A genetic linkage map of swimming crab (Portunus trituberculatus) based on SSR and AFLP markers

A genetic linkage map of the swimming crab (Portunus trituberculatus) was constructed using the simple sequence repeat (SSR) markers and amplified fragment length polymorphism (AFLP) techniques. An F2 family was created consisting of 110 individuals using the “two-way pseudo-testcross” mapping strategy. A total of 1294 polymorphic markers, including 55 SSRs and 1239 AFLPs, were used in the linkage mapping. Out of 1294 markers, 919 (71%) were grouped on the two parental maps, leaving 375 (29%) unlinked. The female linkage map consisted of 479 marker loci (22 SSRs and 457 AFLPs) which formed 51 linkage groups with an average marker space of 7.8 cM; they spanned a total length of 3521.3 cM, covering 74% of the estimated genome size. The male map consisted of 440 marker loci (19 SSRs and 421 AFLPs) which mapped to 50 linkage groups with an average marker spacing of 8.7 cM. They spanned a total length of 3517.6 cM, covering 75% of the estimated genome size. This map is the first medium-density genetic linkage map in the family Portunidae and is a basic framework for further mapping quantitative trait loci (QTL) linked to important economic traits of the swimming crab.

► A genetic linkage map of the swimming crab (Portunus trituberculatus) was constructed.
► The research uses “two-way pseudo-testcross” mapping strategy, SSR and AFLP markers.
► 479 markers formed 51 linkage groups with an average resolution of 7.8 cM in female map.
► 440 markers formed 50 linkage groups with an average resolution of 8.7 cM in male map.
► This map is the first medium density genetic linkage map in the family Portunidae.