Gene expression profiles in the bovine corpus luteum (CL) of the estrous cycle and pregnancy: Possible roles of chemokines in regulating CL function during pregnancy

To determine functional differences between the corpus luteum (CL) of the estrous cycle and pregnancy in cows, gene expression profiles between the CL of the estrous cycle and pregnancy were investigated. A 15 K bovine oligo DNA microarray detected 138, 265 and 455 differentially expressed genes (>2-fold; P<0.05) in the bovine CL of 20-25, 40-45, and 150-160 days of pregnancy compared with 10-12 days of the estrous cycle. The different gene expression profiles may contribute to functional differences between the CL of pregnancy and the CL of the estrous cycle in cows. Chemokines including eotaxin and lymphotactin may regulate CL function during pregnancy. Bovine ovaries containing corpora lutea (CLs) were obtained from Japanese-Black cows in the institute ranch within 10-30 min of exsanguination. Tissue samples were collected from cows on 10-12 days of the estrous cycle (cyclic), 20-25, 40-45, and 150-160 days of the gestation (n=4 animals/stage). The day of artificial insemination was designated as day 1.