High-Density Genetic Linkage Maps Provide Novel Insights Into ZW/ZZ Sex Determination System and Growth Performance in Mud Crab (Scylla paramamosain)

Abstract

Mud crab, Scylla paramamosain is one of the most important crustacean species in global aquaculture. To determine the genetic basis of sex and growth-related traits in S. paramamosain , a high-density genetic linkage map with 16,701 single nucleotide polymorphisms (SNPs) was constructed using SLAF-seq and a full-sib family. The consensus map has 49 linkage groups, spanning 5,996.66 cM with an average marker-interval of 0.81 cM. A total of 516 SNP markers, including 8 female-specific SNPs segregated in two quantitative trait loci (QTLs) for phenotypic sex were located on LG32. The presence of female-specific SNP markers only on female linkage map, their segregation patterns and lower female: male recombination rate strongly suggest the conformation of a ZW/ZZ sex determination system in S. paramamosain . The QTLs of most (90%) growth-related traits were found within a small interval (25.18–33.74 cM) on LG46, highlighting the potential involvement of LG46 in growth. Four markers on LG46 were significantly associated with 10–16 growth-related traits. BW was only associated with marker 3846. Based on the annotation of transcriptome data, 11 and 2 candidate genes were identified within the QTL regions of sex and growth-related traits, respectively. The newly constructed high-density genetic linkage map with sex-specific SNPs, and the identified QTLs of sex- and growth-related traits serve as a valuable genetic resource and solid foundation for marker-assisted selection and genetic improvement of crustaceans.

Comparative Transcriptome Analysis of Gonads for the Identification of Sex-Related Genes in Giant Freshwater Prawns (Macrobrachium Rosenbergii) Using RNA Sequencing

“…Thus, based on the economic impact, developing the monosex population culture as the efficient approach to boost production has received great attention from researchers in M. rosenbergii. Nevertheless, the premise of monosex culture is to understand the molecular mechanism of sex determination, as well as to unravel sex-related genes.Studies on sex determination have proved that many macruran species exhibit the ZW/ZZ sex determination system [3][4][5]. In M. rosenbergii, sex reversal experiments proposed that the female prawns bear the ZW sex chromosomes, and the male individuals bear the ZZ chromosomes [1,6,7].…”

“…Studies on sex determination have proved that many macruran species exhibit the ZW/ZZ sex determination system [3][4][5]. In M. rosenbergii, sex reversal experiments proposed that the female prawns bear the ZW sex chromosomes, and the male individuals bear the ZZ chromosomes [1,6,7].…”

The “IAG-Switch”—A Key Controlling Element in Decapod Crustacean Sex Differentiation

“…The most common GSD systems are the XX/XY and WZ/ZZ systems, in which females are homogametic and males are heterogametic in the former mode of inheritance, and vice versa in the latter (17). With some exceptions (18), most prawn, shrimp and crayfish species bear the WZ/ZZ sex determination system (13,(19)(20)(21)(22)(23), while some species of crabs and lobsters bear the XX/XY system (24)(25)(26)(27). In the animal kingdom, there are only a few reports of sex-determining genes being associated with the W/Z sex chromosomes.…”

Sexual dimorphism in mud crabs: a tale of three sympatricScyllaspecies

“…The current understanding of the sexual size dimorphism of Scylla spp.—males are generally larger—are based on observations and local knowledge. The lack of concrete data in this area greatly hinders the incorporation of numerous biotechnological manipulation techniques associated with commercially important traits, especially body size ( Mei & Gui, 2015 ), into the enhancement of mud crab production ( Shi et al, 2019 ; Waiho et al, 2019 ). For example, the characterisation of sexually dimorphic characteristics would allow better mapping of valuable traits using high-density linkage map, aid in the selection of potential regulatory genes and the identification of sex-specific markers ( Waiho et al, 2019 ).…”