Evaluation of dextran for rabbit sperm cryopreservation: Effect on frozen-thawed rabbit sperm quality variables and reproductive performance.

Effects were analysed of dextran supplementation to Me2SO and acetamide rabbit semen freezing extenders on quality characteristics of rabbit spermatozoa and reproductive performance. The final concentration of cryoprotectants in pooled semen samples was 12.4 % Me2SO for the A extenders, 10.7 % Me2SO and 2.9 % acetamide for the D extenders and 8.9 % Me2SO and 2.9 % acetamide in F extenders, with a supplementation of 1.7 % sucrose in all cases. There was not inclusion of dextran in the A0, D0, F0; while 5 % dextran was included in A5, D5, F5 and 10 % dextran in A10, D10 and F10 extenders. Sperm motility and viability rates were similar with use of the different extenders. Acrosome integrity after the freeze-thawing processes, however, was markedly greater when there was dextran supplementation of D and F extenders. Prolificacy was affected by extender composition. When there was artificial insemination (AI) using semen cryopreserved in the A extenders, number of kits born was similar to when there was AI with fresh semen when there was inclusion of 5% dextran for cryopreservation, while there was no effect on prolificacy when there was cryopreservation of semen using the D and F extenders. In conclusion, dextran supplementation of extenders containing Me2SO and acetamide resulted in greater acrosome integrity. Furthermore, when there was AI using sperm preserved in cryo-diluents containing an intermediate concentration of Me2SO, combined with inclusion of 5 % dextran, there was a marked beneficial effect on rabbit doe reproductive performance.

Long-Term Effects Following Fresh/Vitrified Embryo Transfer Are Transmitted by Paternal Germline in a Large Size Rabbit Cohort.

The concept of developmental programming suggests that the early life environment influences offspring phenotype in later life, whose effects may also be manifested in further generations. Valuable pieces of evidence come from the fields applying assisted reproductive technologies (ARTs), which deprive embryos of their optimal maternal environment and were thus associated with subsequent developmental deviations. Recently, we demonstrated that the in vitro manipulations during a vitrified embryo transfer procedure incurs a cumulative and transgenerational decline in the growth performance of the resulting offspring. Here, we provide a longitudinal study to investigate whether previous developmental deviations could be indistinctly paternally or maternally transmitted using crossbred mattings. Our findings revealed that early embryo manipulations through fresh and vitrified embryo transfer incurred paternally transmissible effects over the growth pattern and adult body weight, which seemed not inheritable via the female germline. Similar inheritable effects were observed after fresh and vitrified embryo transfer, suggesting that disturbing optimal embryo development through in vitro manipulations was the principal trigger of transmissible effects, rather than embryo cryopreservation per se.

Proteomic characterization of rabbit (Oryctolagus cuniculus) sperm from two different genotypes.

The present study was conducted to characterise rabbit sperm proteins focusing on the influence of the genetic origin. Six samples were recovered during two months from five males from genotype A (New Zealand White origin) and five from genotype R (California origin). Sperm proteins were extracted and subjected to in-gel digestion nano LC-MS/MS and bioinformatics analysis. The resulting library included 487 identified proteins validated with ≥95% Confidence (unused Score ≥ 1.3). All the identified proteins belonged to Oryctolagus cuniculus taxonomy. These data are available via ProteomeXchange with identifier PXD007989. Only 7 proteins were specifically implicated in reproductive processes according to Gene Ontology annotation. Regarding the comparison of the sperm proteins abundance between genotypes, forty proteins were differentially expressed. Among them, 25 proteins were over-expressed in genotype A, while 15 proteins were over-expressed in genotype R. In conclusion, this study characterizes for the first time rabbit sperm proteins and provides evidence that genotype is related to a specific abundance of spermatozoa proteins.