Key Laboratory of Freshwater Aquatic Genetic Resources, Ministry of Agriculture, National Demonstration Center for Experimental Fisheries Science Education, Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, 201306, Shanghai, People's Republic of China.
College of Life Science and Technology, Huazhong Agricultural University, 430070, Wuhan, People's Republic of China.
Mar Biotechnol (NY). 2019 Apr;21(2):206-216. doi: 10.1007/s10126-018-09873-8. Epub 2019 Jan 10.
Knowledge on sex determination has proven valuable for commercial production of the prawn Macrobrachium rosenbergii due to sex dimorphism of the male and female individuals. Previous studies indicated that prawn sex is determined by a ZW-ZZ chromosomal system, but no genomic information is available for the sex chromosome. Herein, we constructed a genomic bacterial artificial chromosome (BAC) library and identified the ZW-derived BAC clones for initial analysis of the sex chromosomal DNA sequence. The arrayed BAC library contains 200,448 clones with average insert size of 115.4 kb, corresponding to ∼ 4× coverage of the estimated 5.38 Gb genome. Based on a short female-specific marker, a Z- and a W-fragment were retrieved with the genomic walking method. Screening the BAC library using a ZW-specific marker as probe resulted in 12 positive clones. From these, a Z-derived (P331M17) and a W-derived (P122G2) BAC clones were randomly selected and sequenced by PacBio method. We report the construction of a large insert, deep-coverage, and high-quality BAC library for M. rosenbergii that provides a useful resource for positional cloning of target genes, genomic organization, and comparative genomics analysis. Our study not only confirmed the ZW/ZZ system but also discovered sex-linked genes on ZW chromosomes for the first time, contributing to a comprehensive understanding of the genomic structure of sex chromosomes in M. rosenbergii.
性别的相关知识对于罗氏沼虾（Macrobrachium rosenbergii）的商业生产具有重要意义，因为其雌雄个体存在性二型性。先前的研究表明，罗氏沼虾的性别由 ZW-ZZ 染色体系统决定，但性染色体的基因组信息尚未可知。在此，我们构建了罗氏沼虾的基因组细菌人工染色体（BAC）文库，并鉴定了 Z 染色体来源的 BAC 克隆，用于初步分析性染色体的 DNA 序列。该排列 BAC 文库包含 200,448 个克隆，平均插入片段大小为 115.4 kb，相当于估计的 5.38 Gb 基因组的约 4 倍覆盖度。基于一个短的雌性特异性标记，我们通过基因组步移法获得了 Z 染色体和 W 染色体片段。使用 ZW 特异性标记作为探针筛选 BAC 文库，得到了 12 个阳性克隆。从中，随机选择了一个 Z 染色体来源的（P331M17）和一个 W 染色体来源的（P122G2）BAC 克隆，并通过 PacBio 方法进行了测序。我们报告了罗氏沼虾的大型插入、深度覆盖和高质量 BAC 文库的构建，为目标基因的定位克隆、基因组组织和比较基因组学分析提供了有用的资源。我们的研究不仅证实了 ZW/ZZ 系统，而且首次发现了 ZW 染色体上的性连锁基因，有助于全面了解罗氏沼虾性染色体的基因组结构。
