Kumaresan Arumugam, Elango Kamaraj, Datta Tirtha Kumar, Morrell Jane M
Theriogenology Laboratory, Southern Regional Station of Indian Council of Agricultural Research (ICAR)-National Dairy Research Institute, Bengaluru, India.
Animal Genomics Laboratory, Indian Council of Agricultural Research (ICAR)-National Dairy Research Institute, Karnal, India.
Front Cell Dev Biol. 2021 Jul 8;9:696637. doi: 10.3389/fcell.2021.696637. eCollection 2021.
Crossbreeding of indigenous cattle () with improved () breeds gained momentum and economic relevance in several countries to increase milk production. While production performance of the crossbred offspring is high due to hybrid vigor, they suffer from a high incidence of reproductive problems. Specifically, the crossbred males suffer from serious forms of subfertility/infertility, which can have a significant effect because semen from a single male is used to breed several thousand females. During the last two decades, attempts have been made to understand the probable reasons for infertility in crossbred bulls. Published evidence indicates that testicular cytology indices, hormonal concentrations, sperm phenotypic characteristics and seminal plasma composition were altered in crossbred compared to purebred males. A few recent studies compared crossbred bull semen with purebred bull semen using genomics, transcriptomics, proteomics and metabolomics; molecules potentially associated with subfertility/infertility in crossbred bulls were identified. Nevertheless, the precise reason behind the poor quality of semen and high incidence of sub-fertility/infertility in crossbred bulls are not yet well defined. To identify the underlying etiology for infertility in crossbred bulls, a thorough understanding of the magnitude of the problem and an overview of the prior art is needed; however, such systematically reviewed information is not available. Therefore, the primary focus of this review is to compile and analyze earlier findings on crossbred bull fertility/infertility. In addition, the differences between purebred and crossbred males in terms of testicular composition, sperm phenotypic characteristics, molecular composition, environmental influence and other details are described; future prospects for research on crossbred males are also outlined.
为提高牛奶产量，在一些国家，本地牛（）与改良品种（）的杂交繁殖有了发展势头并具有经济意义。虽然杂交后代由于杂种优势而具有较高的生产性能，但它们却面临着高发的繁殖问题。具体而言，杂交雄性牛患有严重的亚不育/不育症，由于一头雄性牛的精液用于使数千头雌性牛受孕，这可能会产生重大影响。在过去二十年中，人们一直试图了解杂交公牛不育的可能原因。已发表的证据表明，与纯种雄性相比，杂交雄性的睾丸细胞学指标、激素浓度、精子表型特征和精浆成分都发生了改变。最近的一些研究使用基因组学、转录组学、蛋白质组学和代谢组学对杂交公牛精液和纯种公牛精液进行了比较；确定了与杂交公牛亚不育/不育症潜在相关的分子。然而，杂交公牛精液质量差和亚不育/不育症高发背后的确切原因尚未明确界定。为了确定杂交公牛不育的潜在病因，需要全面了解问题的严重程度并概述现有技术；然而，尚无此类系统综述的信息。因此，本综述的主要重点是汇编和分析关于杂交公牛生育力/不育症的早期研究结果。此外，还描述了纯种和杂交雄性在睾丸组成、精子表型特征、分子组成、环境影响和其他细节方面的差异；还概述了杂交雄性研究的未来前景。
