Effects of Mixed Pasture Legume Phytoestrogens on Superovulatory Response and Embryo Quality in Angus Cows

Ovulation and artificial insemination rates have been observed to decrease in sheep and cows when exposed to dietary phytoestrogens at concentrations greater than 25 mg/kg DM. A grazing trial was undertaken to investigate the effects of coumestrol and other key phytoestrogens on the superovulatory response, embryo numbers and quality in beef cows grazing legume pastures. A 7-week controlled grazing trial was conducted with legume and ryegrass pasture treatments, with cows exposed to legumes at two timed treatments, 4 and 7 weeks. Twenty Angus cows were subjected to a conventional estrus synchronization and superovulation protocol. Embryos were recovered via conventional uterine body flushing 7 days post artificial insemination (AI). Numerous phytoestrogens were identified in both pasture and plasma samples, including coumestrol and formononetin. Concentrations of phytoestrogens in the pasture ranged from 0.001 to 47.5 mg/kg DM and 0 to 2.6 ng/mL in plasma. Approximately 50% of cows produced viable embryos 7 days post AI. A significant interaction between the effect of treatment groups on the embryo stage was observed (p < 0.05). The results suggest that concentrations of >25 mg/kg DM of phytoestrogens less than 20 days preceding AI may negatively affect oocyte developmental competence, reduce progesterone production and thus contribute to early embryonic loss.

Transcriptome profiling reveals superovulation with the gonadotropin-releasing hormone agonist trigger impaired embryo implantation in mice

Introduction

Superovulation is a critical step in assisted reproductive technology, but the use of human chorionic gonadotropin (hCG) as a trigger for superovulation can result in ovarian hyperstimulation. Thus, the use of Gonadotropin-releasing hormone agonist (GnRHa) trigger has been increasingly adopted, although it has been associated with a higher rate of pregnancy failure compared to natural cycles. This study aimed to investigate the effect of GnRHa trigger on embryo implantation in a mouse model.

Methods

Mice in the superovulation (PG) group were administered 7.5 IU of PMSG, followed by the injection of 3.5 μg of GnRHa (Leuprorelin) 48 h later, while mice in the control group (CTR) mated naturally. We compared the number of oocytes, blastocysts, and corpus luteum between the two groups and the implantation sites after the transfer of natural blastocysts. Ovaries, uterus, and serum 2 and 4 days after mating were collected for qRT-PCR, transcriptome sequencing, and hormone assays.

Results

The PG group had more oocytes, blastocysts, and corpus luteum after superovulation than the CTR group. However, the mRNA expression of leukemia inhibitory factor (Lif) and the number of implantation sites were reduced in the PG group. The ELISA assay revealed that superovulation increased ovarian estrogen secretion. The transcriptome analysis showed that superphysiological estrogen led to a response of the uterus to a high estrogen signal, resulting in abnormal endometrium and extracellular matrix remodeling and up-regulation of ion transport and inflammation-related genes.

Conclusion

Our findings suggest that a combination of PMSG and GnRHa trigger impaired embryo implantation in mice, as the excessive uterine response to superphysiological estrogen levels can lead to the change of gene expression related to endometrial remodeling, abnormal expression of uterine ion transport genes and excessive immune-related genes.

Ovarian dynamics in progesterone tablet-induced superovulation in goats assessed by magnetic resonance imaging

Controlled internal drug-releasing (CIDR) devices are commonly used for superovulation in goats. However, such devices are unavailable in some countries, including Japan. In this technical note, we aimed to explore the efficacy of an alternative superovulation protocol using progesterone tablets in goats. We employed intravaginal progesterone tablets (LUTINAS® Vaginal Tablet 100 mg) following a standard superovulation protocol. Additionally, we assessed the ovarian dynamics using 3T-magnetic resonance imaging (MRI) 1 day preceding the progesterone treatment (Day "-1") and 3 days before the end of treatment (Days 11-13). The ovarian monitoring was successfully performed in the short tau inversion recovery T2-weighted images of MRI, and ovulation was confirmed by the disappearance of follicles on Day 13 post-administration of the tablets. Immediately after ovulation, oviduct flushing yielded a substantial number of oocytes (13.5 ± 1.8 oocytes per animal). These findings provide evidence that the administration of progesterone tablets can serve as a viable alternative for inducing. Additionally, our findings suggest that 3T-MRI is a promising alternative to conventional ultrasonography for monitoring ovarian dynamics following superovulation in experimental goats.

Ovarian stimulation with excessive FSH doses causes cumulus cell and oocyte dysfunction in small ovarian reserve heifers

Excessive FSH doses during ovarian stimulation in the small ovarian reserve heifer (SORH) cause premature cumulus expansion and follicular hyperstimulation dysgenesis (FHD) in nearly all ovulatory-size follicles with predicted disruptions in cell-signaling pathways in cumulus cells and oocytes (before ovulatory hCG stimulation). These observations support the hypothesis that excessive FSH dysregulates cumulus cell function and oocyte maturation. To test this hypothesis, we determined whether excessive FSH-induced differentially expressed genes (DEGs) in cumulus cells identified in our previously published transcriptome analysis were altered independent of extreme phenotypic differences observed amongst ovulatory-size follicles, and assessed predicted roles of these DEGs in cumulus and oocyte biology. We also determined if excessive FSH alters cumulus cell morphology, and oocyte nuclear maturation before (premature) or after an ovulatory hCG stimulus or during IVM. Excessive FSH doses increased expression of 17 cumulus DEGs with known roles in cumulus cell and oocyte functions (responsiveness to gonadotrophins, survival, expansion, and oocyte maturation). Excessive FSH also induced premature cumulus expansion and oocyte maturation but inhibited cumulus expansion and oocyte maturation post-hCG and diminished the ability of oocytes with prematurely expanded cumulus cells to undergo IVF or nuclear maturation during IVM. Ovarian stimulation with excessive FSH is concluded to disrupt cumulus cell and oocyte functions by inducing premature cumulus expansion and dysregulating oocyte maturation without an ovulatory hCG stimulus yielding poor-quality cumulus-oocyte complexes that may be incorrectly judged morphologically as suitable for IVF during ART.

Cryopreservation and Transfer of Sheep Embryos Recovered at Different Stages of Development and Cryopreserved Using Different Techniques

This article presents data from experiments to determine the cryoresistance of Charollais sheep embryos, depending on the stage of embryo development and the method of freezing, as well as the results of embryo transfer. The study design consisted of a study on the cryopreservation of ewe embryos at different developmental stages (early, 2-8 blastomeric and late, at the morula/blastocyst stage), two cryopreservation protocols (slow freezing and ultra-fast vitrification), and embryo transfer of cryo- and fresh embryos. Embryos from Charollais sheep donors (n = 12) were recovered after induction of superovulation. The embryos were recovered surgically (laparotomy) on days 2 and 6 after insemination. Before there was transfer to recipients, part of embryos was cryopreserved using standard slow freezing and ultra-fast vitrification methods. The average ovarian response was 7.54 ovulations per donor, and 5.83 embryos per donor were collected. No effect of the cryopreservation method and embryo development stage on the preservation of the morphological structure of embryos was found. There were no significant differences in the survival rate of cryoembryos at different development stages, frozen using different techniques, and after transfer to recipients. Differences in cryoresistance between embryonic developmental stages in favor of the morula/blastocyst stage were found (survival after thawing 86.4% vs. 75.0% in early embryos). At different stages of development, the survival rate of fresh embryos (45.8%) compared to cryopreserved ones (30.2%) was significantly higher (p < 0.05), while among fresh ones, the best survival rate (50.0%) was observed after the transfer of morules and blastocysts.

The Use of a Brief Synchronization Treatment after Weaning, Combined with Superovulation, Has Moderate Effects on the Gene Expression of Surviving Pig Blastocysts

The combination of estrus synchronization and superovulation (SS) treatments causes alterations in ovarian and endometrial gene expression patterns, resulting in abnormal follicle and oocyte growth, fertilization, and embryo development. However, the impact of combined SS treatments on the transcriptome of the surviving embryos remains unidentified. In this study, we examined gene expression changes in day 6 blastocysts that survived a brief regimen of synchronization treatment combined with superovulation. The sows were included in one of three groups: SS7 group (n = 6), sows were administered Altrenogest (ALT) 7 days from the day of weaning and superovulated with eCG 24 h after the end of ALT treatment and hCG at the onset of estrus; SO group (n = 6), ALT nontreated sows were superovulated with eCG 24 h postweaning and hCG at the onset of estrus; control group (n = 6), weaned sows displaying natural estrus. Six days after insemination, the sows underwent a surgical intervention for embryo collection. Transcriptome analysis was performed on blastocyst-stage embryos with good morphology. Differentially expressed genes (DEGs) between groups were detected using one-way ANOVA with an un-adjusted p-value < 0.05 and a fold change </> 1.5. The effect of SO treatment on the number of altered pathways and DEGs within each pathway was minimal. Only four pathways were disrupted comprising only a total of four altered transcripts, which were not related to reproductive functions or embryonic development. On the other hand, the surviving blastocysts subjected to SS7 treatments exhibited moderate gene expression changes in terms of DEGs and fold changes, with seven pathways disrupted containing a total of 10 transcripts affected. In this case, the up-regulation of certain pathways, such as the metabolic pathway, with two up-regulated genes associated with reproductive functions, namely RDH10 and SPTLC2, may suggest suboptimal embryo quality, while the down-regulation of others, such as the glutathione metabolism pathway, with down-regulated genes related to cellular detoxification of reactive oxygen species, namely GSTK1 and GSTO1, could depress the embryos' response to oxidative stress, thereby impairing subsequent embryo development. The gene expression changes observed in the present study in SS7 embryos, along with previous reports indicating SS7 can negatively affect fertilization, embryo production, and reproductive tract gene expression, make its use in embryo transfer programs unrecommendable.

Effect of a neurokinin 3 receptor-selective agonist administration on the embryos recovered from superovulated cows

Superovulation (SOV) treatment of cows results in unovulated follicles and inconsistent quality of the recovered embryos. It has been demonstrated that luteinizing hormone (LH) secretion is suppressed during SOV treatment of cows, which may cause insufficient follicle development and variation in the development of recovered embryos and unovulated follicles. Pulsatile gonadotropin-releasing hormone/LH secretion is controlled by the activity of kisspeptin, neurokinin B, and dynorphin (KNDy) neurons in the arcuate nucleus in many mammals. Since neurokinin B promotes the activity of KNDy neurons, we hypothesized that senktide, a neurokinin B receptor agonist, has potential as a therapeutic drug to improve the ovulation rate and quality of recovered embryos in SOV-treated cows via stimulation of LH secretion. Senktide was administered intravenously (30 or 300 nmol/min) for 2 h, beginning from 72 h after the start of SOV treatment. LH secretion was examined before and after administration, and embryos were collected 7 d after estrus. Senktide administration increased LH secretion in SOV-treated cows. The ratios of code 1, code 1 and 2, and blastocyst stage embryos to recovered embryos were increased by senktide (300 nmol/min) administration. Moreover, the mRNA levels of MTCO1, COX7C, and MTATP6 were upregulated in recovered embryos of senktide (300 nmol/min)-administered animals. These results indicate that the administration of senktide to SOV-treated cows enhances LH secretion and upregulates the expression of genes involved in mitochondrial metabolism in embryos, thereby improving embryo development and embryo quality.

Factors affecting superovulation induction in goats (Capra hericus): An analysis of various approaches

Goats are generally called a "poor man's cow" because they not only provide meat and milk but also other assistance to their owners, including skins for leather production and their waste, which can be used as compost for fertilizer. Multiple ovulation and embryo transfer (MOET) is an important process in embryo biotechnology, as it increases the contribution of superior female goats to breeding operations. The field of assisted reproductive biotechnologies has seen notable progress. However, unlike in cattle, the standard use of superovulation and other reproductive biotechnologies has not been widely implemented for goats. Multiple intrinsic and extrinsic factors can alter the superovulatory response, significantly restricting the practicability of MOET technology. The use of techniques to induce superovulation is a crucial step in embryo transfer (ET), as it accelerates the propagation of animals with superior genetics for desirable traits. Furthermore, the conventional superovulation techniques based on numerous injections are not appropriate for animals and are labor-intensive as well as expensive. Different approaches and alternatives have been applied to obtain the maximum ovarian response, including immunization against inhibin and the day-0 protocol for the synchronization of the first follicular wave. While there are several studies available in the literature on superovulation in cattle, research on simplified superovulation in goats is limited; only a few studies have been conducted on this topic. This review describes the various treatments with gonadotropin that are used for inducing superovulation in various dairy goat breeds worldwide. The outcomes of these treatments, in terms of ovulation rate and recovery of transferrable embryos, are also discussed. Furthermore, this review also covers the recovery of oocytes through repeated superovulation from the same female goat that is used for somatic cell nuclear transfer (SCNT).

Potential role for human menopausal gonadotropin in ovine superovulatory regimens during the breeding season

Human menopausal gonadotrophin (hMG) has been reported to produce a comparable superovulatory response to that of follicle stimulating hormone (FSH). Furthermore, hMG has a long half-life as compared with FSH. The present study was designed to compare hMG administered once daily and FSH administered twice daily over a 4 - day period on superovulatory response of Suffolk ewes. During the mid-luteal phase, twenty-four Suffolk donor ewes received intravaginal sponges at day 0 for 12 days. The superovulatory regimens in the Control group (n = 12) and the Treatment group (n = 12) consisted of eight injections of FSH given at twice daily and four injections of hMG given at once daily, respectively. At day 13, the donor ewes were subjected to laparoscopic insemination. Embryos were recovered, classified, and transferred to recipient ewes at day 19. Pregnancy status was determined by ultrasound examination 40 days after transfer. Lambing rate was calculated after all the ewes had delivered. No significant differences were observed between the two groups in terms of the structures recovered, transferable embryos, degenerated embryos, unfertilized oocytes, pregnancy rate and lambing rate. The results showed that once daily injection of hMG can produce a comparable superovulatory response and embryo transfer outcomes to those obtained by twice daily injection of FSH over a 4 - day period. It is feasible that hMG is used to replace FSH and reduce the number of injection treatments in ovine superovulatory regimens.

Luteal Function, Biometrics, and Echotextural Attributes in Santa Inês Ewes Superovulated with Different Total Doses of Porcine Follicle-Stimulating Hormone

Premature regression of corpora lutea (PRCL) may adversely affect the outcome of hormonal ovarian superstimulation in small ruminants, and the total dose of exogenous gonadotropins used may be one of the causes of this condition. There were two major objectives of the present study: (1) to evaluate the effects of different superovulatory doses of porcine follicle-stimulating hormone (pFSH) on the biometry, blood perfusion (Doppler), and echotextural characteristics of luteal structures; and, (2) to determine the usefulness of biometric, vascular, and echotextural luteal variables, as well as measurements of circulating progesterone (P₄) concentrations for early detection of PRCL in superovulated Santa Inês ewes. Twenty-seven Santa Inês ewes received an intravaginal P₄-releasing device (CIDR) from Days 0 to 8 (Day 0 = random day of the anovulatory period). An IM injection of d-cloprostenol (37.5 μg) was given at the time of the CIDR insertion and withdrawal. On Day 6, all the ewes received 300 IU of eCG IM and were divided into three treatment groups (each n = 9): G100 (100 mg); G133 (133 mg); and G200 (200 mg of pFSH) administered IM every 12 h in eight injections. Transrectal ovarian ultrasonography and jugular blood sampling for serum P₄ measurements were performed on Days 11 to 15. On the day of embryo recovery (Day 15), all the ewes underwent diagnostic videolaparoscopy and were classified, based on their luteal characteristics, into three response groups: nCL (ewes with normal CL only); rCL (ewes with regressing CL only); and ewes with both nCL and rCL following the superovulatory regimen. Our present results indicate that the total pFSH doses of 100 mg and 200 mg result in similar ovulatory responses and luteal function/biometrics, although the percentage of donor ewes with nCL was greater (p < 0.05) for G100 compared with the G200 animals. An application of 133 mg of pFSH was associated with diminished luteogenesis. Lastly, circulating P₄ concentrations, ultrasonographic estimates of total luteal area, and CL pixel heterogeneity (standard deviation of numerical pixel values) are promising markers of luteal inadequacy in superovulated ewes.

Embryo production and transplantation in non-breeding season of meat sheep breeds by stimulating superovulation with different follicle-stimulating hormone preparations

The objective of this study was to investigate the response of Charolais and Ile-de-France meat sheep breeds to stimulate superovulation with various follicle-stimulating hormone (FSH) preparations. A total of 14 adult ewes of meat sheep breeds were used in our study as donors, including Charolais breed (n = 8) and Ile-de-France breed (n = 6). Donors ewes were randomly divided into two groups in equal numbers (first group, n = 7; second group, n = 7), every group included Charolais breed (n = 4) and Ile-de-France breed (n = 3). Ewes in the first group were treated with Folltropin-V (total dose of 200 mg per ewe, seven injections), and ewes in the second group were treated with FSH-P (total of 280 IU per ewe, six injections). Thirty-seven ewes of Edilbay breed used as recipients were divided into two groups (first group, n = 20; second group, n = 17). Our results showed that the number of corpora lutea in donor groups treated with Folltropin-V was significantly higher than in donor groups treated with FSH-P (p < .01). A greater number of embryos recovery and embryos suitable for transplantation were found in the first group compared with the second group of donors. After 30 days from transplantation, transabdominal ultrasonography showed that the presence of pregnancy in recipients groups was found in 16 recipient ewes (43.2%), in the first group of recipients were registered nine pregnant ewes of 20 recipient ewes (45.0%), and in the second group of recipients were registered seven pregnant ewes of 17 recipient ewes (41.2%). In conclusion, using Folltropin-V in Charolais and Ile-de-France meat sheep breeds is a more effective scheme for stimulating superovulation than using FSH-P.

Low-Dose Sodium Salicylate Promotes Ovulation by Regulating Steroids via CYP17A1

To meet the current demand of assisted reproduction and animal breeding via superovulation and reduce the impact of hormone drugs, it is necessary to develop new superovulation drugs. This study examined the role of inflammation and steroids in ovulation. Sodium salicylate can regulate inflammation and steroids. However, the effect of sodium salicylate on ovulation has not been studied. In this study, mice were intraperitoneally injected with different concentrations of sodium salicylate for four consecutive days. The effects of sodium salicylate on oocyte quality and on the number of ovulations were examined, and these effects were compared with those of pregnant horse serum gonadotropin (PMSG)/follicle-stimulating hormone (FSH) treatment. We found that low-dose sodium salicylate increased the levels of ovulation hormones and inflammation by promoting the expression of CYP17A1. Sodium salicylate had the same effect as the commonly used superovulation drug PMSG/FSH and reduced the histone methylation level. Sodium salicylate can promote ovulation in mice and Awang sheep. It can greatly decrease the use of hormone drugs, reduce breeding costs and physical impacts, and can thus be used for livestock breeding.

Adverse effect of assisted reproductive technology-related hyperoestrogensim on the secretion and absorption of uterine fluid in superovulating mice during the peri-implantation period

OBJECTIVES

This study aimed to investigate the potential mechanism of hyperoestrogensim elicited by ovulation induction affects endometrial receptivity and leads to embryo implantation abnormality or failure.

STUDY DESIGN

Establishment of ovulation induction mouse model. Changes in mouse body weight, ovarian weight, serum E2 level and oestrous cycle were observed. During the peri-implantation period, morphological changes in the mouse uterus and implantation sites and the localization and protein levels of oestrogen receptors ERα and ERβ, the tight junction factors CLDN3 and OCLN, the aquaporins AQP3, AQP4 and AQP8, and the sodium channel proteins SCNN1α, SCNN1β and SCNN1γ were observed. The expression and cellular localization of ERα, CLDN3, AQP8 and SCNN1 β in RL95-2 cell line were also detected by western blotting and immunofluorescence.

RESULTS

Ovarian and body weights were significantly higher in the 5 IU and 10 IU groups than in the CON group. The E2 level was significantly higher in the 10 IU group than in the CON group. The mice in the 10 IU group had a disordered oestrous cycle and were in oestrus for a long time. At 5.5 dpc, significantly fewer implantation sites were observed in the 10 IU group than in the CON (p<0.001) and 5 IU (p<0.05) groups. The probability of abnormal implantation and abortion was higher in the 10 IU group than in the CON and 5 IU groups. CLDN3, OCLN, AQP8 and SCNN1β in the mouse endometrium were localized on the luminal epithelium and glandular epithelium and expression levels were lower in the 10 IU group than in the CON group. The protein expression level of ERα was increased by 50% in the 10 IU group compared to the CON group. The expressions of CLDN3, AQP8, SCNN1β in RL95-2 cell line were significantly depressed by the superphysiological E2, ERα agonist or ERβ agonist, which could be reversed by the oestrogen receptor antagonist.

CONCLUSION

ART-induced hyperoestrogenism reduces CLDN3, AQP8 and SCNN1β expression through ERα, thereby destroying tight junctions and water and sodium channels in the endometrial cavity epithelium, which may cause abnormal implantation due to abnormal uterine fluid secretion and absorption.

Multiple ovulation and embryo transfer in sheep: Effects of embryo developmental stage and quality on viability in vivo under farm conditions

Multiple ovulation and embryo transfer (MOET) technologies are integral to genetic improvement programs in the sheep industries. Despite the protocols being well established, previous findings regarding the effects of embryo properties on MOET success remain contradictory. The objective of this study was to determine the effects of embryo developmental stage and quality on embryo viability following transfer to recipient ewes. Data including details of 377 embryos collected from 45 Merino donor ewes were obtained from MOET trials conducted on three separate farms on day 6 after laparoscopic artificial insemination (AI). A total of 270 embryos were classified as being of transferrable grade (grade 1: n = 233; grade 2: n = 37). One or two transferrable grade embryos were transferred to each of 256 synchronised recipient ewes and pregnancy diagnosis was performed on day 36 after embryo transfer. Embryos at the hatched blastocyst stage tended to have greater viability in vivo compared to embryos at the late morula stage (59.0 ± 10.6% vs. 36.2 ± 9.7%; P = 0.083). The viability of grade 1 embryos was greater than that of grade 2 embryos (53.6 ± 7.8% vs. 35.9 ± 10.2%; P < 0.05). The results suggest that the success of the MOET trials was influenced by the transfer of embryos at the late morula stage, almost half of which were classified as grade 2 embryos. These findings highlight the importance of following strict embryo quality grading criteria to inform the most economical management of recipient ewes and maximize pregnancy outcomes.

Expression profile analysis of sheep ovary after superovulation and estrus synchronisation treatment

Superovulation is a widely used reproductive technique in livestock production, but the mechanism of sheep's superovulation is not yet clear. Here, a method of superovulation and estrus synchronisation was used to treat female Duolang sheep. After treatment, there were significant differences in serum FSH and LH levels and the number of dominant follicles between the two groups of sheep. We identified a total of 5021 differentially expressed genes (11, 13 and 15 days after treatment) and performed RT‐qPCR analysis to identify several mRNA expression levels. GO and KEGG enrichment analysis revealed that differentially expressed genes were involved in the regulation of signalling pathways of follicular development, cell cycle, material synthesis, energy metabolism, such as COL3A1, RPS8, ACTA2, RPL7 RPS6 and TNFAIP6 may play a key role in regulating the development of follicles. Our results show a comprehensive expression profile after superovulation and estrus synchronisation treatment. We provide the basis for further research on breeding techniques to improve the ovulation rate and birth rate of livestock.

Plasma profile of follicle-stimulating hormone and sex steroid hormones after a single epidural administration of follicle-stimulating hormone via caudal vertebrae in Holstein dry cows

The conventional follicle-stimulating hormone (FSH) treatment for bovine superstimulation involves multiple intramuscular injections, which is stressful for animals and onerous. We herein investigated whether a single epidural injection of porcine FSH (pFSH) can induce superovulation and peripheral concentrations of pFSH and steroid hormones after the treatment in Holstein dry cows. We intramuscularly administered pFSH twice daily to three cows for 3 days (control) or a single epidural pFSH administration (epidural). Numbers of follicles (≥10 mm in diameter) at estrus and corpora lutea at luteal phase were counted by ultrasonography. Blood was sampled from 0 to 104 h after the first pFSH administration and plasma pFSH, progesterone, androstenedione, testosterone, and estradiol-17β concentrations were measured. Numbers of follicles (control: 18.3 ± 7.5, epidural: 15.7 ± 4.0; mean ± SD) and corpora lutea (control: 7.3 ± 4.2, epidural: 8.0 ± 2.6) were similar between both treatments. Plasma pFSH concentrations were higher in epidural than in control (p < 0.01). Although no significant differences were observed in progesterone, androstenedione, or estradiol-17β concentrations between the groups, testosterone concentrations were slightly lower with the epidural treatment than with the control treatment (p = 0.08). In conclusion, superovulation was induced by a single epidural injection of pFSH, which achieved higher pFSH level than the multiple injections in Holstein dry cows.

Ovarian response to P4-PGF-FSH treatment in Suffolk sheep and P4-PGF-PMSG synchronization in cross-bred ewes, for IVD and ET protocol

Background

The success of an embryo transfer protocol in sheep depends on many factors, but the choice of drugs for the desired superovulation as well as the conception rate (CR) are most essential. Reproductive activity in sheep is characterized by a seasonality influenced by several factors such as photoperiod, latitude, temperature, nutrition and breed. Reproductive seasonality and nutritional condition are the main factors that influence embryo production in sheep. In sheep, some anatomical peculiarities limit the application of traditional reproductive biotechnologies used in cattle.

Objectives

The aim of this study was to conclude on the effectiveness of a wider on farm in vivo embryo transfer development programme in Suffolk sheep by streamlining hormone therapies and optimizing technique.

Methods

A total number of 60 sheep and three rams were included in this study, divided into two groups (receptors and donors). Donor Suffolk sheep were treated for superovulation using the P4‐PGF‐FSH multiple ovulation embryo transfer (MOET) protocol, while the cross‐bred recipients’ group was synchronized with P4‐PGF‐PMSG.

Results

On the first day after superovulation, all ovaries had more than five dominant follicles, while corpora lutea were later observed in 83.3% sheep. The recovery rate was 83.3%, while 72.9% embryos were transferable. Embryos were transferred directly into recipients. Fertility after 30 days was 68.57%, lambing rate was 91.6% and CR was 62.85%. This study showed that veterinary drugs (P4, FSH, LH, PMSG, PGF) used for superovulation optimized by us were capable of producing by this improved technique the optimization of the reproduction indices at embryo‐transfer (ET) and to be able to be used successfully.

Conclusions

The application of an MOET protocol has a positive effect in the production of in vivo embryo production (IVD) embryos in Suffolk sheep and can guarantee the success of embryo transfer activity to ewes with lower genetic merit. Our research aimed at representing a model for sheep farms for a rapid improvement of productive traits.

Effects of Extra-Long-Acting Recombinant Bovine FSH (bscrFSH) on Cattle Superovulation

Over the last few years, several commercial FSH products have been developed for cattle superovulation (SOV) purposes in Multiple Ovulation and Embryo Transfer (MOET) programs. The SOV response is highly variable among individuals and remains one of the main limiting factors in obtaining a profitable number of transferable embryos. In this study, follicle stimulating hormone (FSH) from different origins was included in two SOV protocols, (a) FSH from purified pig pituitary extract (NIH-FSH-p; two doses/day, 12 h apart, four consecutive days); and (b) extra-long-acting bovine recombinant FSH (bscrFSH; a single dose/day, four consecutive days), to test the effects of bscrFSH on the ovarian response, hormone profile levels, in vivo embryo production and the pluripotency gene expression of the obtained embryos. A total of 68 healthy primiparous red Angus cows (Bos taurus) were randomly distributed into two experimental groups (n = 34 each). Blood sample collection for progesterone (P4) and cortisol (C) level determination was performed together with ultrasonographic assessment for ovarian size, follicles (FL) and corpora lutea (CL) quantification in each SOV protocol (Day 0, 4, 8, and 15). Moreover, FSH profiles were monitorised throughout both protocols (Day 0, 4, 5, 6, 7, 8, 9, 10, and 15). In vivo embryo quantity and quality (total structures, morulae, blastocysts, viable, degenerated and blocked embryos) were recorded in each SOV protocol. Finally, embryo quality in both protocols was assessed by the analysis of the expression level of crucial genes for early embryo development (OCT4, IFNt, CDX2, BCL2, and BAX). P4 and cortisol concentration peaks in both SOV protocols were obtained on Day 15 and Day 8, respectively, which were statistically different compared to the other time-points (p < 0.05). Ovarian dimensions increased from Day 0 to Day 15 irrespective of the SOV protocol considered (p < 0.05). Significant changes in CL number were observed over time till Day 15 irrespective of the SOV protocol applied (p < 0.05), being non- significantly different between SOV protocols within each time-point (p > 0.05). The number of CL was higher on Day 15 in the bscrFSH group compared to the NIH-FSH-p group (p < 0.05). The number of embryonic structures recovered was higher in the bscrFSH group (p = 0.025), probably as a result of a tendency towards a greater number of follicles developed compared to the NIH-FSH-p group. IFNt and BAX were overexpressed in embryos from the bscrFSH group (p < 0.05), with a fold change of 16 and 1.3, respectively. However, no statistical differences were detected regarding the OCT4, CDX2, BCL2, and BCL2/BAX expression ratio (p > 0.05). In conclusion, including bscrFSH in SOV protocols could be an important alternative by reducing the number of applications and offering an improved ovarian response together with better embryo quality and superior performance in embryo production compared to NIH-FSH-p SOV protocols.

Factors affecting outcomes of embryo transfer in dromedary camels: a retrospective study

The present study aimed to use a comprehensive approach for evaluating 12 factors related to embryo quality (shape, size and transparency), donors (age, ET type, number of recovered embryos and day of uterine flushing), recipients (age), males (age and individual variations), and environment (season and year) which could affect the outcome of ET in terms of pregnancy (PR) and pregnancy losses in dromedary camels. During three breeding seasons, 116 donors females were mated repeatedly at 12 to 14-day intervals by fertile camel males (n=33) without stimulation of the ovaries (WSPO). Superovulation (SPO ET) regimen was applied for each donor female twice or thrice per season. In the occasions of applying superovulation regimen, donor females having an ovulatory follicle were mated instead of GnRH administration and superovulation regimen was applied 4 days post-mating (MIX ET). The uteri of all donor females were flushed at Day 8 or 9 post-mating and a total of 2095 embryos were recovered and transferred individually to 924 recipient females. Pregnancy diagnoses were conducted at Day 10 after ET (Days 18 to 19 of gestation) by using progesterone assay and by transrectal ultrasonography (TRU) at Days 30 and 60 of gestation. By using logistic regression analysis, transparency of embryos and age of recipient females had significant effects on PR at Days 18 to 19 (P< 0.01), 30 (P < 0.01) and 60 (P < 0.01; P < 0.05, respectively) of gestation. The shape of embryos had significant effects on the PR at Days 30 (P < 0.05) and 60 (P < 0.01) of gestation. Type of ET and the breeding season (year) had significant (P< 0.05) effects on the PR at Day 30, while day of flushing had the same effect on PR at Day 60. Regarding the pregnancy losses, transparency and shape of the embryo, type of ET, breeding season had significant (P<0.05) effect on the late embryonic mortalities (LEM) and shape and season of year had significant (P<0.01 and P< 0.05, respectively) effect on LEM/early fetal mortalities (EFM). Regarding male individual factor, there was a tendency for a significant (P =0.055) effect of camel males on the PR at Days 18 to 19 and rate of LEM. In conclusion, transferring a spherical, transparent or a large-sized embryo (> 750 µm) into recipient females aging between 8 and 11 y could greatly improve the PR from Days 18 to 60 of gestation. Also, embryo recovered from donor females with Mix ET type or embryos sired by certain camel male or at Day 8 post mating of the donor could improve the two-month PR. In addition, transferring a transparent or spherical-shaped embryo or embryos recovered from donor females with SPO or Mix ET could reduce the pregnancy losses during the first two months of pregnancy.

A study of the factors affecting embryo yields and quality in superovulated Morada Nova ewes that underwent non-surgical uterine flushing

The present study compared the outcomes of in vivo embryo production in Morada Nova ewes subjected to either 9-day (G-9_SOV , n=21) or 12-day (G-12_SOV , n=21) progesterone (P₄ )-based estrus synchronization protocol coupled with superovulatory treatment with decreasing doses of porcine follicle-stimulating hormone (133 mg of pFSH given over 3 days). Non-surgical embryo recovery (NSER) was performed 6-7 days after the onset of estrus. Total antral follicle count doubled from the 1^st to the 6^th pFSH dose in both groups (P < 0.05). Estrus responses did not vary between the two groups of animals (95.2%). Corpora lutea (CL) were detected in 85.0% and 60.0% of ewes that previously manifested estrus behavior in G-9_SOV and G-12_SOV , respectively. NSER was successfully completed in 86.2% of ewes that had CL (P > 0.05). The mean number of CL per ewe/successfully flushed donor ewe was greater (P < 0.05) in G-12_SOV (12.3 ± 1.7/12.1 ± 1.9) than in G-9_SOV (7.9 ± 1.4/8.2 ± 1.6). Mean numbers of retrieved blastocysts and viable embryos were greater (P > 0.05) in G-12_SOV (5.8 ± 1.9 and 3.7 ± 1.7) than G-9_SOV (3.5 ± 1.1 and 0.8 ± 0.3, respectively). The total follicle count (all follicles ≥ 2 mm in diameter) at the 6^th pFSH dose (at P₄ -device removal) was positively correlated (P < 0.05) with the number of CL (r = 0.95) and viable embryos (r = 0.91) in G-12_SOV . The ewes with ≥ 10 CL (48% of all flushed donors) yielded 80.5% of viable embryos. In summary: i. Morada Nova ewes from G-12_SOV group had better superovulatory responses compared with G-9_SOV group; ii. total follicle count at the last pFSH dose was a good predictor of superovulatory responses only in the ewes primed with P₄ for 12 days; and iii. animals with ≥ 10 ovulations are main contributors to viable embryo production in Morada Nova ewes.

The efficiency of low-dose letrozole plus clomiphene citrate for ovulation induction in intrauterine insemination cycles: A randomized clinical trial

OBJECTIVE

To investigate if combination therapy with clomiphene citrate (CC) plus letrozole (L) was associated with a higher efficacy than L and CC alone in patients undergoing ovarian induction plus intrauterine insemination.

METHODS

The present multicenter randomized controlled clinical trial was performed between 2018 and 2020. Participants were randomized into three groups: L (n = 167; 5 mg/day), CC (n = 167; 100 mg/day), and L + CC (n = 167) (2.5 mg/day + 50 mg/day) from day 3. Ovarian stimulation was continued with the appropriate dose of gonadotropins daily starting from day 8 and continued until follicular size was 20 mm or more followed by administration of human chorionic gonadotropin (10 000 IU). Semen samples were prepared by direct swim-up technique.

RESULTS

In the CC group, gonadotropin dose was significantly higher but endometrial thickness was significantly lower compared with other groups. Number of follicles of 18 mm or more was significantly lower in the L group compared with the other two groups. Number of follicles less than 15 mm was meaningfully higher in the CC group compared with the other groups. In the L + CC group, total and largest follicular size, and the rates of chemical, clinical, and ongoing pregnancy, and live birth were significantly higher compared with other groups.

CONCLUSION

Combination therapy with L + CC was superior to either L or CC for achieving pregnancy in women undergoing ovarian induction plus intrauterine insemination.

A Short-Term Altrenogest Treatment Post-weaning Followed by Superovulation Reduces Pregnancy Rates and Embryo Production Efficiency in Multiparous Sows

Although embryo transfer (ET) is a biotechnology ready for the swine industry, there are factors to be solved, the availability of embryo donors as one. Multiparous sows as donors ought to be considered since weaning is a natural and efficient method for estrus synchronization. In addition, superovulation treatments at weaning are effective in increasing the efficiency of donor embryo production. However, ET programs typically require more donors than those available from a single weaning, imposing grouping several weanings to establish a batch for ET. Since short-term administration of Altrenogest is effective in delaying estrus after weaning without effects on ovulation and embryo development, we investigated how Altrenogest combined with superovulation would affect reproductive parameters and embryo quality and quantity of weaned multiparous donor sows. The sows were administered Altrenogest from the day of weaning for 14 (SS-14 group; N = 26), 7 (SS-7 group; N = 31) and 4 (SS-4 group; N = 32) days. The sows were superovulated with eCG 24 h after the last administration of Altrenogest and with hCG at the onset of estrus. Sows not treated with Altrenogest that were superovulated with eCG 24 h post-weaning and hCG at the onset of estrus (SC group; N = 37) and sows with natural estrus after weaning (C group; N = 34) were used as control groups. The percentage of sows showing estrus within 10 days was not affected by the treatment, but the interval from Altrenogest withdrawal to estrus was longer (P < 0.05) in the SS groups than the interval from weaning to estrus in the controls. SS treatments increased (P < 0.05) the percentage of sows with ovarian cysts and the development of polycystic ovaries. The pregnancy and the fertilization rates, and the overall embryo production efficiency were also negatively affected by the SS treatments (P < 0.05). Interestingly, almost 70% of the structures classified as unfertilized oocytes or degenerated embryos in sows from the SS groups were immature oocytes. In conclusion, although superovulation of weaned sows was highly efficient, short-term administration of Altrenogest in combination with superovulation had negative effects on most of the reproductive parameters assessed, particularly affecting the overall efficiency of pregnancy and embryo production.

Superovulation Does Not Alter Calcium Oscillations Following Fertilization

Superovulation is a common approach to maximize the number of eggs available for either clinical assisted reproductive technologies or experimental animal studies. This procedure provides supraphysiological amounts of gonadotropins to promote continued growth and maturation of ovarian follicles that otherwise would undergo atresia. There is evidence in mice, cows, sheep, and humans that superovulation has a detrimental impact on the quality of the resulting ovulated eggs or embryos. Here we tested the hypothesis that eggs derived from superovulation have a reduced capacity to support calcium oscillations, which are a critical factor in the success of embryo development. Eggs were obtained from mice that were either naturally cycling or underwent a standard superovulation protocol. The eggs were either parthenogenetically activated using strontium or fertilized in vitro while undergoing monitoring of calcium oscillatory patterns. Following parthenogenetic activation, superovulated eggs had a slightly delayed onset and longer duration of the first calcium transient, but no differences in oscillation persistence, frequency, or total calcium signal. However, in vitro fertilized superovulated eggs had no differences in any of these measures of calcium oscillatory behavior relative to spontaneously ovulated eggs. These findings indicate that although subtle differences in calcium signaling can be detected following parthenogenetic activation, superovulation does not disrupt physiological calcium signaling at fertilization, supporting the use of this method for both clinical and experimental purposes.

[Preparation of GH/tPA double transgenic mice and gene expression analysis]

OBJECTIVE

To obtain GH/tPA double transgenic mice, analyze the expression level of tissue plasminogen activator (tPA) in the mammary glands and observe the growth and development of the transgenic mice.

METHODS

We obtained the offspring mice of 2 tPA single transgenic mice (P03 and P05) mated with a female nontransgenic mouse by microinjection of linearized GH plasmid into the fertilized eggs and embryo transfer. PCR was used to detect the gene integration. The expression levels of tPA in single gene and double gene transgenic mice were compared using ELISA and Western blotting. We assessed the effects of GH gene transduction on the growth and development of the transgenic mice by observing body weight changes of the mice at each developmental stage.

RESULTS

A total of 286 fertilized eggs were collected from P03 mice, and after embryo transfer, 77 offspring mice were obtained, including 16 tPA single transgenic mice (7 male, 9 female) and 13 GH/tPA double transgenic mice (8 male, 5 female) as confirmed by PCR. The integration rate of the double genes was 16.9%. A total of 175 fertilized eggs were collected from P05 mice, and 34 offspring mice were obtained including 12 tPA single transgenic mice (5 male, 7 female) and 7 GH/tPA double transgenic mice (3 male, 4 female), in which the integration rate of the double genes was 20.6%. The highest expression level of tPA in the mammary gland was significantly higher in double than in single transgenic mice (674 μg/mL vs 82.5 μg/mL, P < 0.05). In the whole growth cycle of the mice, no significant difference in weight gain was observed in the single or double transgenic mice as compared with the na?ve mice (P>0.05).

CONCLUSION

We successfully prepared GH/tPA double transgenic mice, in which GH gene transduction significantly increases the expression level of target gene tPA without affecting the growth and development of the transgenic mice. This success suggests a promising approach to preparing transgenic animals for producing pharmaceutical proteins and the breeding of the transgenic animals.

Relationship of the Temperature-Humidity Index (THI) with Ovarian Responses and Embryo Production in Superovulated Thai-Holstein Crossbreds under Tropical Climate Conditions

Heat stress strongly negatively affects reproductive traits in dairy cattle. The purpose of the present study was to investigate the effect of heat stress in superstimulated Thai-Holstein crossbreds under tropical climate conditions. Data included 75 records from 12 superovulated Thai-Holstein crossbreds between 2018 and 2020. Cows were superstimulated with conventional treatment. The mean temperature-humidity index (THI) was evaluated for three data collection periods: during the 9, 21 and 42-day periods before the insemination day to determine the period in which THI mostly affected superstimulation responses. The THI levels/thresholds were determined and interpreted together with the superovulatory response. A significantly negative correlation was obtained for the THI during the period 9 days before insemination. Negative effects on the number of large follicles and corpora lutea began at a THI of 72 and were apparently severe after a THI of 77, similar to the ovulation rate, fertilized ova and transferable embryos (p < 0.05). Meanwhile, more degenerated embryos were found with THI values (p < 0.05). The superovulatory response in Thai-Holstein crossbreds under tropical climate conditions is highly affected by heat stress starting at a THI of 72 and becomes more severe at a THI higher than 77.

Nonsurgical Embryo Recovery as a Feasible Tool for Supporting Embryo Biobanks of Locally Adapted Brazilian Sheep and Goats

This study assessed the outcomes of nonsurgical embryo recovery (NSER) after superovulation (SOV) in five locally adapted Brazilian breeds of sheep and goats. The objective was to evaluate the feasibility and efficiency of using SOV combined with a less-invasive embryo collection technique for supplying the Brazilian animal gene bank with germplasm from specific genotypes of interest. Morada Nova (n = 20), Santa Inês (n = 20), and Somalis (n = 20) ewes received an intravaginal progesterone (330 mg) device for 9 days, while Canindé (n = 15) and Moxotó (n = 15) goats received an intravaginal medroxyprogesterone acetate (60 mg) device for 6 days. All females received 133 mg of porcine follicle-stimulating hormone (pFSH) administrated in six decreasing doses 12 hours apart, starting 60 hours before device removal, plus 37.5 μg of d-cloprostenol at the fifth and sixth pFSH dose. Donors in estrus were mated with fertile males. The corpora lutea (CL) number was assessed by ultrasonography 1 day before NSER. On day 6.5 or 7 after estrus, NSER was performed following hormonally induced cervical relaxation. A total of 97% of sheep and 90% of goats responded with estrus, and among those, 91% of sheep and 85% of goats presented a CL. In ewes, the numbers of CL were greater (p < 0.05) in the Santa Inês breed, while similar (p > 0.05) CL numbers were found among the goat breeds. All viable embryos were freezable (excellent and good quality) and the number per donor was 7.8 for sheep and 4.9 for goats. All parameters of NSER efficiency, embryo yield, and fertility post-NSER did not differ (p > 0.05) between breeds among each species. The SOV-NSER procedures applied for an embryo biobank supply of locally adapted Brazilian breeds of small ruminants were efficient regarding production of cryopreservable embryos, and preservation of donor fertility. Therefore, SOV followed by NSER is recommended for embryo biobank assembly in sheep and goats.

Superovulation with human chorionic gonadotropin (hCG) trigger and gonadotropin releasing hormone agonist (GnRHa) trigger differentially alter essential angiogenic factors in the endometrium in a mouse ART model†

Gonadotropin-releasing hormone agonists (GnRHa) are used as an alternative to human chorionic gonadotropin (hCG) to trigger ovulation and decrease the risk of ovarian hyperstimulation syndrome. GnRHa is less potent at inducing ovarian vascular endothelial growth factor (VEGF), but may also affect endometrial angiogenesis and early placental development. In this study, we explore the effect of superovulation on endometrial angiogenesis during critical periods of gestation in a mouse model. We assigned female mice to three groups: natural mating or mating following injection with equine chorionic gonadotropin and trigger with GnRHa or hCG trigger. Females were killed prior to implantation (E3.5), post-implantation (E7.5), and at midgestation (E10.5), and maternal serum, uterus, and ovaries were collected. During peri-implantation, endometrial Vegfr1 and Vegfr2 mRNA were significantly increased in the GnRHa trigger group (P < 0.02) relative to the hCG group. Vegfr1 is highly expressed in the endometrial lining and secretory glands immediately prior to implantation. At E7.5, the ectoplacental cone expression of Vegfa and its receptor, Vegfr2, was significantly higher in the hCG trigger group compared to the GnRHa group (P < 0.05). Soluble VEGFR1 and free VEGFA were much higher in the serum of mice exposed to the hCG trigger compared to GnRHa group. At midgestation, there was significantly more local Vegfa expression in the placenta of mice triggered with hCG. GnRHa and hCG triggers differentially disrupt the endometrial expression of key angiogenic factors during critical periods of mouse gestation. These results may have significant implications for placental development and neonatal outcomes following human in vitro fertilization.

Induction of oestrus by administering Inhibin antiserum along with equine chorionic gonadotropin in anoestrous bitches

As dogs experience oestrus only once or twice a year, it is necessary to establish an effective method of oestrous induction for efficient breeding. In the present study, we evaluated inhibin antiserum (IAS) on oestrous induction in anoestrous females. Bitches were administered 0.5 ml/kg IAS or a mixture of 50 IU/kg equine chorionic gonadotropin (eCG) and 0.5 ml/kg IAS and 500 IU human chorionic gonadotropin (hCG) administered 7 days after the mixture injection. As a control, bitches received 50 IU/kg eCG, with 500 IU hCG administered 7 days after eCG injection. Blood-tinged vaginal discharge, vulvar swelling, plasma progesterone concentrations and ovarian follicular development were assessed from day 0 to day 14. IAS alone injection did not induce oestrus in bitches at the anoestrous stage. Conversely, vulvar swelling, blood-tinged vaginal discharge and an estimated luteinizing hormone (LH) surge appeared on days 3-7, days 3-6 and days 7-9 after the IAS+eCG mixture injection, respectively, in all five bitches at the anoestrous stage. The average number of developing and ovulated follicles in bitches administered IAS+eCG was 8.8 and 9.6 respectively. A single eCG injection followed by hCG induced oestrous signs, with an average of 8.3 developing follicles and 4.5 ovulated follicles. This study revealed that IAS alone did not induce oestrus, but when IAS was used in combination with eCG, it induced oestrus and promoted a considerable number of ovulations in anoestrous dogs.

Ovulation induction is associated with altered growth but with preservation of normal metabolic function in murine offspring

OBJECTIVE

To study the effects of ovulation induction on mouse postnatal health, with a focus on growth pattern and glucose tolerance. To study the effect of ovulation induction on DNA methylation, we took advantage of the agouti viable yellow (Avy) mouse.

DESIGN

Animal study.

SETTING

University Setting.

ANIMALS

Agouti viable yellow (Avy) mice on a C57BL/6 background.

INTERVENTION(S)

Avy female mice were either allowed to mate spontaneously (control group, C) or after superovulation with 5 IU of PMSG and hCG (ovulation induction group, OI).

MAIN OUTCOME MEASURE(S)

Birth parameters and postnatal growth of the offspring were followed up to 29 weeks of age. Body composition analysis was performed by EchoMRI; fasting insulin, intraperitoneal glucose tolerance tests, and glucose-stimulated insulin secretion by beta cells were assessed to study glucose metabolism.

RESULT(S)

Mice born to superovulated dams had lower survival rates, shorter anogenital distances, and shorter crown-rump lengths. Female mice generated by OI weighed less at birth, whereas male mice generated by OI had lower weight gain and had reduced lean mass. Glucose parameters, including islet functions, did not differ between the groups. No difference in agouti coat color was noted between the groups.

CONCLUSION(S)

Ovulation induction resulted in mice having increased morphometric differences at birth and male mice showing reduced weight gain but no difference in glucose tolerance or agouti coat color.

A novel route of follicle-stimulating hormone administration with a split-single ischiorectal fossa in Thai-Holstein crossbred superovulation programs under heat stress conditions

The objectives of this study were to compare the efficiency of a split single injection of follicle-stimulating hormone (FSH) given by either intramuscular (split-single IM) or ischiorectal fossa (split-single IRF) injection to the traditional treatment and to determine the concentrations of FSH. The temperature and humidity index (THI) values were interpreted together with the ovarian responses and embryo characteristics. The ovarian responses in the split-single IRF group were similar to those of the control group (p > .05) but higher compared with the split-single IM group (p < .05). Higher peak levels of plasma FSH in the split-single IRF group did not differ compared with the control group (p > .05) but were lower in split-single IM administration (p < .05). The results showed a significant decrease in the numbers of large follicles and corpora lutea (CLs) in the moderate THI compared with low and high THI (p < .05). The high THI affected ovulation rate as well as the numbers of transferable embryos and degenerated embryos (p < .05). In conclusion, the split-single IRF administration had a comparable superovulatory response to the traditional twice-daily protocol. Moreover, the ovulation rate, ovarian follicle responses, and embryo quality were affected by heat stress.

Feasibility of Secondary Follicle Isolation, Culture and Achievement of In-Vitro Oocyte Maturation from Superovulated Ovaries: An Experimental Proof-of-Concept Study Using Mice

Fertility preservation through ovarian stimulation, aiming at cryopreserving mature oocytes or embryos, is sometimes unsuccessful. This clinical situation deserves novel approaches to overcome infertility following cancer treatment in patients facing highly gonadotoxic treatment. In this controlled experimental study, we investigated the feasibility of in-vitro culturing secondary follicles isolated from superovulated ovaries of mice recently treated with gonadotropins. The follicle yields of superovulated ovaries were 45.9% less than in unstimulated controls. Follicles from superovulated ovaries showed faster growth pace during the initial 7 days of culture and secreted more 17β-estradiol by the end of culture vs controls. Parameters reflecting the outcome of follicular development and oocyte maturation competence in vitro were similar between superovulated and control groups, with a similar follicle size at the end of culture and around 70% survival. Nearly half of cultured follicles met the criteria for in-vitro maturation in both groups and approximately 60% of those achieved a mature MII oocyte, similarly in both groups. Over 60% of obtained MII oocytes displayed normal-looking spindle and chromosome configurations, without significant differences between the groups. Using a validated follicle culture system, we demonstrated the feasibility of secondary follicle isolation, in-vitro culture and oocyte maturation with normal spindle and chromosome configurations obtained from superovulated mice ovaries.

Real-time assessment of the superovulatory effect of FSH and eCG with laparoscopy at different seasons in Akkaraman ewes

Conventional methods for determining the reproductive performance of sheep bred either after estrus synchronization during the breeding season or after induction of estrus/ovulation during the non-breeding season take a long time and may give misleading results due to the effect of environmental factors. Laparoscopic observations allow real-time monitoring of ovarian activity around estrus or ovulation. This study was aimed at assessing the superovulatory effects of follicle-stimulating hormone (FSH) and equine chorionic gonadotropin (eCG) treatments by laparoscopy during breeding (September-November, n=12) and non-breeding (April-June, n=12) seasons in Akkaraman sheep. In both seasons, after CIDR withdrawal, the ewes were injected either with 600 IU eCG or 300 μl (20 mg/ml) FSH twice at 12 hour intervals. Plasma P4, E2 and LH concentrations were determined at the time of intra-vaginal CIDR insertion (day 0) and then at its withdrawal (day 12), followed by 3 and 6 days of eCG or FSH injections. After 3 (first observation) and 6 (second observation) days of hormone injections, laparoscopy was performed to record ovarian activity in both seasons. The eCG increased (p⟨0.05) the numbers of large follicles (first observation) and CL (first and second observations) in the breeding season compared to FSH treatment. CL, small-moderate and large follicle numbers of eCG treated ewes were higher (p⟨0.05) than those of FSH at both observations in the non-breeding season. In the breeding season, eCG treated ewes had higher (p⟨0.05) plasma P4 (3 and 6 days after hormones injections) and E2 (3 days after hormones injections) concentrations than those of FSH. In conclusion, the results of the present study indicate that treatment with eCG during the non-breeding season can support ovarian activity, and thus increase ovulation rate and plasma hormone concentrations around induced estrus/ovulation in Akkaraman ewes.

Superovulation with gonadotropin-releasing hormone agonist or chorionic gonadotropin for ovulation trigger differentially affects leukocyte populations in the peri-implantation mouse uterus

OBJECTIVE

To investigate the effect of superovulation with human chorionic gonadotropin (hCG) or gonadotropin-releasing hormone agonist (GnRHa) trigger on leukocyte density and expression of leukocyte-specific genes in the peri-implantation period in the mouse uterus.

DESIGN

Laboratory research.

SETTING

University laboratory facility.

INTERVENTIONS

Female mice were mated to fertile male mice in one of three protocols: (1) natural mating or mating following injection with pregnant mare serum gonadotropin followed by trigger with (2) GnRHa or (3) hCG. Female mice were killed prior to implantation, 3 days after ovulation (E3.5), and the ovaries and uterine tissue were collected. Total RNA was isolated and assayed using quantitative reverse transcription polymerase chain reaction, and the uterine tissue was stained for histologic analysis of immune cell markers.

MAIN OUTCOME MEASURES

Endometrial leukocyte (CD45) and vessel density (CD31) by immunohistochemical staining; expression of leukocyte markers CD11b, CD335, and CD22, by quantitative reverse transcription polymerase chain reaction in the whole uterine tissue.

RESULTS

Superovulation decreased (compared with controls) the endometrial leukocyte density, based on the number of cells staining for CD45, and endometrial vessel density, based on the number of cells staining for CD31. Leukocyte density was additionally decreased in the GnRHa trigger group compared with that in the hCG trigger group. Superovulation with hCG and GnRHa triggers decreased the uterine expression of the B-cell marker CD22 compared with controls. The expression of the natural killer cell marker CD11b was decreased by the hCG trigger but not by the GnRHa. Abundance of mRNA encoding the CD335 natural killer cell marker was not affected by superovulation or trigger agent.

CONCLUSIONS

In mice, superovulation with the GnRHa trigger compared with that with the hCG trigger differentially alters key immunologic factors in the uterine peri-implantation. These altered immunologic factors have roles in angiogenesis that may assist in elucidating the effects of assisted reproductive technologies on implantation efficiency and fetal growth and development.

NonSurgical Embryo Recovery from Estrus-Synchronized or Superovulated Morada Nova Ewes: A Feasible Strategy for Sheep Embryo Banking

This study assessed the feasibility of in vivo embryo production and nonsurgical embryo recovery (NSER) in Morada Nova ewes (an endangered native Brazilian breed of sheep) subjected to different estrus synchronization and/or superovulation protocols. Ewes received intravaginal sponges soaked with 60 mg medroxyprogesterone acetate (MAP), which were kept in place for six (G6; n = 12), nine (G9; n = 12), or 12 (G12; n = 12) days. Half of the ewes in each group remained estrus synchronized only (_SYNCH) and the other half was superovulated (_SOV) with 133 mg porcine follicle-stimulating hormone (pFSH). There were no differences (p > 0.05) in antral follicle counts determined with ultrasonography 60 hours before MAP sponge removal (or at the time of the first pFSH dose) among G6 (6.4 ± 0.9), G9 (6.2 ± 0.7), and G12 (5.5 ± 0.6). Estrus responses and NSER success rates did not vary (p > 0.05) among the three progestin-treatment groups of ewes for either estrus-induced or superovulated animals. The onset of estrus occurred 10-12 hours later (p < 0.01) in G9_SYNCH ewes compared with G6_SYNCH and G12_SYNCH, and the duration of estrus was ∼19 hours greater (p < 0.01) in G9_SOV than in G6_SOV. The average duration of the NSER procedure was 32.6 ± 1.3 minutes. At least one structure was recovered in 85.7% of synchronized and in 87.5% of superovulated ewes. Viable embryo recovery rates were also similar (p > 0.05) for G6 (1.0 ± 0.3 and 2.5 ± 1.5), G9 (1.3 ± 0.5 and 4.8 ± 2.0), and G12 groups (1.0 ± 0.3 and 4.8 ± 2.3; estrus-synchronized and superovulated ewes, respectively). In conclusion, progestogen pretreatment of different durations and NSER can be employed in Morada Nova ewes, resulting in reasonable viable embryo recovery rates in both estrus-synchronized and superovulated animals. Therefore, both techniques are suitable for use in commercial settings as well as small ruminant conservation programs.

Sire contribution to fertilization failure and early embryo survival in cattle

Despite passing routine laboratory tests of semen quality, bulls used in artificial insemination (AI) exhibit a significant range in field fertility. The objective of this study was to determine whether subfertility in AI bulls is due to issues of sperm transport to the site of fertilization, fertilization failure, or failure of early embryo or conceptus development. In experiment 1, Holstein-Friesian bulls (3 high fertility, HF, and 3 low fertility, LF) were selected from the national population of AI bulls based on adjusted fertility scores from a minimum of 500 inseminations (HF: +4.37% and LF: -12.7%; mean = 0%). Superovulated beef heifers were blocked based on estimated number of follicles at the time of AI and inseminated with semen from HF or LF bulls (n = 3-4 heifers per bull; total 19 heifers). Following slaughter 7 d later, the number of corpora lutea was counted and the uteri were flushed. Recovered structures (oocytes/embryos) were classified according to developmental stage and stained with 4',6-diamidino-2-phenylindole to assess number of cells and accessory sperm. Overall recovery rate (total structures recovered/total corpora lutea) was 52.6% and was not different between groups. Mean (± standard error of the mean) number of embryos recovered per recipient was 8.7 ± 5.2 and 9.4 ± 5.5 for HF and LF, respectively. Overall fertilization rate of recovered structures was not different between groups. However, more embryos were at advanced stages of development (all blastocyst stages combined), reflected in a greater mean embryo cell number on d 7 for HF versus LF bulls. Number of accessory sperm was greater for embryos derived from HF than for LF bulls. The aim of experiment 2 was to evaluate the effect of sire fertility on survival of bovine embryos to d 15. Day 7 blastocysts were produced in vitro using semen from the same HF (n = 3) and LF (n = 3) bulls and transferred in groups of 5-10 to synchronized heifers (n = 7 heifers per bull; total 42 heifers). Conceptus recovery rate on d 15 was higher in HF (59.4%,) versus LF (45.0%). Mean length of recovered conceptuses for HF bulls was not affected by fertility status. In conclusion, while differences in field fertility among AI sires used in this study were not reflected in fertilization rate, differences in embryo quality were apparent as early as d 7. These differences likely contributed to the higher proportion of conceptuses surviving to d 15 in HF bulls.

Evaluation of the relationship between serum paraoxonase-1 activity and superovulation response/embryo yield in Holstein cows

In this study, the effect of serum paraoxonase-1 (PON-1) activity on superovulation response and embryo yield was evaluated. The study material comprised 50 Holstein cows aged 3–4 years on postpartum day 90–120 with a body condition score of 3–3.25. A progesterone-based estrus synchronization protocol was initially administered to the selected donors. For this purpose, progesterone source was inserted intravaginally (day 0) and gonadotropin-releasing hormone injection was performed (day 6). Seven days after the insertion of progesterone device, follicle-stimulating hormone injections (total dose of 500 µg in decreasing doses for 4 days) were administered for superovulation. On the morning of the ninth day, prostaglandin (PG) F2α was administered, and the progesterone device was removed from the vagina in the evening on the same day. Two days after PGF2α administration, fixed-time artificial insemination was performed in the morning and in the evening. On the day of artificial insemination, blood samples were taken from the donors to determine the serum PON-1 activity. Uterine flushing was performed seven days after insemination. The results revealed that the serum PON-1 activity (mean ± SD, 562.71 ± 140.23 U/l) of the cows that responded to superovulation (donors with total corpus luteum count of ≥3 in both ovaries) was higher than those (389.91 ± 80.51 U/l) that did not (P<0.05). On the day of insemination, a positive correlation was determined between serum PON-1 activity and the counts of total corpus luteum (r=0.398), total oocyte/embryo (r=0.468), transferable embryo (r=0.453), and Code I embryos (r=0.315, P<0.05). Unlike the Code I embryos, there was no significant correlation between serum PON-1 activity and the number of Code III embryos. Moreover, no significant difference in the number of Code III embryos between the two PON-1 groups was observed. However, embryo yield and quality were found to have increased with increased PON-1 activity. Therefore, it was concluded that serum PON-1 activity may be associated with superovulation response, embryo yield and quality in donor cows.

Transcript abundance of anti-Mullérian hormone and follicle-stimulating hormone receptor predicted superstimulatory response in embryo donor Holstein cows

The goal was to investigate the relationship among mRNA expressions of anti-Mullérian hormone (AMH), follicle-stimulating hormone receptor (FSHR) and responses to superovulation (SO) in embryo donor dairy cows. Holstein cows (n = 19) were submitted to a standard SO protocol, with twice daily FSH treatments, and artificially inseminated. Prior to SO (Day 0), relative mRNA expressions of AMH and FSHR in blood were determined for all cows. Day 7 embryos were collected and were graded to determine superovulatory response for each donor. Results showed that relative mRNA expressions of AMH and FSHR were positively correlated (R²  = 0.94). Relative mRNA expressions of both AMH and FSHR were positively correlated with total embryos (R²  = 0.68 and 0.69, respectively), total transferable embryos (R²  = 0.92 and 0.97, respectively) and total grade 1 embryos (R²  = 0.54 and 0.59, respectively). Further, transcript abundances of AMH and FSHR positively associated with milk production of donor cows, and meanwhile, they were negatively associated with days in milk (DIM) at submission of cows to SO (p < .05) protocol. The relative mRNA expression of AMH was higher (p < .05) in donor cows <5 years of age. However, age of donor at superovulation did not influence mRNA expression of FSHR. Collectively, we infer that the mRNA expressions of AMH and FSHR prior to superovulation can predict donor cows' positive response to superovulation.

Negative impact of high doses of follicle-stimulating hormone during superovulation on the ovulatory follicle function in small ovarian reserve dairy heifers†

When women with small ovarian reserves are subjected to assisted reproductive technologies, high doses of gonadotropins are linked to high oocyte and embryo wastage and low live birth rates. We hypothesized that excessive follicle-stimulating hormone (FSH) doses during superovulation are detrimental to ovulatory follicle function in individuals with a small ovarian reserve. To test this hypothesis, heifers with small ovarian reserves were injected twice daily for 4 days, beginning on Day 1 of the estrous cycle with 35, 70, 140, or 210 IU doses of Folltropin-V (FSH). Each heifer (n = 8) was superovulated using a Williams Latin Square Design. During each superovulation regimen, three prostaglandin F2α injections were given at 12-h interval, starting at the seventh FSH injection to regress the newly formed corpus luteum (CL). Human chorionic gonadotropin was injected 12 h after the last (8th) FSH injection to induce ovulation. Daily ultrasonography and blood sampling were used to determine the number and size of follicles and corpora lutea, uterine thickness, and circulating concentrations of estradiol, progesterone, and anti-Müllerian hormone (AMH). The highest doses of FSH did not increase AMH, progesterone, number of ovulatory-size follicles, uterine thickness, or number of CL. However, estradiol production and ovulation rate were lower for heifers given high FSH doses compared to lower doses, indicating detrimental effects on ovulatory follicle function.

Effects of the mycotoxin metabolite de-epoxy-deoxynivalenol (DOM-1) on embryo development and sperm motility in cattle

Contamination of animal feed with Fusarium spp results in accumulation of mycotoxins including deoxynivalenol. In animals, deoxynivalenol is metabolized to de-epoxy deoxynivalenol (DOM-1), which is generally considered to be a non-toxic metabolite; however, recent studies demonstrated that DOM-1 can reduce steroid production and induce apoptosis in the bovine ovary. The objectives of this study were to assess the effects of DOM-1 on applied aspects of reproductive function in cattle, specifically sperm function and embryo development in vitro and follicle growth and superovulatory responses in vivo. The effect of naturally contaminated feed on superovulatory responses was assessed; a dose of 6 ppm deoxynivalenol increased blood DOM-1 concentrations to 20 ng/ml, but this did not alter the number of viable embryos recovered on day 7. However, intrafollicular injection of DOM-1 (100 ng/ml) directly into the growing dominant follicle resulted in cessation of follicular growth over the subsequent 3 days. Treatment with DOM-1 reduced motility of bull spermatozoa over a 10-h period in vitro. Addition of DOM-1 to oocytes in vitro during IVM did not alter rates of cumulus expansion and nuclear maturation, but treatment during IVF reduced the rate of blastocyst formation. These data illustrate that DOM-1 is more biologically active than previously thought and negatively impacted reproductive outcomes in cattle.

Development of assisted reproductive technologies for Mus spretus†

The genus Mus consists of many species with high genetic diversity. However, only one species, Mus musculus (the laboratory mouse), is common in biomedical research. The unavailability of assisted reproductive technologies (ARTs) for other Mus species might be a major reason for their limited use in laboratories. Here, we devised ARTs for Mus spretus (the Algerian mouse), a commonly used wild-derived Mus species. We found that in vitro production of M. spretus embryos was difficult because of low efficacies of superovulation with equine chorionic gonadotropin or anti-inhibin serum (AIS) (5-8 oocytes per female) and a low fertilization rate following in vitro fertilization (IVF; 15.2%). The primary cause of this was the hardening of the zona pellucida but not the sperm's fertilizing ability, as revealed by reciprocal IVF with laboratory mice. The largest number of embryos (16 per female) were obtained when females were injected with AIS followed by human chorionic gonadotropin and estradiol injections 24 h later, and then by natural mating. These in vivo-derived 2-cell embryos could be vitrified/warmed with a high survival rate (94%) using an ethylene glycol-based solution. Importantly, more than 60% of such embryos developed into healthy offspring following interspecific embryo transfer into (C57BL/6 × C3H) F1 female mice. Thus, we have devised practical ARTs for Mus spretus mice, enabling efficient production of embryos and animals, with safe laboratory preservation of their strains. In addition, we have demonstrated that interspecific embryo transfer is possible in murine rodents.

Identification of key bacterial populations affecting early embryonic development in cattle uterus

Superovulation is an important animal breeding biotechnology, while the quality of embryos obtained from superovulation is unstable in cattle. The relationship between the microorganisms in the cattle uterus and embryo qualities was determined to identify the key bacterial populations affecting early embryonic development. A total of 10 Xia Nan cows underwent superovulation, we collected cervical mucus and flush samples to investigated by 16S rDNA sequencing. Results showed that there were abundant microorganisms in cervical mucus, but no obvious relationship with the quality of embryos. The clustering results of flush samples were consistent with the grouping of embryo quality. Proteobacteria accounted for more than 95% of the total bacterial community in group A with the best embryo quality (qualified embryo ratio above 0.8), and as embryo quality decreased, the Proteobacteria proportion also decreased. In contrast to the proportion of Proteobacteria, the proportions of Firmicutes and Bacteroidetes significantly increased as embryo quality decreased. For group C with the worst embryo quality, the proportions of Firmicutes and Bacteroidetes increased to 4.7 times and 12.3 times of group A, respectively. These results showed that the quantities and proportions of Firmicutes and Bacteroidetes may be related to early embryonic development in cattle.

Comparison of clomiphene and letrozole for superovulation in patients with unexplained infertility undergoing intrauterine insemination: A systematic review and meta-analysis

BACKGROUND

With the medical advancement some studies put forward that letrozole (LE), a specific aromatase inhibitor with the function of reducing oestrogen synthesis, has recently been applied as a potentially better alternative compared with clomiphene citrate (CC), owing to that it has a superior efficacy as compared with CC in patients of unexplained infertility undergoing intrauterine insemination (IUI). However, there is no one study can clear and definite whether LE can replace the CC as first line drug.

OBJECTIVE

Our objective is to compare the LE with CC in the induction of ovulation in patients with unexplained infertility IUI.

METHOD

Searching databases consist of all kinds of searching tools, such as Medline, The Cochrane Library, Embase, PubMed, etc. All the include studies should meet our demand of this meta-analysis: RESULT:: Based on the current meta-analysis, we rigorously consider that LE has a likelihood to improve dominant follicles (MD= -0.56, I= 100%, P= .04; MD= -0.39, I= 73%, P = .0003, respectively) and reduces the miscarriage rate (RR= 0.61, I= 0%, P = .03). There is no significant differences between the 2 groups in The total rate of pregnancy, pregnancy rate per cycle, multiple pregnancy and endometrial thickness. (RR= 1.06, I= 11%, P = .38; RR= 1.09, I= 7%, P = .32; RR= 0.79, I= 0%, P = .46; respectively) CONCLUSION:: Combined with the results of current systematic review and meta-analysis through subgroup analysis and sensitivity analysis, we can be cautious: in general, compared with CC, LE is an effective treatment in the IUI cycle, has a likelihood to improve dominant follicles and reduces the miscarriage rate.

Implications of Assisted Reproductive Technologies for Pregnancy Outcomes in Mammals

Development of assisted reproductive technologies has been driven by the goals of reducing the incidence of infertility, increasing the number of offspring from genetically elite animals, facilitating genetic manipulation, aiding preservation and long-distance movement of germplasm, and generating research material. Superovulation is associated with reduced fertilization rate and alterations in endometrial function. In vitro production of embryos can have a variety of consequences. Most embryos produced in vitro are capable of establishing pregnancy and developing into healthy neonatal animals. However, in vitro production is associated with reduced ability to develop to the blastocyst stage, increased incidence of failure to establish pregnancy, placental dysfunction, and altered fetal development. Changes in the developmental program mean that some consequences of being produced in vitro can extend into adult life. Reduced competence of the embryo produced in vitro to develop to the blastocyst stage is caused largely by disruption of events during oocyte maturation and fertilization. Conditions during embryo culture can affect embryo freezability and competence to establish pregnancy after transfer. Culture conditions, including actions of embryokines, can also affect the postnatal phenotype of the resultant progeny.

Efficient production of immunodeficient non-obese diabetic/Shi-scid IL2rγnull mice via the superovulation technique using inhibin antiserum and gonadotropin

Severe immunodeficient mice are an essential tool for the examination of the efficacy and safety of new therapeutic technologies as a humanized model. Previously, non-obese diabetic (NOD)/Shi-scid IL2rγ^null (NOG) mice were established as immunodeficient mice by combining interleukin-2 receptor-γ chain-knockout mice and NOD/Shi-scid mice. The NOG mice are used frequently in the research of therapeutic monoclonal antibodies and regenerative medicine for human diseases. Establishment of an efficient production system of NOG mice, using optimized reproductive techniques, is required to accelerate research. In this study, we investigated the efficacy of the superovulation technique using equine chorionic gonadotropin (eCG) and inhibin antiserum (IAS) in NOG mice of various ages (4, 8, 12, 24, or 54 weeks). Additionally, we examined the fertilizing and developmental ability of the oocytes through in-vitro fertilization using frozen-thawed sperm, embryo culture and embryo transfer. The results showed that NOG mice produced the highest number of oocytes at 12 weeks old following the co-administration of eCG and IAS (collectively IASe) (70 oocytes/female). IASe was more effective in increasing the number of oocytes v. eCG at all ages. The IASe-derived oocytes demonstrated the ability to fertilize and develop into blastocysts and pups. Finally, we demonstrated that three strains of genetically modified NOG mice were efficiently produced through the optimized reproductive techniques. In summary, we developed an efficient system for the production of immunodeficient mice using 12-week-old, IASe-treated female NOG mice.

The Outcome and Economic Viability of Embryo Production Using IVF and SOV Techniques in the Wagyu Breed of Cattle

The Japanese black cattle breed (Wagyu) has an improved metabolism, which allows them to have a higher marbling score when compared with other cattle breeds. However, this may affect other aspects of the animal’s physiology, including hormone secretion and their reproductive success, such as their response to synchronization protocols and embryo production. Therefore, the objectives of this study were to test a superovulation protocol (SOV) developed with low doses of FSH and to evaluate the outcome and economic viability of embryo production using the SOV and in vitro fertilization (IVF) approaches in the Wagyu cattle breed. For that, ten Wagyu cows were submitted to five SOVs over a period of 15 months using a standard protocol: CIDR + 3 mg estradiol benzoate (D0), 35 mg FSH (Folltropin^®) a.m. and p.m. (D4), 35 mg Folltropin^® a.m. and 20 mg p.m. (D5), 20 mg Folltropin^® a.m. and 10 mg p.m. (D6), 10 mg Folltropin^® and 0.5 mg cloprostenol, both a.m. and p.m., + CIDR removal (D7), 0.05 mg GnRH + insemination 12 and 24 h after (D8) and embryo collection + 0.5 mg of cloprostenol (D16). Thirty days after each SOV, a follicular aspiration was conducted to produce IVF embryos without any pre-synchronization using standard semen in the same group of animals. The average number of embryos produced was 7.63 ± 5.61 (SOV) and 4.52 ± 2.44 (IVF) (p = 0.303). There was no significant correlation between the number of embryos produced by the different techniques (SOV and IVF), indicating that cows that respond well to SOV did not respond well to IVF and vice versa (r = 0.379, p = 0.529). The total cost of each embryo produced by SOV was R$215.00 and R$410.00 for IVF. Therefore, cows that produce less than five embryos by SOV are not economically viable due their lack of response to FSH, and the use of IVF in those animals may be more effective.

Uterine aquaporin expression is dynamically regulated by estradiol and progesterone and ovarian stimulation disrupts embryo implantation without affecting luminal closure

The study investigated the effect of normal and supraphysiological (resulting from gonadotropin-dependent ovarian stimulation) levels of estradiol (E2) and progesterone (P4) on mouse uterine aquaporin gene/protein (Aqp/AQP) expression on Day 1 (D1) and D4 of pregnancy. The study also examined the effect of ovarian stimulation on uterine luminal closure and uterine receptivity on D4 of pregnancy and embryo implantation on D5 and D7 of pregnancy. These analyses revealed that the expression of Aqp3, Aqp4, Aqp5 and Aqp8 is induced by E2 while the expression of Aqp1 and Aqp11 is induced by P4. Additionally, P4 inhibits E2 induction of Aqp3 and Aqp4 expression while E2 inhibits Aqp1 and Aqp11 expression. Aqp9, however, is constitutively expressed. Ovarian stimulation disrupts Aqp3, Aqp5 and Aqp8 expression on D4 and AQP1, AQP3 and AQP5 spatial expression on both D1 and D4, strikingly so in the myometrium. Interestingly, while ovarian stimulation has no overt effect on luminal closure and uterine receptivity, it reduces implantation events, likely through a disruption in myometrial activity and embryo development. The wider implication of this study is that ovarian stimulation, which results in supraphysiological levels of E2 and P4 and changes (depending on the degree of stimulation) in the E2:P4 ratio, triggers abnormal expression of uterine AQP during pregnancy, and this is associated with implantation failure. These findings lead us to recognize that abnormal expression would also occur under any pathological state (such as endometriosis) that is associated with changes in the normal E2:P4 ratio. Thus, infertility among these patients might in part be linked to abnormal uterine AQP expression.

Improvement of Embryo Recovery in Holstein Cows Treated by Intra-Ovarian Platelet Rich Plasma before Superovulation

The current research was designed to evaluate if intra-ovarian administration of autologous platelet rich plasma (PRP) before superovulation could increase the number of follicles responsive to gonadotropin treatment in order to improve embryo recovery in donor cows. Eight Holstein-Friesian cows of proven fertility were employed. After estrous synchronization, at the 18th day of diestrous, the right ovary of each cow was left untreated and served as control while the left ovary was inoculated with 5 mL of PRP. Cows were left to spontaneously return to estrous, and nine days later, a standard superovulation was initiated for every cow. Seven days after artificial insemination (AI), putative embryos were collected by flushing the right and left uterine horns separately. All statistics were calculated by ANOVA. The mean number of follicles, evaluated by transrectal ultrasound scanning, did not statistically differ before PRP treatment between right (control) and left (treated) ovaries (9.18 ± 1.35 and 7.32 ± 1.67, p = 0.28, respectively) as well as at 48 h after PRP injection (7.67 ± 2.52 and 8.00 ± 2.00, p = 0.73, respectively). A statistical (p = 0.023) difference was found in the average number of follicles at the last gonadotropin injection between control and treated ovaries (11.33 ± 2.89 and 20.00 ± 9.17, respectively). The statistically different (p = 0.0037) number of grade 1-2 blastocysts harvested from the uterine horn ipsilateral to control ovaries in comparison to that collected from the treated ones (6.63 ± 2.92 and 14.75 ± 5.92, respectively) suggests that intra-ovarian injection of PRP before superovulation could exert beneficial effects both in latent follicle growth and in vivo embryo production.

Evaluation of Diabetes Effects on the Expression of Leukemia Inhibitory Factor and Vascular Endothelial Growth Factor A Genes and Proteins at the Time of Endometrial Receptivity after Superovulation in Rat Model

Background:

Diabetes, a major metabolic disorder, seems to affect the fertility rates of women in various ways. Due to the uncertainty of the effects of diabetes along with superovulation treatment on the infertility, we investigate the effects of ovulation induction treatment as therapeutic approach on the expression of leukemia inhibitory factor (LIF) and vascular endothelial growth factor A (VEGFA) as two main factors which are involved in the implantation in the streptozotocin (STZ)-induced type 1 diabetic rats.

Materials and Methods:

Type 1 diabetes was induced by injections of STZ in Wistar rats. The animals were kept in diabetic conditions for 4 weeks, while some were treated with insulin for treatment. After treatment, the ovulation was induced by human menopausal gonadotropin (hMG) and human chorionic gonadotropin (hCG). The rats were then sacrificed and the expression of LIF and VEGFA was checked by immunohistochemistry staining method, and the relative expression of LIF and VEGFA was measured by quantitative reverse transcription polymerase chain reaction (RT-PCR) and Western blotting methods.

Results:

It was observed that diabetes and insulin treatment for diabetes altered the expression of Lif and VEGFA in both mRNA and protein levels. However, superovulation treatment seems to ameliorate this alternation for both factors.

Conclusion:

According to our results, diabetes and insulin therapy could alter the expression of Lif and VEGFA genes and proteins that are effective in endometrial receptivity and implantation process. It seems in diabetic cases, the effect of hCG and hMG therapy by itself could regulate the level of expression and presence of these two genes and proteins.

Simple Recommendations for Improving Efficiency in Generating Genome-Edited Mice

The generation of transgenic model organisms (primarily mice) is an integral part of modern fundamental and applied research. Simple techniques based on the biology of these laboratory rodents can often increase efficiency when generating genome-edited mouse strains. In this study, we share our three years of experience in the optimization of mouse genome editing based on microinjection of CRISPR/Cas9 components into ca. 10,000 zygotes. We tested a number of techniques meant to improve efficiency in generating knockout mice, such as optimization of the superovulation method and choosing the optimal mouse strains to be used as zygote donors and foster mothers. The presented results might be useful to laboratories aiming to quickly and efficiently create new mouse strains with tailored genome editing.

AMH: Could It Be Used as A Biomarker for Fertility and Superovulation in Domestic Animals?

Anti-Müllerian hormone (AMH) is a reliable and easily detectable reproductive marker for the fertility competence of many farm animal species. AMH is also a good predictor of superovulation in cattle, sheep, and mares. In this review, we have summarized the recent findings related to AMH and its predictive reliability related to fertility and superovulation in domestic animals, especially in cattle. We focused on: (1) the dynamics of AMH level from infancy to prepubescence as well as during puberty and adulthood; (2) AMH as a predictor of fertility; (3) the association between antral follicle count (AFC) and plasma AMH level; (4) AMH as a predictor of superovulation; and (5) factors affecting AMH levels in domestic animals, especially cattle. Many factors affect the circulatory levels of AMH when considering the plasma, like nutrition, activity of granulosa cells, disease state and endocrine disruptions during fetal life. Briefly, we concluded that AMH concentrations are static within individuals, and collection of a single dose of blood has become more popular in the field of assisted reproductive technologies (ART). It may act as a potential predictor of fertility, superovulation, and ovarian disorders in domestic animals. However, due to the limited research in domestic animals, this potential of AMH remains underutilized.