Ph.D., Texas A&M University
The overall goal of our research program is to explicate maternal factors and the molecular mechanisms governing oogenesis, embryogenesis, and fetal development in horses. Our focus has centered on maternal exercise and heat stress on embryonic outcomes in mares. It is common practice in the horse industry for mares to continue to be trained and compete during the breeding season. Recent evidence from our laboratory has indicated that these activities are detrimental to embryo recovery rate and quality; resulting in altered gene expression patterns as embryo quality decreased. The molecular pathways that allow mammalian embryos either to expire, or recover and thrive are still poorly understood. Therefore, our current work continues to investigate stress in the mare and resulting embryonic gene expression patterns, with focus on stress response, DNA repair, apoptotic and autophagy genes, among others.
Another focus in our laboratory is the roles ovarian and uterine blood flow influences have on fertility and uterine gene expression. Recent work in livestock animals, to include mares, has linked increased blood flow to the female reproductive tract with improvements to fertility. Our work has begun to investigate the role increased blood flow through a nitric oxide donor (L-arginine) has on post-partum and non-pregnant mares as it relates to fertility and the uterine environment. Nitric oxide is a potent vasodilator and our preliminary work indicates that uterine and ovarian blood flow is increased in the mare via supplemental L-arginine. Endometrial gene expression patterns with focus on nitric oxide, angiogenic, prostaglandin, cytokine, and inflammatory genes are also currently being investigated to delineate any influence of increased uterine blood flow due to L-arginine supplementation.
Mortensen CJ, Choi YH, Ing NH, Kraemer DC, Vogelsang MM, Hinrichs K. Heat shock protein 70 gene expression in equine blastocysts after exposure of oocytes to high temperatures in vitro or in vivo after exercise of donor mares. Theriogenology 2010; 74:374-383.
Kelley DE, Smith RL, Gibbons JR, Vernon KL, Mortensen CJ. Effects of exercise on ovarian blood flow and embryo recovery rates in mares. Anim Reprod Sci 2010; 121S:S284-S285.
Mortensen CJ, Smith RL, Kelley DE, Gibbons JR. Stress negatively impacts mare reproductive efficiency. Proceedings of the 5th International Conference of Veterinary Research Division. Cairo, Egypt 2010; 5:59-66.
Mortensen CJ, Anton J, Kelley DE, Pratt SE, Smith RL, Vernon KL. Uterine blood flow characteristics of exercised pregnant mares measured by Doppler ultrasonography. Anim Reprod Sci 2010; 121S:S364-S366.