Cytokine profile in peripheral blood mononuclear cells differs between embryo donor and potential recipient sows

Introduction

Pregnancy success relies on the establishment of a delicate immune balance that requires the early activation of a series of local and systemic immune mechanisms. The changes in the immunological profile that are normally occurring in the pregnant uterus does not take place in cyclic (non-pregnant) uterus, a fact that has been widely explored in pigs at the tissue local level. Such differences would be especially important in the context of embryo transfer (ET), where a growing body of literature indicates that immunological differences at the uterine level between donors and recipients may significantly impact embryonic mortality. However, whether components of peripheral immunity also play a role in this context remains unknown. Accordingly, our hypothesis is that the immune status of donor sows differs from potential recipients, not only at the tissue local level but also at the systemic level. These differences could contribute to the high embryonic mortality rates occurring in ET programs.

Methods

In this study differences in systemic immunity, based on cytokine gene expression profile in peripheral blood mononuclear cells (PBMCs), between embryo-bearing donor (DO group; N = 10) and potential recipient sows (RE group; N = 10) at Day 6 after the onset of the estrus were explored. Gene expression analysis was conducted for 6 proinflammatory (IL-1α, IL-1β, IL-2, GM-CSF, IFN-γ, and TNF-α) and 6 anti-inflammatory (IL-4, IL-6, IL-10, IL-13, TGF-β1, and LIF) cytokines.

Results and discussion

All cytokines were overexpressed in the DO group except for IL-4, suggesting that stimuli derived from the insemination and/or the resultant embryos modify the systemic immune profile in DO sows compared to RE (lacking these stimuli). Our results also suggest that certain cytokines (e.g., IL-1α and IL-1β) might have a predictive value for the pregnancy status.

In-depth proteome characterization of endometrium and extraembryonic membranes during implantation in pig

BACKGROUND

Proteome characterization of the porcine endometrium and extraembryonic membranes is important to understand mother-embryo cross-communication. In this study, the proteome of the endometrium and chorioallantoic membrane was characterized in pregnant sows (PS) during early gestation (d 18 and 24 of gestation) and in the endometrium of non-pregnant sows (NPS) during the same days using LC-MS/MS analysis. The UniProtKB database and ClueGO were used to obtain functional Gene Ontology annotations and biological and functional networks, respectively.

RESULTS

Our analysis yielded 3,254 and 3,457 proteins identified in the endometrium of PS and NPS, respectively; of these, 1,753 being common while 1,501 and 1,704 were exclusive to PS and NPS, respectively. In addition, we identified 3,968 proteins in the extraembryonic membranes of PS. Further analyses of function revealed some proteins had relevance for the immune system process and biological adhesion in endometrium while the embryonic chorion displayed abundance of proteins related to cell adhesion and cytoskeletal organization, suggesting they dominated the moment of endometrial remodeling, implantation and adhesion of the lining epithelia. Data are available via ProteomeXchange with identifier PXD042565.

CONCLUSION

This is the first in-depth proteomic characterization of the endometrium and extraembryonic membranes during weeks 3 to 4 of gestation; data that contribute to the molecular understanding of the dynamic environment during this critical period, associated with the majority of pregnancy losses.

Cryopreservation of highly extended pig spermatozoa remodels its proteome and counteracts polyspermic fertilization in vitro

BACKGROUND

Currently, high polyspermy remains a significant obstacle to achieving optimal efficiency in in vitro fertilization (IVF) and in vitro embryo production (IVP) systems in pigs. Developing strategies that would prevent polyspermy is essential in overcoming this challenge and maximizing the potential of this reproductive biotechnology. Previous results have demonstrated that using boar spermatozoa subjected to a high-extension and reconcentration procedure and then cryopreserved resulted in significant improvements in IVF/IVP systems with high rates of monospermy and penetration.

OBJECTIVE

The aim of the present study was to unveil the molecular mechanisms that may underlie the changes in fertilization patterns exhibited by highly extended and cryopreserved boar spermatozoa.

MATERIALS AND METHODS

To achieve this goal, we used quantitative proteomic analysis (LC-ESI-MS/MS SWATH) to identify differentially abundant proteins (DAPs) between highly extended (HE) and conventionally (control; CT) cryopreserved boar spermatozoa. Prior to the analysis, we evaluated the in vitro post-thawing fertilizing ability of the sperm samples. The results demonstrated a remarkable improvement in monospermy and IVF efficiency when using HE spermatozoa in IVF compared with CT spermatozoa.

RESULTS

At the proteomic level, the combination of high-extension and cryopreservation had a significant impact on the frozen-thawed sperm proteome. A total of 45 proteins (24 downregulated and 21 upregulated) were identified as DAPs (FC > 1 or ≤1; p < 0.05) when compared with CT spermatozoa. Some of these proteins were primarily linked to metabolic processes and the structural composition of sperm cells. The dysregulation of these proteins may have a direct or indirect effect on essential sperm functions and significantly affect spermatozoa-oocyte interaction and, therefore, the sperm fertilization profile under in vitro conditions. While these findings are promising, further research is necessary to comprehend how the disturbance of specific proteins affects sperm fertilization ability.

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.

Cryotop vitrification of large batches of pig embryos simultaneously provides excellent postwarming survival rates and minimal interference with gene expression

The most commonly used technique to vitrify pig embryos is the super open pulled straw (SOPS), where a maximum of 6 embryos can be vitrified simultaneously per device without compromising the minimum volume necessary for optimal preservation. Since optimal embryo transfer (ET) demands a transfer of 20-40 embryos per recipient, the customary use of SOPS complicates embryo warming and ET in field conditions. Such complications could be avoided when using the Cryotop® (OC) system, which has been proven to be an effective option for vitrifying at least 20 porcine embryos simultaneously. This study aimed to investigate the changes in the transcriptome of blastocysts caused by vitrification using both systems. In vivo-derived blastocysts were OC- (n = 60; 20 embryos/device) and SOPS- (n = 60; 4-6 embryos/device) vitrified and cultured for 24 h after warming. Nonvitrified blastocysts (n = 60) cultured for 24 h postcollection acted as controls. At the end of culture, 48 viable embryos from each group (6 pools of 8 embryos) were selected for microarray (GeneChip® Porcine Genome Array, P/N 900624, Affymetrix) analysis of differentially expressed genes (DEGs). The survival rate of embryos vitrified with the OC and SOPS systems (>97%) was similar to that of the control embryos (100%). Microarray analysis of each vitrification system compared to the control group showed 245 DEGs (89 downregulated and 156 upregulated) for the OC system and 210 (44 downregulated and 166 upregulated) for the SOPS system. Two pathways were enriched for the DEGs specifically altered in each vitrification system compared to the control (glycolysis/gluconeogenesis and carbon metabolism pathways for the OC system and amino sugar and nucleotide sugar metabolism and lysosome pathways in the SOPS group). The OC group showed 31 downregulated and 24 upregulated genes and two enriched pathways (mineral absorption and amino sugar and nucleotide sugar metabolism pathways) when compared to the SOPS group. In summary, vitrification with the OC system altered fewer genes related to apoptosis and activated genes related to cell proliferation. We conclude that vitrification with either the OC or SOPS system has a moderate to low effect on the transcriptome of in vivo-derived porcine blastocysts. Further investigation is needed to elucidate how the differences in the transcriptome of embryos vitrified with these systems affect their subsequent developmental ability after ET.

Air pollution and health prevention: A document of reflection

Ambient air quality, pollution and its implication on health is a topic of enormous importance that is normally dealt with by major specialists in their particular areas of interest. In general, it is not discussed from multidisciplinary approaches or with a language that can reach everyone. For this reason, the Health Sciences Foundation, from its prevention area, has formulated a series of questions to people with very varied competences in the area of ambient air quality in order to obtain a global panorama of the problem and its elements of measurement and control. The answers have been produced by specialists in each subject and have been subjected to a general discussion that has allowed conclusions to be reached on each point. The subject was divided into three main blocks: external ambient air, internal ambient air, mainly in the work-place, and hospital ambient air and the consequences of its poor control. Along with the definitions of each area and the indicators of good and bad quality, some necessary solutions have been pointed out. We have tried to know the current legislation on this problem and the competences of the different administrations on it. Despite its enormous importance, ambient air quality and health is not usually a topic of frequent presence in the general media and we have asked about the causes of this. Finally, the paper addresses a series of reflections from the perspective of ethics and very particularly in the light of the events that the present pandemic raises. This work aims to provide objective data and opinions that will enable non-specialists in the field to gain a better understanding of this worrying reality.

The Open Cryotop System Is Effective for the Simultaneous Vitrification of a Large Number of Porcine Embryos at Different Developmental Stages

The Superfine Open Pulled Straw (SOPS) system is the most commonly used method for vitrification of pig embryos. However, this system only allows the vitrification of four to seven embryos per straw. In this study, we investigated the effectiveness of the open (OC) and closed (CC) Cryotop^® systems to simultaneously vitrify a larger number of porcine embryos. Morulae, early blastocysts and full blastocysts were vitrified with the open Cryotop^® (n = 250; 20 embryos per device) system, the closed Cryotop^® (n = 158; 20 embryos per device) system and the traditional superfine open pulled straw (SOPS; n = 241; 4–7 embryos per straw) method. Fresh embryos from each developmental stage constituted the control group (n = 132). Data expressed as percentages were compared with the Fisher's exact test. The Kruskal-Wallis test was used to analyze the effect of the different vitrification systems on the embryo quality parameters and two-by-two comparisons were accomplished with the Mann-Whitney U test. Differences were considered statistically significant when p < 0.05. Vitrified and control embryos were incubated for 24 h and examined for viability and quality. At the warming step, the embryo recovery rate for the CC system was 51%, while all embryos were recovered when using OC and SOPS. There were no differences between the vitrification and control groups in the postwarming viability of full blastocysts. In contrast, morulae and early blastocysts that were vitrified-warmed with the SOPS system had lower viability (p < 0.01) compared to those from the OC, CC and control groups. The embryonic viability was similar between the OC and control groups, regardless of the developmental stage considered. Moreover, the embryos from the OC group had comparable total cell number and cells from the inner cell mass and apoptotic index than the controls. In conclusion, the OC system is suitable for the simultaneous vitrification of 20 porcine embryos at different developmental stages and provides comparable viability and quality results to fresh embryos subjected to 24 h of in vitro culture.

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.

Vitrification Effects on the Transcriptome of in vivo-Derived Porcine Morulae

Despite the reported promising farrowing rates after non-surgical and surgical transfers of vitrified porcine morulae and blastocysts produced in vivo (range: 70–75%), the pregnancy loss is 5–15 fold higher with vitrified than with fresh embryos. The present study aimed to investigate whether vitrification affects the transcriptome of porcine morulae, using microarrays and RT-qPCR validation. Morulae were obtained surgically from weaned sows (n = 13) on day 6 (day 0 = estrus onset). A total of 60 morulae were vitrified (treatment group). After 1 week of storage, the vitrified morulae were warmed. Vitrified-warmed and non-vitrified fresh morulae (control; n = 40) were cultured for 24 h to assess embryo survival by stereomicroscopy after. A total of 30 vitrified/warmed embryos that were deemed viable and 30 fresh control embryos (three pools of 10 for each experimental group) were selected for microarray analysis. Gene expression was assessed with a GeneChip® Porcine Genome Array (Affymetrix). An ANOVA analysis p-unadjusted <0.05 and a fold change cut-off of ±1.5 were set to identify differentially expressed genes (DEGs). Data analysis and biological interpretation were performed using the Partek Genomic Suite 7.0 software. The survival rate of morulae after vitrification and warming (92.0 ± 8.3%) was similar to that of the control (100%). A total of 233 DEGs were identified in vitrified morulae (38 upregulated and 195 downregulated), compared to the control group. Nine pathways were significantly modified. Go-enrichment analysis revealed that DEGs were mainly related to the Biological Process functional group. Up-regulated DEGs were involved in glycosaminoglycan degradation, metabolic pathways and tryptophan metabolism KEGG pathways. The pathways related to the down-regulated DEGs were glycolysis/gluconeogenesis, protein export and fatty acid elongation. The disruption of metabolic pathways in morulae could be related to impaired embryo quality and developmental potential, despite the relatively high survival rates after warming observed in vitro. In conclusion, vitrification altered the gene expression pattern of porcine morulae produced in vivo, generating alterations in the transcriptome that may interfere with subsequent embryo development and pregnancy after embryo transfer.

Transcriptional Profiling of Porcine Blastocysts Produced In Vitro in a Chemically Defined Culture Medium

The development of chemically defined media is a growing trend in in vitro embryo production (IVP). Recently, traditional undefined culture medium with bovine serum albumin (BSA) has been successfully replaced by a chemically defined medium using substances with embryotrophic properties such as platelet factor 4 (PF4). Although the use of this medium sustains IVP, the impact of defined media on the embryonic transcriptome has not been fully elucidated. This study analyzed the transcriptome of porcine IVP blastocysts, cultured in defined (PF4 group) and undefined media (BSA group) by microarrays. In vivo-derived blastocysts (IVV group) were used as a standard of maximum embryo quality. The results showed no differentially expressed genes (DEG) between the PF4 and BSA groups. However, a total of 2780 and 2577 DEGs were detected when comparing the PF4 or the BSA group with the IVV group, respectively. Most of these genes were common in both in vitro groups (2132) and present in some enriched pathways, such as cell cycle, lysosome and/or metabolic pathways. These results show that IVP conditions strongly affect embryo transcriptome and that the defined culture medium with PF4 is a guaranteed replacement for traditional culture with BSA.

Effects of Vitrification on the Blastocyst Gene Expression Profile in a Porcine Model

This study was designed to investigate the impact of vitrification on the transcriptome profile of blastocysts using a porcine (Sus scrofa) model and a microarray approach. Blastocysts were collected from weaned sows (n = 13). A total of 60 blastocysts were vitrified (treatment group). After warming, vitrified embryos were cultured in vitro for 24 h. Non-vitrified blastocysts (n = 40) were used as controls. After the in vitro culture period, the embryo viability was morphologically assessed. A total of 30 viable embryos per group (three pools of 10 from 4 different donors each) were subjected to gene expression analysis. A fold change cut-off of ±1.5 and a restrictive threshold at p-value < 0.05 were used to distinguish differentially expressed genes (DEGs). The survival rates of vitrified/warmed blastocysts were similar to those of the control (nearly 100%, n.s.). A total of 205 (112 upregulated and 93 downregulated) were identified in the vitrified blastocysts compared to the control group. The vitrification/warming impact was moderate, and it was mainly related to the pathways of cell cycle, cellular senescence, gap junction, and signaling for TFGβ, p53, Fox, and MAPK. In conclusion, vitrification modified the transcriptome of in vivo-derived porcine blastocysts, resulting in minor gene expression changes.

Allogeneic Embryos Disregulate Leukemia Inhibitory Factor (LIF) and Its Receptor in the Porcine Endometrium During Implantation

Despite its advantages for pig breeding, embryo transfer (ET) has a major handicap: high embryo mortality during the pre- and implantation period, probably caused by divergent phenomena of tolerance between the immunologically unrelated (i.e., allogeneic) embryos and the recipient sow. Thus, to reach a similar maternal tolerance as in conventional breeding by artificial insemination (AI) would be the key to ET-success. For this reason, we studied the expression of the leukemia inhibitory factor (LIF) cytokine and its receptor in the pig endometrium during the implantation period (days 18 and 24) in sows subjected to ET (AL group) vs. post-cervical-AI controls (Hemi-AL group). Quantification of expression was performed at both mRNA (rt-qPCR) and protein (WB) levels. The expression of endometrial LIF on day 24 was considerably lower in ET than in AI pregnancies. Correlations between endometrial mRNA levels of LIF and LIF-R showed that, contrary to early AI-pregnancies, ET-pregnancies lack an inverse relation between cytokine and receptor levels. In conclusion, ET-pregnancies lack sufficient endometrial levels of LIF to develop adequate immunotolerance mechanisms to prevent the rejection of allogeneic ET-embryos.

Blastocyst-Bearing Sows Display a Dominant Anti-Inflammatory Cytokine Profile Compared to Cyclic Sows at Day 6 of the Cycle

Simple Summary

A proper uterine environment is basic for obtaining optimal embryo transfer outputs in domestic species, including the pig. However, scarce information is available about the uterine immune response of recipient (uninseminated) sows when receiving embryos during embryo transfer. Endometrial cytokine profile is among the main factors regulating uterine receptivity to embryos. In this study, using Luminex MAP^® technology, we found important differences in the endometrial production in most of the 16 cytokines analyzed between recipient sows and embryo-bearing (inseminated) sows six days after estrus, with a predominant cytokine anti-inflammatory environment in the embryo-bearing endometria. These observations suggest that insemination components and/or early embryos induce an endometrium immune-tolerant cytokine profile at Day 6 of the cycle. The findings could contribute importantly to design strategies to maximize the reproductive performance of recipients after embryo transfer in swine.

Abstract

In the context of porcine embryo transfer (ET) technology, understanding the tightly regulated local uterine immune environment is crucial to achieve an adequate interaction between the transferred embryos and the receiving endometrium. However, information is limited on the uterine immune status of cyclic-recipient sows when receiving embryos during ET. The present study postulated that the anti- and proinflammatory cytokine profile 6 days after the onset of estrus differs between endometria from uninseminated cyclic sows and blastocyst-bearing sows. On Day 6 of the cycle, endometrial explants were collected from sows inseminated or not inseminated during the postweaning estrus and cultured for 22 h. The culture medium was then analyzed for the contents of a total of 16 cytokines using Luminex MAP^® technology. The results showed important differences in the endometrial production of most cytokines between the sow categories, with a predominant anti-inflammatory environment displayed by the blastocyst-bearing endometria. These findings suggest that sperm, seminal plasma (SP) and/or early embryos modify the uterine environment by inducing an immune-tolerant cytokine profile already visible at Day 6. Whether the SP or some of its active components may help to develop strategies to maximize the reproductive performance of recipients after ET needs further investigation.

Seminal Plasma Modifies the Transcriptional Pattern of the Endometrium and Advances Embryo Development in Pigs

Background: Seminal plasma (SP) promotes sperm survival and fertilizing capacity, and potentially affects embryo development, presumably via specific signaling pathways to the internal female genital tract.

Objectives: This study evaluated how heterologous SP, infused immediately before postcervical artificial insemination (AI) affected embryo development and the transcriptional pattern of the pig endometria containing embryos.

Materials and Methods: Postweaning estrus sows (n = 34) received 40-mL intrauterine infusions of either heterologous pooled SP or Beltsville Thawing Solution (BTS; control) 30 min before AI of semen extended to 10% of homologous SP. Embryos (all sows) and endometrium samples (3 sows/group) were removed during laparotomy 6 days after the infusion of SP or BTS to morphologically evaluate the embryos to determine their developmental stage and to analyze the endometrial transcriptome using microarrays (PORGENE 1.0 ST GeneChip array, Affymetrix) followed by qPCR for further validation.

Results: Embryo viability was equal between the groups (~93%), but embryo development was significantly (P < 0.05) more advanced in the SP-treated group compared to control. A total of 1,604 endometrium transcripts were differentially expressed in the SP group compared to the control group. An enrichment analysis showed an overrepresentation of genes and pathways associated with the immune response, cytokine signaling, cell cycle, cell adhesion, and hormone response, among others.

Conclusions: SP infusions prior to AI positively impacted the preimplantation embryo development and altered the expression of the endometrial genes and pathways potentially involved in embryo development.

Three-to-5-day weaning-to-estrus intervals do not affect neither efficiency of collection nor in vitro developmental ability of in vivo-derived pig zygotes

An efficient system to collect large numbers of vital zygotes is a pre-requisite for application of zygote genome-editing technology, including development of efficient models for xenotransplantation using pigs. Owing to the sub-optimal in vitro production of zygotes in pigs, efficient collection of in vivo developed zygotes is required. Timing of ovulation is a key factor to sustain efficiency since the interval between pronuclear formation and the first division is very short in pigs. The weaning-to-estrus interval can, due to its inverse relation with length of estrus and time of ovulation, interfere with ovulation and make it asynchronous, which reduces the probability of obtaining zygotes. This retrospective study compared the effects of three weaning-to-estrus intervals of 3, 4 or 5 days on zygote collection efficiency in a total of 17 trials over a 3-year period including 223 sows. Donor sows in groups of 10-15 animals were super-ovulated with eCG 24 h after weaning and those in estrus at 48-72 h post-eCG were immediately treated with hCG, followed by insemination 6 and 24 h thereafter. Collected structures during laparotomy on Day 2 (Day 0: onset of estrus) were morphologically evaluated and only those with a single cell and two visible polar bodies were considered as zygotes. Zygotes were injected with CRISPR-Cas9 editor mixture and cultured for 6 days to evaluate their developmental ability against non-injected control zygotes. Of all recovered structures (N = 5,468), 67.4%, 30.8% and 1.8% were zygotes, 2-cell embryos and oocytes-degenerated embryos, respectively. The different weaning-to-estrus intervals did not affect either the percentages of collected zygotes (range: 64.1%-70.0%) or the percentages of sows with zygotes at collection time (range: 69.0%-73.3%). The weaning-to-estrus intervals did not affect the in vitro developmental ability of zygotes. After 24 h of culture, 78.1 ± 2.0% and 95.1 ± 0.6 (P < 0.05) of injected (N = 2,345) and non-injected (N = 335) zygotes, respectively, developed to 2-to-4-cell embryo stage. The total efficiency of the system was 64.1 ± 2.2% and 85.8 ± 1.5% (P < 0.05) for injected and non-injected zygotes, respectively. In conclusion, the results indicate that neither the efficiency of collecting in vivo derived porcine zygotes from superovulated sows nor the zygote ability to develop to blastocyst after cytoplasmic genome-editing injection were affected by a weaning-to-estrus interval between 3-to-5 days.

Social information drives ecological outcomes among competing species

Through its behavior, an organism intentionally or unintentionally produces information. Use of this "social information" by surrounding conspecifics or heterospecifics is a ubiquitous phenomenon that can drive strong correlations in fitness-associated behaviors, such as predator avoidance, enhancing survival within and among competing species. By eliciting indirect positive interactions between competing individuals or species, social information might alter overall competitive outcomes. To test this potential, we present new theory that quantifies the effect of social information, modeled as predator avoidance signals/cues, on the outcomes from intraspecific and interspecific competition. Our analytical and numerical results reveal that social information can rescue populations from extinction and can shift the long-term outcome of competitive interactions from mutual exclusion to coexistence, or vice versa, depending on the relative strengths of intraspecific and interspecific social information and competition. Our findings highlight the importance of social information in determining ecological outcomes.

Prevention of hatching of porcine morulae and blastocysts by liquid storage at 20 °C

Vitrification is the ideal method for long-lasting storage of porcine embryos. However, both strict airline regulations for transport of liquid nitrogen dewars and the technical problems experienced when vitrified embryos are transferred using non-surgical procedures have led to the introduction of alternative storage methods, such as preserving embryos in liquid state. This study evaluated whether a pH-stable medium containing high concentrations of either foetal calf serum (FCS; 50%) or BSA (4%) combined with storage at temperatures of 17 °C or 20 °C maintained in vivo-derived morulae and blastocysts alive and unhatched (a sanitary requirement for embryo transportation) during 72 h of storage. Neither FCS nor BSA supplements were able to counteract the negative effect of low temperatures (17 °C) on embryonic survival after storage. At 20 °C, the protective effect of FCS or BSA depended on embryo stage. While FCS successfully arrested embryo development of only blastocysts, BSA arrested the development of both morulae and blastocysts. Over 80% of BSA arrested embryos restarted development by conventional culture and progressed to further embryonic stages, including hatching. In conclusion, porcine morulae and blastocysts can survive and remain unhatched during at least 72 h when stored at 20 °C in a BSA-containing medium.

High pre-freezing sperm dilution improves monospermy without affecting the penetration rate in porcine IVF

The high incidence of polyspermy is still an unresolved problem for the production of in vitro-produced porcine embryos. In this work, we modified the usual sperm processing sequence for in vitro fertilization (IVF), and the spermatozoa from four boars were frozen directly at a low sperm concentration of 20 × 10⁶ sperm/mL (high pre-freezing sperm dilution group; F20), thawed and processed for IVF in three replicates. Spermatozoa from the same boars frozen at a conventional concentration (1000 × 10⁶ sperm/mL) were used as the control group. The post-thaw sperm quality evaluation demonstrated that despite there being no differences in the percentage of motile spermatozoa between groups, the proportion of live spermatozoa with intact acrosomes was significantly higher in the F20 group than in the control. The in vitro penetration rate was also similar between groups; however, the co-incubation of oocytes with F20 sperm increased monospermy, IVF efficiency, cleavage rate and the efficiency of blastocyst formation compared with the results for oocytes co-incubated with control spermatozoa. These results indicate, for the first time, that a high pre-freezing sperm dilution increases monospermy without affecting penetration rates, thereby increasing blastocyst formation.

Importance of oil overlay for production of porcine embryos in vitro

Technologies to edit the zygote genome have revolutionized biomedical research not only for the creation of animal models for the study of human disease but also for the generation of functional human cells and tissues through interspecies blastocyst complementation technology. The pig is the ideal species for these purposes due to its great similarity in anatomy and physiology to humans. Emerging biotechnologies require the use of oocytes and/or embryos of good quality, which might be obtained using in vitro production (IVP) techniques. However, the current porcine embryo IVP systems are still suboptimal and result in low monospermic fertilization and blastocyst formation rates and poor embryo quality. During recent years, intensive investigations have been performed to evaluate the influence of specific compounds on gametes and embryos and to avoid the use of undefined supplements (serum and serum derivate) in the incubation media. However, little consideration has been given to the use of the mineral oil (MO) to overlay incubation droplets, which, albeit being a routine component of the IVP systems, is a totally undefined and thus problematic product for the safety of gametes and embryos. In this review, we provide an overview on the advantages and disadvantages of using MO to cover the incubation media. We also review one important concern in IVP laboratories: the use of oils containing undetected contamination. Finally, we discuss the effects of different types of oils on the in vitro embryo production outcomes and the transfer of compounds from oil into the culture media.

The overlaying oil type influences in vitro embryo production: differences in composition and compound transfer into incubation medium between oils

The oil overlay micro-drop system is widely used for cultures of mammalian gametes and embryos. We evaluated hereby the effects of two unaltered commercial oils- Sigma mineral oil (S-MO) and Nidoil paraffin oil (N-PO)-on in vitro embryo production (IVP) outcomes using a pig model. The results showed that while either oil apparently did not affect oocyte maturation and fertilization rates, S-MO negatively affected embryo cleavage rates, blastocyst formation rates, and, consequently, total blastocyst efficiency of the system. No differences in the oxidation state were found between the oils or culture media incubated under S-MO or N-PO. Although both oils slightly differed in elemental composition, there were no differences in the concentrations of elements between fresh media and media incubated under oils. By contrast, we demonstrated clear oil-type differences in both the composition of volatile organic compounds (VOC) and the transfer of some of these VOC´s (straight-chain alkanes and pentanal and 1,3-diethyl benzene) to the culture medium, which could have influenced embryonic development.

Developmental competence of porcine genome-edited zygotes

Genome editing in pigs has tremendous practical applications for biomedicine. The advent of genome editing technology, with its use of site-specific nucleases-including ZFNs, TALENs, and the CRISPR/Cas9 system-has popularized targeted zygote genome editing via one-step microinjection in several mammalian species. Here, we review methods to optimize the developmental competence of genome-edited porcine embryos and strategies to improve the zygote genome-editing efficiency in pigs.

Effects of meiotic inhibitors and gonadotrophins on porcine oocytes in vitro maturation, fertilization and development

This study evaluated the effect of three reversible meiotic inhibitors (MINs) and their interaction with gonadotrophins (Gns) on the meiotic maturation and developmental competence of porcine oocytes. In experiment 1, the oocytes were matured for 22 hr in the presence or absence of dbcAMP (1 mM), cycloheximide (7 μM) or cilostamide (20 μM) with or without Gns, and for an additional 22 hr in the absence of MINs and Gns. At 22 hr of maturation, regardless of the presence of Gns, a higher proportion (p < .001) of oocytes cultured in the presence of MINs were effectively arrested at the germinal vesicle stage compared with the oocytes cultured without MINs. At 44 hr of maturation, the proportion of oocytes that reached MII was higher (p < .05) in groups with Gns compared with groups without Gns. In experiment 2, oocytes that were matured as in experiment 1 were inseminated and cultured for 7 days to evaluate fertilization parameters and blastocyst formation. Only oocytes from the dbcAMP + Gns group had higher (p < .05) efficiency of fertilization compared with the other treatment groups. The presence of dbcAMP during maturation also increased (p < .05) blastocyst formation and efficiency of blastocyst formation in both the presence and absence of Gns. These results indicate that the interaction of Gns with the tested MINs improved meiotic progression. In addition, regardless of supplementation with Gns, the presence of dbcAMP during the first maturation period increased and even doubled the capacity of oocytes to develop to the blastocyst stage.

Effective vitrification and warming of porcine embryos using a pH-stable, chemically defined medium

The use of pH-stable media would simplify embryo vitrification and the warming of porcine embryos and might facilitate the application of embryo transfer in practice. In this work, we investigated whether a pH-stable basal medium constituted of Tyrode’s lactate medium, polyvinyl alcohol, and HEPES for buffering was suitable for porcine embryo vitrification warming in place of the conventional gas-equilibrated media. A high percentage (>90%) of embryos survived vitrification and warming in this medium, achieving in vitro survival rates similar to embryos vitrified-warmed using the conventional protocol and their fresh counterparts. The pH-stable medium did not affect the in vivo developmental competence of the vitrified-warmed embryos. A farrowing rate of 71.4% (5/7) with 10.4 ± 3.1 piglets born was obtained for the embryos vitrified and warmed in this medium and transferred to selected recipients. This medium will enable the use of simple, safe and standardized protocols for the vitrification and warming of porcine embryos for optimal embryo survival and quality when applied under field conditions. This study opens new possibilities for the widespread use of embryo transfer in pigs.

The Recipients' Parity Does Not Influence Their Reproductive Performance Following Non-Surgical Deep Uterine Porcine Embryo Transfer

With the development of the non-surgical deep uterine (NsDU) embryo transfer (ET) technology, the commercial applicability of ET in pigs is now possible. There are, nevertheless, many factors that influence NsDU-ET effectiveness that need to be addressed. The aim of this study was to evaluate the effects of the weaned recipients' parity on fertility and prolificacy following NsDU-ET. The recipients (n = 120) were selected based on their reproductive history and body condition and grouped into three categories according to their parity: primiparous sows, sows of parity 2 and sows of parities from 3 to 5. Thirty fresh embryos (morulae and unhatched blastocysts) were non-surgically transferred into one uterine horn of each recipient. It was possible to insert the NsDU-ET catheter through the cervix along a uterine horn in 98.3% of the recipients. The parity had no influence on the difficulty grade of the insertions or on the percentage of correct insertions. The cervix and uterine wall were not perforated during the insertions, and vaginal discharge was not observed after transfer in any of the recipients. There were no differences in the pregnancy rates (74.8%), farrowing rates (71.2%) or litter sizes (9.6 ± 3.3) between groups. Also, there were no differences between groups regarding to the piglets' birthweights or piglet production efficiency. In conclusion, these results demonstrate that weaned sows from parity 1 to 5 are appropriate to be used as recipients in NsDU-ET programs, which increase the possibilities for the utilization of ET in the recipient farms.

Recent advances toward the practical application of embryo transfer in pigs

Porcine embryo transfer (ET) technology has been in demand for decades because of its potential to provide considerable improvements in pig production with important sanitary, economic, and animal welfare benefits. Despite these advantages, the commercial use of ET is practically nonexistent. However, the two main obstacles hindering the commercial use of ET in pigs in the past several decades (i.e., surgical transfer and embryo preservation) have recently been overcome. A technique for nonsurgical deep-uterine (NsDU) ET of nonsedated gilts and sows, which was seemingly an impossible challenge just a few years ago, is a reality today. The improvements in embryo preservation that have been achieved in recent years and the excellent reproductive performance of the recipients after the NsDU-ET technique coupled with short-term and long-term-stored embryos represent essential progress for the international trade of porcine embryos and the practical use of ET by the pig industry. This review focuses, with an emphasis on our own findings, on the recent advances in embryo preservation and NsDU-ET technologies, which are starting to show potential for application under field conditions.

Heat-shock protein A8 restores sperm membrane integrity by increasing plasma membrane fluidity

The constitutive 70  kDa heat-shock protein, HSPA8, has previously been shown to contribute to the long-term survival of spermatozoa inside the mammalian female reproductive tract. Here, we show that a recombinant form of HSPA8 rapidly promotes the viability of uncapacitated spermatozoa, the ability of spermatozoa to bind to oviductal epithelial cells, enhances IVF performance, and decreases sperm mitochondrial activity. Fluorescence recovery after photobleaching revealed that the repair of membrane damage is achieved by an almost instantaneous increase in sperm membrane fluidity. The ability of HSPA8 to influence membrane stability and fluidity, as well as its conserved nature among mammalian species, supports the idea that this protein protects sperm survival through membrane repair mechanisms. Free Persian abstract A Persian translation of the abstract is freely available online at http://www.reproduction-online.org/content/147/5/719/suppl/DC1.

Drug interactions with sunitinib

PURPOSE

Sunitinib is a tyrosine kinase inhibitor indicated for the treatment of gastrointestinal stromal tumor, advanced renal cell carcinoma, and pancreatic neuroendocrine tumors. The aim of this article is to describe the pharmacological interactions between sunitinib and commonly prescribed drugs.

METHOD

We reviewed available information on pharmacological interactions between sunitinib and concomitantly prescribed drugs. Drugs were grouped into different therapeutic groups according to the Anatomical Therapeutic Chemical (ATC) classification.

RESULTS

Sunitinib interacts with CYP3A4 inducers or inhibitors and with P-glycoprotein and ABCG2 substrates. Pharmacodynamic interactions with drugs have also been found.

CONCLUSION

Current information on drug interactions between sunitinib and other drugs is scarce and most of the times it is difficult to apply to clinical practice. Even so, this difficulty in managing drug interactions should not be a reason to ignore them as they can help to explain intolerances and treatment failures.

The effects of superovulation of donor sows on ovarian response and embryo development after nonsurgical deep-uterine embryo transfer

This study aimed to evaluate the effectiveness of superovulation protocols in improving the efficiency of embryo donors for porcine nonsurgical deep-uterine (NsDU) embryo transfer (ET) programs. After weaning (24 hours), purebred Duroc sows (2-6 parity) were treated with 1000 IU (n = 27) or 1500 IU (n = 27) of eCG. Only sows with clear signs of estrus 4 to 72 hours after eCG administration were treated with 750 IU hCG at the onset of estrus. Nonhormonally treated postweaning estrus sows (n = 36) were used as a control. Sows were inseminated and subjected to laparotomy on Days 5 to 6 (Day 0 = onset of estrus). Three sows (11.1%) treated with the highest dosage of eCG presented with polycystic ovaries without signs of ovulation. The remaining sows from nonsuperovulated and superovulated groups were all pregnant, with no differences in fertilization rates among groups. The number of CLs and viable embryos was higher (P < 0.05) in the superovulated groups compared with the controls and increased (P < 0.05) with increasing doses of eCG. There were no differences among groups in the number of oocytes and/or degenerated embryos. The number of transferable embryos (morulae and unhatched blastocysts) obtained in pregnant sows was higher (P < 0.05) in the superovulated groups than in the control group. In all groups, there was a significant correlation between the number of CLs and the number of viable and transferable embryos, but the number of CLs and the number of oocytes and/or degenerated embryos were not correlated. A total of 46 NsDU ETs were performed in nonhormonally treated recipient sows, with embryos (30 embryos per transfer) recovered from the 1000-IU eCG, 1500-IU eCG, and control groups. In total, pregnancy and farrowing rates were 75.1% and 73.2%, respectively, with a litter size of 9.4 ± 0.6 piglets born, of which 8.8 ± 0.5 were born alive. There were no differences for any of the reproductive parameters evaluated among groups. In conclusion, our results demonstrated the efficiency of eCG superovulation treatments in decreasing the donor-to-recipient ratio. Compared with nonsuperovulated sows, the number of transferable embryos was increased in superovulated sows without affecting their quality and in vivo capacity to develop to term after transfer. The results from this study also demonstrate the effectiveness of the NsDU ET procedure used, making possible the commercial use of ET technology by the pig industry.

Suitability and effectiveness of single layer centrifugation using Androcoll-P in the cryopreservation protocol for boar spermatozoa

The goal of the present experiment was to evaluate the suitability and effectiveness of single layer centrifugation (SLC), using the pig-specific colloid Androcoll-P, as a routine procedure for selecting boar spermatozoa for cryopreservation. The study focuses special attention on the effectiveness of SLC for processing a whole sperm rich ejaculate fraction and the fertilizing ability of frozen-thawed (FT) sperm selected using SLC prior to freezing. Thirteen sperm rich ejaculate fractions (one per boar) were split into three aliquots. Two aliquots of 15 and 150mL were SLC-processed (500×g for 20min) using 15 and 150mL (v/v) of Androcoll-P-Large and Androcoll-P-XL, respectively. The third aliquot remained un-processed as a control. The percentages of spermatozoa that were morphologically normal and showed rapid and progressive motility (assessed by CASA) spermatozoa were higher (P<0.01) and those with fragmented nuclear DNA (sperm chromatin dispersion test) were lower (P<0.01) after SLC than control semen samples, regardless of the Androcoll-P used. The recovery rates of total, motile, viable (flow cytometric evaluated after staining with H-42, PI and FITC-PNA) and morphologically normal spermatozoa ranged between 20 and 100% and those with intact nuclear DNA ranged between 60 and 100%, irrespective of the Androcoll-P used. Thereafter, the semen samples were cryopreserved using a standard 0.5-mL straw freezing protocol. Post-thaw percentages of sperm motility (both total motility and rapid progressive motility), viability and intact nuclear DNA were higher (P<0.05) in SLC-processed than in control semen samples, irrespective of the Androcoll-P used. SLC-processing also improved the in vitro fertilizing ability of FT-sperm (679 in vitro matured oocytes inseminated with a viable sperm:oocyte ratio of 300:1 and coincubated for 6h), measured as the percentage of penetrated oocytes and the mean number of swollen sperm heads and/or male pronuclei in penetrated oocytes. However, there was no effect of SLC-processing on the in vitro ability of putative zygotes to develop to blastocysts. Overall these results indicate that SLC-processing of boar ejaculates using Androcoll-P improves the quality and fertilizing ability of cryosurvival boar sperm. However, efforts should be made to ensure continued high recovery yields before considering the inclusion of SLC as a routine procedure in the cryopreservation protocol of boar ejaculates.

Survival and Fertility of Boar Spermatozoa After Freeze-Thawing in Extender Supplemented With Butylated Hydroxytoluene

This study evaluated the protective effect of butylated hydroxytoluene (BHT), a lipid-soluble antioxidant, against cryopreservation injuries to boar spermatozoa. In experiment 1, the lowest BHT concentrations able to reduce lipid peroxidation in boar spermatozoa were determined. Nine BHT concentrations (ranging from 0.025 to 3.2 mM) were evaluated, and the lowest (P <.05) production of malondialdehyde (MDA), as an indicator of lipid peroxidation, was obtained when BHT ranged from 0.2 to 1.6 mM. In experiment 2, sperm survivability was evaluated when BHT was added to a postthaw freezing extender by measuring the degree of sperm lipid peroxidation (using MDA production) and by measuring parameter such as motility, plasma membrane and acrosome integrity, and cell apoptosis. The ability of thawed spermatozoa to fertilize in vitro-matured oocytes and of embryos to develop to the blastocyst stage in vitro was also assessed. Pooled sperm-rich fractions collected from 3 mature Pietrain boars were frozen in 0.5-mL straws after dilution with lactose-egg yolk-glycerol-Orvus ES Paste extender supplemented with 0, 0.2, 0.4, 0.8, and 1.6 mM BHT. Postthaw sperm survival, evaluated 30 and 150 minutes after thawing, was higher in BHT-treated spermatozoa, being significant (P <.05) when the freezing extender was supplemented with 0.2, 0.4, and 0.8 mM BHT. The addition of BHT to the freezing extender resulted in a significant (P <.05) decrease in the MDA concentration in thawed spermatozoa, irrespective of the level of BHT used. BHT had no effect on oocyte cleavage rates, but the development to blastocyst was improved for embryos derived from spermatozoa frozen in extender supplemented with 0.4 mM BHT (16% vs 29% of blastocysts per total oocytes; P <.05). In conclusion, under the conditions tested in the present study, the addition of BHT to the freezing extender improved the overall efficiency of thawed boar spermatozoa.

Does Seminal Plasma PSP-I/PSP-II Spermadhesin Modulate the Ability of Boar Spermatozoa to Penetrate Homologous Oocytes In Vitro?

Low concentration (0.15 mg per million of spermatozoa) of seminal plasma-derived PSP-I/PSP-II spermadhesin heterodimer is able to preserve the viability of highly extended boar spermatozoa. Whether spermatozoa also keep their fertilizing capacity is not yet known. The present study evaluated the effect of exposing freshly extended and frozen-thawed boar spermatozoa (10 million/mL) to PSP-I/PSP-II (1.5 mg/mL) for 30 or 120 minutes on sperm characteristics and the outcome of in vitro penetration of immature (IM) and in vitro matured (IVM) homologous oocytes, aiming to identify this spermadhesin as a suitable modulator for sperm-handling protocols. Although exposure to the heterodimer improved sperm viability and motility without increasing the levels of sperm acrosome exocytosis in both freshly extended and frozen-thawed spermatozoa, this pretreatment did not affect sperm penetration rates or sperm numbers per oocyte when pretreated fresh spermatozoa were coincubated with IM or IVM oocytes compared with controls. When cryopreserved spermatozoa were tested, however, on IVM oocytes, already a 30-minute preincubation exposure to PSP-I/PSP-II showed a significant blocking effect on penetration rate (from 90% to 32%, P < .05) and on mean sperm numbers per oocyte (2.9 to 1.6, P < .05). To disclose the nature of this paradox, frozen-thawed spermatozoa were cleansed (by centrifugation in saline bovine serum albumin or through Percoll density gradient separation) and the procedure repeated. Oocyte penetration (but not number of spermatozoa per oocyte) increased (P < .05) when spermatozoa were cleansed with Percoll compared with either washed or unwashed controls (53% vs 13% vs 31%, respectively). In addition, the percentages of polyspermic oocytes remained lower than control (38.5% vs 68.7%, respectively; P < .05). In conclusion, the results confirm that exposure of fresh or frozen-thawed boar spermatozoa to a low dose of seminal PSP-I/PSP-II spermadhesin preserves sperm viability and motility in vitro. Although there was no obvious influence of the heterodimer on the capability of freshly extended boar spermatozoa to penetrate homologous oocytes (either IM or IVM), PSP-I/PSP-II exerted a deleterious effect when frozen-thawed spermatozoa were used to penetrate IVM oocytes. Such an effect of cryopreservation seems to a certain extent reversible, since cleansing of the sperm surface decreased, at least partially, this blocking effect, increasing both penetration and the monospermic rates.

Non-surgical deep intrauterine transfer of superfine open pulled straw (SOPS)-vitrified porcine embryos: evaluation of critical steps of the procedure

Previous trials achieved extremely poor results when using the one-step warming method in a syringe in combination with non-surgical deep intrauterine transfer (NET) of superfine open pulled straw (SOPS)-vitrified embryos. This study aimed to assess the effect of the warming procedure on the in vitro and in vivo development of SOPS-vitrified embryos. The effect of the passage of the vitrified-warmed (VW) embryos through the NET catheter was also evaluated. Groups of 4 to 6 morulae and blastocysts, collected from weaned sows, were SOPS-vitrified in 1 μL of vitrification medium, warmed by the one-step warming method in a dish or in a 1-mL syringe and cultured in vitro for 48 h to evaluate the embryo survival (ES) and hatching rates (HR). Warming in syringe had a deleterious effect (P < 0.05) on the in vitro ES (60.5 ± 10.4%) and HR (39.6 ± 9.5%) of VW embryos in comparison with embryos warmed in a dish (85.4 ± 10.6% and 69.0 ± 8.4%, respectively). This decreased embryonic development was due to the increased time required between the removal of the straws from the liquid nitrogen and the contact of the embryos with the warming medium when the warming was performed in a syringe in comparison with that for the warming in a dish. After verifying that the passage of VW embryos through the NET catheter does not have a damaging effect on their further in vitro development, the negative effect of warming in a syringe was also confirmed after NET. Fifteen fresh and SOPS-vitrified embryos warmed in a syringe or in a dish were transferred to each recipient (n = 28) and recovered 24 h later to assess their developmental progression. All embryos from the syringe group were found to have degenerated at recovery. The in vivo ES and HR from the dish group (80.4 ± 3.4% and 14.2 ± 7.2%, respectively) were lower (P < 0.05) than those from the fresh group (94.0 ± 4.1% and 36.8 ± 7.8%, respectively). Combining the warming in a dish and the NET procedure, 35 VW embryos were transferred to each of 10 gilts. Five recipients farrowed an average of 10.4 ± 0.9 piglets. In conclusion, the method of one-step warming in a syringe has a negative effect on the in vitro and in vivo viability of SOPS-vitrified porcine embryos. In addition, NET of SOPS-vitrified embryos warmed by the one-step method in a dish showed promising reproductive performance of recipients. However, despite the great potential of this technology, further developments are required for large-scale commercial applications.

Unusual systemic metastases of malignant seminoma in a dog

Unilateral enlargement of left testicle and scrotum was detected in an 8-year-old West Highland White Terrier. The histopathological diagnosis after surgery was a seminoma (SEM) tumour, and a diagnosis of metastatic foci was also detected in vaginal tunic and scrotum. Two months later, new metastatic SEM foci in the skin were diagnosed. Twenty-two months after the initial orchiectomy new multiple cutaneous nodules and a swelling of periesophageal structures were observed. Finally, the necropsy revealed multiple malignant metastatic SEM focus. To the author's knowledge, this is the first description of a canine SEM with unusual widespread metastasis on the base of tongue, soft palate, trachea and pericardium.

Vitrification and warming of in vivo-derived porcine embryos in a chemically defined medium

The aim of this study was to design a protocol for vitrification and warming of porcine embryos in a chemically defined medium. A total of 663 morulae and blastocysts were collected from weaned crossbred sows (Large White-Landrace) 5 to 6 d after estrus and vitrified with the Superfine Open Pulled Straw method. In Experiment 1, embryos were vitrified using as a basic medium TCM-199-HEPES supplemented with 20% newborn calf serum (NBCS) or with 0, 0.1%, 0.5%, or 1% polyvinyl alcohol (PVA). Nonvitrified embryos were used as a fresh control group. Survival and hatching rates were evaluated after 72 h of in vitro culture to assess embryo viability. In addition, some hatched blastocysts derived from morulae and blastocysts were processed to determine the total cell number and the cell proliferating index as measures of their quality. Within each stage of embryo development, the different vitrification groups and the fresh control group showed similar high embryo survival (range, 70.5+/-7.1% to 84.9+/-8.1% and 85.3+/-8.1% to 98.4+/-8.2% for morulae and blastocysts, respectively) and hatching rate (range, 46.3+/-10.1% to 66.7+/-11.2% and 73.7+/-11.3% to 89.4+/-11.2% for morulae and blastocysts, respectively) and quality after in vitro culture. In Experiment 2, embryos were vitrified using 0.1% PVA and warmed with TCM-199-HEPES-0.13 M sucrose supplemented with 20% NBCS or either 0 or 0.1% PVA. Nonvitrified embryos were used as a fresh control group. As in Experiment 1, no significant differences were detected in embryo survival (range, 67.9+/-6.6% to 74.5+/-6.6% and 91.9+/-7.0% to 99.5+/-6.3% for morulae and blastocysts, respectively) and hatching rate (range, 47.0+/-7.2% to 64.8+/-9.9% and 89.4+/-7.4% to 98.2+/-6.9% for morulae and blastocysts, respectively) and quality among the warming groups or among vitrified and fresh control embryos. In both experiments, the developmental embryo stage influenced the survival and hatching rates, as well as the number of cells (P<0.01), with the blastocyst stage yielding the best results. In conclusion, PVA can be used as a substitute for serum in vitrification and warming solutions without detrimental effects on the in vitro development of in vivo-derived porcine morulae and blastocysts.

Pre-pubertal Di(2-ethylhexyl) Phthalate (DEHP) Exposure of Young Boars Did Not Affect SpermIn vitroPenetration Capacity of Homologous Oocytes Post-puberty

Di(2-ethylhexyl) phthalate (DEHP), a plastic softener used in polyvinylchloride (PVC) products (e.g., plastic bags and medical equipment), has been reported to have toxic effects on animal reproduction and is considered an environmental hazard based, mostly, on rodent studies. However, the doses used in these studies are often considerably higher than that presumed in human exposure. In the present study we used young boars as model animals to assess the effects of pre-pubertal DEHP exposure on the ability of spermatozoa to penetrate homologous oocytes in vitro. Eight pairs of cross-bred male boar siblings were used. One brother in each pair became, at random, the test animal exposed to DEHP per os, three times a week, from 3 to 7 weeks of age while the other acted as the control, i.e., placebo-exposed. Semen was collected and frozen between 8 and 9 months of age and stored until spermatozoa were evaluated for their ability to in vitro penetrate in vitro-matured homologous oocytes post-thaw. Both the penetration rate and the number of spermatozoa per oocyte were considered within expected ranges for frozen boar semen of good quality. Penetration rate did not significantly differ (p > 0.05) between the groups with DEHP-exposed: 50%; control: 59%, which could be owing to a large variation between boars, and between replicates. The number of spermatozoa in the ooplasm was low and similar (p > 0.05) between the groups with DEHP-exposed: 1.5 and the control: 1.7. Under the conditions of the present experiment, pre-pubertal exposure to DEHP does not seem to cause a deleterious effect on the in vitro fertilizing ability of frozen spermatozoa post-puberty.

Improving the efficiency of insemination with sex-sorted spermatozoa

The sorting of X- and Y-chromosome-bearing spermatozoa by flow cytometry is nowadays one of the most apt assisted-reproduction technologies in livestock production. Potential economic and biological benefits, as well as those related to easier management of herds, have been reported arising out of the application of this technique, especially in cattle. Yet, the sex-sorting procedure induces damage to spermatozoa, affecting their function and fertilizing ability. Different species present varying degrees of susceptibility to damage from the sorting process and each has its own requirements for sex-sorted insemination procedures. Thus, several new protocols and strategies have been designed for the handling of sorted spermatozoa, with the main objective of optimizing their fertilizing ability and the consequent application of flow-cytometric sex-sorting technology. This article reviews current advances in this technology, pointing out the components to be improved before this technology may be widely applied in different domestic species.

Optimal characteristics of spermatozoa for semen technologies in pigs

Despite the great potential of sperm technologies such as sperm cryopreservation and sperm sex sorting for the improvement of different aspects of swine production, artificial insemination with fresh or stored semen is currently the only sperm technology used at a commercial scale in the pig industry. The lower reproductive performance associated with the use of these sperm technologies is the reason for such limited use. Since optimal characteristics are required for successful application of frozen-thawed and sex-sorted boar spermatozoa, the present paper summarises the value of the current available methods for their functional assessment as well as the effects of these technologies on boar sperm functionality. In addition, strategies developed to reduce sperm damage and improve the yields of both sperm technologies in swine production are also reviewed with particular attention to the contributions of the authors.

In vitro maturation of porcine oocytes with retinoids improves embryonic development

In the present study, the effects of retinoid metabolite administration during in vitro maturation (IVM) on oocyte maturation, parameters of in vitro fertilisation (IVF) and embryo development were examined. Varying concentrations of 9-cis retinoic acid (RA; 0, 5, 50 and 500 nm; Experiment 1) and all-trans retinol (ROH; 0, 125, 1250 and 12 500 nm; Experiment 2) were included in the maturation medium. Cumulus-oocyte complexes were matured in vitro and inseminated with frozen-thawed spermatozoa. Presumptive zygotes were cultured for 16 h to assess IVF parameters or for 7 days to assess embryo development and quality. In Experiment 1, the oocyte maturation rate to metaphase II was significantly decreased (P < 0.001), with values below 5%, in the presence of the highest concentration of RA (500 nm). However, 5 and 50 nm RA had no effect compared with control. Treatment with 5 nm RA improved the blastocyst development rate (P < 0.001). In Experiment 2, the oocyte maturation rate did not differ between 125 and 1250 nm ROH treatment groups and control. However, treatment with 12 500 nm ROH was deleterious because no matured oocytes were observed following the treatment. The penetration rate was lower in the group treated with 1250 nm ROH compared with the 125 nm ROH-treated and control groups, but the blastocyst formation rate did not differ among the three groups. In conclusion, 5 nm RA in the IVM medium significantly increased the blastocyst formation rate, suggesting that RA may play an important role during IVM.