Animal Reproduction最新文献

This study aimed to evaluate the effect of three inclusion levels of Opuntia ficus-indica mucilage (OFM) to the lactose-egg yolk extender on the quality of frozen-thawed boar semen. Semen samples (n=22) were split into four OFM treatments: 0.0 (control), 3.3, 6.7, or 10.0% OFM. The semen was packaged in 0.5 mL straws and frozen using conventional methods. The sperm motility, viability, membrane integrity (HOST), and morphology (intact acrosome and normal sperm) characteristics were evaluated immediately post-thaw. Additionally, sperm were incubated at 37 ºC during 3.5 h and monitored hourly in a termoresistance test (TRT) to assess sperm motility, viability, and membrane integrity, The study showed that adding OFM to the freezing extender significantly improved (P < 0.05) sperm quality characteristics, without affecting (P > 0.05) acrosome integrity or sperm abnormalities. Furthermore, the OFM addition improved (P < 0.05) the sperm viability and membrane integrity for up to 3.5 h of incubation. Results indicate that OFM can be added to the extender at a 6.7% OFM inclusion level to improve the quality of cryopreserved boar sperm.

This study investigates the protective effects of melatonin against heat exposure during PGF-induced luteal regression in rats. Seventy-five PMSG and hCG primed rats were divided into three groups: non-heat-exposure (NHE), heat-exposure (HE), and melatonin plus heat-exposure (M+HE). The HE group underwent daily heat exposure (41°C for 2 h) for 7 days, while the M+HE group received intraperitoneal injection of melatonin (10 mg/kg body weight) before each heat session. On Day 7, PGF was administered, and ovarian samples were collected at 0, 1, 2, 8, and 24 h post-PGF. One set of ovaries was processed for histological analysis, including H&E staining, immunohistochemistry, and transmission electron microscopy and the other set was processed for Western blot for apoptotic protein expression. Results showed that heat exposure increased ovarian weight, disrupted follicular development, and elevated ovarian apoptotic markers (Caspase-3 and Bax), leading to luteal cell damage. Melatonin preserved ovarian weight, improved follicular and luteal structure, reduced atretic follicles, and mitigated luteal cell degeneration. In addition, melatonin decreased apoptotic marker expression and the Bax/Bcl-2 ratio, particularly at 16 and 24 h. These findings suggest melatonin protects luteal cells from heat-induced apoptosis during PGF-triggered regression, supporting reproductive function.

The quality of pig sperm is one of the crucial determinants of reproductive ability, and sperm defects can shorten the reproductive life of boars and affect the production of offspring. During transcription and translation, the DAZAP1 gene exerts regulatory control over alternative splicing, thereby exerting influence on vital cellular processes including cell growth, development, and spermatogenesis. In this study, we employed second- and third-generation transcriptome sequencing techniques to isolate and identify the DAZAP1 gene and its transcripts using Banna mini-pig inbred line (BMI) testicular cDNA as a template. We identified three splice variants of the DAZAP1 gene, including ENSSSCT00000023438.4 (DAZAP1_X1), ENSSSCT00000051975.3 (DAZAP1_X2), and ENSSSCT00000074738.2 (DAZAP1_X3). Furthermore, the transcript DAZAP1_X2, was subjected to comprehensive analysis. The DAZAP1_X2 variant comprises 13 exons, with a coding sequence (CDS) length of 1254 bp (417 aa). Subsequently, enrichment analyses based on GO and KEGG pathways revealed that DAZAP1_X2 primarily participated in pathways associated with spermatogenesis, movement of the 9+2 cilium structure, germ cell development, gamete generation, and sexual reproduction. The ceRNA analysis identified three miRNAs interacting with DAZAP1_X2: ssc-miR-107, ssc-miR-127, and ssc-miR-1343, which were primarily linked to spermatogenesis. Both the testis and urethral bulb had significant levels of DAZAP1 expression, according to multi-tissue expression analysis. Subcellular localization indicated that the DAZAP1 was mainly distributed in the cell nucleus. DAZAP1 was critical for sperm formation and was essential for reproductive. These results shed light on the biological roles of DAZAP1 in pigs.

Ketosis is a significant metabolic disorder caused by negative energy balance (NEB). β-hydroxybutyrate (BHBA) is the most abundant circulating ketone body and is known to accumulate within follicular fluid. Although NEB and metabolic stress conditions have been associated with reduced fertility in cows, the effect of increased BHBA on the viability and functionality of bovine cumulus-oocyte complexes (COC) is poorly understood. The aim of this study was to determine the effects of BHBA on expansion, oxidative status, and endoplasmic reticulum (ER) stress in cumulus cells, oocyte nuclear maturation, and in vitro embryo production (IVP) in cattle. Cumulus-oocyte complexes were treated with 0, 2, or 4 mM of BHBA for 6, 12, 18, or 24 h during oocyte in vitro maturation (IVM.) Cumulus expansion and mRNA levels of genes related to cumulus expansion, oxidative status, ER stress, and autophagy were evaluated. The oocytes were fixed for nuclear maturation analysis at 24 h of IVM. In addition, after IVM with BHBA for 24 hours, cleavage and blastocyst rates were examined. No difference was observed in the rates of oocytes reaching metaphase II, cleavage, and blastocysts. Furthermore, the oxidative status and relative abundance of mRNA for genes associated with antioxidant enzymes and autophagy were not altered by BHBA in cumulus cells. However, BHBA altered the total area of the COC and increased the mRNA levels of genes associated with ER. In conclusion, BHBA affects the expansion and induces ER stress in bovine cumulus cells during IVM without compromising oocyte nuclear maturation, oxidative status, cleavage, and blastocyst rates.

Intensive semen collection often leads to "kidney yang deficiency" in male yaks, with symptoms like lethargy and poor semen quality. Our modified "Yijing Fang" was tested. Eight 3 - 6-year-old male yaks with this condition were split into treatment and negative control groups; four healthy yaks were a blank control. The treated yaks got the formula in feed for 5 days, then a 20-day break, repeating 3 times over 65 days. Semen was collected, and cAMP, cGMP, T/E2 levels, and mitochondrial apoptosis factors were analyzed. Results showed the formula boosted semen quality. cAMP and testosterone rose (p < 0.01), cGMP and estradiol fell (p < 0.01), cAMP/cGMP and T/E2 ratios climbed (p < 0.01). Bcl-2 upregulated, Bax, Cyt-C, and Caspase-3 downregulated (p < 0.01). In conclusion, the modified "Yijing Fang" is effective for yak reproduction, enhancing hormone secretion and reducing sperm apoptosis. Long-term studies are needed.

Artificial insemination (AI) in sheep presents variable results, especially when combined with estrus induction treatments during the anestrous period. Alternatives for obtaining better results without significantly altering the costs of hormonal protocols are essential because of the importance of this biotechnology in production systems. One alternative that potentially meets these requirements is double-AI. Therefore, this article aims to review the literature on double-cervical AI in sheep and identify gaps in existing knowledge. Double cervical superficial (CS) AI with frozen-thawed (F.T.) semen after estrus detection significantly increased pregnancy rates (PR) in most (6/8) evaluated studies, with an increase of 7 to 34.2 percentual points (p.p.), compared to single AI. Regarding fixed-time AI (FTAI), all studies used fresh (F) or chilled (C) semen, and no positive effects were observed for double FTAI in most cases (8/9). Most studies have not applied current estrous synchronization protocols and insemination doses. Therefore, further studies are needed to evaluate the potential benefits of double FTAI, especially using F.T. semen in combination with hormonal protocols and insemination doses aligned with current practices.

Sperm cells require time to adjust to lower temperatures. While some studies have established stabilization periods ranging from two to four hours for ovine semen, the exploration of longer periods of stabilization remains limited. The objective of the study is to evaluate the 12-hour refrigeration curve during ovine semen cryopreservation and the impact of a diluent medium containing egg yolk and liposomes. Eight mixed-breed rams (½ Dorper and ½ Santa Inês) provided two ejaculates each, divided into two groups. Group A used a commercial egg yolk-based diluent (Botu-Bov® - Botupharma Ltda, Brazil), while Group B used a commercial liposome-based diluent (OptiXcell®, IMV Technologies, France). Semen was packaged in French straws, cooled, cryopreserved, and thawed for analysis. Group A exhibited superior values (P < 0.05) in progressive motility (MP), progressive linear velocity (VSL), straightness (STR), and linearity (LIN) post-thawing and after 3 hours at 37°C (TTR). Conversely, Group B showed higher (P < 0.05) values for path velocity (VAP), curvilinear velocity (VCL), lateral head displacement amplitude (ALH) post-thawing, and VAP, VSL, VCL, and ALH after TTR. Flow cytometry revealed Group A's higher (P > 0.05) plasma and acrosomal membrane integrity and membrane stability. However, Group B exhibited greater (P > 0.05) superoxide anion generation and lipid peroxidation, indicative of higher oxidative stress. In conclusion, the egg yolk-based diluent outperformed the diluent containing liposomes in sperm kinetic parameters evaluated by CASA, although liposomes showed increased oxidative stress, 12 hours of refrigeration at 5.0°C is an alternative viable for semen cryopreservation in sheep.

Hypertension is an age-related pathology that causes a decline in the function of all organ systems, including the reproductive system, due to its association with increased oxidative stress and inflammation. The inflammatory cytokine levels increase as a result of hypertension and cause inflammation and tissue injury. Although high-intensity interval training (HIIT) has shown promise as a nondrug treatment for hypertensive individuals, its effects on the reproductive system of hypertensive individuals remain unknown. The aim of this study was to investigate the effects of HIIT on plasma hormone concentrations and the expression of inflammatory mediators in the testes of spontaneously hypertensive rats (SHRs). Male SHRs were divided into 2 groups: SHR (control, n=8) and HIIT (SHRs subjected to HIIT on a treadmill for 8 weeks, n=9) groups. The expression of inflammatory mediators (TNFα and IL-6) in the testes and testosterone, prolactin, and corticosterone concentrations in plasma were measured. No difference in TNFα expression was found between the groups. The groups also showed no significant differences in hormone levels. However, SHRs that underwent HIIT showed lower immunostaining for IL-6 in their testes than did SHRs that did not undergo HIIT training (P < 0.05) and the HIIT group presented lower lower systolic blood pressure than did the SHR group. We concluded that HIIT for two months reduces the BSP and IL-6 levels in the testes of hypertensive rats.

Elevated temperature-humidity index (THI) levels, common in subtropical summers, can impair bovine oocyte development by increasing reactive oxygen species (ROS) accumulation, leading to oxidative stress and reduced developmental competence. Alpha-tocopherol, a potent antioxidant, has the potential to mitigate these effects by scavenging ROS. However, its seasonal efficacy during bovine oocyte in vitro maturation (IVM) remains underexplored. This study evaluated the impact of 100 µM α-tocopherol supplementation during IVM on oocytes collected in spring (THI: 68.7±3) and summer (THI: 73±3) in Northern Uruguay. Oocytes underwent IVM, fertilization, and embryos were cultured in vitro until day 9 post-fertilization. Blastocysts were assessed for ROS levels, apoptosis, and the abundance of transcripts linked to development and oxidative stress. Results showed a season-specific response to α-tocopherol supplementation. While no significant effects were observed in spring, summer oocytes exhibited increased maturation, cleavage, and blastocyst rates, along with improved blastocyst quality characterized by reduced apoptosis and lower BAX transcript levels. These findings indicate that α-tocopherol supplementation during IVM enhances oocyte developmental competence under heat stress conditions, supporting its potential as a strategy to mitigate oxidative damage and improve bovine embryo production during summer.

It remains a problem to efficiently improve the boar sperm quality of liquid storage due to reactive oxygen species (ROS) accumulation. To reduce the effects of ROS on boar sperm, in this study, 1 μg/mL zinc oxide nanoparticles (ZnO NPs) was added into the extender of boar semen during liquid storage at 4°C and 17°C for 7 days. The finding revealed that sperm motility, viability, plasma membrane integrity (PMI) and acrosome integrity significantly increased when compared with the control group (P ˂ 0.05) Additionally, ZnO NPs significantly increased the levels of adenosine triphosphate (ATP), mitochondrial membrane potential (MMP), and antioxidation abilities (P ˂ 0.05) in boar sperm. Moreover, ZnO NPs could protect boar sperm from oxidative stress (OS) by inhibiting ROS-induced decrease of phosphorylation of PKA substrates (P-PKAs). Together, the current results suggest that ZnO NPs could be used as a novel antioxidant agent for semen preservation, which is helpful in improving the application of assisted reproductive technology in domestic animals.