Nico Menjivar

Graduate Assistant - Tesfaye lab Biomedical Sciences


About Nico

Initially, Nico completed his B.S. in Animal Sciences at Colorado State University (CSU). Following his undergraduate studies, he then worked on his M.S. in Biomedical Sciences with a Specialization in Assisted Reproductive Technologies (ARTs) under the advisement of Dr. Jennifer Barfield. Today, he is a Ph.D. Candidate and USDA-NIFA-AFRI Predoctoral Fellow at the Animal Reproduction and Biotechnology Laboratory (ARBL) in the College of Veterinary Medicine and Biomedical Sciences (CVMBS), under the direct supervision of Dr. Dawit Tesfaye. His current research focus involves investigating the role of extracellular vesicle (EV)-mediated molecular signaling during oocyte and preimplantation embryo development and furthermore deciphering their molecular cargoes to engineer EVs for potential downstream application in ART procedures.


M.S., Biomedical Sciences, Assisted Reproductive Technologies. Colorado State University., 2020B.S., Animal Sciences. Colorado State University., 2019A.S., Animal Sciences. Connors State College, 2017


International Society for Extracellular Vesicles (ISEV)-Junior Member
American Embryo Transfer Association (AETA)-Student Member
Society for the Study of Reproduction (SSR)- Trainee Member
International Embryo Technology Association (IETS)- IETS Trainee Member
American Society of Animal Science (ASAS)-Graduate Student Member


Gad A, Menjivar NG, Felton R, Durrant B, Tesfaye D, Ruggeri E. Mapping the follicle-specific regulation of extracellular vesicle-mediated microRNA transport in the southern white rhinoceros (Ceratotherium simum simum). Biology of Reproduction. 2024:ioae081. Menjivar NG, Oropallo J, Gebremedhn S, Souza LA, Gad A, Puttlitz CM, Tesfaye D. MicroRNA Nano-Shuttles: Engineering Extracellular Vesicles as a Cutting-Edge Biotechnology Platform for Clinical Use in Therapeutics. Biological Procedures Online. 2024;26:14.Welsh JA, Goberdhan DCI, O'Driscoll L, et al. Minimal information for studies of extracellular vesicles (MISEV2023): From basic to advanced approaches [published correction appears in J Extracell Vesicles. 2024 May;13(5):e12451]. J Extracell Vesicles. 2024;13(2):e12404.Menjivar NG, Gad A, Thompson RE, Meyers MA, Hollinshead FK, Tesfaye D. Bovine oviductal organoids: a multi-omics approach to capture the cellular and extracellular molecular response of the oviduct to heat stress. BMC Genomics 2023; 24(1):646.Gad A, Joyce K, Menjivar NG, Heredia D, Rojas CS, Tesfaye D, Gonella-Diaza A. Extracellular vesicle-microRNAs mediated response of bovine ovaries to seasonal environmental changes. J Ovarian Res. 2023 May 23;16(1):101.Menjivar NG, Gad A, Gebremedhn S, Ghosh S, Tesfaye D. Granulosa cell-derived extracellular vesicles mitigate the detrimental impact of thermal stress on bovine oocytes and embryos. Frontiers in Cell and Developmental Biology; 11. Gebremedhn S, Gad A, Ishak GM, Menjivar NG, Gastal MO, Feugang JM, Prochazka R, Tesfaye D, Gastal EL. Dynamics of extracellular vesicle-coupled microRNAs in equine follicular fluid associated with follicle selection and ovulation. Mol. Hum. Reprod. 2023. Tesfaye D, Menjivar N, Gebremedhn S. Current knowledge and the future potential of extracellular vesicles in mammalian reproduction. Reprod. Fertil. Dev. 2021; 34(2):174–189.

Research Specialty

Reproductive Physiology