BackgroundRecent transcriptomic analysis of the bovine Y chromosome revealed at least six multi-copy protein coding gene families, including TSPY, HSFY and ZNF280BY, on the male-specific region (MSY). Previous studies indicated that the copy number variations (CNVs) of the human and bovine TSPY were associated with male fertility in men and cattle. However, the relationship between CNVs of the bovine Y-linked HSFY and ZNF280BY gene families and bull fertility has not been investigated.ResultsWe investigated the copy number (CN) of the bovine HSFY and ZNF280BY in a total of 460 bulls from 15 breeds using a quantitative PCR approach. We observed CNVs for both gene families within and between cattle breeds. The median copy number (MCN) of HSFY among all bulls was 197, ranging from 21 to 308. The MCN of ZNF280BY was 236, varying from 28 to 380. Furthermore, bulls in the Bos taurus (BTA) lineage had a significantly higher MCN (202) of HSFY than bulls in the Bos indicus (BIN) lineage (178), while taurine bulls had a significantly lower MCN (231) of ZNF280BY than indicine bulls (284). In addition, the CN of ZNF280BY was positively correlated to that of HSFY on the BTAY. Association analysis revealed that the CNVs of both HSFY and ZNF280BY were correlated negatively with testis size, while positively with sire conception rate.ConclusionThe bovine HSFY and ZNF280BY gene families have extensively expanded on the Y chromosome during evolution. The CN of both gene families varies significantly among individuals and cattle breeds. These variations were associated with testis size and bull fertility in Holstein, suggesting that the CNVs of HSFY and ZNF280BY may serve as valuable makers for male fertility selection in cattle.

Background Preferentially expressed antigen in melanoma (PRAME) is a cancer/testis antigen (CTA) that is predominantly expressed in normal gametogenic tissues and a variety of tumors. Members of the PRAME gene family encode leucine-rich repeat (LRR) proteins that provide a versatile structural framework for the formation of protein–protein interactions. As a nuclear receptor transcriptional regulator, PRAME has been extensively studied in cancer biology and is believed to play a role in cancer cell proliferation by suppressing retinoic acid (RA) signaling. The role of the PRAME gene family in germline development and spermatogenesis has been recently confirmed by a gene knockout approach. To further understand how PRAME proteins are involved in germ cell development at a subcellular level, we have conducted a systematic immunogold electron microscopy (IEM) analysis on testis sections of adult mice with gene-specific antibodies from two members of the mouse Prame gene family: Pramel1 and Pramex1. Pramel1 is autosomal, while Pramex1 is X-linked, both genes are exclusively expressed in the testis. Results Our IEM data revealed that both PRAMEL1 and PRAMEX1 proteins were localized in various cell organelles in different development stages of spermatogenic cells, including the nucleus, rER, Golgi, mitochondria, germ granules [intermitochondrial cement (IMC) and chromatoid body (CB)], centrioles, manchette, and flagellum. Unlike other germ cell-specific makers, such as DDX4, whose proteins are evenly distributed in the expressed-organelle(s), both PRAMEL1 and PRAMEX1 proteins tend to aggregate together to form clusters of protein complexes. These complexes were highly enriched in the nucleus and cytoplasm (especially in germ granules) of spermatocytes and spermatids. Furthermore, dynamic distribution of the PRAMEL1 protein complexes were observed in the microtubule-based organelles, such as acroplaxome, manchette, and flagellum, as well as in the nuclear envelope and nuclear pore. Dual staining with PRAMEL1 and KIF17B antibodies further revealed that the PRAMEL1 and KIF17B proteins were co-localized in germ granules. Conclusion Our IEM data suggest that the PRAMEL1 and PRAMEX1 proteins are not only involved in transcriptional regulation in the nucleus, but may also participate in nucleocytoplasmic transport, and in the formation and function of germ cell-specific organelles during spermatogenesis.

The mammalian sex chromosomes evolved from an ordinary pair of autosomes during evolution. Unlike the X chromosome that is highly conserved, the Y chromosome is poorly conserved among mammalian lineages. Several special features set the Y chromosome apart from the rest of genome: male-limited transmission, absence of recombination, abundance of Y-specific repetitive sequences, degeneration of Y-linked genes during evolution, acquisition of autosomal genes, and accumulation and functional cluster of "testis genes" for maleness and reproduction. Since the degeneration process is lineage-dependent, different lineages retain different subsets of genes from the ancestral proto-Y chromosome, resulting in a diverse and lineage-specific Y chromosome gene content. During bovine evolution, a lineage-specific 'autosome-to-Y' transposition event resulted in three bovid-specific Y chromosome gene families, PRAMEY, ZNF280BY and ZNF280AY. Together, the male-specific region (MSY) of the bovine Y chromosome (BTAY) contains ~ 1200 protein coding genes that can be classified into 12 single copy and 16 multiple copy protein families. The copy number (CN) of these Y-linked gene families varies from 13 for PRAMEY to 236 for ZNF280BY, with significant differences between the taurine and indicine Y lineages. In addition, 367 non-coding RNA families (ncRNAs) were also identified on BTAY. Transcriptome analysis revealed that 95% of the BTAY genes/ncRNAs are expressed predominantly in testis and may be involved in spermatogenesis and male fertility. Though the functional role for the majority of the Y-linked genes needs to be determined, the preliminary data on PRAMEY clearly indicated a role in spermiogenesis. Furthermore, copy number variations (CNVs) of PRAMEY, ZNF280BY, TSPY and HSFY were found to be associated with testis size, sperm quality and fertility in dairy bulls. The authors discuss several challenges that influence male fertility selection associated with the bovine Y chromosome. * The copy number was estimated from the bovine Y chromosome draft sequence assembly (acc. no. CM001061).

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：In this paper, two models are built to solve the water scarcity problem, from which 1.6 billion people are suffering. In order to improve the water scarcity situation, an interbasin water transfer model and an agricultural water-saving model are built.