Animal Reproduction Science最新文献

This study aimed to compare the inter-software and inter-observer reliability and agreement for the assessment of follicular and luteal morphometry and echotexture parameters in beef crossbreed females (3/8 Bos taurus indicus and 5/8 Bos taurus taurus). B-mode and color Doppler ultrasonographic ovarian images were obtained at specific time points of estradiol-progesterone-based protocols for timed artificial insemination (TAI). Sonograms were analyzed by two observers using a licensed (IASP1) and an open access (IASP2) software package. A total of 292 snap-shot sonograms were analyzed for morphometric parameters and 504 for echotexture parameters. inter-software reliability was judged moderate to excellent (ICC or CCC=0.73–0.98), whereas inter-observer reliability for morphometric parameters was deemed good to excellent (ICC or CCC=0.82–0.98). A small percentage (up to 10.95 %) of measured parameters fell outside the limits of inter-software and inter-observer agreement. For echotexture parameters, inter-software reliability varied widely (ICC or CCC=0.16–0.95) based on the size of regions of interest (ROI), while inter-observer reliability ranged from moderate to excellent (ICC or CCC= 0.71–0.97). The highest inter-software reliability for pixel value and heterogeneity value was observed for the corpus luteum (ICCs=0.81–0.95; P>0.05), followed by the peripheral follicular antrum (ICCs=0.75–0.78; P<0.05). However, lower reliability was determined for the follicular wall (ICCs=0.08–0.33; P<0.0001) and perifollicular stroma (ICCs=0.16–0.46; P<0.05). In conclusion, both software packages showed high reproducibility for morphometric measurements, while echotexture measurements were more challenging to replicate based on ROI sizes. Caution is advised when selecting ROI sizes for echotexture measurements in bovine ovaries.

Intrafollicular Transfer of Immature Oocytes (IFIOT) has emerged as an alternative to the currently used systems for bovine embryo production. This technique associates the rapid multiplication of bovine females under a completely in vivo culture condition, eliminating the need for superstimulatory hormones in the in vivo system (IVD) and the costly laboratory setup required for in vitro embryo production (IVP). Despite being a promising technique, the results obtained to date have been unsatisfactory for commercial use. Only approximately 10 % –12 % of viable embryos are recovered from the total number of injected oocytes, which limits their use in genetic improvement programs. IFIOT problems can occur in any of the steps involved; therefore, each step must be carefully examined to identify those that have the most negative impact on the final embryo recovery. This review summarizes the different studies conducted using the IFIOT to provide a comprehensive analysis of the main factors that can influence the effectiveness of this technique.

Present study describes the spawning induction of striped Snakehead, Channa striata using carp pituitary extract (CPE) and LH-RH agonist i.e. Buserelin (Glp-His-Trp-Ser-Tyr-Ser-tBu-Leu-Arg-Pro-NHEt). Total four treatments were designed under both hormones trail and treated as control group, T₁, T₂, and T₃ with three replications of each treatment. While breeders under all hormone treatments showed spawning performances, no spawning performance was observed in control group. Latency time after hormonal treatment was lowest (20–24 hrs) in case of CPE than Buserelin (25–30 hrs). Regarding to CPE, spawning, fertilization and hatching rate were higher with the increasing doses of CPE in different treatments. The highest mean ± Standard deviation spawning, fertilization and hatching rate were 85.60±8.58 %, 79.38±4.89 % and 64.33±6.60 % respectively in T₃ where dose of CPE was 80 mg kg⁻¹. Similarly, in case of Buserelin hormone highest spawning rate was found in T₃ (80.61±5.59) where dose of Buserelin was 0.80 µg kg⁻¹ body weight. Fertilization rate was on the level 48.57±5.99, 70.62±5.33 and 90.32±4.79 respectively for T₁, T₂, and T₃.Whilst, hatching rate was found 20.81±4.91, 37.11±4.50 and 61.33±6.61 in T₁, T₂, and T₃ treatments respectively. However, T₃ exhibited best performance regarding spawning, fertilization and hatching rate which were significantly higher than other two treatments.The current study revealed that spawning induction using carp pituitary extract and Buserelin is effective and might be useful for artificial breeding of Channa striata. Regarding to dose application i.e. 80 mg kg⁻¹ of CPE and 0.80 µg kg⁻¹ of Buserelin may be successfully applied to ovulation stimulation of Channa striata.

Several studies have demonstrated the correlation between Doppler velocimetric parameters of testicular artery and semen quality in domestic species, but in felines data are scarce. This study aimed to correlate the Doppler velocimetry of the testicular artery with sperm kinetics and sperm defects, in sedated and non-sedated cats. Forty tomcats were divided into two groups: sedated (SG; n=20) with dexmedetomidine (10 µm/kg) and ketamine (12 mg/kg), and non-sedated (NSG; n=20). The animals were subjected to ultrasound Doppler velocimetry of the distal supratesticular and marginal region of the testicular artery and subsequently orchiectomized. Epididymal tail spermatozoa were recovered and analyzed using a CASA system for motility, and morphology took place. Animals of SG presented a significantly higher velocity in the marginal region of the cat’s testicular artery [peak systolic velocity (PSV) 11.51 cm/s; end-diastolic velocity (EDV) 7.72 cm/s] compared to NSG (PSV 7.72 cm/s, P < 0.001; EDV 4.93 cm/s, P < 0.001). Sedated cats presented higher pulsatility and resistivity indexes than non-sedated cats. The supratesticular PSV of NSG was moderately correlated with major (r_s = 0621; P < 0.001) and total sperm defects (r_s = 0614; P < 0001). Doppler velocimetry was fairly correlated with minor, major, and total sperm defects. In conclusion, Doppler velocimetric evaluation emerges as an important possibility in the reproductive evaluation of tomcats, once the testicular artery hemodynamics were associated with sperm defects. However, it is advisable to carry out this evaluation in non-sedated animals. If sedation is necessary, peripheral vasoconstriction should be considered.

Escherichia coli (E. coli), a Gram-negative bacterium, is the primary pathogen responsible for endometritis in dairy cattle. The outer membrane components of E. coli, namely lipopolysaccharide (LPS) and bacterial lipoprotein, have the capacity to trigger the host's innate immune response through pattern recognition receptors (PRRs). Tolerance to bacterial cell wall components, including LPS, may play a crucial role as an essential regulatory mechanism during bacterial infection. However, the precise role of Braun lipoprotein (BLP) tolerance in E. coli-induced endometritis in dairy cattle remains unclear. In this study, we aimed to investigate the impact of BLP on the regulation of E. coli infection-induced endometritis in dairy cattle. The presence of BLP was found to diminish the expression and release of proinflammatory cytokines (IL-8 and IL-6), while concurrently promoting the expression and release of the anti-inflammatory cytokine IL-10 in endometrial epithelial cells (EECs). Furthermore, BLP demonstrated the ability to impede the activation of MAPK (ERK and p38) and NF-κB (p65) signaling pathways, while simultaneously enhancing signaling through the STAT3 pathway in EECs. Notably, BLP exhibited a dual role, acting both as an activator of TLR2 and as a regulator of TLR2 activation in LPS- and E. coli-treated EECs. In E. coli-infected endometrial explants, the presence of BLP was noted to decrease the release of proinflammatory cytokines and the expression of HMGB1, while simultaneously enhancing the release of anti-inflammatory cytokines. Collectively, our findings provide evidence that the bacterial component BLP plays a protective role in E. coli-induced endometritis in dairy cattle.

This study aims to investigate the influence of thymol on primordial follicle growth and survival, as well as on collagen fibers and stromal cells density in bovine ovarian tissues cultured in vitro. The activity of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), the thiol levels and the expression of mRNAs for SOD1, CAT, periredoxin 6 (PRDX6) and GPX1 were also investigated. Ovarian cortical tissues were cultured in α-MEM⁺ alone or with thymol (400, 800, 1600 or 3200 μg/mL) for six days. Before and after culture, the tissues were processed for histological analysis to evaluate follicular activation, growth, morphology, ovarian stromal cell density and collagen fibers. The levels of mRNA for SOD1, CAT, GPX1 and PRDX6 were evaluated by real-time PCR. The results show that tissues cultured with thymol (400 and 800 µg/mL) had increased percentages of normal follicles, when compared to tissues cultured in other treatments. At concentrations of 400 and 800 µg/mL, thymol maintained the rate of normal follicles similar to the uncultured control. In addition, 400 µg/mL thymol increased follicle activation, collagen fibers and stromal cell density of when compared to tissues cultured in control medium. The presence of 800 µg/mL thymol in culture medium increased CAT activity, while 400 or 800 µg/mL thymol reduced mRNA levels for SOD1, CAT and PRDX6, but did not alter GPX1 expression. In conclusion, 400 µg/mL thymol increases primordial follicle activation, preserves stromal cells, collagen fibers, and down-regulates expression of mRNA for SOD1, CAT and PRDX6 in cultured bovine ovarian tissues.

Irisin is a hormone secreted by muscle in response to exercise. The irisin receptor (IrisinR) is a heterodimer of integrin alpha V (ITGAV) and integrin beta 5 (ITGB5) subunits. Since irisin may mediate some beneficial effects of exercise on animal reproduction, we tested the hypothesis that bovine gonadotrophs express IrisinR and irisin stimulates luteinizing hormone (LH) and follicle stimulating hormone (FSH) secretion by gonadotrophs. Reverse transcription polymerase chain reaction was used to detect the mRNA expression of both ITGAV and ITGB5 in the anterior pituitary glands (APs) of post pubertal heifers and mouse gonadotroph cell line “LβT2.” Western blotting was used to detect protein expression in bovine APs. Immunofluorescence microscopy, utilizing the same antibody, visualized IrisinR on the plasma membrane of majority of gonadotrophs. We prepared AP cells from healthy postpubertal heifers, cultured them for 3.5 d, and treated them with increasing concentrations (0, 0.01, 0.1, 1, or 10 nM) of irisin for 5 min before either no treatment or gonadotropin-releasing hormone (GnRH) stimulation. After 2 h, media were harvested for LH and FSH assays. Irisin (0.1–10 nM) stimulated basal LH and FSH secretion, and these stimulatory effects were inhibited by the extracellular signal-regulated kinase or SMAD pathway inhibitors. In the presence of GnRH, irisin at 0.01–1 nM stimulated LH and FSH secretion. A higher dose of irisin (10 nM), however, suppressed the GnRH-induced LH and FSH levels. In conclusion, bovine gonadotrophs expressed IrisinR, and irisin controlled LH and FSH secretion from bovine gonadotrophs.

Sperm cryopreservation plays an important role in the artificial insemination (AI) industry of small ruminants. It, however the use of frozen-thawed goat semen is limited due to the insufficient number of sperm with good biological functions. Mitochondria are the most sensitive organelles to cryopreservation damage in sperm. This study was conducted to determine the effects of MitoQ, the mitochondrial-targeted antioxidant, in a plant-based extender on the quality parameters of Markhoz goat sperm after the freezing and thawing process. Semen samples were collected and diluted in the extender, divided into five equal aliquots and supplemented with 0, 1, 10, 100 and 1000 nM MitoQ and cryopreserved in liquid nitrogen. After thawing, sperm motility, membrane functionality, abnormal morphology, mitochondrial activity, acrosome integrity, lipid peroxidation (LPO), DNA fragmentation, reactive oxygen species (ROS) concentration, viability and apoptotic-like changes were measured. The use of 10 and 100 nM MitoQ resulted in higher (P≤0.05) total motility (TM), progressive motility (PM), viability, membrane functionality, mitochondrial activity, and acrosome integrity compared to the other groups. On the other hand, LPO, apoptotic-like changes, DNA fragmentation and ROS concentration were lower (P≤0.05) in MQ10 and MQ100 groups compared to the other groups. MitoQ has no effect (P>0.05) on sperm abnormal morphology and velocity parameters. In conclusion, MitoQ can reduce oxidative stress by regulating mitochondrial function during the cryopreservation process of buck sperm and could be an effective additive in the cryopreservation media to protect sperm quality.