Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Bovine embryo”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1978

Non-surgical transfer of bovine embryos.

Bovine embryos obtained from donors six to nine days after oestrus were transferred non-surgically at a rate of one per recipient using a sterile insemination instrument, protected from contamination by the vagina with a plastic sheath. The percentage of recipients pregnant increased with the age of embryo transferred and for day 6 and 7 embryos was 33% compared to 58% for day 9 and 8 embryos. This difference approached statistical significance. Bacterial contamination of the instrument on withdrawal after transfer was not related to the success or failure of pregnancy. Maintenance of pregnancy to term and calving appeared to be normal. It is suggested that this method could be used for the routine transfer of eight and nine day embryos.

Animals↗
PubMed1979

Surgical and non-surgical transfer of bovine embryos.

Methods of transferring one bovine embryo to the ipsilateral uterine horn have been compared. In heifers mid-ventral surgical laparotomy under general anaesthesia (n=22) was compared with flank surgery with paravertebral anaesthesia (n=21). Pregnancy rate was higher with a midventral approach (P less than 0.05) (77.3 per cent of 42.9 per cent respectively). In heifers mid-ventral surgery (n=36) was compared with two methods of non-surgical transfer either using the Cassou insemination gun (n=36) or a modification of it (n=39) with embryos collected on days 7, 8 or 10 after oestrus. There were no differences in pregnancy rate between methods or different ages of embryos (methods: 55.6, 55.6, 43.6 per cent respectively; Day: 48.8, 55.8, 48.1 per cent respectively) but the condition score of recipients affected success (P less than 0.05). Of 10 cows which each received an embryo using the modified Cassou gun eight became pregnant.

Anesthesia↗
PubMed1978

Non-surgical recovery of bovine embryos.

The non-surgical recovery of bovine embryos was examined using a three-lumen PVC catheter passed to the tip of each uterine horn. The recovery of eggs placed in Dulbecco's phosphate buffered saline, with protein was very efficient whether in boiling tubes or funnels. In the absence of protein egg recovery was considerably lower. In a group of 42 heifers, superovulated on two occasions, embryos were recovered non-surgically on day 7 after the first superovulation (Day 0 = oestrus) and surgically after the second. Laparotomy was performed on each occasion and the number of corpora lutea counted. Ovulation rate was lower at the second superovulation and a correspondingly greater recovery of embryos was obtained surgically (P less than 0.02). Non-surgical recovery rates from anaesthetised cows and heifers and from standing sedated heifers were found to be similar. The distance of the catheter tip from the utero-tubal junction (UTJ) significantly affected recovery rate (P less than 0.001). Best results were obtained when the catheter tip was within 5 cm of the UTJ. Most embryos were recovered in the first 100 ml of recovered medium. The method compares favourably with other reported methods.

Anesthesia↗
PubMed2026

Rapid CRISPR-based bovine embryo sexing to streamline genotype-informed cattle breeding.

Cattle in vitro fertilisation and embryo transfer programmes increasingly rely on embryo-level selection to accelerate genetic gain, but current sexing and genotyping workflows can be costly, slow and logistically demanding. This study developed an efficient, low-resource workflow for bovine embryo sexing that combines whole genome amplification (WGA) with recombinase polymerase amplification-CRISPR-Cas12a (RPA-Cas12a). It also assessed whether the same WGA biopsy products could be used for downstream single nucleotide polymorphism (SNP) microarray genotyping. A one-tube RPA-Cas12a assay targeting the bovine Y-chromosome S4 repeat was developed for fluorescence and lateral flow assay (LFA) readouts. Analytical sensitivity was assessed using serially diluted bovine genomic DNA (gDNA), and breed robustness was tested using male and female gDNA from five major beef breeds and Holstein cattle. The workflow was then applied to WGA products from 22 bovine blastocyst biopsies, with sex calls validated against an established real-time PCR melt curve assay and 100K SNP microarray genotyping. The assay detected male bovine gDNA down to 100 pg using both fluorescence and LFA readouts, with no signal from female gDNA. Male-specific detection was consistent across all breeds tested. All WGA-RPA-Cas12a sex calls from blastocyst biopsies were concordant with real-time PCR and SNP microarray sex calls, and WGA biopsy products produced genome-wide SNP call rates above 85%. This workflow provides a practical approach for rapid bovine embryo sex triage and could reduce unnecessary cryopreservation and genotyping while improving the efficiency of genotype-informed cattle breeding programmes.

Bovine embryo↗
PubMedDate not supplied

[Preparation and characteristics of diploid cell strains from the tissues of a bovine embryo].

Two strains of diploid cells were prepared from the lung (BEL-2) and skin-muscle (SMBE-3) tissues of a bovine embryo. According to the results of morphological and karyological studies, these cultures consisted of fibroblast-like cells retaining diploid chromosome number (60) in the process of long-term cultivation. These cell populations have a limited life span (75-80 passages) and 3 growth phases. The species appurtenance of BEL-2 and SMBE-3 cells was confirmed. The cells were not contaminated with mycoplasma or extraneous viruses, had no tumorigenic activity. The BEL-2 cell culture is most susceptible to measles virus, SMBE-3 culture to vaccinia virus.

Animals↗
PubMed1977

Successful transfer of a bovine embryo through a cannulated fallopian tube.

The fallopian tubes of a recipient cow were surgically cannulated and the cannulae brought out through the flank. Two fertilised eggs, recovered surgically from a donor cow, were transferred to the uterus of the recipient cow through the cannulae. The recipient became pregnant and gave birth to a live normal female calf 289 days after the transfer. After the birth of the calf one cannula was found to be patent.

Animals↗
PubMedDate not supplied

Transcervical transfer of bovine embryos.

Six-to nine-day-old embryos collected either surgically or nonsurgically from superovulated donor cows were transferred transcervically to recipient cows. Polyethylene tubes and plastic insemination pipettes were used to transfer the embryos. When embryos were transferred under controlled conditions (laboratory transfer) to 12 recipients, 10 (83.3 per cent) and eight (66.7 per cent) were tested pregnant at 45 and 90 days after transfer respectively. When transfers were made to 12 recipients under field conditions (paddock transfer), nine (75 per cent) and five (41.7 per cent) were tested pregnant at 45 and 90 days after transfer respectively. The difference in pregnancy rates between laboratory and paddock transfers was not statistically significant.

Animals↗
PubMed1977

Electronmicroscopy of the replication of the ISU-2 strain of IBR/IPV-herpes virus in inoculated cultures of bovine embryo kidney (BEK) cells.

Studies on the replication of the ISU-2 strain of IBR/IPV-Herpes virus and on its behaviour in inoculated BEK cultures have shown that the replication of viral DNA as well as the production of icosahedral particles occur within the cell nucleus. Similarly like in each Herpes virus group, while passing through the nuclear envelope and the cell membrane the virus obtains an additional envelope that enlarges its diameter. The viral particles produced in a large quantity, may pass through the cell membrane into the extracellular spaces or may be caught by the cytoplasmic vacoules, where they are decomposed.

Cells, Cultured↗
PubMed2026

Epigenetic reduction OF H3K9me3 and H3K27me3 by RK-701 and GSK 126 improves the developmental competence of bovine SCNT embryos.

Somatic cell nuclear transfer (SCNT) failure has largely been attributed to incomplete epigenetic reprogramming, particularly the dysregulation of repressive histone modifications such as H3K9me3 and H3K27me3. Reducing these repressive marks has been shown to improve reprogramming efficiency in SCNT embryos. Although histone demethylase mRNA injection has been used for this purpose, it is labor-intensive, technically demanding, and time-consuming. In this study, we investigated a simplified approach that combined RK-701 and GSK-126 to reduce H3K9me3 and H3K27me3 levels, respectively, in bovine SCNT embryos. Three experimental groups were established: IVF embryos (control), SCNT-control (SCNT-C) embryos, and inhibitor-treated SCNT embryos (SCNT-T). The IVF group was used as a reference standard. Fused one-cell SCNT embryos were treated with 2&#x202f;&#x3bc;M RK-701 and 0.2&#x202f;&#x3bc;M GSK-126 from the one-cell stage to the 16-cell stage. Gene expression analysis at the 16-cell stage revealed a significant reduction in histone methyltransferase (HMT) expression (p&#x202f;<&#x202f;0.05), and immunofluorescence analysis confirmed marked decreases in H3K9me3 and H3K27me3 levels. In addition, the expression of genes associated with zygotic genome activation (ZGA) and pluripotency was significantly higher in SCNT-T embryos than in SCNT-C embryos. Assessment of blastocyst quality revealed reduced reactive oxygen species (ROS) levels, decreased expression of apoptosis-related genes, and improved mitochondrial membrane potential in the treated group, as indicated by JC1 staining. Overall, this approach effectively reduced repressive histone marks, enhanced epigenetic reprogramming, and improved ZGA, thereby increasing the developmental rate and adhesion potential of bovine SCNT embryos. These findings suggest that combined treatment with RK-701 and GSK-126 may provide a simple and practical strategy for improving the efficiency of bovine cloning.

Bovine embryos↗