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Results for “Embryo Transfer”

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At least 55 records · Page 3Linked to original sources
PubMed1979

Time-dependent effects of alpha-amanitin on blastocyst formation in the mouse.

Early compacting mouse morulae were placed in alpha-amanitin at various times after HCG and the effect of this transcriptional inhibitor during formation of the blastocyst was noted. No cavitation was observed in those embryos transferred into alpha-amanitin before 77 h after HCG but the percentage of cavitation increased dramatically in those embryos transferred after 80 h post HCG. The large increase in amino acid incorporation which normally occurs during fomration of the blastocyst was blocked in those embryos placed in the inhibitor before 80 h post HCG. Two-dimensional polyacrylamide gel electrophoresis of radiolabelled embryos showed that the changes in synthesis of certain polypeptides normally associated with blastocyst formation did not occur in those embryos placed in alpha-amanitin before 80 h after HCG. Only one cleavage division appears to occur in the presence of alpha-amanitin. However, groups of embryos which had completed their fifth division before exposure to the drug subsequently were able to form blastocysts and showed the quantitative and qualitative changes associated with blastocyst formation despite the continued presence of the inhibitor. These results suggest that a critical transcriptional event concerned with blastocyst formation occurs around 80 h after HCG and may be associated with the fifth cleavage division.

Amanitins↗
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↗
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↗
PubMed1976

Jugular levels of 13, 14-dihydro-15-keto-prostaglandin F and progesterone around luteolysis and early pregnancy in the ewe.

Six non-pregnant ewes at day 12 of the estrous cycle each had a day-12 embryo transferred into the uterine horn ipsilateral to the corpus luteum, and 4 non-pregnant ewes at day 13 each had a day-13 embryo similarly transferred. Four control ewes, 2 at day 12 and 2 at day 13 received sheep serum into the uterine horn ipsilateral to the corpus luteum. Jugular blood samples were taken at 2-hourly intervals for 3 days post-surgery, then twice-daily for a further 4 days, and the plasma radioimmunoassayed for progesterone and 13, 14-dihydro-15-keto-prostaglandin F. All control ewes exhibited estrus within the expected time range and pulsatile peaks of 13, 14-dihydro-15-keto-prostaglandin F occurred coincident with declining progesterone levels. With one exception, the recipient owes had prolonged cycles and those ewes found pregnant at necropsy, 30 days after transfer, showed no progesterone decline and no pulsatile peaks of prostaglandin during days 12 to 16 after estrus. These observations suggest that the presence of the embryo at a critical stage after mating suppresses the release of uterine prostaglandin F2alpha.

Animals↗
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↗
PubMed1978

Effect of implantation delay on transfer of rat embryos to mice.

Rat and mouse blastocysts were transferred to the uteri of ovariectomized mice, maintained by progesterone for a few days and induced to implant by oestradiol administration. Mouse implantation sites contained normal embryos; all rat embryos were retarded, although some had developed to the egg-cylinder stage.

Animals↗
PubMed1977

Atresia coli in a twin calf.

Atresia coli was diagnosed in a newborn calf. The calf was an identical twin, as evidenced by identical blood type and identical electrophoretic patterns for hemoglobin, transferrin, and amylase. The other calf was clinically normal. The calves resulted from embryo transfer and represented cleavage of a single embryo in the recipient animal. These findings indicate atresia coli in this calf was probably not hereditary.

Animals↗
PubMed1979

Effects of age and parity on the breeding potential of mice with one or two ovaries.

Although removal of one ovary from young CBA/Ca mice and CFLP mice did not reduce the overall numbers of ova shed at ovulation, the total number of live offspring delivered during the lifespan was reduced to 65% and 50%, respectively, of control values. This reduction was due to fewer and smaller litters. The capacity of intact and unilaterally ovariectomized animals to support gestation of embryos transferred from young donors was tested to determine whether premature exhaustion of uterine function had occurred as a result of embryo overloading. An effect of breeding history on embryo survival to Day 19 of pregnancy was found after unilateral transfer, the least favourable sites for survival being the primigravid horns of ageing intact and unilaterally ovariectomized mice (0% and 1% survival, respectively, in CBA/Ca mice). The proportion of embryos surviving in multiparous horns of the one-ovary animals (24%) was greater than in horns of primigravidae and less than in horns of intact multigravidae of similar age and parity (48%). A larger proportion of ova survived in young uteri than in any of these aged horns. The results suggested that the normal decline with age in breeding potential is due to decreased uterine capacity and that the rate of loss is accelerated by both repeated embryo overloading and prolonged nulliparity, probably as a result of local factors. The decidual response was reduced in older animals, although there was no clear-cut variation with parity. Ageing uteri accumulated mass cells and macrophages, but the latter were abundant only in multiparous horns and were probably related to puerperal involutionary activities. There was no evidence that these changes in cell number or response were responsible for decreased gestational potential in ageing animals.

Animals↗
PubMed1992

Coping and the ineffectiveness of coping influence the outcome of in vitro fertilization through stress responses.

The effect of a coping-ineffectiveness of coping construct and of psychoendocrine stress responses upon the outcome of in vitro fertilization treatment was investigated in 40 women. Women with a high Zung depression score, high active coping, high avoidance, and a high expression of emotion have lower pregnancy rates. The mechanisms for this personality effect are not clear, although the desensitization-stimulation process (FSH, E2 concentrations) seems to be involved. The psychoendocrinological responses to the stress of oocyte retrieval and embryo transfer are important: Women with high anticipatory state anxiety levels and high anticipatory cortisol concentrations have lower pregnancy rates. The influence of prolactin stress concentrations is unclear: Women with high prolactin concentrations seem to have more oocytes but lower fertilization rates.

Adaptation, Psychological↗
PubMed2026

Hysteroscopic platelet-rich plasma and medically assisted reproduction outcomes: a systematic review and SWOT analysis.

BACKGROUND: Platelet-rich plasma (PRP) has been proposed as an adjuvant treatment in reproductive medicine. While most evidence refers to blind intrauterine instillation, subendometrial administration under hysteroscopic guidance allows targeted delivery under direct visualisation. This systematic review aimed to synthesise the available evidence on hysteroscopic PRP administration and its impact on clinical medically assisted reproduction (MAR) outcomes. METHODS: A systematic search was conducted from inception to December 2025 across major databases. Studies were included if they evaluated hysteroscopic PRP administration in women undergoing MAR, comparing reproductive outcomes between treated and control groups. RESULTS: Out of 142 records, 3 studies met the inclusion criteria. Study populations were heterogeneous and included women with refractory thin endometrium and/or a history of implantation failure. Hysteroscopic PRP administration protocols varied in timing, technique, and dosage. In a prospective case-control study, hysteroscopic intraendometrial PRP injection at a depth of 2-3 mm in the four uterine walls, using an ovum aspiration needle, on days 11-13 of the cycle prior to euploid frozen embryo transfer (ET), was associated with higher implantation (IR), clinical pregnancy (CPR), and live birth rates (LBR) compared with standard therapy. Conversely, no significant differences in CPR, miscarriage rate, or LBR were observed in an observational study evaluating a single intraendometrial PRP injection (35-40 mL, 2-3 mm depth), administered via endoscopic needle on days 6-8 of the menstrual cycle preceding frozen ET, alone or after electrical impulse therapy. A randomised controlled trial in women undergoing intrauterine insemination reported a significant improvement in CPR following hysteroscopic subendometrial PRP instillation in the four uterine walls (1.0 mL each). CONCLUSIONS: Current literature on hysteroscopic PRP administration in reproductive medicine is limited, and robust conclusions cannot yet be drawn. Well-designed randomised controlled trials with standardised protocols are needed to clarify its clinical role.

Humans↗
PubMed1976

In vitro fertilization, culture, and transfer of rabbit ova.

Ovulated rabbit oocytes were fertilized in vitro in chemically defined media supplemented with bovine serum albumin and either cultured up to the expanding blastocyst stage or transferred to recipients after varying periods of culture. Embryos transferred after up to 72 hours of in vitro culture were born as viable young. Oocytes from young virgin does were superior to oocytes from nonvirgin does for the purpose of in vitro fertilization (54% versus 26% fertilized, P less than 0.01). Capacitated sperm from artificially inseminated capacitators resulted in fertilization rates slightly lower than those from naturally mated does (46% versus 57% fertilized, P less than 0.025). Removal of cumulus and corona cells from oocytes with hyaluronidase and repeated aspiration through a fine pipette resulted in lowered fertilization rates (51% versus 73%, P less than 0.025). Linbro Disposo Tray wells were as good as glass tissue-culture dishes for the in vitro mixing of gametes and were more convenient to use. Modified Ham's F10 medium was used to culture the in vitro-fertilized embryos. However, when a modified Brackett's medium was used instead of modified Ham's F10 for the initial 4-hour period after mixing gametes, more oocytes were fertilized (52% versus 28%, P less than 0.01).

Animals↗
PubMed1978

Transfer to chick embryos of incompatible DNA.

After the transfer of chicken DNA to chick embryos incompatible at the B locus a retardation of growth was observed. Retarded differentiation of muscle fibres was histochemically detected in hatched chicks by the demonstration of enzymatic activities. The manifestations of apparent weakness of the dorsal muscles resembled a "myasthenia-like" syndrome. Infection with Marek's disease virus was not responsible for the damage caused by transferred DNA.

Animals↗