Proteomic profile of vitrified in vitro-produced bovine embryos (Bos taurus indicus)

BACKGROUND

The proteomic profile of cryopreserved in vitro produced bovine embryos is little known but can provide insights on the successful application of cryo procedures in support of animal breeding.

OBJECTIVE

To identify embryonic proteins and biomarkers related to improved cryotolerance of vitrified in vitro produced bovine embryos.

MATERIALS AND METHODS

Proteins were isolated from embryo pools (n = 25 embryos per replicate) and analyzed using the nanoLC - MS/MS system. Further, the UniProtKB database (Uniprot -http://www.uniprot.org/) was used for protein identification. Proteins were classified based on their molecular mass, isoelectric point, and enzymatic activity. Post-translational modification predictions and functional gene ontology analysis were performed as well. Finally, a protein-protein interaction network was created to shed light on the embryo interactome.

RESULTS

Based on the MS/MS approach, 66 proteins were identified from vitrified Bos taurus embryos. The retrieved proteins were presumably annotated, which allowed a description of the qualitative and functional aspects of the embryo proteome after the vitrification process.

CONCLUSION

These findings allowed us to conclude that in vitro-produced vitrified embryos expressed proteins that underlie biological processes related to reproduction, stress and lipid metabolic process, which are essential to maintain embryo viability. doi.org/10.54680/fr22410110512.

Cryopreservation of Bovine Semen Using Extract of Bertholletia excelsa (Brazil Nuts)

BACKGROUND

Semen cryopreservation is essential in animal breeding programs for improving the availability of genetic resources from animals with high breeding value.

OBJECTIVE

To evaluate the addition of Brazil nut extract as a replacement for egg yolk in bovine semen cryopreservation.

MATERIALS AND METHODS

Semen was collected from five Nelore bulls and cryopreserved with the addition (treatments) of 0, 25, 50, 75, or 100% Brazil nut extract in the cryoprotectant medium. After thawing, spermatic cells were evaluated for morphology, plasma membrane integrity, spermatic kinetics, and in vitro fertilization. The experimental design was in randomized blocks, and the data were submitted to regression analysis.

RESULTS

The minor-type and total defects, and plasma membrane integrity were affected (P < 0.05) as a function of egg yolk substitution with Brazil nut extract. There was a significant effect (P < 0.05) of Brazil nut extract addition on the spermatic kinetics and cleavage rate.

CONCLUSION

The addition of Brazil nut extract in the cryoprotective medium as a substitute of egg yolk for freezing bovine semen negatively affects sperm quality and fertility.

The Addition of AçaÍ Palm Fruit Extract in the Cryopreservation Diluent of Bull's Semen with Low Performance on Freezing

BACKGROUND

Semen freezing is of great importance for animal production because it allows the use and the rapid diffusion of the genetic material from economically important animals.

OBJECTIVE

To evaluate the effect of açai (Euterpe oleracea; Arecaceae family) extract addition to the semen cryopreservation diluent on the morphology, sperm motility parameters, and plasma membrane integrity of spermatozoa.

MATERIALS AND METHODS

The ejaculates, obtained from five bulls with low performance on semen freezing, were fractionated and distributed according to the experimental group. The control samples did not have açaí extract added, whereas to the treated groups were added 5, 10, 15 or 20 mg ml^-1 of açaí extract into the semen diluent. The sperm morphology was evaluated with a formalin-saline-buffered solution. The plasma membrane integrity was evaluated by the epifluorescent test, while the cellular kinetics was assessed by an automated analysis of the spermatic movement.

RESULTS

The sperm defects showed a linearly decreasing effect (P < 0.05) with the addition of different concentrations of açaí extract. The plasma membrane integrity was higher (P < 0.05) after the açaí addition to the cryopreservation diluent. There was no significant effect (P > 0.05) of the açaí extract on the kinetics of spermatozoa.

CONCLUSION

The addition of açaí extract to the cryopreservation diluent provided better preservation of the structural integrity of the sperm plasma membrane in the bull's semen with low tolerance to the cryopreservation process.

Evaluation of morphology, morphometry and follicular dynamics in FecGE genotyped ewes

This study aimed to evaluate the effect of FecG^E mutation on the development of ovarian follicles. To this end, 42 Santa Inês ewes were genotyped for FecG^E mutation and classified as wild-type (FecG^+/+), heterozygous (FecG^+/E) or mutant homozygous (FecG^E/E). Ovarian fragments were processed, and the follicles were analyzed with regard to the morphology and morphometry using classical histology. For the evaluation of follicular dynamics, ewes underwent oestrous synchronization and were monitored throughout an interovulatory period. A higher (P < 0.05) percentage of morphologically normal follicles in the primordial stage was identified in FecG^E/E (90.0%) and FecG^+/E (88.1%) ewes than in the FecG^+/+ (73.0%) ewes. There was also a significantly greater (P < 0.05) number of morphologically normal follicles in the FecG^E/E (87.3%) and FecG^+/E (83.3%) ewes than in FecG^+/+ (76.8%) ewes in the transitional stage. A smaller (P < 0.05) diameter was observed in the secondary follicles in FecG^E/E (93.8 μm) ewes than in FecG^+/E (171.8 μm) ewes. Regarding follicular dynamics, FecG^E/E ewes showed a greater (P < 0.05) number of ovulations (2.5 ± 0.2) than FecG^+/+ ewes (1.5 ± 0.3) ewes. Ovulatory follicles were smaller (P < 0.05) in the FecG^E/E (5.1 mm) and FecG^+/E (5.2 mm) ewes than in FecG^+/+ (5.8 mm) ewes. Santa Inês nulliparous ewes carrying the FecG^E mutation showed a greater proportion of morphologically normal follicles in the primordial and transitional stages than those not carrying the mutation. FecG^E/E ewes demonstrated a higher number of ovulated follicles and that FecG^E/E and FecG^+/E ewes presented ovulatory follicles with a smaller diameter.

In Vitro and In Vivo Efficiency of Extenders Added to Thawed Stallion Semen

BACKGROUND

Addition of extenders to thawed semen could improve fertility.

OBJECTIVE

To determine the efficiency of extenders to increase viability of thawed semen, measured by sperm parameters in vitro and pregnancy rates after artificial insemination (AI).

MATERIALS AND METHODS

Sperm motility and acrosin activity were measured during a thermoresistance test (TRT).

RESULTS

Progressive motility decreased (P<0.05) after 30 min in thawing semen treated with saline solution (SS) and only after 60 min with Tyrode's solution (TS) or freezing diluent (FD). The total motility decreased (P<0.05) after 60 min in thawed semen treated with SS, and after 90 min in thawed semen containing TS or FD. The acrosin activity decreased (P<0.05) after 60 min during the TRT, but there was no difference among treatments throughout the TRT. The pregnancy rates were similar among thawed-semen supplemented with SS, TS or FD.

CONCLUSION

The extenders neither improve sperm parameters nor enhance AI results.

Variable Inter-assay Estimation of Sperm DNA Fragmentation In Stallions Classified as Good and Bad Semen Freezers

BACKGROUND

Semen cryopreservation causes DNA damage, thus requiring continuous monitoring.

OBJECTIVE

To compare two assays for sperm DNA fragmentation (SDF) from stallions with contrasting semen freezability.

MATERIALS AND METHODS

Thirteen stallions were classified as good semen freezers (GSF) or bad semen freezers (BSF). Ejaculates were cryopreserved with three diluents. Semen was subject to SDF evaluation using the sperm chromatin structure assay (SCSA) and Halomax after thawing (0 h) and after a 4 h thermoresistance test.

RESULTS

On semen of BSF, analysis by SCSA was similar between evaluations, but Halomax showed increased SDF at 4 h. The GSF group was similar between time points in both assays. Diluents did not affect SDF, irrespective of the assay. Halomax showed differences for BSF between time points, differently from SCSA. Linear regression did not show any correlation between assays.

CONCLUSION

The use of Halomax should be encouraged for sperm DNA fragmentation analysis in horse frozen-thawed semen, particularly under field conditions.