A Genetic Linkage Map Of Large Yellow Croaker Pseudosciaena Crocea

Genetic linkage maps were constructed for large yellow croaker Pseudosciaena crocea (Richardson 1846) using AFLP and microsatellite markers in an F1 family.A total of 523 polymorphic loci were produced with the 29 AFLP primer pairs (selected from 64 primer combinations). Among all the polymorphic markers, 231 dominantly inherited bands were from the female parent, 191 were from the male , and 62 (14.7%) markers showed a significant distortion from the expected 1:1 ratio (P<0.05), then 360 (85.3%) markers were used for linkage analysis. Among the 13 informative microsatellites, 11 and 10 markers valued for the female and the male map, respectively.One hundred and eighty-eight markers (181 AFLP and 7 microsatellite markers) were assigned to the female map. The final linkage map consisted of 24 linkage groups spanning 2959.1 cM with an average distance of 18.0 cM. For the male map, one hundred and sixty-one markers (153 AFLP and 8 microsatellite markers) were assigned. The total length of the male map,which consisted of 23 linkage groups,was 2205.7 cM with an average distance of 15.9 cM. By using two kinds of methods to estimate the genome length, the average estimate length was 3829.7 cM for female and 2970.0 cM for male with coverage of 77.3% and 74.3%,By using 4 microsatellite markers (LYC0012, LYC0020, LYC0024 and LYC0033) heterozygous in both parents, 4 homologous pairs of linkage groups between the male and female maps have been identified. The sex was mapped to the 12th linkage group of the male map, and tightly linked to the marker agacta355 with zero recombination,may validate the hypothesis that the male was the heterogametic sex in large yellow,and the AFLP locus completely linked to the sex-determined region, which could be used as a starting point for identification of the sex-determining locus or eventually yielding sex-determining gene sequences in larger yellow croaker..