Identification of Sex-determining Loci in Pacific White Shrimp Litopeneaus vannamei Using Linkage and Association Analysis

Abstract

The Pacific white shrimp Litopenaeus vannamei is a predominant aquaculture shrimp species in the world. Like other animals, the L. vannamei exhibited sexual dimorphism in growth trait. Mapping of the sex-determining locus will be very helpful to clarify the sex determination system and further benefit the shrimp aquaculture industry towards the production of mono-sex stocks. Based on the data used for high-density linkage map construction, linkage-mapping analysis was conducted. The sex determination region was mapped in linkage group (LG) 18. A large region from 0 to 21.205 cM in LG18 showed significant association with sex. However, none of the markers in this region showed complete association with sex in the other populations. So an association analysis was designed using the female parent, pool of female progenies, male parent, and pool of male progenies. Markers were de novo developed and those showing significant differences between female and male pools were identified. Among them, three sex-associated markers including one fully associated marker were identified. Integration of linkage and association analysis showed that the sex determination region was fine-mapped in a small region along LG18. The identified sex-associated marker can be used for the sex detection of this species at genetic level. The fine-mapped sex-determining region will contribute to the mapping of sex-determining gene and help to clarify sex determination system for L. vannamei.

QTL Mapping and Marker Identification for Sex-Determining: Indicating XY Sex Determination System in the Swimming Crab (Portunus trituberculatus)

“…In addition, 46 markers detected by genome-wide association studies (GWASs) were heterozygous and segregated only in the female parent, which documents a ZW sex determination system in E. sinensis (Cui et al, 2015). In L. vannamei , the sex determination region was fine-mapped to a small region along LG18 via the integration of linkage and association analysis (Yang et al, 2017). One fully sex-associated marker was identified, supporting the ZW sex determination mechanism in L. vannamei .…”

Identification of a quantitative trait loci (QTL) associated with ammonia tolerance in the Pacific white shrimp (Litopenaeus vannamei)

“…Yu et al constructed a high-density genetic map for L. vannamei and detected several QTLs for body weight and body length [30]. Yang et al mapped the sex determination region in L. vannamei based on the data used for high-density linkage map construction [45]. Du et almapped a QTL for L. vannamei gender using a genebased SNP linkage map [46].…”

Identification of a quantitative trait loci (QTL) associated with ammonia tolerance in the Pacific white shrimp (Litopenaeus vannamei)

“…Whole-genome deep resequencing is relatively costly for large genomes and is often not necessary for gene/QTL mapping [43,44]. In recent years, several genetic linkage maps based on SNPs were constructed and QTL analyses were conducted in L. vannamei [30,[45][46][47]. In this study, a high-density genetic map of L. vannamei was constructed using SLAF-seq, which is an effective method for discovering large numbers of SNPs and to perform large-scale genotyping [20].…”