Seminal plasma and seminal plasma proteins added to bulk sorted sperm do not alter the mRNA expression of in vitro produced bovine embryos

Corpora lutea affect in vitro maturation of bovine cumulus-oocyte complexes and embryonic development after fertilization with sex-sorted or conventional semen

Influence of both the presence of a corpus luteum on the ovary and semen sex-sorting on development following in vitro fertilization is not yet conclusive. To determine the effect of these factors, 376 bovine oocytes were processed in vitro according to luteal presence on the ovary (CL+ and CL-) and type of semen used (sexed or conventional). Maturation rate was higher (P < 0.01) in CL- (136/138; 98.6%) than in CL+ (217/238; 91.2%). Cleavage rate was lower (P < 0.01) in CL+ with sexed semen (60/172; 34.9%) than in CL- with sexed semen (42/71; 59.1%), CL+ with conventional semen (47/66; 71.2%), and CL- with conventional semen (54/67; 85.1%). Compaction was similar (P = 0.69) in CL- (49/99; 49.4%) and CL+ (50/107; 46.7%). Blastulation rate was higher (P < 0.01) in CL- (26/99, 26.2%) than in CL+ (13/107; 12.1%) group. Expansion rate was higher (P = 0.01) in CL- (22/99; 22%) than in CL+ (11/107; 10.2%) group. Compaction rates were similar (P = 0.78) in sex-sorted (50/102; 49.0%) or conventional semen (49/104; 47.1%) groups. Blastulation was also similar (P = 0.91) with sex-sorted semen (19/102; 18.6%) and conventional semen (20/104; 19.2%). The rate of expanded blastocysts was similar (P = 0.89) in sex-sorted (16/102; 15.6%) and conventional (17/104; 16.3%) semen groups. In conclusion, the presence of CL can compromise maturation of the oocytes and their development, as a higher proportion of cleavage-stage embryos can be obtained with non-sexed semen with oocytes from ovaries without a CL.

Effects of sexed semen and interactive effects on commercial in vitro embryo production when oocytes are collected from cows of Bos indicus, and Bos taurus breeding and crossbred cows of these subspecies

A large scale commercial in vitro embryo production and in vitro fertilization record is reported when there was use of oocytes from Bos taurus (BT), Bos indicus (BI), and Bos Taurus/indicus (BT/BI) crossbred subspecies fertilized with sexed (SS) and conventional (CS) semen. The aim of the study was to analyze the impacts of use SS in a commercial embryo production center in Colombia. Non-pregnant (n=800), healthy, and estrous cycling BT, BI, and BI/BT crossbred cows were selected to be used as oocyte donors. Viable oocytes from 733 ovum pick up sessions in cows of the BT (4663) and BI (7305), BT/BI (3605) groups were matured and fertilized with frozen thawed semen from commercial sires. Of all cultured oocytes (n=15,573), 52.3% of the embryos (n=8607) underwent cleavage while 3062 (19.7%) developed to the blastocyst stage. For cows of the BT, SS and CS groups, there were similar cleavage rates; however, use of SS decreased blastocyst formation (15.6% versus 18.9%). In the BI group, use of SS increased cleavage rates (59.1% versus 53%, respectively) although there was no effect on blastocyst rate development (22.9% versus 21.9). In the BI/BT groups, use of SS decreased cleavage (44.4% versus 57.1%, respectively) and blastocyst rate development compared with the CS group (15.3% versus 20.1%, respectively). Data from this study indicate embryos from cows of the BT purebred or BI/BT crossbred had less in vitro developmental capacity compared to embryos derived from oocytes of cows that were purebred BI in tropical-subtropical regions.

Dimethylsulfoxide and conjugated linoleic acids affect bovine embryo development in vitro

Conjugated linoleic acids (CLA) are employed to overcome the bovine periparturitional negative energy balance. Especially of interest are trans10,cis12 -linoleic acid (t10c12-CLA) and cis9,trans11-linoleic acid (c9t11-CLA). Their impact on embryonic development, though, is not clear. Here, effects of both above-mentioned CLA on bovine in vitro-produced embryos were assessed. Zygotes (n = 2098) were allocated to one of seven groups: cultured with 50 or 100 µM of either c9t11-CLA or t10c12-CLA, with 14 or 28 mM DMSO or without supplement (control). Messenger RNA analysis of target gene transcripts (IGF1R, IGFBP2, IGFBP4, CPT2, ACAA1, ACAA2, FASN, SCD) via RT-qPCR was performed in single blastocysts. Cleavage rates did not differ, whereas development rates were decreased in both t10c12-supplemented groups in comparison to the unsupplemented group (31.7% ± 2.2 control vs 20.2% ± 2.0 50 µM t10c12 vs 21.0% ± 2.8 100 µM t10c12). Compared with the unsupplemented group, SCD was expressed at a lower level in embryos cultured with 50 µM c9t11-CLA. The relative amount of several transcripts was increased in embryos cultured with 14 mM DMSO in comparison to those that developed in the presence of 50 µM t10c12-CLA (IGFBP2, ACAA1, CPT2, FASN, SCD) or 50 µM c9t11-CLA (IGF1R, IGFBP2, ACAA1, CPT2, FASN, SCD). The molecular analyses show that CLA influence embryonic fat metabolism.