Contributions of an Animal Scientist to Reproductive Biology

Abstract

I became interested in biology as an undergraduate in a premedical curriculum but developed a passion for the field of reproductive biology because of a course in physiology of reproduction taken to meet requirements for admission to veterinary school. My career path changed, and I entered graduate school, obtained the Ph.D., and have enjoyed an academic career as a reproductive biologist conducting research in uterine biology and pregnancy in animal science departments at the University of Florida and at Texas A&M University. However, I have never allowed academic boundaries to interfere with research and graduate education as that is contrary to collegiality, the cornerstone of great universities. I consider that my major contributions to science include 1) identification of proteins secreted by cells of the uterine endometrium that are critical to successful establishment and maintenance of pregnancy; 2) discovery of steroids and proteins required for pregnancy recognition signaling and their mechanisms of action in pigs and ruminant species; 3) investigation of fetal-placental development and placental transport of nutrients, including water and electrolytes; 4) identification of linkages between nutrition and fetal-placental development; 5) defining aspects of the endocrinology of pregnancy; and 6) contributing to efforts to exploit the therapeutic value of interferon tau, particularly for treatment of autoimmune diseases. My current studies are focused on the role of select nutrients in the uterine lumen, specifically amino acids and glucose, that affect development and survival of the conceptus and translation of mRNAs and, with colleagues at Seoul National University, gene expression by the avian reproductive tract at key periods postovulation. Another goal is to understand stromal-epithelial cell signaling, whereby progesterone and estrogen act via uterine stromal cells that express receptors for sex steroids to stimulate secretion of growth factors (e.g., fibroblast growth factors and hepatocyte growth factor) that, in turn, regulate functions of uterine epithelial cells and conceptus trophectoderm.

The Male Fetal Biomarker INSL3 Reveals Substantial Hormone Exchange between Fetuses in Early Pig Gestation

“…Looking at INSL3 in these different compartments of the male fetus, then it is evident that whereas the amniotic fluid concentration remains relatively stable throughout gestation, being consistently about one-third that of fetal plasma, allantoic fluid is changing quite dramatically, from having very high values early in gestation, to having only very low concentrations later in gestation. This change is consistent with its changing role, from being a continuum between fetus and placenta early in gestation prior to fetal keratinization, to being a specialist hypo-osmotic nutrient environment largely though not exclusively contributed by the mother in the second half of pregnancy [ 38 , 39 ].…”

“…150 ml, and allantoic fluid to a maximum of almost 300 ml [ 37 ]. By this time, allantoic fluid has become quite dilute and comprises very much a maternal product of the epitheliochorial placenta [ 38 , 39 ]. By the end of gestation amniotic fluid and allantoic fluid volumes are both reduced, each being about 100 ml, presumably due to the space limitations of having a large litter.…”

Amino acid metabolism in intestinal bacteria and its potential implications for mammalian reproduction

“…glutamine, glycine, threonine, leucine, sulfur AA, taurine, tryptophan and tyrosine) are required to maintain gut integrity and function, stimulate intestinal protein synthesis and cell growth, sustain body metabolism, and support reproduction (Bazer, 2011;Wang et al, 2012;Wu et al, 2012bWu et al, , 2013c. Considering the adverse effects of a high-protein diet on the metabolism and health of pregnant women and their offspring (Herrick et al, 2003;Thone-Reineke et al, 2006;Andreasyan et al, 2007;Lönnerdal, 2014), dietary supplementation with these functional AA in an adequate amount to avoid an excess of dietary protein can be beneficial for the reproductive performance of both humans and animals (Wu et al, 2009(Wu et al, , 2013aWu, 2010).…”

Early Embryonic Development in Agriculturally Important Species

“…Uterine fluids of pigs contain many molecules secreted or transported into the uterine lumen to form histotroph [104]. Histotroph includes uteroferrin, now known as ACP5 (phosphatase, acid, type 5, tartrate resistant), which transports iron to the conceptus for erythropoiesis and stimulation of hematopoiesis [42].…”