Comparative genome analysis of the primary sex-determining locus in salmonid fishes.
We compared the Y-chromosome linkage maps for four salmonid species (Arctic charr, Salvelinus alpinus; Atlantic salmon, Salmo salar; brown trout, Salmo trutta; and rainbow trout, Oncorhynchus mykiss) and a putative Y-linked marker from lake trout (Salvelinus namaycush). These species represent the three major genera within the subfamily Salmoninae of the Salmonidae. The data clearly demonstrate that different Y-chromosomes have evolved in each of the species. Arrangements of markers proximal to the sex-determining locus are preserved on homologous, but different, autosomal linkage groups across the four species studied in detail. This indicates that a small region of DNA has been involved in the rearrangement of the sex-determining region. Placement of the sex-determining region appears telomeric in brown trout, Atlantic salmon, and Arctic charr, whereas an intercalary location for SEX may exist in rainbow trout. Three hypotheses are proposed to account for the relocation: translocation of a small chromosome arm; transposition of the sex-determining gene; or differential activation of a primary sex-determining gene region among the species.
Woram
Rachael A
RA
Department of Zoology, University of Guelph, Guelph, Ontario, Canada N1G 2W1.
Gharbi
Karim
K
Sakamoto
Takashi
T
Hoyheim
Bjorn
B
Holm
Lars-Erik
LE
Naish
Kerry
K
McGowan
Colin
C
Ferguson
Moira M
MM
Phillips
Ruth B
RB
Stein
Jake
J
Guyomard
René
R
Cairney
Margaret
M
Taggart
John B
JB
Powell
Richard
R
Davidson
William
W
Danzmann
Roy G
RG
D000818:Animals; D002874:Chromosome Mapping; D019143:Evolution, Molecular; D015321:Gene Rearrangement / Q000235:genetics; D008040:Genetic Linkage / Q000235:genetics; D005819:Genetic Markers / Q000235:genetics*; D016678:Genome; D018895:Microsatellite Repeats / Q000235:genetics; D017686:Oncorhynchus mykiss / Q000235:genetics; D020317:Salmo salar / Q000235:genetics; D012474:Salmon / Q000235:genetics; D012487:Salmonidae / Q000235:genetics*; D019849:Sex Determination Processes; D014337:Trout / Q000235:genetics; D014998:Y Chromosome / Q000235:genetics
D005819:Genetic Markers