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| Qualifications |
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1998 License to Practice Veterinary Medicine in Pennsylvania
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| Memberships |
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American Veterinary Medical Association |
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| Clinical Interests |
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| assisted reproductive techniques, food animal reproduction |
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| Research Interests |
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Research in my laboratory is directed toward studying the biology of male germ line stem cells and spermatozoa in non-rodent mammalian species. Currently, we pursue three research areas. 1). My group was the first to successfully apply the technique of germ cell transplantation in domestic animals, using pigs and goats as models. This system serves as a bioassay for stem cell potential of a given germ cell population, and will allow the manipulation of different aspects of spermatogenesis. Furthermore, it provides the foundation for manipulation of the male germ line as an alternate approach to generate germ line transgenic animals. Currently, available technology is limited to pronuclear microinjection or nuclear transfer, both of which are hampered by low efficiency due to excessive pregnancy wastage and perinatal losses.  Figure 1. A: Schematic overview of germ cell transplantation in goats. A single-cell suspension is prepared from the testes of a transgenic donor goat. The cells are infused into the seminiferous tubules of wild-type recipient goats. Donor-derived spermatogonial stem cells generate colonies of transgenic spermatogenesis. Mating the recipient goat to a wild-type doe produces progeny, some of which are transgenic for the donor transgene. B: A transgenic goat produced as a result of germ cell transplantation. (Biol. Reprod. 2003, 69, 1260-1264).
2) Experimentation in non-rodent target species is inherently difficult, time consuming and expensive. In order to have a model system for the study and manipulation of spermatogenesis that is applicable to a variety of mammalian species including primates, we developed the technique of testis tissue xenografting into mouse hosts. This approach allowed for the first time complete spermatogenesis and production of functional sperm from immature testis tissue obtained from different domestic animal species and non-human primates in a mouse host. We now employ this strategy not only as a basic science tool for the study of spermatogenesis in different species, but also for preservation of male genetics from immature individuals like endangered animals, valuable laboratory strains or farm animals, and potentially even human childhood cancer patients.
3). In the female reproductive tract, spermatozoa undergo an essential maturational process known as “capacitation” that renders them capable to fertilize an egg. We are exploring the molecular events of sperm capacitation that are initiated by interaction of sperm with the microenvironment of the female oviduct. By studying the signaling pathways involved in this process in bovine and porcine sperm, we hope to increase our understanding of its role in the regulation of male fertility as well as to ultimately be able to improve protocols for sperm preservation in domestic animals by regulation of capacitation-associated changes. |
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| Selected Publications |
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RATHI, R., A. HONARAMOOZ, W. ZENG, R. TURNER & I. DOBRINSKI (2006): Germ cell development in equine testis tissue xenografted into mice. Reproduction 131: 1091-1098. ZENG, W., G.F. AVELAR, R. RATHI, L.R. FRANCA & I. DOBRINSKI (2006): The length of the spermatogenic cycle is conserved in porcine and ovine testis xenografts. J. Androl. 27(4), 527-533. GALANTINO-HOMER, H.L., W. ZENG, S. O. MEGEE, M. DALLMEYER, D.VOELKL & I. DOBRINSKI (2006): Effects of 2-hydroxypropyl-?-cyclodextrin and cholesterol on porcine sperm viability and capacitation status following cold shock or incubation. Mol. Reprod. Dev. 73: 638-650. SCHLATT, S. A. HONARAMOOZ, J. EHMCKE, P.J. GOEBELL, H. RUBBEN, R. DHIR, I. DOBRINSKI* & P. PATRIZIO (2006): Limited survival of adult human testicular tissue as ectopic xenograft. Hum. Reprod. 21(2): 384-389. RATHI, R., A. HONARAMOOZ, W. ZENG, S. SCHLATT & I. DOBRINSKI (2005): Germ cell fate and seminiferous tubule development in bovine testis xenografts. Reproduction 130: 923-929. HONARAMOOZ, A., E. BEHBOODI, C.L. HAUSLER, S. BLASH, S. AYRES, C. AZUMA, Y. ECHELARD & I. DOBRINSKI (2005): Depletion of endogenous germ cells in male pigs and goats in preparation for germ cell transplantation. J. Androl. 26(6): 698-705. SNEDAKER, A., A. HONARAMOOZ & I. DOBRINSKI (2004): A game of cat and mouse: Xenografting of testis tissue from domestic kittens results in complete cat spermatogenesis in a mouse host. J. Androl. 25(6); 926-930. HONARAMOOZ, A., M.-W. LI, C.T. PENEDO, S.A. MEYERS & I. DOBRINSKI (2004): Accelerated maturation of primate testis by xenografting into mice. Biol. Reprod. 70, 1500-1503. HONARAMOOZ, A., E. BEHBOODI, S.O. MEGEE, S.A. OVERTON, H. GALANTINO-HOMER, Y. ECHELARD & I. DOBRINSKI (2003): Fertility and germline transmission of donor haplotype following germ cell transplantation in immuno-competent goats. Biol. Reprod., 69, 1260-1264. SCHLATT, S., A. HONARAMOOZ, M. BOIANI, H.R. SCHÖLER & I. DOBRINSKI (2003): HONARAMOOZ, A., A. SNEDAKER, M. BOIANI, H.R. SCHÖLER, I. DOBRINSKI* & S. SCHLATT (2002): Sperm from neonatal mammalian testes grafted in mice. Nature 418: 778-781. HONARAMOOZ, A., S.O. MEGEE & I. DOBRINSKI (2002): Germ cell transplantation in pigs. Biol. Reprod. 66: 21-28. |
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