Enhancing Animal Reproduction

Division of Animal Sciences receives more than $1 million in USDA NIFA funding

The United States Department of Agriculture’s (USDA) National Institute of Food and Agriculture (NIFA) awarded nearly $11 million in funding for grants related to enhancing animal reproduction, and improving the welfare and well-being of agriculture animals.

Researchers in the University of Missouri College of Agriculture, Food and Natural Resources (CAFNR) Division of Animal Sciences earned three of the 15 grants related to enhancing animal reproduction. MU was awarded just more than $1 million of the $6.72 million total investment in animal reproduction.

“Our researchers in the Division of Animal Sciences continue to make great strides related to animal reproduction research,” said Shibu Jose, associate dean in the CAFNR Office of Research. “These awards will allow us to build on the current stellar research being conducted within CAFNR.”

As part of the funding, Rodney Geisert, professor, earned a $500,000 grant to research the functional analysis of porcine conceptus estrogens and prostaglandins in maintenance of pregnancy. Peter Sutovsky, professor, was awarded $500,000 to look into ubiquitin-dependent proteolysis in farm animal spermatogenesis, fertilization and embryo development. And finally, Randy Prather, Curators’ Distinguished Professor, earned $20,000 in funding to support the 11th International Conference on Pig Reproduction.

Functional Analysis of Porcine Conceptus Estrogens and Prostaglandins in Maintenance of Pregnancy

According to Geisert, the increased litter size in pigs in commercial breeding herds has resulted in a greater number of lighter weight piglets at birth with compromised health and survivability due to the increased fetal crowding during gestation. Establishing the fundamental roles of conceptus- and uterine-secreted factors is an essential step to develop strategies to increase placental and fetal growth to improve overall health and survivability of piglets before and after birth.

“Our long-term research goals center on discovering and understanding the physiological, cellular and molecular mechanisms in the conceptus and endometrium that are essential for establishment and maintenance of pregnancy in livestock,” Geisert said. “We will use this fundamental knowledge to improve reproductive efficiency and profitability of animal production enterprises.”

Geiserts’s project will include three studies, and the general approach for each study will be to design an in vitro validation of guide RNAs to build specific CRISPRs for Cas9 nuclease targeted genome editing; fetal fibroblast cell engineering and genotyping; SCNT embryo production; in vitro culture; and embryo transfer and subsequent collection conceptuses and uterine endometrium for analysis.

“Our objective is to utilize gene editing technology to knockout specific embryonic genes to determine their role in early embryonic development and survival,” Geisert said. “Research is expected to provide clear information on the role of specific embryonic genes that regulate placental development and fetal growth. Fundamental knowledge gained from the research will be used to determine the direction and focus of subsequent translational research to improve reproductive efficiency of pigs and thus overall profitability of swine production enterprises.”

Ubiquitin-Dependent Proteolysis in Farm Animal Spermatogenesis, Fertilization and Embryo Development

Sutovsky said that artificial insemination (AI) is the preferred method of breeding in the swine and dairy cattle industries. Despite decades of technological development, the efficiency of AI, measured by pregnancy rates and number of offspring, is severely reduced by shortcomings in the processing and distribution of semen. In particular this is due to inadequate, potentially harmful (to sperm cells) composition of semen extenders, the diluents used to prepare multiple AI semen doses from each semen collection.

“During previous funding period of this project, we confirmed that the main protein recycling cellular machinery, the ubiquitin-proteasome system (UPS), regulates the sperm capacitation process,” Sutovsky said. “If it occurs inside female reproductive tract after AI, capacitation makes the sperm cells competent to fertilize an egg, but it kills them if it happens prematurely during semen processing and distribution. We discovered new factors that affect the process of sperm capacitation, including our groundbreaking discovery of zinc requirement for sperm survival after semen collection.

“Consequently, we observed that supplementing the AI doses with zinc increased their longevity and fertilizing ability. We termed this approach ‘zinc reloading’. Based on these advances, the goal of this renewed project is to harness the power of UPS and zinc reloading to develop semen extenders that will yield higher pregnancy rates after AI.”

Building on discoveries from previous funding period (2015-2020), Sutovsky added that this renewed project has an overarching goal of understanding of how UPS regulates in vitro capacitation (IVC) in livestock spermatozoa, specifically focusing on the recent discovery of new zinc-dependent pathway that intersects with UPS, and regulates sperm capacitation, as well as survival of spermatozoa collected and processed for livestock AI.

“Using primarily the domestic boar model, yet relevant to other livestock species, we set three specific objectives guided by extensive preliminary data supporting our hypothesis that zinc ion regulation is essential for sperm sustenance and fertilizing potential,” Sutovsky said. “The first objective is to establish zinc signature as a tool for semen analysis and sperm capacitation management. The second objective is to translate this knowledge into semen extenders optimized for sperm zinc and UPS management. The final objective is to characterize the zinc-interacting proteome of boar spermatozoa, with emphasis on UPS components dependent on zinc homeostasis.

“We will use state-of-the-art image-based flow cytometry for sperm zinc fluorometry, affinity purification of sperm zincoproteins by immobilized metal ion affinity chromatography coupled with mass spectrometry, and the zinc and proteasome optimized semen extender testing by in vitro fertilization and artificial insemination.”

Control of Pig Reproduction XI

The International Conference on Pig Reproduction (ICPR), to be held at “Het Pand” in the city center of Ghent, Belgium, will provide a unique setting for exchange and integration of research in state of the art fundamental and applied areas of pig reproduction. Prather said the focus on pigs is particularly relevant in that pork is the main source of protein consumed on a worldwide basis. Exchange of technical information and personal interactions between investigators is necessary to maximize advancements in reproduction of pigs.

Four of the 11 ICPR meetings have been hosted by the University of Missouri, including the last event, which was held in 2017.

“The main scientific program will include three sessions composed of four plenary presentations each dealing with Highly Prolific Sows (HPS); Genes, Genomes and Genetics; and Gametes, Embryos and Pregnancy,” Prather said. “Parallel sessions dealing with applied pig reproduction and state of the art topics will occur in the afternoon. The conference will provide a platform for information exchange between speakers and delegates for technology exchange that will increase swine reproductive efficiency, profitability and trade throughout the world.”

Prather added that the ICPR has established a tradition of holding meetings at four-year intervals to provide a forum to discuss the latest developments in pig reproductive biology and applied management. It is consistent with the Program Priority Area of Animal Reproduction since the major goal of this conference is to stimulate multi- and cross-disciplinary exchange of novel cutting-edge ideas between basic and applied scientists with the ultimate goal of improving reproductive efficiency in swine. Each day will include poster sessions focusing on each broad topic. Applied topics will cover a diverse array of subjects including but not limited to insemination protocols for frozen/thawed sperm, gene editing to prevent reproductive diseases, translational genomics, and group housing.

“The ICPR will provide an international scientific meeting of the highest quality and expertise,” Prather said. “The conference will provide a mixture of research topics in pig reproduction that address fundamental, state of the art and applied topics. The conference will provide a platform for information exchange between speakers and delegates for technology exchange that will increase swine reproductive efficiency, profitability and trade throughout the world.”