The effect of oviductal cells on in vitro maturation of canine oocytes in different culture media

Abstract

The aims of this study were to investigate the effect of oviductal cells on in vitro maturation (IVM) of canine oocyte in Tissue Culture Medium 199 (TCM-199) or synthetic oviductal fluid (SOF) supplemented with bovine serum albumin (BSA) or fetal calf serum (FCS) and to compare the maturation rates of oocytes from the diestrus and anestrus stages. Following ovariohysterectomy, 13 pairs of ovaries were collected from bitches in anestrus (n = 10) or diestrus (n = 3) and oocytes were harvested by slicing. The oviducts were flushed with TCM-199 containing 10% FCS and were scraped and squeezed into a tube in order to obtain oviductal cells. Selected oocytes were divided into groups for IVM over 48 h for each of the diestrus and anestrus stages as follows: Group Ia, SOF+BSA; Group Ib, SOF+BSA+oviductal cells; Group IIa, SOF+FCS; Group IIb, SOF+FCS+oviductal cells; Group IIIa, TCM-199+BSA; Group IIIb, TCM-199+BSA+oviductal cells; Group IVa, TCM-199+FCS; and Group IVb, TCM-199+FCS+oviductal cells. Afterwards, oocytes were fixed with acetic acid-ethyl alcohol and stained with aceto-orcein to determine nuclear maturation. When compared between anestrus and diestrus stages for all parameters (undetermined nuclear material, germinal vesicles, germinal vesicle break down, metaphase I, metaphase II, and degenerated) in different media, the differences were found to be significant statistically in Group IIa (22.9%) and Group IIIb (35.7%) for the germinal vesicle stage (P < 0.05) as compared to the other groups. In conclusion, in the oocytes obtained from bitches in diestrus and anestrus supplemented with FCS or BSA in SOF medium without oviductal cells, more positive effects were seen on canine oocyte maturation than with TCM-199 medium supplemented with same protein sources and oviductal cells.