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    Expression dynamics of Integrin Subunit Beta 5 in bovine gametes and embryos imply functions in male fertility and early embryonic development
    (WILEY, 2019) Velho, Ana.; Wang, Hongfeng.; Koenig, Leslie.; Grant, Kamilah E.; Menezes, Erika S.; Kaya, Abdullah.; Moura, Arlindo.; Memili, Erdogan.
    Integrins have been shown to act as signalling receptors, and they primarily recognise extracellular matrix ligands on the oocyte surface. However, their possible roles in oocyte activation and embryo development are not clearly understood. The objectives of this study were to evaluate expression of Integrin Subunit Beta 5 (ITG beta 5) in bovine sperm, oocytes, and early embryos and to ascertain the evolutionary conservation of ITG beta 5. To accomplish these objectives, we used western blotting to study expression levels of ITG beta 5 protein in sperm and RT-qPCR to determine expression levels of ITG beta 5 transcripts in oocytes and embryos. We have also used bioinformatic analysis to determine the evolutionary conservation of the ITG beta 5 protein among various species. Western blotting showed that ITG beta 5 protein was detectable in bull sperm. Moreover, results of RT-qPCR showed that levels of ITG beta 5 were significantly higher in the two-cell embryos, followed by the 8-16-cell embryos. However, no significant difference in expression levels were noted for the morula and blastocyst stages as compared to MII oocytes. Bioinformatic analysis revealed that ITG beta 5 is conserved among various species. We conclude that expression of ITG beta 5 in bovine gametes and embryos implies an important role in fertilisation and embryogenesis.
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    Sperm miR-15a and miR-29b are associated with bull fertility
    (WILEY, 2020) Menezes, Erika S. B.; Badial, Peres Ramos.; El Debaky, Hazem.; Ul Husna, Asma.; Ugur, Muhammet Rasit.; Kaya, Abdullah.; Topper, Einko.; Bulla, Camilo.; Grant, Kamilah E.; Bolden-Tiller, Olga.; Moura, Arlindo A.; Memili, Erdoğan.
    MicroRNAs modulate male fertility by regulating gene expression. In this study, dynamics of sperm miR-15a, miR-29b and miR-34a from high fertility (HF) and low fertility (LF) bulls using RT-qPCR were evaluated. Bioinformatic tools were employed to ascertain genes of interest of the sperm miRNAs. The expression levels of p53, BCL2, BAX and DNMT1 in bull spermatozoa were determined by immunoblotting. MicroRNA levels of miR-15a and miR-29 were higher in LF sires when compared with those present in HF bulls. Expression levels of miR-34a did not differ between the two groups. We found an inverse correlation between miR-15a and bull fertility. MiR29-b was also negatively associated with fertility scores. BCL2 and DNMT1 were higher in HF bulls while BAX was higher in the LF group. Our data showed a positive correlation between BCL2 and bull fertility. In addition, DNMT1 was positively associated with bull fertility. Furthermore, levels of BAX were negatively linked with bull fertility scores. Identification of miRNAs found in the spermatozoa of sires with different in vivo fertility helps understand the alterations in the fertilising capacity from cattle and other mammals. These potential biomarkers can be used in reproductive biotechnology as fertility markers to assess semen quality and predict male fertility.
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    Sperm superoxide dismutase is associated with bull fertility
    (CSIRO PUBLISHING, 2016) Grant, Kamilah E.; de Oliveira, Rodrigo V.; Hennington, Bettye Sue; Govindaraju, Aruna; Perkins, Andy; Stokes, John; Rowe, Dennis
    Decreasing mammalian fertility and sperm quality have created an urgent need to find effective methods to distinguish non-viable from viable fertilising spermatozoa. The aims of the present study were to evaluate expression levels of beta-tubulin 2C (TUBB2C), heat shock protein 10 (HSP10), hexokinase 1 (HXK1) and superoxide dismutase 1 (SOD1) in spermatozoa from Holstein bulls with varying fertility using western blotting and to analyse the biological networks of these key sperm proteins using a bioinformatics software (Metacore; Thomson-Reuters, Philadelphia, PA, USA). The rationales behind this study were that the sperm proteins play crucial roles in fertilisation and early embryonic development in mammals and ascertaining the biological networks of the proteins helps us better understand sperm physiology and early mammalian development. The results showed that expression of SOD1 was higher in spermatozoa from high fertility bulls (P< 0.05) and that SOD1 is the best protein to diagnose bulls based on the fertility index (P< 0.05). Using Metacore analysis, we identified an SOD1 network with pathways and linkages with other relevant molecules. We concluded that SOD1 sperm expression is associated with in vivo bull fertility. The findings are important because they illuminate molecular and cellular determinants of sperm viability and the identified protein markers can be used to determine bull fertility.