SSLP-based Linkage Map Construction in Black Tiger Shrimp (Penaeus monodon Fabricius)

Abstract

Microsatellites represent an abundant source for genetic markers in eukaryotic genomes. We developed microsatellite or simple sequence length polymorphism (SSLP) markers for the black tiger shrimp genetic improvement programs. Construction of a genetic linkage map was initiated for Penaeus monodon using 57 SSLPs, EST and SCAR markers with 76 individuals of an F1 inter-cross family. Segregation markers were scored and analyzed with the JoinMap 2.0 program. A total of 50 markers, confirmed with expected Mendelian segregation ratios of 1:1 or 1:1:1:1 (χ2-test at the α = 0.01 level), were grouped with a LOD score of 5.0. Results showed that 27 loci formed 9 linkage groups and there were 23 unlinked loci. The largest group had 7 markers spanning 29.5 cM. The average distance between markers was 3.8 cM. This linkage map covered a total genetic distance of 103.6 cM.