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Richard J. Oko PhD
 Richard J. Oko
Position(s)
Professor
Contact Info

Faculty Bio

Our research is focused on the developmental biology of specialized mammalian sperm head and tail components and their roles during fertilization. In the sperm head we are identifying proteins making up the perinuclear theca (PT). We as well as others have implicated the PT in a number of cellular processes such as acrosome formation during spermiogenesis and egg activation during fertilization. Our objectives are to gain a mechanistic insight into these processes by characterizing the PT proteins. We are also characterizing the proteins of the inner acrosomal membrane to find out how these proteins are involved in sperm penetration through the zona pellucida of the oocyte. In the sperm tail we are characterizing the outer dense fibers and the fibrous sheath proteins and exploring their mode of assembly. In summary, using morphological, biochemical and molecular approaches we are studying how novel sperm proteins are involved in germ cell differentiation and in fertilization.

Research Interests

Our research is focused on the developmental biology of specialized mammalian sperm head and tail components and their roles during fertilization.  In the sperm head we are identifying proteins making up the perinuclear theca (PT).  We as well as others have implicated the PT in a number of cellular processes such as acrosome formation during spermiogenesis and egg activation during fertilization.  Our objectives are to gain a mechanistic insight into these processes by characterizing the PT proteins.  We are also characterizing the proteins of the inner acrosomal membrane to find out how these proteins are involved in sperm penetration through the zona pellucida of the oocyte.  In the sperm tail we are characterizing the outer dense fibers and the fibrous sheath proteins and exploring their mode of assembly.  In summary, using morphological, biochemical and molecular approaches we are studying how novel sperm proteins are involved in germ cell differentiation and in fertilization.

Sources of Research Funds: Canadian Institutes of Health Research; National Science and Engineering Research Council of Canada.

Selected Publications

1. Wu AT, Sutovsky P, Manandhar G, Xu W, Katayama M, Day BN, Park KW, Yi YJ, Xi YW, Prather RS, Oko R. PAWP, a sperm-specific WW domain-binding protein, promotes meiotic resumption and pronuclear development during fertilization. J. Biol. Chem. 2007; 282: 12164-12175.

2. Fitzgerald C, Sikora C, Lawson V, Dong K, Cheng M, Oko R, van der Hoorn FA. Mammalian transcription in support of hybrid mRNA and protein synthesis in testis and lung. J. Biol. Chem. 2006; 281: 38172-38180.

3. Yu Y, Xu W, Yi YJ, Sutovsky P, Oko R. The extracellular protein coat of the inner acrosomal membrane is involved in zona pellucida binding and penetration during fertilization: characterization of its most prominent polypeptide (IAM38). Dev. Biol. 2006; 290: 32-43.

4. Tovich PR, Sutovsky P, Oko RJ. Novel aspect of perinuclear theca assembly revealed by immunolocalization of non-nuclear somatic histones during bovine spermiogenesis. Biol. Reprod. 2004; 71: 1182-1194.

5. Miranda-Vizuete A, Sadek CM, Jimenez A, Krause WJ, Sutovsky P, Oko R. The mammalian testis-specific thioredoxin system. Antioxid. Redox. Signal. 2004; 6: 25-40.

6. Tovich PR, Oko RJ. Somatic histones are components of the perinuclear theca in bovine spermatozoa. J. Biol. Chem. 2003; 278: 32431-32438.

7. Miranda-Vizuete A, Tsang K, Yu Y, Jimenez A, Pelto-Huikko M, Flickinger CJ, Sutovsky P, Oko R. Cloning and developmental analysis of murid spermatid-specific thioredoxin-2 (SPTRX-2), a novel sperm fibrous sheath protein and autoantigen. J. Biol. Chem. 2003; 278: 44874-44885.

8. Sutovsky P, Manandhar G, Wu A, Oko R. Interactions of sperm perinuclear theca with the oocyte: implications for oocyte activation, anti-polyspermy defense, and assisted reproduction. Microsc. Res. Tech. 2003; 61: 362-378.