We study metabolic fetal programming related to maternal stress, placental insufficiency, and intrauterine growth restriction. In humans and companion animals, IUGR-born individuals (~10% of all US-born babies; ~25% worldwide) are at much greater risk for obesity, diabetes, hypertension, and other metabolic disorders that shorten life expectancy and reduced quality of life. In food animals, IUGR leads to less efficient growth and poorer carcass quality, which reduces the financial sustainability of meat animal production.
Our lab utilizes pregnant sheep and rodents as physiological models for humans and ruminant livestock species. We have developed research techniques to allow us to measure fetal physiological responses to maternal stress factors in real-time over the last trimester of pregnancy. In addition, we can study glucose metabolism in live animals, primary tissue samples, and cells cultures. A large factor in metabolic homeostasis is proper skeletal muscle growth, and we have developed ex vivo and in vitro protocols for measuring functional capacity of muscle stem cells, as well as microscopy and immunoblot techniques for determining muscle fiber dynamics.
Our long-term research goal is to identify the developmental adaptations that occur in utero in response to maternal stressors and then use those findings to develop postnatal nutritional/pharmacological intervention strategies for IUGR-born offspring.
Our approach encompasses investigation at 3 levels: the cellular/molecular level, the physiological system level, and the whole-animal level. The benefit of this approach is two-fold. First, our findings generate a broader understanding of the physiological issues that we study. Second, our grad students and undergrads gain experience in a wider range of research skills. It would not be uncommon for a lab member to feed and weigh sheep, stain tissue sections for microscopy, change media in cell cultures, perform a hormone assay on blood samples, surgically implant fetal femoral catheters, measure gene expression in isolated RNA, and attend a seminar by an internationally-recognized leader in the field all within a normal week. In addition, our grad students have the opportunity to develop teaching and lecture skills by acting as teaching assistants for Dr. Yates' Animal Physiological Systems course taught each Fall. TAs get hands-on experience in developing teaching materials and guiding 20 junior-level undergrads through hands-on learning activities once a week.
Overview of Research Topics
- Adaptive changes in adrenergic regulation of muscle growth and metabolism in IUGR fetuses
- Adaptive changes in cytokine/prostaglandin regulation of muscle growth and metabolism in IUGR fetuses
- Adaptive changes in immune cell populations in IUGR fetal skeletal muscle
- Mechanistic differences between β1 and β2 agonists in feedlot animals, especially regarding their effects on growth, metabolic phenotypes, and animal well-being
- Differences between long-term and intermediate-length maternal stressor on fetal metabolic and growth adaptations
- Interactions between adrenergic and inflammatory systems during fetal stress
Dustin Yates, PhD – Dr. Yates was born and raised in the small “Cotton & Cattle” town of Weinert, Texas in the west-central part of the state. He graduated from Texas A&M University in 2004 with a BS in animal science. After managing the graveyard shift in a large feedmill for a year, Dr. Yates returned to school at Angelo State University in San Angelo, Texas and earned a MS in reproductive physiology with Dr. Mike Salisbury in 2006. His Master’s thesis examined the mitigating effects of seaweed extract on heat stress-induced subfertility in male goats. Dr. Yates then joined the lab of Dr. Tim Ross at New Mexico State University and graduated with a PhD in reproductive physiology in 2009. His dissertation produced eight manuscripts related to stress-induced male and female subfertility. In 2010, Dr. Yates began a four-year postdoctoral research fellowship in the lab of Dr. Sean Limesand at The University of Arizona. During this time, Dr. Yates gained many of the research skills and techniques that his lab uses today. His research with Dr. Limesand produced several key new pieces of information regarding fetal programming of muscle growth and metabolism, as well as several novel laboratory and surgical techniques for studying fetal physiology. In March of 2013, Dr. Yates began his current faculty position at University of Nebraska - Lincoln as Animal Stress Physiologist in the Animal Science department. He is also a member of the Nebraska Center for Prevention of Obesity Diseases (NPOD). Dr. Yates and his wife reside in nearby Eagle, NE and have two wonderful young children, a couple dogs, and a 1962 Cadillac Fleetwood.
Eileen Marks-Nelson M.S.
Eileen is originally from Northeast Ohio. She was first introduced to research during her undergraduate degree in Psychology at Belmont University in Nashville, Tennessee. She then went on to complete her MS in Neuroscience under the mentorship of Dr. Jonathan Fox at the University of Wyoming in Laramie, Wyoming. Her Master’s thesis involved using a mouse model to study dysregulated brain iron homeostasis in Huntington’s disease. Eileen moved to Nebraska for a job opportunity at the beginning of 2013, and has extensive experience working in and managing research labs including a renal physiology lab in the Cellular and Integrative Physiology department at UNMC and the Sports and Exercise Nutrition lab in the department of Nutrition and Health Sciences here at UNL. She joined the Yates lab in 2019 with a lot of laboratory experience and no large animal experience and has enjoyed learning about sheep, which remind her of her Uncle Kenny’s small farm in Northern Ireland. When she’s not working Eileen spends her time with her husband and son and their two cats, and is always working to improve her photography, painting, drawing, embroidery, baking, and cooking skills.
Haley was born and raised on a secluded acreage on the outskirts of Chadron, Nebraska. Being immersed in diverse ecosystems growing up, Haley’s instilled reverence and captivation of wildlife led her to pursue a bachelor’s degree in Animal Science at the University of Nebraska-Lincoln. Although her emphasis primarily focused on companion animals, Haley unveiled a profound passion for conservation work during a semester abroad. Upon returning, she graduated and fortunately, was hired at the Lincoln Children’s Zoo as the primary avian keeper where she enjoyed learning more about animal behavior and teaching the public about the significance of conservation. In 2018, Haley was accepted at the University of Nebraska-Lincoln to pursue a master’s degree in Animal Science under Dr. Lisa Karr, where she studied the effects of chronic stress in captive and free-ranging giraffe. During her graduate program, the interest to continue researching stress deepened, guiding her to apply for a position in Dr. Yates’ lab. Haley ecstatically accepted a PhD position co-advised by Dr. Yates and Dr. Schmidt with plans to investigate the utilization of machine-learning technology for behavior quantification in captive animals.AWARDS:
2018 - M.J. Cooksley Memorial Travel Award
Shawna Clement earned bachelor's degrees in English and sociology from Doane College before she attended Nebraska College of Technical Agriculture and became a licensed veterinary technician. While in tech school, she worked as a tutor and developed a profound love of teaching. Thus, when presented with the opportunity to become an instructor for UNL's Professional Program in Veterinary Medicine (PPVM), she leapt at the chance. She is now a PPVM faculty member and teaches neuroanatomy, anatomical radiology, and medical terminology, and she acts as a lab instructor for gross anatomy. Her most recent degree is a Masters of Applied Science, which focused on animal anatomy and physiology. Shawna is grateful to be pursuing her PhD in Dr. Yates' lab. Her research projects include the implementation and testing of novel anatomical instructional techniques and the evaluation of infrared thermography as a means of detecting temperature stress in giraffes. Shawna and her husband live on an acreage where they run a senior dog sanctuary called “The Farm”.
Rachel grew up in Ballinger, Texas where her family raised Rambouillet and Southdown sheep. She was heavily involved in 4-H and FFA growing up where she primarily showed lambs and goats and competed in multiple judging events. Her strong agricultural background is what has fed her passion for the livestock industry and what ultimately led her to Texas A&M University following graduation from Ballinger High School in 2015. While at Texas A&M, she was a member of the 2016 National Champion Collegiate Wool Judging Team and served as the assistant coach for the 2017 Reserve National Champion Collegiate Wool Judging Team. In December of 2018 she graduated with honors with her Bachelors of Science Degree in Animal Science. Rachel's interest in research began throughout her last year at TAMU where she served as an undergraduate research assistant in a reproductive physiology lab where they studied the effects of gene editing on male fertility using mice as a model. Her interest in not only research with the use of large animal models but also in overall physiology is what led Rachel to the Yates lab. Rachel finished her MS in summer 2020 and chose to stay on in the Yates lab to complete her PhD.
Taylor Lacey, B.S. (M.S. expected 2022)
Although she grew in the agriculture-rich valley in the Northern California, Taylor’s path in animal science wasn’t always clear. Hailing from Oroville, California, Taylor’s initial interest surfaced after immense involvement in the FFA fueling a drive to pursue veterinary medicine. However, after working in a veterinary hospital and becoming involved with undergraduate research and teaching, Taylor’s interests became more fixated on biomedical rather than clinical. While completing her undergraduate education at California State University, Chico, Taylor worked in public relations for the college, served as a laboratory teaching assistant for undergraduate courses, managed youth-based veterinary science competitions, and coordinated agricultural education exhibits for the Silver Dollar Fair fueling a passion for animal science research and education. Upon graduation in May 2020, she graduated with a B.S. in Animal Science and a B.S. in Agriculture with an option in education before joining the Yates lab in June 2020. Taylor’s thesis project will focus on the effects of Omega-3 Polyunsaturated Fatty-acids on developmental pathologies in the IUGR fetal sheep.
Micah Most, B.S. (M.S. Expected 2022)
Micah Most grew up on a small family farm & ranch near Ogallala, Nebraska. His early exposure to beef cattle, farm dogs, barn cats, and later experiences with 4-H livestock projects led him to pursue a career working with animals. After a two-year detour as a biology/chemistry major at Concordia University- Nebraska, Micah transferred to the University of Nebraska- Lincoln in the fall of 2017. An Animal Science major with the Food Animal Production & Management option, he was involved in the Block and Bridle and CASNR Coffee Clubs while also working part time in the Ruminant Nutrition lab for Dr. Mary Drewnoski. Micah received UCARE funding for a summer 2018 undergraduate research project in the Stress Physiology lab, where he worked under the supervision of Dr. Dustin Yates— a formative experience that ultimately led him to graduate school. Upon graduating in December of 2019 with his Bachelor of Science in Animal Science degree, Micah spent the spring semester (and onset of the COVID pandemic) at home working on the family operation. His master’s journey in the Yates lab began in June of 2020. Micah’s current research centers around the effect of anti-inflammatory agents on heat stress pathologies in feedlot lambs. Micah hopes to someday return to western Nebraska in a position that keeps him involved in animal agriculture and research. In his free time, he finds joy in his faith, in gathering people around good food, and in curating his Spotify playlists.
Jesse Mandina (B.S. expected 2021)
Taylor Barnes, MS - Taylor grew up in Gretna, Nebraska surrounded by animals both large and small. She showed horses and other species in 4-H which sparked a passion for animal science and teaching at an early age. After two years at two other colleges, she made the move to UNL to study animal science which ended up sparking an interest in physiology classes. She had the opportunity to be a teaching assistant for three of those physiology classes. After graduating with her Bachelor's Degree in Animal Science in May 2016 she joined Dr. Yates and Dr. Jessica Peterson’s labs to earn her Master's degree in 2018. Her research involved looking at the effects of Zilmax and Ractopamine supplementation on muscle growth and metabolism. Taylor is currently pursuing her PhD at Texas A&M with the goal of obtaining an academic teaching appointment.
Joslyn Beard, PhD - Joslyn was born on a 2-acre farm just outside the city limits of Las Cruces, New Mexico were she developed a passion for the agriculture lifestyle growing up with cattle, sheep, and pigs. Having a desire for a career in veterinarian medicine, Joslyn attended New Mexico State University earning her Bachelor’s Degree in Animal Science in 2015. During her undergraduate career she found a passion for research while working for Dr. Hallford, and decided to switch paths and pursue a master’s degree at New Mexico State University. During her master’s program Joslyn served as the wool judging coach and a teaching assistant for the introductory animal science class. In regards to her research, she investigated the mechanisms involved with maternal stimuli during fetal development on beef progeny performance. At the end of her masters Joslyn’s interest in fetal programming only grew, and she sought out a greater understanding of the underlying mechanisms that affect animal performance based on insults received in-utero, which led her to UNL in January of 2018 where she is was co-advised by Dr. Yates and Dr. Mulliniks. Joslyn successfully defended her PhD thesis in November 2020 and is pursuing a career in research & extension.
Caitlin Cadaret, PhD - Caitlin found her passion for animal agriculture at a young age growing up on a part-time cow-calf operation in Northern California. While the original intent was to go to veterinary school, during her undergraduate career she found a special interest in Physiology and a desire to teach. After receiving her Bachelor’s Degree in Animal Science from California State University, Chico she joined the Yates lab in 2015. Caitlin completed a Master’s Degree in 2017 and continued onto a PhD looking at how maternal stress effects fetal growth, development, and metabolism. Part of Caitlin’s assistantship involves a 50% teaching appointment in which she teaches and performs pedagogical research aimed at increasing long-term retention of knowledge in the undergraduate Animal Physiological Systems course. Upon graduating with her PhD, Caitlin accepted an Assistant Professor position in the Animal Science department at Colorado State University.
Elena Merrick, MS - Elena grew up in the rural community of Danvers, Illinois. Elena began her college career at Eastern Wyoming College in Torrington, Wyoming where she received her Associate’s Degree in Animal Science. After, she decided to move back home to Central Illinois and attend Illinois State University where she received her Bachelor’s degree in Animal Science in May of 2015. In August of 2015, she started graduate school at UNL in Dr. Yates’s lab. Her research involved the effects of maternal stress on prenatal muscle development and glucose metabolism. She received her Master’s Degree in August 2017 and has since took a job in Extension Outreach in Central Nebraska.
Robert Posont, MS - Robert was born in Denver, Colorado before moving to a small acreage just outside of Lincoln, Nebraska in 2001. He grew up in rural Nebraska attending District 145 schools surrounded by his own pets, and working with the livestock of his neighbors. Robert found his true passion for animal agriculture and care in 2013 when he spent the Summer working as Wrangler at YMCA Camp Kitaki. Upon graduation from Waverly High School that same year he began his undergraduate degree at The University of Toronto. In May of 2017 Robert received his Honors Bachelor’s Degree with a double major in Animal Physiology and Health & Disease, and a minor in Immunology. During his final year of study Robert found himself drawn toward research in Comparative Endocrinology and Stress Physiology. In June of 2017 he joined Dr. Yates’ laboratory, and began his graduate career at the University of Nebraska-Lincoln. His current research involves the effects of maternal immunological activation and cytokine release on both fetal and lamb muscle development and metabolism. Robert is currently a PhD student at George Mason University/Research Fellow at the Smithsonian Conservation Biology Institute.
Rebecca Swanson, MS - Rebecca grew up in Vacaville, California on her family’s hobby ranch where she developed a passion for raising livestock. Her passion led to her involvement in FFA and the livestock show industry throughout high school and an opportunity to be employed at a custom butcher shop and commercial cow-calf operation. Upon graduating from high school, Rebecca attended California State University, Chico where she earned a B.S. in Animal Science and a B.S. in Agricultural Business. During her time at CSU, Chico, Rebecca was a Research Associate and Herdsmen at the University Farm Beef Unit. She held several Executive Board positions for the California Young Cattlemen’s Committee and the Chico State Young Cattlemen’s Association during her time as an undergraduate. Rebecca had the opportunity to work on several research projects and even lead a project during her junior and senior years. At the conclusion of the research project, she was able to present her research at WSASAS and several other meetings and classes associated with CSU, Chico. Rebecca was a member of the 2017 nationally ranked WSASAS Champion Academic Quadrathlon team. Rebecca’s passion for Animal Science Research and Education led to her decision to attend graduate school landing her in the Yates Lab at UNL. Rebecca is currently pursuing a PhD at Mississippi State University.
Visual Research Projects
- Posont RJ and Yates DT. 2019. Postnatal nutrient repartitioning due to adaptive developmental programming. Vet Clin Food Anim Pract (in press)
- Beard JK, Mulliniks JT, Yates DT. Function and dysfunction of fatty acid mobilization: a review. Diabesity (in press)
- Beede KA, Limesand SW, Petersen JL, Yates DT. 2019. Real supermodels wear wool: Summarizing the impact of the pregnant sheep as an animal model for adaptive fetal programming. Animal Frontiers (in press)
- Cadaret CN, Posont RJ, Beede KA, Riley HE, Loy JD, Yates DT. 2019. Maternal inflammation at mid-gestation impairs subsequent fetal myoblast function and skeletal muscle growth in rats, resulting in intrauterine growth restriction at term. Transl Anim Sci. (in press)
- Yates DT, Petersen JL, Schmidt TB, Cadaret CN, Barnes TB, Posont RJ, and Beede KA. 2018. ASAS-SSR Triennnial Reproduction Symposium: Looking Back and Moving Forward-How Reproduction Physiology has Evolved: Fetal origins of impaired muscle growth and metabolic dysfunction: Lessons from the heat-stressed pregnant ewe. J. Animal Sci. 96(7):2987-3002.
Cadaret CN, Yates DT. 2017. Retrieval practices are more beneficial to long-term information retention when spaced 5 days after introducing physiology topics compared to 1 day afterward. Adv. Physiol. Educ. (in press).
Cadaret CN, Beede KA, Riley HE, Yates DT. 2017. Acute exposure of primary rat soleus muscle to zilpaterol HCl (β2 adrenergic agonist), TNFα, or IL-6 in culture increases glucose oxidation rates independent of the impact on insulin signaling or glucose uptake. Cytokine. 96:107-113. PDF (681 kb)
- Posont RJ, Cadaret CN, Barnes TL, Yates DT. 2017. A potential role for mTORC1/2 in β2 adrenergic regulation of skeletal muscle glucose oxidation in models of intrauterine growth restriction. Diabesity. 3:9-12. PDF (639 kb)
- Yates DT, Cadaret CN, Beede KA, Riley HE, Macko AR, Anderson MJ, Camacho LE, Limesand SW. 2016. Intrauterine growth-restricted sheep fetuses exhibit smaller hindlimb muscle fibers and lower proportions of insulin-sensitive Type I fibers near term. Am J Physiol Regul Integr Comp Physiol. 310:R1020-1029. PDF (1,084 kb)
- Posont RJ, Beede KA, Limesand SW, Yates DT. 2018. Changes in myoblast responsiveness to TNFα and IL-6 contribute to decreased skeletal muscle mass in intrauterine growth restricted fetal sheep. Proc. West. Sect. Am. Soc. Anim. Sci. 2:S44-S47. PDF (380 KB)
- Barnes TL, Beede KA, Merrick EM, Cadaret CN, Cupp AS, Yates DT. 2018. Impaired muscle stem cell function in cows with high concentrations of androstenedione in their follicular fluid. Proc. West. Sect. Am. Soc. Anim. Sci. 2:S27-30. PDF (341 KB)
- Cadaret CN, Merrick EM, Barnes TL, Beede KA, Posont RJ, Peterson JL, Yates DT. 2018. Sustained maternal inflammation during the early third trimester yields fetal adaptations that impair subsequent skeletal muscle growth and glucose metabolism in sheep. Proc. West. Sect. Am. Soc. Anim. Sci. 2:S14-18. PDF ( )
- Merrick EM, Cadaret CN, Barnes TL, Beede KA, Yates DT. 2017. Metabolic regulation by stress systems in bovine myoblasts and ovine fetal skeletal muscle. Proc. West. Sect. Am. Soc. Anim. Sci. 68: 87-91. PDF (418 kb)
- Cadaret CN, Beede KA, Merrick EM, Barnes TL, Loy JD, Yates DT. 2017. Maternal inflammation at mid-gestation in pregnant rats impairs fetal muscle growth & development at term. Proc. West. Sect. Am. Soc. Anim. Sci. 68: 213-218. PDF (401 kb)
- Barnes TL, Kubik R, Cadaret CN, Beede KA, Merrick EM, Chung S, Schmidt TB, Petersen JL, Yates DT. 2017. Identifying hyperthermia in heat-stressed lambs and its effects on β agonist–stimulated glucose oxidation in muscle. Proc. West. Sect. Am. Soc. Anim. Sci. 68: 106-110. PDF (402 kb)
- Cadaret CN, Beede KA, Riley HE, Yates DT. 2016. Insulin-associated and insulin-independent impacts of β adrenergic agonists and pro-inflammatory cytokines on glucose metabolism in primary rat soleus muscle. Proc., West. Sect., Am. Soc. Anim. Sci. 67:115-119. PDF (624 kb)
University of Nebraska-Lincoln, Assistant Professor
Animal Functional Genomics
University of Nebraska-Lincoln, Professor
Reproductive Physiologist/Beef Physiologist
University of Arizona, Professor
Fetal Development and Growth