Genetic analysis of cavefish reveals molecular convergence in the evolution of albinism.
The genetic basis of vertebrate morphological evolution has traditionally been very difficult to examine in naturally occurring populations. Here we describe the generation of a genome-wide linkage map to allow quantitative trait analysis of evolutionarily derived morphologies in the Mexican cave tetra, a species that has, in a series of independent caves, repeatedly evolved specialized characteristics adapted to a unique and well-studied ecological environment. We focused on the trait of albinism and discovered that it is linked to Oca2, a known pigmentation gene, in two cave populations. We found different deletions in Oca2 in each population and, using a cell-based assay, showed that both cause loss of function of the corresponding protein, OCA2. Thus, the two cave populations evolved albinism independently, through similar mutational events.
Protas
Meredith E
ME
Department of Genetics, Harvard Medical School, Boston, Massachusetts 02115, USA.
Hersey
Candace
C
Kochanek
Dawn
D
Zhou
Yi
Y
Wilkens
Horst
H
Jeffery
William R
WR
Zon
Leonard I
LI
Borowsky
Richard
R
Tabin
Clifford J
CJ
D000417:Albinism / Q000235:genetics*; D000818:Animals; D002460:Cell Line; D003433:Crosses, Genetic; D019143:Evolution, Molecular; D005091:Exons; D005260:Female; D029941:Fish Proteins / Q000235:genetics; D005399:Fishes / Q000235:genetics* / Q000502:physiology; D005828:Genetics, Population; D015810:Linkage Disequilibrium; D008297:Male; D008544:Melanocytes / Q000166:cytology / Q000502:physiology; D051379:Mice; D008969:Molecular Sequence Data; D010858:Pigmentation / Q000235:genetics*; D011110:Polymorphism, Genetic; D040641:Quantitative Trait Loci
D029941:Fish Proteins