupled with increased connectivity at lowland locations to increase genetic diversity levels in these areas. A large proportion of local fish (up to 50%) were dispersers, often originated from locations within the same river basin. High dispersal capability, ecological tolerance, and reproductive traits likely promote river colonization. Finally, our results also confirmed that human-assisted translocations promote within and among basin gene flow and maintained levels of genetic diversity, particularly in upstream locations.

Out to sea: ocean currents and patterns of asymmetric gene flow in an intertidal fish species

“…While our discussion is focused on broad scale clustering results (K = 8), an AMOVA suggests significant population structure between regions (Central America, Bahamas, South Florida, West Florida, East Florida), populations within regions, sampling locations within populations, individuals within sampling locations, and within individuals ( Table 1 ). Strong population structure is common in intertidal fish ( Díez-del-Molino et al, 2016 ; Hurt et al, 2017 ; Xie et al, 2022 ) and species occupying highly fragmented landscapes ( Browne et al, 2015 ; Wultsch et al, 2016 ). We also expect strong population structure in mixed-mating species ( Mori et al, 2015 ), those that can outcross or self-fertilize, with more structure emerging as outcrossing rates decrease ( Duminil, et al, 2007 ; Hodgins and Yeaman, 2019 ).…”

Molecules of Lost Time

“…Led by Love Dalén, David Diezdel-Molino and colleagues compared the genome of the early mammoth to the ones from the last 100,000 years, where more abundant genomic information is available, as well as to those of Asian elephants [4] . They discovered numerous genetic dispositions that can plausibly be connected to the adaptation to Arctic conditions.…”

The history of Coast Salish “woolly dogs” revealed by ancient genomics and Indigenous Knowledge

“…KRT77 is a member of the keratin gene family responsible for the structural integrity of cells in the epithelium and hair follicles. Mutations in keratin genes are linked to curly-hair phenotype in other dogs, rats, and mice (31), and to woolly hair and hereditary hair loss in humans (26,30); and multiple KRT genes underwent selection in woolly mammoths (25). CERS3, PRDM5, and HAPLN1 are associated with maintaining the integrity of the skin or connective tissue in humans (27,28).…”