Trophoblastic disregulations in pregnancies resulting from transfer of cloned embryos in the bovine species

in 12e Colloque Scientifique de l'Association Européenne du Transfert Embryonnaire (1996)

Regulation de la croissance folliculaire et lutéale. 2. Ovulation, corps jaune et lutéolyse

in Point Vétérinaire (1996), 28

Field evaluation of pregnancy diagnosis using bovine pregnancy-associated glycoprotein (bPAG)

in Cattle Practice (1996), 4(3), 281-284

Production of anti-PMSG antibodies and its relation to the productivity of rabbit does

in World Rabbit Science (1996), 4(2), 57-62

Glycoproteins of the aspartyl proteinase gene family secreted by the developing placenta

in Advances in Experimental Medicine and Biology (1995)

Pregnancy in cattle and sheep can be diagnosed by the presence of placentally-derived antigens (pregnancy-associated glycoproteins or PAG-1) in maternal serum soon after implantation begins at about Day ... [more ▼]

Pregnancy in cattle and sheep can be diagnosed by the presence of placentally-derived antigens (pregnancy-associated glycoproteins or PAG-1) in maternal serum soon after implantation begins at about Day 20 following conception. Molecular cloning of their cDNA has revealed that PAG-1 belong to the aspartic proteinase gene family and have about 50% amino acid sequence identity to pepsin. However, critical amino acid substitutions at the active site regions suggest that both bovine and ovine PAG-1 are enzymatically inactive. PAG-1 expression has been shown by in situ hybridization and immunocytochemistry to be localized to the trophoblast binucleate cells, which invade maternal uterine endometrium during implantation. The glycoproteins are concentrated in dense cytoplasmic granules that are discharged after the binucleate cells have migrated to the maternal side of the placental barrier. We suggest, therefore, that the PAG-1 might have an endocrine function either as carriers of other bioactive peptides or by acting as hormones themselves. Recently screening of placental libraries with nucleic acid probes has identified additional cDNA that are very abundant and code for polypeptides (PAG-2 and PAG-3) related to, but antigenically and structurally distinct from PAG-1 described above. These molecules have sequences of amino acids at their catalytic centers that are consistent with their being potentially functional proteinases but their role during pregnancy, like that of PAG-1, is unclear. [less ▲]

Fractionation and partial characterization of proteins extracted from the bovine fallopian tube: preparation of tools for further purifications

in Theriogenology (1995), 44(1), 95-107

Described in the present paper is a combined biochemical and immunological approach to study oviductal proteins in the bovine. Antisera were raised against semi-purified proteins extracted from bovine ... [more ▼]

Described in the present paper is a combined biochemical and immunological approach to study oviductal proteins in the bovine. Antisera were raised against semi-purified proteins extracted from bovine tubal mucosal tissue and were characterized. These antisera are available to monitor puritications of specific oviductal proteins in the future. Oviducts from 170 cyclic cows were collected at a slaughterhouse, and high amounts of mucosal proteins were extracted. The proteins were fractionated after precipitation with ammonium sulfate, anti-bovine serum albumin (bSA) and anti-bovine immunoglobulins bIg) afiinity chromatography and ion exchange chromatography. Each of the 12 fractions obtained after ion exchange chromatography was used to immunize a rabbit. Conditioned media were recovered from bovine oviduct cell monolayers cultured without serum to cot&m the oviductal origin of the extracted proteins. After Western blot analysis, 15 proteins were detected in the bovine oviductal extracts, and their molecular weights and isoelectric points were determined by 2 dimensional electrophoresis. Among these 15 proteins, 11 were also detected in conditioned media of bovine oviductal cells. These results demonstrate an oviductal origin of the 11 detected proteins and strongly suggest their secretion by the oviductal cells. [less ▲]

Effects of fetal bovine serum, FSH and 17ß-Estradiol on the culture of bovine preantral follicles

in Theriogenology (1995), 44(2), 217-226

We describe a 7-d culture in droplets of collagen gel of isolated small bovine preantral follicles in medium with or without 10% fetal bovine serum (FBS). In addition, the effect of human recombinant FSH ... [more ▼]

We describe a 7-d culture in droplets of collagen gel of isolated small bovine preantral follicles in medium with or without 10% fetal bovine serum (FBS). In addition, the effect of human recombinant FSH and 17beta-estradiol on the morphology and growth of the preantral follicles was investigated in medium without FBS. After culture in medium with 10% FBS, the increase in follicle diameter was 13.1 +/- 8.4 microm, the percentage of BrdU-labeled cells was 49.9 +/- 11.3 and the number of cells per area granulosa was 11.1 +/- 1.8. Omission of serum from the culture medium had no effect on the percentage of labeled cells, but the diameter increase was lower and the cells were smaller. Apparently, serum affects the size of the granulosa cells from small preantral follicles rather than the stimulation of cell proliferation. Addition of human recombinant FSH and/or 17beta-estradiol to serum-free medium resulted in a larger diameter increase during culture compared with that of the control. With FSH, this was due to an increase in cell proliferation, while with estradiol this was caused by an increase in granulosa cell size. The effects of simultaneous treatment with FSH and estradiol was simply the combination of their individual effects. In conclusion, small bovine preantral follicles can be cultured for 7 d in the absence of serum and hormones. The follicles increase in diameter and react to FSH with enhanced cell proliferation and to estradiol with an increase in cell size. [less ▲]

Superovulation of goats with purified pFSH supplemented with defined amounts of pLH

in Theriogenology (1995), 43

The superovulatory response of goats treated with purified pFSH supplemented with 30, 40 or 50% pLH was compared. Sixty-four Boer goat does were synchronized by progestagen-containing ear implant ... [more ▼]

The superovulatory response of goats treated with purified pFSH supplemented with 30, 40 or 50% pLH was compared. Sixty-four Boer goat does were synchronized by progestagen-containing ear implant, randomly allotted to 3 groups and, beginning 2 d before implant removal, treated with purified pFSH supplemented with 30, 40 or 50% pLH. Each animal received 16 Armour Units of pFSH administered in 6 descending doses at 12-h intervals. Along with the last 2 injections, the does received 5 mg PGF(2alpha). Embryos were flushed either surgically or after slaughter on Day 5 or 6 after the last day of standing estrus. The percentage of animals responding to treatment was not different among groups treated with pFSH supplemented with 30, 40 or 50% pLH (76, 71 and 63%, respectively). The corresponding data for number of ovulations was 11.3 +/- 1.6, 16.3 +/- 1.8 and 16.4 +/- 2.6, for number of ova and embryos recovered 8.1 +/- 1.9, 12.0 +/- 1.5 and 13.5 +/- 2.9 and for number of transferable embryos 6.6 +/- 1.9, 9.1 +/- 1.5 and 7.1 +/- 2.1 (x +/- SEM). Results confirm the earlier finding of a good response of goats to pFSH preparations with a high FSH:LH ratio, and, although group differences were statistically nonsignificant (P > 0.05), they suggest that supplementation with approximately 40% pLH may be close to the optimum [less ▲]

Extracellular matrix proteins and basement membrane identification in bovine ovaries and significance for the attachment of cultured preantral follicles

in Theriogenology (1995), 43(5), 845-858

Described in the present paper is the immunolocalization of the extracellular matrix proteins (e.g., fibronectin, collagen Types I and III) in the bovine ovary, with special attention to preantral ... [more ▼]

Described in the present paper is the immunolocalization of the extracellular matrix proteins (e.g., fibronectin, collagen Types I and III) in the bovine ovary, with special attention to preantral follicles. In addition, we have shown, histochemically and ultrastructurally, that mechanically isolated bovine preantral follicles are surrounded by an intact basement membrane. After 24 h of culture in serum-free medium, only 20.4% of these follicles attached to a plastic substrate. We showed that covering the plastic with extracellular matrix proteins (i.e., fibronectin, collagen Type I and matrigel) significantly increased the percentage of attached follicles to 76.0, 65.2 and 80.4%, respectively, while laminin had no effect (18.6%). When preantral follicles were embedded within three-dimensional collagen gels, no loss of follicles was observed. Restoring surface interactions between preantral follicles and the extracellular matrix in vitro, either in a two- or a three-dimensional system, might be important for maintaining follicular viability and growth in the future. [less ▲]

Evaluation of cryopreservation techniques for goat embryos

in Reproduction Nutrition Development (1995), 35