Nuclear DNA content correlates with depth, body size, and diversification rate in amphipod crustaceans from ancient Lake Baikal, Russia.
Lake Baikal in Russia is a large, ancient lake that has been the site of a major radiation of amphipod crustaceans. Nearly 400 named species are known in this single lake, and it is thought that many more await description. The size and depth of Lake Baikal, in particular, may have contributed to the radiation of endemic amphipods by providing a large number of microhabitats for species to invade and subsequently experience reproductive isolation. Here we investigate the possibility that large-scale genomic changes have also accompanied diversification in these crustaceans. Specifically, we report genome size estimates for 36 species of Baikal amphipods, and examine the relationship between genome size, body size, and the maximum depths at which the amphipods are found in the lake. Genome sizes ranged nearly 8-fold in this sample of amphipod species, from 2.15 to 16.63 pg, and there were significant, positive, phylogenetically corrected relationships between genome size, body size, maximum depth, and diversification rate among these species. Our results suggest that major genomic changes, including transposable element proliferation, have accompanied speciation that was driven by selection for differences in body size and habitat preference in Lake Baikal amphipods.
a Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada.
Nicholas W
NW
Jeffery
b Department of Biological Sciences, East Tennessee State University, Johnson City, TN 37614, USA.
Lev
L
Yampolsky
a Department of Integrative Biology, University of Guelph, Guelph, ON N1G 2W1, Canada.
T Ryan
TR
Gregory
D033304:Amphipoda / Q000145:classification / Q000235:genetics* / Q000502:physiology; D000818:Animals; D049628:Body Size; D002467:Cell Nucleus / Q000235:genetics*; D004247:DNA / Q000032:analysis*; D049810:Genetic Speciation; D059646:Genome Size; D060106:Lakes; D010802:Phylogeny; D012426:Russia; D012641:Selection, Genetic
D004247:DNA
C-value; ancient lakes; crustaceans; crustacés; cytométrie en flux; flow cytometry; genome size; lacs anciens; speciation; spéciation; taille du génome; valeur C