Effects of oocyte quality and semen donor on the efficiency of <i>in vitro</i> embryo production in cattle

Abstract

The aim of the study was to determine whether immature bovine oocytes selected by morphology and BCB test (brilliant cresyl blue) and used for in vitro embryo production would increase the blastocyst rate when inseminated with sperm derived from bulls of reduced in vitro fertilizability.To relate oocyte quality and bull effect to blastocyst quality, morphology, ability for hatching and caspase-3 activity (marker of apoptosis) were evaluated.Both, oocytes originating from BCB+ and from Control COCs exhibited higher cleavage and blastocyst rates (P<0.001) compared with BCB-oocytes. Signifi cant differences in cleavage and blastocyst rates between the two bulls were observed. The highest blastocyst rate was noticed for BCB+ oocytes, regardless the bull. Comparison of the caspase-3 activity shows a signifi cant overbalance of blastocysts with high caspase-3 activity, regardless the stage of blastocyst development and their origin. Thus, using excellent quality oocytes and sperm with reduced in vitro fertilizability it was possible to some extent to overcome bull effect on embryo production.

Brilliant Cresyl Blue Negative Oocytes Show a Reduced Competence for Embryo Development after In Vitro Fertilisation with Sperm Exposed to Oxidative Stress

“…oocytes compared with unstained oocytes [ 24 , 31 , 32 , 34 , 35 , 39 , 41 , 46 ]. However, in the present work and other studies [ 36 , 37 , 38 , 44 , 48 ] no significant differences between unstained oocytes and BCB-pos. oocytes were noticed.…”

Evaluation of changes arising in the pig mesenchymal stromal cells transcriptome following cryopreservation and Trichostatin A treatment

“…We observed that after re-placing in culture the cells maintained their phenotype although part of them did not attach which is a normal observation as around 1/5 of the frozen cells dies during the freezing/thawing procedure [ 43 ]. This method of freezing has been routinely performed in our laboratory to freeze somatic cells [ 44 , 45 ] and mesenchymal stem cells [ 46 ] used as donors of nuclei for somatic cell cloning purposes as well as VERO cells used as co-culture cells for bovine and goat embryo in vitro culture [ 47 , 48 ]. Presently the cooling protocol of MSCs from various tissues and species is mostly based on controlled freezing [ 49 ] although different approaches of cryopreservation of porcine MSC are rather scarcely described compared to other species.…”

Effect of Hyaluronan on Developmental Competence and Quality of Oocytes and Obtained Blastocysts fromIn VitroMaturation of Bovine Oocytes

“…IVF was performed according to our standard protocol that was previously described [ 20 , 21 ]. Briefly, after 22–24 hrs of maturation, the selected oocytes were fertilised using frozen semen from single bull.…”

“…After washing and partial deprivation of the expanded cumulus, the mature COCs were transferred in groups of 10 into 50 μ L of fertilisation medium. Gametes were incubated together for 18 to 21 h at 38.5°C under 5% CO 2 in air [ 20 , 21 ].…”

“…IVC and VERO cell preparation was performed according to our previously described standard protocol [ 20 , 21 ]. Briefly, at 24 h after fertilisation, the presumptive zygotes were transferred into 50 μ L drops of B 2 medium (C.C.D., Paris, France) under mineral oil.…”