Combined synchronization and superovulation treatments negatively impact embryo viability possibly by the downregulation of WNT/β-catenin and Notch signaling genes in the porcine endometrium.

The combination of estrus synchronization and superovulation treatments introduces molecular modifications whose effects are yet to be disclosed. Here, reproductive parameters and gene expression changes in ovaries and endometrium were explored on day 6 after artificial insemination (AI), when synthetic progestin altrenogest (ALT) was combined with gonadotropins. Sows were administered ALT for 7 d beginning on the day of weaning and superovulated with equine chorionic gonadotropin (eCG) 24 h later and human chorionic gonadotropins (hCG) at the onset of estrus (SS-7 group; n = 6).

Equilibration time with cryoprotectants, but not melatonin supplementation during in vitro maturation, affects viability and metaphase plate morphology of vitrified porcine mature oocytes.

The aims of this study were to investigate the effects of different equilibration times with cryoprotectants on viability and metaphase plate morphology of vitrified-warmed porcine mature oocytes (Experiment 1) and to evaluate the effects of supplementation with 10 M melatonin during in vitro maturation on these parameters (Experiment 2). In Experiment 1, 2,392 mature oocytes were vitrified using different equilibration times of oocytes with cryoprotectants (3, 10, 15, 20, 30, 40, 60 and 80 min). Fresh oocytes matured in vitro for 44 hr (n = 509) were used as controls.

Immunological uterine response to pig embryos before and during implantation.

The establishment of a successful pregnancy can only occur through a concerted functioning of the entire female reproductive system, allowing for fertilization, subsequent embryo development and implantation of the conceptus. In this context, the uterine immunological responses responsible for rejection or tolerance of the conceptus are of critical importance. The aim of the present review is to summarize our current knowledge about those cellular and molecular immunological events occurring at the uterine level during pre-implantation and implantation stages of pregnancy in the pig.

Neither frozen-thawed seminal plasma nor commercial transforming growth factor-β1 infused intra-utero before insemination improved fertility and prolificacy in sows.

Seminal plasma (SP) affects reproduction, inducing cell and molecular changes in the female genital tract. A main active component in SP is the modulatory transforming growth factor-β (TGF-β), particularly its TGF-β1 isoform, which affects the synthesis of other cytokines as granulocyte-macrophage colony-stimulating factor, relevant for embryo development and pregnancy. This study evaluated the effect of pooled frozen-thawed SP and commercial TGF-β1 infused during oestrus in sows post-cervically inseminated with liquid extended semen, containing ~4 ml of residual SP, on their fertility and prolificacy.

Boar seminal plasma: current insights on its potential role for assisted reproductive technologies in swine.

Seminal plasma (SP) supports not only sperm function but also the ability of spermatozoa to withstand biotechnological procedures as artificial insemination, freezing or sex sorting. Moreover, evidence has been provided that SP contains identifiable molecules which can act as fertility biomarkers, and even improve the output of assisted reproductive technologies by acting as modulators of endometrial and embryonic changes of gene expression, thus affecting embryo development and fertility beyond the sperm horizon. In this overview, we discuss current knowledge of the composition of SP, mainly proteins and cytokines, and their influence on semen basic procedures, such as liquid storage or cryopreservation.

Supplementation with exogenous coenzyme Q10 to media for in vitro maturation and embryo culture fails to promote the developmental competence of porcine embryos.

The coenzyme Q10 (CoQ10) is a potent antioxidant with critical protection role against cell oxidative stress, caused by the mitochondrial dysfunction. This study evaluated the effects of CoQ10 supplementation to in vitro maturation (IVM) or embryo culture media on the maturation, fertilization and subsequent embryonic development of pig oocytes and embryos. Maturation (Experiment 1) or embryo culture (Experiment 2) media were supplemented with 0 (control), 10, 25, 50 and 100 μM CoQ10.

Achievements and future perspectives of embryo transfer technology in pigs.

Commercial embryo transfer (ET) has unprecedented productive and economic implications for the pig sector. However, pig ET has been considered utopian for decades mainly because of the requirements of surgical techniques for embryo collection and embryo deposition into recipients, alongside challenges to preserve embryos. This situation has drastically changed in the last decade since the current technology allows non-surgical ET and short- and long-term embryo preservation.

Interspecies Chimerism with Mammalian Pluripotent Stem Cells.

Interspecies blastocyst complementation enables organ-specific enrichment of xenogenic pluripotent stem cell (PSC) derivatives. Here, we establish a versatile blastocyst complementation platform based on CRISPR-Cas9-mediated zygote genome editing and show enrichment of rat PSC-derivatives in several tissues of gene-edited organogenesis-disabled mice. Besides gaining insights into species evolution, embryogenesis, and human disease, interspecies blastocyst complementation might allow human organ generation in animals whose organ size, anatomy, and physiology are closer to humans.

Successful non-surgical deep uterine transfer of porcine morulae after 24 hour culture in a chemically defined medium.

Excellent fertility and prolificacy have been reported after non-surgical deep uterine transfers of fresh in vivo-derived porcine embryos. Unfortunately, when this technology is used with vitrified embryos, the reproductive performance of recipients is low. For this reason and because the embryos must be stored until they are transferred to the recipient farms, we evaluated the potential application of non-surgical deep uterine transfers with in vivo-derived morulae cultured for 24 h in liquid stage.

An earlier uterine environment favors the in vivo development of fresh pig morulae and blastocysts transferred by a nonsurgical deep-uterine method.

This study aimed to evaluate the effect of recipient-donor estrous cycle synchrony on recipient reproductive performance after nonsurgical deep-uterine (NsDU) embryo transfer (ET). The transfers (N=132) were conducted in recipients sows that started estrus 24 h before (-24 h; N=9) or 0 h (synchronous; N=31), 24 h (+24 h; N=74) or 48 h (+48 h; N=18) after the donors. A total of 30 day 5 morulae or day 6 blastocysts (day 0=onset of estrus) were transferred per recipient.

The battle of the sexes starts in the oviduct: modulation of oviductal transcriptome by X and Y-bearing spermatozoa.

Background: Sex allocation of offspring in mammals is usually considered as a matter of chance, being dependent on whether an X- or a Y-chromosome-bearing spermatozoon reaches the oocyte first. Here we investigated the alternative possibility, namely that the oviducts can recognise X- and Y- spermatozoa, and may thus be able to bias the offspring sex ratio.

Results: By introducing X- or Y-sperm populations into the two separate oviducts of single female pigs using bilateral laparoscopic insemination we found that the spermatozoa did indeed elicit sex-specific transcriptomic responses.

Effects of Hoechst 33342 staining and ultraviolet irradiation on mitochondrial distribution and DNA copy number in porcine oocytes and preimplantation embryos.

Hoechst 33342 (H342), in combination with ultraviolet (UV) irradiation, is frequently used to aid or confirm the enucleation of porcine oocytes in somatic cell nuclear transfer programs. The exposure of oocytes to H342 and UV irradiation has a deleterious effect on the development of in vitro-fertilized porcine oocytes, with increasing exposure to UV irradiation (up to 30 sec) having more drastic effects. It has been hypothesized that this decrease in embryonic development could be due to damage to the mitochondrial DNA (mtDNA).

Improving the efficiency of sperm technologies in pigs: the value of deep intrauterine insemination.

The use of AI in pigs has dramatically expanded in the last few years. New methodological advances in AI are required to serve the requirements of new sperm technologies, such as the use of low dose AI, because the use of cervical AI has a very low efficiency leading to low fertility results. One of the strategies devised to meet these requirements is the deposition of semen near the site of fertilization in the oviduct.

Effect of the volume of medium and number of oocytes during in vitro fertilization on embryo development in pigs.

The present study was designed to determine the effect of the volume of medium (VM) and the number of oocytes (NOOC) during in vitro fertilization (IVF) on embryo development in pigs. Groups of 15, 30 and 50 in vitro matured oocytes were transferred to 2, 1 and 0.1 ml of modified Tris-buffered medium (mTBM) and inseminated with frozen-thawed spermatozoa (2000 spermatozoa/oocyte) in a 3 x 3 factorial experiment.

Birth of piglets after deep intrauterine insemination with flow cytometrically sorted boar spermatozoa.

The present study was carried out to determine the pregnancy rates, farrowing rates and litter size in sows with either induced or spontaneous ovulation inseminated with flow cytometric sorted spermatozoa using deep intrauterine insemination technology. Spermatozoa were stained with Hoechst 33342 and sorted by flow cytometry/cell sorting but not separated into separate X and Y populations. In Experiment 1, sows (n=200) were weaned and treated for estrus/ovulation induction with eCG/hCG.