Genetic linkage maps of the guppy (Poecilia reticulata): Assignment of RAPD markers to multipoint linkage groups

Abstract

Genetic linkage maps of the guppy (Poecilia reticulata) were constructed from independent crosses between the Tuxedo strain and a feral line (Wildtype). Segregation patterns of random amplified polymorphic DNA (RAPD) markers and phenotypic markers were investigated in F2 offspring of Tuxedo ♂♂ x Wildtype♀♀ and Wildtype ♂♂ x Tuxedo ♀♀ crosses. Among the 300 and 276 RAPD markers scored for the respective crosses, linkages were identified for 230 and 212, respectively. The Tuxedo ♂♂ x Wildtype ♀♀ and Wildtype ♂♂ x Tuxedo ♀♀ maps spanned 2100 Kosambi centiMorgans (cMK) and 1900 CMK, respectively, in 28 linkage groups. Average marker resolution was 10 CMK. Genome length was estimated at 4410 CM K and 4060 CMK for the respective crosses, with an average physical distance of 166 kbp/cMK. Several RAPD markers were closely linked to or mapped onto the loci for the sex-determining region (SdR), and the sex-linked black caudal-peduncle (Bcp) and red tail (Rdt) genes. These primary linkage maps are the initial step toward the construction of a composite high-density map to facilitate map-based cloning and marker-assisted selection of quantitative trait loci that are essential for the development of comprehensive breeding programs for the guppy.