The genetic architecture of growth rate in juvenile Takifugu species.
Closely related species have often evolved dramatic differences in body size. Takifugu rubripes (fugu) is a large marine pufferfish whose genome has been sequenced, whereas T. niphobles is the smallest species among Takifugu. We show that, unsurprisingly, the juvenile growth rate of T. rubripes is higher than that of T. niphobles in a laboratory setting. We produced F(2)  progenies of their F(1)  hybrids and found one quantitative trait locus (QTL) significantly associated with variation in juvenile body size. This QTL region (3.5 Mb) contains no known genes directly related to growth phenotype (such as IGFs) except Fgf21, which inhibits growth hormone signaling in mouse. The QTL in Takifugu spp. is distinct from the region previously known to control body size variations in stickleback or tilapia. Our results suggest that in the fish tested herein, genomic regions underlying body size evolution might have different genetic origins. They also suggest that many diverse traits in Takifugu spp. are amenable to genetic mapping.
Fisheries Laboratory, Graduate School of Agricultural and Life Sciences, University of Tokyo, Maisaka, Shizuoka 431-0214, Japan.
Sho
S
Hosoya
Wataru
W
Kai
Masashi
M
Fujita
Kadoo
K
Miyaki
Hiroaki
H
Suetake
Yuzuru
Y
Suzuki
Kiyoshi
K
Kikuchi
D000818:Animals; D049628:Body Size / Q000235:genetics*; D003433:Crosses, Genetic; D019143:Evolution, Molecular; D005346:Fibroblast Growth Factors / Q000235:genetics; D014644:Genetic Variation; D010641:Phenotype; D040641:Quantitative Trait Loci; D023741:Takifugu / Q000235:genetics* / Q000254:growth & development
C414620:fibroblast growth factor 21; D005346:Fibroblast Growth Factors