Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 3/8/2013
Publication Date: 7/8/2013
Citation: Rempel, L.A., Cushman, R.A., McDaneld, T.G., Miles, J.R., Kuehn, L.A., Lindholm-Perry, A.K. 2013. Lipogenic-associated gene activity of adipose tissue from beef heifers and relation to production and reproductive traits. Journal of Animal Science. 91 (E-Supplement 2):466 (Abstract #510).
Technical Abstract: Transition from adolescence to puberty is marked by changes in metabolic activity. Fatty acid synthase (FASN) catalyzes the de novo synthesis of fatty acids and increased expression has been linked to excess energy intake and obesity. The enzyme, DNA-protein kinase (DNA-PK) plays a role in DNA damage repair, but can also influence transcription of lipogenic genes, including FASN. The objectives of our study were to 1) evaluate the expression of these lipogenic-affiliated genes, FASN and DNA-PK, at one year of age and 2) evaluate their association with production and reproductive traits in crossbred heifers. Subcutaneous adipose tissue was collected at approximately one year of age from 130 crossbred beef heifers. Total RNA was extracted from adipose tissue and reverse transcribed to generate cDNA for real-time PCR. Raw expression data was log transformed and normalized against two housekeeping genes. Relative expression of FASN and DNA-PK were not correlated (P = 0.6148) with each other. The relationship between gene expression and growth and reproductive traits was modeled using a regression analysis with covariates heterosis and breed included. Relative expression of adipose FASN in beef heifers at one year of age had a positive association (P = 0.0028) with ADG (0.08 ± 0.025 kg) and weight at puberty (81.3 ± 26.54 kg). Similarly, relative DNA-PK expression was also positively associated (P = 0.0068) with ADG (0.12 ± 0.042 kg) and weight at puberty (139.7 ± 40.84 kg). Moreover relative DNA-PK expression at one year of age in beef heifers was positively associated (P = 0.0007) with age at puberty (73.1 ± 21.03 d) while a negative association (P = 0.0610) was observed with weight at first breeding (-37.7 ± 19.94 kg). Relative expression of FASN and DNA-PK in adipose from heifers at one year of age was related to growth parameters, however age at puberty and weight at first breeding were affiliated with DNA-PK expression only. DNA-PK may be contributing to metabolic gene activation, which influences growth and puberty. USDA is an equal opportunity provider and employer.