Conference Paper
Gene flow from surface to cave populations of Astyanax mexicanus is ongoing
Borowsky, R.
Record Number:
4318
Year:
2019
Journal:
AIM 2019
Pages:
68
Abstract:
Several population genetic studies conclude that there was significant and consequential gene
flow among cave and surface populations of Astyanax mexicanus, and that this occurred in the
past and continues into the present. The possibility that gene flow from surface into cave
populations is ongoing is of considerable interest because, if true, it suggests that the eyed and
pigmented states of the surface fish are significantly detrimental in the cave. Several cave
populations are known to sustain ongoing immigration from the surface, but the surface fish do
not do well under cave conditions. It has been suggested that their poor condition prevents them
from contributing their alleles to the cave population. Here I present data from observations of the
Pachón and Yerbaniz cave populations demonstrating that the surface migrants can successfully
contribute their alleles to the recipient gene pools. Nevertheless, they seem to be eliminated within
a few generations, suggesting they are significantly deleterious. The source of the selection is not
straightforward, however, and may derive from events during meiosis in the F1 hybrids. Significant
departures from Mendelian expectations of segregation and independent assortment occur in the
F1 and may select against surface alleles in the cave gene pool.
Times Cited:
1
Conference Name:
Astyanax Interrnational Meeting
Relevent Species: