Jason R. Herrick
Assistant Professor, Veterinary Biosciences
Professional Interests: Comparative reproductive biology, preimplantation embryonic development, oocyte maturation, in vitro fertilization, embryo culture, endangered species conservation
The pre-implantation period of development, from ovulation to implantation, is one of the most sensitive periods of embryonic development. Procedures like in vitro fertilization require some or all of this developmental period to occur in an unnatural environment, a plastic Petri dish in an incubator. This nonphysiological environment places stress on the embryo that can alter embryonic physiology and ultimately affect pre- and post-implantation development, as well as the health of the offspring. Metabolism is necessary for the embryo to convert internal and external substrates into the energy necessary to support embryonic development and maintain homeostasis in the presence of various stressors. Therefore, the metabolic activity of the embryo is a key indicator of embryonic viability.
My primary research interests are the mechanisms controlling metabolism in gametes and embryos, how the different metabolic pathways are interrelated, how the environment affects these relationships, and how these relationships differ between species with different diets. In vitro, the metabolic activity of the embryo is influenced by the nutrients supplied in the culture medium and the amount of cellular stress caused by the culture environment. In vivo, nutrient availability is determined by the maternal diet. Optimizing culture media for embryo viability and modifying diets for improved reproductive performance could improve the efficiency of offspring production in valuable livestock or animal models for biomedical research and benefit humans with metabolic disorders undergoing fertility treatments.
omparative research on embryonic physiology could also facilitate the application of assisted reproductive technologies (ARTs) to endangered species conservation. Despite promising results in a handful of species, ARTs remain too inefficient for routine use in any nondomestic species. Unfortunately, the research necessary to improve the efficiency of ARTs requires large numbers of samples or highly invasive techniques not applicable to endangered species. Instead, researchers rely on a variety of domestic animals that are closely related to the species of interest. Information concerning the basic reproductive biology and the use ARTs in domestic ruminants, pigs, horses, dogs, and cats are fundamental to the success of ARTs in antelope, warthogs, rhinos, wolves, and tigers, respectively, to name a few.
Selected Publications:
Herrick JR, Bond JB, Magarey GM, Bateman HL, Krisher RL, Dunford SA, WF Swanson. 2007. Toward a Feline Optimized Culture Medium: Impact of Ions, Carbohydrates, Essential Amino Acids, Vitamins, and Serum on Development and Metabolism of IVF-Derived Feline Embryos Relative to Embryos Grown In Vivo. Biology of Reproduction 76:858-870.
Herrick J, Campbell M, Benson K, Coke R, Swanson WF. 2007. In vitro function of black-footed cat (Felis nigripes) spermatozoa following cryopreservation. Biology of Reproduction (Special Issue 2007):131(abstract#228).
Krisher RL, Brad AM, Herrick JR, Sparman ML, Swain JE. 2007. A comparative analysis of metabolism and viability in porcine oocytes during in vitro maturation. Animal Reproduction Science 98:72-96.
Herrick JR, West G, Benson K, Coke R, Campbell M, Swanson WF. 2006. Semen evaluation and in vitro sperm function in the black-footed cat (Felis nigripes). Biology of Reproduction (Special Issue 2006):89(abstract#81).
Herrick J, Leiske K, Magarey G, Swanson W. 2006. Basal seminal traits and in vitro fertilization in the sand cat (Felis margarita). Reproduction, Fertility, and Development 18:218-219(abstract#221).
Swanson WF, Stoops MA, Magarey GM, Herrick JR. 2006. Sperm cryopreservation in endangered felids: developing linkage of in situ – ex situ cat populations. In: Spermatology, Society for Reproduction and Fertility Vol. 65. Editors ERS Roldan and Gomendio, Nottingham Press. 417-432.
Herrick JR, Brad AM, Krisher RL. 2006. Chemical manipulation of glucose metabolism in porcine oocytes: effects on nuclear and cytoplasmic maturation in vitro. Reproduction 131:289-298.
Herrick JR, Lane M, Gardner DK, Behboodi E, Memili E, Blash S, Echelard Y, Krisher RL. 2006. Metabolism, protein content, and in vitro embryonic development of goat cumulus-oocyte complexes matured with physiological concentrations of glucose and L-lactate. Molecular Reproduction and Development 73:256-266.
Herrick JR, Bartels P, Krisher RL. 2004. Postthaw evaluation of in vitro function in epididymal spermatozoa from four species of free-ranging African bovids. Biology of Reproduction 71:948-958.
Herrick JR, Behboodi E, Memili E, Blash S, Echelard Y, Krisher RL. 2004. Effect of macromolecule supplementation during in vitro maturation of goat oocytes on developmental potential. Molecular Reproduction and Development 69:338-346.
Herrick JR, Conover-Sparman ML, Krisher RL. 2003. Reduced polyspermic fertilization of porcine oocytes utilizing elevated bicarbonate and reduced calcium concentrations in a single medium system. Reproduction, Fertility, and Development 15:249-254.
