Copy Number Variation of Testis-Specific Protein, Y-Encoded <i>(TSPY)</i> in 14 Different Breeds of Cattle <i>(Bos taurus)</i>

Abstract

Multi-copied gene families are prevalent in mammalian genomes, especially within the Y chromosome. Testis specific protein Y-encoded (TSPY) is present in variable copy number in many mammalian species. Previous studies have estimated that TSPY ranges from 50–200 copies in cattle. To examine TSPY localization on the Y chromosome we employed fluorescence in situ hybridization (FISH) and fiber-FISH. The results show a strong signal on the short arm of the Y chromosome (Yp). To investigate TSPY copy number we used relative real-time polymerase chain reaction (PCR) to analyze the DNA of 14 different cattle breeds. Variation both within and between breeds was observed. All breeds show significant variation in TSPY copy number among individual members. Brown Swiss (161 copies, CI = 133–195) had higher average levels of TSPY and Western Fjord Cattle (63 copies, CI = 45–86) had lower levels than some breeds. Overall, however, most breeds had a similar average TSPY copy number. The pooled average was 94 copies (CI = 88–100). The significance of the TSPY array remains uncertain, but as the function of TSPY is unraveled the purpose of the array may become clearer.

Male-specific region of the bovine Y chromosome is gene rich with a high transcriptomic activity in testis development

“…1). Strong TSPY signals were observed in the proximal region of Yp (14,22), revealing the location of the TSPY array (Fig. 1) and supporting the draft sequence assembly and a previous report about the different clusters of the TSPY subfamilies (21).…”

“…1) and supporting the draft sequence assembly and a previous report about the different clusters of the TSPY subfamilies (21). It is important to point out that the number of repeat units on the BTAY varies among individuals and among populations, as evidenced by previous studies on the copy number variations of TSPY, ranging from 45 to ∼200 (21,22).…”

“…Further cytogenetic characterization indicated that the bovid Y chromosome underwent rearrangements caused by centromeric transposition or pericentric inversion (12). Only eight genes on BTAY-DDX3Y, OFD1Y, PRAMEY, SRY, TSPY, HSFY, ZNF280AY, and ZNF280BY-have been characterized previously (14)(15)(16)(17)(18)(19)(20)(21)(22).…”

Copy number variations of five Y chromosome genes in donkeys

“…Then, relying on additional three equations (listed as follows) described in Hamilton et al (2009), the CNVs of CUL4BY, ETSTY1, ETSTY4, ETSTY5, and SRY were estimated. In the equations, the C T values of the calibrator were determined by the average of all C T values obtained in different plates for each gene, and C T = C T of the calibrator -C T of the test sample.…”

“…The testisspecific protein Y-encoded (TSPY) gene shows 20-76 copies and the CNVs have been found to be associated with semen quality and reproduction by regulating cell division in the process of spermatogenesis in men (Nickkholgh et al, 2010;Vodicka et al, 2007). The TSPY gene shows 37-200 copies on the bovine Y chromosome (BTAY) (Hamilton et al, 2009;Jakubiczka et al, 1993). The heat-shock transcription factor, Y-linked (HSFY) gene contains around 70 copies in bulls (Hamilton et al, 2011).…”