Microsatellite–centromere mapping in walking catfish Clarias macrocephalus (Günther, 1864) using gynogenetic diploids

摘要

Thirty new microsatellite loci were isolated from a microsatellite-enriched genomic library of walking catfish Clarias macrocephalus. The CA motif was the most abundant, although several other motifs were also isolated. Two gynogenetic diploid families, each consisting of a female and 50 offspring, were genotyped at 56 microsatellite loci, including 30 loci developed in the present study and 26 loci reported in the previous study. Overall, 33 anonymous microsatellites derived from genomic library and 11 EST-linked microsatellites were mapped to their centromeres. High levels of chiasma interference were apparent in the walking catfish genome as indicated by an average frequency of second-division segregation (y) of 0.643 ± 0.248. Twenty-six loci (59%) showed a high microsatellite–centromere recombination, with a frequency >0.67, and three loci had recombination frequencies >0.9. This study demonstrated that gene–centromere mapping provided a rapid method for the expansion of the initial linkage map of walking catfish.