Date of this Version
2014 Nebraska Beef Cattle Report, UNL Extension MP99, pp. 11-13.
Within the University of Nebraska–Lincoln physiology herd, two sub-populations of cows with different concentrations of androstenedione have been identified. Androstenedione is a precursor for estradiol production, and androstenedione concentration is increased 24.5-fold in the high androstenedione cows. Our objective was to determine the cause of increased androstenedione production in high androstenedione cows and the effects on theca cell and oocyte gene expression. High androstenedione cows had increased steroidogenic enzyme abundance in theca cells and altered oocyte mRNA abundance. Increased androgen production in high androstenedione cows is associated with altered gene expression and/or mRNA stability during oocyte growth and maturation, which may reducefertility.