The Fish Molecular Genetics and Biotechnology Laboratory, School of Fisheries, Aquaculture and Aquatic Sciences, Auburn University, Auburn, AL 36849, USA.
Fujian Key Laboratory of Genetics and Breeding of Marine Organisms, College of Ocean and Earth Sciences, Xiamen University, Xiamen 361102, China.
Int J Mol Sci. 2022 May 13;23(10):5471. doi: 10.3390/ijms23105471.
Channel catfish has an XY sex determination system. However, the X and Y chromosomes harbor an identical gene content of 950 genes each. In this study, we conducted comparative analyses of methylome and transcriptome of genetic males and genetic females before gonadal differentiation to provide insights into the mechanisms of sex determination. Differentially methylated CpG sites (DMCs) were predominantly identified on the sex chromosome, most notably within the sex determination region (SDR), although the overall methylation profiles across the entire genome were similar between genetic males and females. The drastic differences in methylation were located within the SDR at nucleotide position 14.0-20.3 Mb of the sex chromosome, making this region an epigenetically marked locus within the sex determination region. Most of the differentially methylated CpG sites were hypermethylated in females and hypomethylated in males, suggesting potential involvement of methylation modification in sex determination in channel catfish. Along with the differential methylation in the SDR, a number of differentially expressed genes within the SDR were also identified between genetic males and females, making them potential candidate genes for sex determination and differentiation in channel catfish.
斑点叉尾鮰的性别决定系统为 XY 型。然而，X 和 Y 染色体各自携带了 950 个基因，基因内容完全相同。在这项研究中，我们对遗传雄性和遗传雌性在性腺分化前进行了甲基化组和转录组的比较分析，以深入了解性别决定的机制。差异甲基化 CpG 位点（DMC）主要位于性染色体上，尤其是在性别决定区（SDR）内，但遗传雄性和雌性之间整个基因组的整体甲基化谱相似。在性染色体的核苷酸位置 14.0-20.3 Mb 内，甲基化的剧烈差异位于 SDR 内，使该区域成为性别决定区域内的一个表观遗传标记基因座。大多数差异甲基化的 CpG 位点在雌性中呈高甲基化，在雄性中呈低甲基化，这表明甲基化修饰可能参与了斑点叉尾鮰的性别决定。除了 SDR 中的差异甲基化外，还在遗传雄性和雌性之间的 SDR 内鉴定出了许多差异表达的基因，这些基因可能成为斑点叉尾鮰性别决定和分化的候选基因。
