Exploration of an XX/XY Sex Determination System and Development of PCR-Based Sex-specific Markers in Procambarus clarkii Based on Next-Generation Sequencing Data.

Yudong Shen,Yanhe Li,Qishuai Wang,Weimin Wang

doi:10.3389/fgene.2022.850983

Abstract

Many economic crustacean species have sex dimorphisms during their growth. Exploring the sex determination system and developing sex-specific molecular marker(s) are very helpful for carrying out sex control breeding, and next-generation sequencing has been used as an efficient way to explore them in recent years. In this study, first, the genetic sex determination system of P. clarkii was explored as an XX/XY system by analyzing the 2b-RAD sequencing data. Furthermore, DNA samples of male and female individuals from a P. clarkii family were pooled separately for whole-genome resequencing. Based on the data of whole-genome resequencing, the 9,163 male- and female-specific bias sites with higher feasibility were obtained based on the assumption of the XX/XY sex determination system, and four sites were selected to design the sex-specific marker primers. One efficient sex-specific marker was identified with a sex discrimination rate of 99.49% (195/196) when applied to five different geographical groups with 196 individuals. The results of this study would provide a foundation for the realization of P. clarkii sex control and could provide some reference for investigating the sex determination system and sex molecular marker(s) of other crustacean species based on next-generation sequencing data.

Highlights

Large numbers of economic crustaceans, including prawn, shrimp, lobster, crayfish, and crab, have sex dimorphisms (Sun and Li, 2021)
After elimination of redundancy of clean reads of each sample, all clean reads were screened, and the reads existing in all male crayfish, but not in all female crayfish, were selected; the reads that exist in all female crayfish, but not in all male crayfish, were selected, each of which could reflect the XX/XY sex determination system and
The results showed that the number of reads existing in all male crayfish but not in all female crayfish was 160,609, which conforms to the hypothesis of the XX/XY sex determination system (Figure 1; Supplementary Table S2)

Summary

Introduction

Large numbers of economic crustaceans, including prawn, shrimp, lobster, crayfish, and crab, have sex dimorphisms (Sun and Li, 2021). The red swamp crayfish, Procambarus clarkii, commonly known as ‘little lobster’ in China, which is native to the southern United States and northern Mexico (Huner, 1988), has recently become an important farmed aquatic economic species in China (Jin et al, 2019). There is sex dimorphism between the male and female morphology of P. clarkii. The meat content of female crayfish is higher than that of male crayfish in the same weight condition (Peng et al, 2021). All-female production could bring significant economic implications in aquaculture. The realization of sex control of P. clarkii and unisexual culture of P. clarkii

Methods

Results

Conclusion