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A Microsatellite Linkage Map of Rainbow Trout ( Oncorhynchus mykiss ) Characterized by Large Sex-Specific Differences in Recombination Rates

2000; Oxford University Press; Volume: 155; Issue: 3 Linguagem: Inglês

10.1093/genetics/155.3.1331

1943-2631

Takashi Sakamoto, Roy G. Danzmann, Karim Gharbi, P. J. Howard, Akiyuki Ozaki, Sok Kean Khoo, Rachael A. Woram, Nobuaki Okamoto, Moira M. Ferguson, Lars‐Erik Holm, René Guyomard, Bjørn Høyheim,

Genetic and phenotypic traits in livestock

Abstract We constructed a genetic linkage map for a tetraploid derivative species, the rainbow trout (Oncorhynchus mykiss), using 191 microsatellite, 3 RAPD, 7 ESMP, and 7 allozyme markers in three backcross families. The linkage map consists of 29 linkage groups with potential arm displacements in the female map due to male-specific pseudolinkage arrangements. Synteny of duplicated microsatellite markers was used to identify and confirm some previously reported pseudolinkage arrangements based upon allozyme markers. Fifteen centromeric regions (20 chromosome arms) were identified with a half-tetrad analysis using gynogenetic diploids. Female map length is ~10 M, but this is a large underestimate as many genotyped segments remain unassigned at a LOD threshold of 3.0. Extreme differences in female:male map distances were observed (ratio F:M, 3.25:1). Females had much lower recombination rates (0.14:1) in telomeric regions than males, while recombination rates were much higher in females within regions proximal to the centromere (F:M, 10:1). Quadrivalent formations that appear almost exclusively in males are postulated to account for the observed differences.