Department of Animal and Avian Sciences, University of Maryland, College Park, MD, 20742, USA.
College of Animal Science, South China Agricultural University, Guangzhou, GD, 510642, China.
BMC Genomics. 2018 Apr 10;19(1):244. doi: 10.1186/s12864-018-4548-6.
Striped bass (Morone saxatilis) spermatozoa are used to fertilize in vitro the eggs of white bass (M. chrysops) to produce the preferred hybrid for the striped bass aquaculture industry. Currently, only one source of domestic striped bass juveniles is available to growers that is not obtained from wild-caught parents and is thus devoid of any genetic improvement in phenotypic traits of importance to aquaculture. Sperm epigenetic modification has been predicted to be associated with fertility, which could switch genes on and off without changing the DNA sequence itself. DNA methylation is one of the most common epigenetic modification types and changes in sperm epigenetics can be correlated to sub-fertility or infertility in male striped bass. The objective of this study was to find the differentially methylated regions (DMRs) between high-fertility and sub-fertility male striped bass, which could potentially regulate the fertility performance.
In our present study, we performed DNA methylation analysis of high-fertility and sub-fertility striped bass spermatozoa through MBD-Seq methods. A total of 171 DMRs were discovered in striped bass sperm correlated to fertility. Based on the annotation of these DMRs, we conducted a functional classification analysis and two important groups of genes including the WDR3/UTP12 and GPCR families, were discovered to be related to fertility performance of striped bass. Proteins from the WDR3/UTP12 family are involved in forming the sperm flagella apparatus in vertebrates and GPCRs are involved in hormonal signaling and regulation of tissue development, proliferation and differentiation.
Our results contribute insights into understanding the mechanism of fertility in striped bass, which will provide powerful tools to maximize reproductive efficiencies and to identify those males with superior gametes for this important aquaculture species.
条纹鲈（Morone saxatilis）的精子用于体外受精白鲈（M. chrysops）的卵子，以生产条纹鲈水产养殖行业所需的首选杂交种。目前，养殖者只能获得一种非野生来源的国内条纹鲈幼鱼，因此缺乏对水产养殖重要表型特征的任何遗传改良。精子表观遗传修饰被预测与生育能力有关，它可以在不改变 DNA 序列本身的情况下打开和关闭基因。DNA 甲基化是最常见的表观遗传修饰类型之一，精子表观遗传的变化可能与雄性条纹鲈的亚生育力或不育有关。本研究的目的是找到高生育力和低生育力雄性条纹鲈之间的差异甲基化区域（DMRs），这些区域可能调节生育能力。
在我们目前的研究中，我们通过 MBD-Seq 方法对高生育力和低生育力的条纹鲈精子进行了 DNA 甲基化分析。共发现 171 个与生育力相关的条纹鲈精子 DMRs。基于这些 DMRs 的注释，我们进行了功能分类分析，发现了 WDR3/UTP12 和 GPCR 家族等两个重要的基因群与条纹鲈的生育性能有关。WDR3/UTP12 家族的蛋白质参与脊椎动物精子鞭毛器的形成，而 GPCRs 参与激素信号传递和组织发育、增殖和分化的调节。
我们的研究结果有助于了解条纹鲈生育能力的机制，这将为最大限度地提高繁殖效率提供有力工具，并识别出那些具有优秀配子的雄性，用于这一重要的水产养殖物种。
