Bulls managed on a negative plane of nutrition for 112 days have increased abundance of mammalian Target of Rapamycin (mTOR) in testicular biopsies

Authors: BOCHANTIN, KERRI - North Dakota State University; BOROWICZ, PAWEL - North Dakota State University; FLATEN, JORDAN - North Dakota State University; UNDERDAHL, SARAH - North Dakota State University; Crouse, Matthew; MCCARTHY, KACIE - University Of Nebraska; KASSETAS, CIERRAH - North Dakota State University; BAUMGAERTNER, FRIEDERIKE - North Dakota State University; MENEZES, ANA CLARA - North Dakota State University; KIRSCH, JAMES - North Dakota State University; DORSAM, SHERI - North Dakota State University; SEDIVEC, KEVIN - North Dakota State University; WARD, ALISON - North Dakota State University; CATON, JOEL - North Dakota State University; DAHLEN, CARL - North Dakota State University

Submitted to: State University Ag Report
Publication Type: Other
Publication Acceptance Date: 9/30/2021
Publication Date: 10/8/2021
Citation: Bochantin, K.A., Borowicz, P.P., Flaten, J., Underdahl, S.R., Crouse, M.S., McCarthy, K.L., Kassetas, C.J., Baumgaertner, F., Menezes, A.B., Kirsch, J.D., Dorsam, S.T., Sedivec, K.K., Ward, A.K., Caton, J.S., Dahlen, C.R. 2021. Bulls managed on a negative plane of nutrition for 112 days have increased abundance of mammalian Target of Rapamycin (mTOR) in testicular biopsies. 2021 North Dakota Livestock Research Report. 46-49. Available: https://www.ag.ndsu.edu/publications/livestock/north-dakota-livestock-research-report

Interpretive Summary:

Technical Abstract: The objective of this study was to evaluate the influence of divergent plane of nutrition on nutrient sensing pathways and androgen receptor abundance in testicular tissue of bulls. Angus bulls (n = 15; 4 to 5 years old) were randomly assigned to one of two treatments: 1) a positive plane of nutrition managed to gain 12% body weight (BW) over 112 d (POS, n = 8); or 2) a negative plane of nutrition managed to lose 12% BW over 112 days (NEG, n = 7). On day 113, testicular biopsies were performed on all bulls. Parenchyma tissue samples were fixed in formalin, embedded in paraffin, cut at 5 µm and placed on glass slides. Slides underwent processing followed by incubation with antibodies to mammalian Target of Rapamycin (mTOR), phosphorylated mTOR (p-mTOR), or androgen receptor (AR), followed by a fluorescent-tagged antibody. Slides were examined for fluorescent intensity of the specific antibody and optical density was quantified for three to five randomly selected images of seminiferous tubules. The number of Sertoli cells and germ cells within each seminiferous tubule were counted and a ratio of germ cells to Sertoli cells was calculated. No differences were observed between treatments for mTOR (P = 0.89), ratio of p-mTOR to mTOR (P = 0.32) and AR abundance (P = 0.64), or Sertoli and germ cell counts (P = 0.78, P = 0.35, respectively) within the seminiferous tubules. Similarly, no differences were observed in the interstitial space for mTOR abundance (P = 0.86) or AR abundance (P = 0.62). However, p-mTOR abundance tended to be increased in the seminiferous tubules (P = 0.06) and increased in the interstitial space (P = 0.004) of NEG bulls compared with POS bulls. These findings suggest that dietary factors influence testicular abundance of signaling proteins involved in metabolic function of the cell, potentially influencing the developing sperm and ultimately affecting sperm quality, sire fertility, or epigenetic messages carried by sperm to future offspring.