Mechanisms of Reproductive Control in the Animals

This study aimed to investigate the selective effect of the reproductive tract mucus in cows that have consistently produced offspring of a single sex on X/Y spermatozoa. We collected mucus from the reproductive tract of cows that had given calvings to offspring of the same sex, or alternated between sexes, for more than five consecutive calvings. We evaluated the pH of reproductive tract mucus. Subsequently, we conducted a spermatozoa penetration assay; the proportions of X and Y spermatozoa after penetration were then identified by dual TaqMan qPCR and flow cytometry. This was followed by in vitro fertilization and embryo sex determination experiments. Immediately afterwards, computer-aided spermatozoa analysis was employed to analyze the spermatozoa that had penetrated through different types of mucus in the reproductive tract. The analysis indicated that the reproductive tract mucus of cows consistently producing male or female calves exhibited selectivity towards X/Y spermatozoa. The differences in the pH values of the reproductive tract mucus among cows continuously producing male calves, those continuously producing female calves, and those alternately giving birth to male and female calves were not significant (p ≥ 0.05). The outcome of dual TaqMan qPCR for cows consistently producing male calves was Y: 79.29 ± 4.28% vs. X: 21.67 ± 4.53%; for cows consistently producing female calves, the equation was Y: 25.05 ± 4.88% vs. X: 75.34 ± 5.13%. The results of flow cytometry processing revealed the following proportions: for cows consistently producing male calves: Y: 83.33 ± 5.52% vs. X: 17.23 ± 4.74%; for cows consistently producing female calves: Y: 24.81 ± 4.13% vs. X: 76.64 ± 4.21%. The outcomes of embryo sex determination for cows consistently producing male calves were as follows: male embryos vs. female embryos (79.60 ± 2.87% vs. 21.07 ± 2.51%); for cows consistently producing female calves, the outcomes for male embryos vs. female embryos were 25.58 ± 3.96% vs. 75.63 ± 3.55%. Computer-aided analysis revealed that the concentration of spermatozoa penetrating the reproductive tract mucus in cows alternating between male and female calves (9.09 ± 0.72 million/mL) was significantly higher than that in cows consistently producing male calves (6.01 ± 1.19 million/mL) and cows consistently producing female calves (5.61 ± 0.60 million/mL). There were no significant differences in spermatozoa motility, the proportion of progressive motile spermatozoa, and curvilinear, straight-line, and average path velocities. Collectively, these findings indicate that the reproductive tract mucus of cows consistently producing offspring of a single sex exhibits selectivity towards either X or Y spermatozoa. This finding is of great significance for studying the impact of maternal factors on offspring sex. Full article

Lactating oocytes consume a lot of energy during maturation, a large part of which comes from lipid metabolism. PPARγ is a key regulator of lipid metabolism. In this study, rosiglitazone (RSG), an activator of PPARγ, was added to a mature medium to investigate its effects on the levels of spindle and the chromosome arrangement, lipid deposition, reactive oxygen species (ROS), and glutathione (GSH) levels, oocyte secretion factors, apoptosis and lipid metabolism-related gene expression, and subsequent embryonic development during the maturation of sheep oocytes. The oocyte secretion factor affects gene expression related to apoptosis and lipid metabolism and subsequent embryonic development. The results showed that the proportion of spindle and normal chromosome arrangements increased in the 5 μM RSG treatment group, the lipid content increased after cell maturation, the ROS level decreased, and the GSH level increased. The expressions of oocyte secretion factor (GDF9 and BMP15), anti-apoptosis gene (BCL2), and lipid metabolism-related genes (ACAA1, CPT1A, PLIN2) were increased in the 5 μM treatment group. Finally, the development of blastocysts was examined. After the oocytes were treated with 5 μM RSG, the blastocyst rate and the gene expression of the totipotency gene (OCT4) were increased. It was concluded that increasing PPARγ activity during ovine oocyte maturation could promote lipid metabolism, reduce oxidative stress, and improve the ovine oocyte maturation rate and subsequent embryo development. Full article

Luteinizing hormone (LH) and follicle-stimulating hormone (FSH) play key roles in regulating testosterone secretion and spermatogenesis in male mammals, respectively, and they maintain the fertility of male animals by binding to their corresponding receptors. We designed and prepared a recombinant LH receptor (LHR) subunit vaccine and a recombinant FSH receptor (FSHR) subunit vaccine and used male Sprague Dawley (SD) rats as a model to examine their effects on testicular development, spermatogenesis, and testosterone secretion in prepubertal and pubertal mammals. Both vaccines (LHR-DTT and FSHR-DTT) significantly decreased the serum testosterone level in prepubertal rats (p < 0.05) but had no effect on the testosterone secretion in pubertal rats; both vaccines decreased the number of cell layers in the seminiferous tubules and reduced spermatogenesis in prepubertal and pubertal rats. Subunit vaccine FSHR-DTT decreased the sperm density in the epididymis in both prepubertal and pubertal rats (p < 0.01) and lowered testicular index and sperm motility in pubertal rats (p < 0.05), whereas LHR-DTT only reduced the sperm density in the epididymis in pubertal rats (p < 0.05). These results indicate that the FSHR subunit vaccine may be a promising approach for immunocastration, but it still needs improvements in effectiveness. Full article

The purpose of the present research was to define ovarian follicular dynamics and plasma endocrine profiles in response to a single PGF_2α injection, administered indiscriminately during the breeding season of Barbari goats. Ovarian dynamics were observed at every 12 h interval by using B mode ultrasonography, blood samples for hormonal analysis such as estradiol 17β and progesterone were collected at every 12 h interval, and bucks with aprons were used to identify standing estrus at every 6 h interval. Relative to PGF_2α, the start of standing estrus and ovulation differ (p < 0.05) between early- (n = 7), intermediate- (n = 6), and late-responding (n = 6) goats. The highest plasma level of estradiol 17β was detected 12 h prior to ovulation. The average diameter of the ovulatory follicle and length of standing estrus were comparable (p > 0.05) between the goats. The corpus luteum degenerated more quickly (p < 0.05) in early- than intermediate- and late-responding goats. Dominant follicle diameter and estradiol 17β concentration also differ (p < 0.05) among groups. Although the plasma level of progesterone did not vary (p = 0.065), the variation in progesterone concentration with time differed (p < 0.05) amongst the goats. As a result, this research indirectly reveals that the beginning of standing estrus, end of estrus, and ovulation after PGF_2α might fluctuate in Barbari goats because of follicular and hormonal dynamics during the luteal phase. Full article

Unfavorable conditions compromise animal reproduction by altering the ovarian granulosa cells’ follicular dynamics and normal physiological function (GCs), eventually resulting in oxidative damage and cell apoptosis. Activin is produced in the GCs and plays a vital role in folliculogenesis. This study investigated the effects of activin A (ACT-A) treatment in vitro on the apoptosis of porcine GCs and the underlying molecular mechanism. We found that ACT-A could attenuate the apoptosis of the GCs and enhance the synthesis of estrogen (E2). ACT-A also enhanced FSH-induced estrogen receptor-β (ERβ) expression, inhibiting ERβ aggravated intracellular accumulation of the reactive oxygen species (ROS) and apoptosis. The E2 levels in the culture medium, the mRNA expression pattern of the apoptosis-related genes (CASPASE 3, BCL2, and BAX), steroidogenesis-related gene (CYP19A1), and cell viability were analyzed to confirm the results. In summary, this study indicated the protective role of ACT-A in apoptosis by attenuating the ROS accumulation through ERβ. These results aim to enhance the follicular functions and improve animal reproductive performance. Full article

This study investigates the implementation of deep learning (DL) approaches to the fertile egg-recognition problem, based on incubator images. In this study, we aimed to classify chicken eggs according to both segmentation and fertility status with a Mask R-CNN-based approach. In this manner, images can be handled by a single DL model to successfully perform detection, classification and segmentation of fertile and infertile eggs. Two different test processes were used in this study. In the first test application, a data set containing five fertile eggs was used. In the second, testing was carried out on the data set containing 18 fertile eggs. For evaluating this study, we used AP, one of the most important metrics for evaluating object detection and segmentation models in computer vision. When the results obtained were examined, the optimum threshold value (IoU) value was determined as 0.7. According to the IoU of 0.7, it was observed that all fertile eggs in the incubator were determined correctly on the third day of both test periods. Considering the methods used and the ease of the designed system, it can be said that a very successful system has been designed according to the studies in the literature. In order to increase the segmentation performance, it is necessary to carry out an experimental study to improve the camera and lighting setup prepared for taking the images. Full article

Cocaine is one of the most widely used drugs that, due to its molecular properties, causes various behavioral alterations, including sexual behavior. In vivo and in vitro studies conducted mainly in mammals have shown various disorders of sexual activity and morpho-functional dysfunctions of the gonads in both sexes. Although the modalities are still unclear, cocaine has been shown to alter the cell cycle, induce apoptosis, and alter sperm motility. In females, this drug alters the formation of the meiotic spindle as well as may obstruct the ovulation mechanism of mature oocytes. The data provided in this review, in addition to reviewing the current literature on the main effects of cocaine on spermatogenesis and oogenesis mainly in mammals, will hopefully provide a basic overview that may help and support further future studies on the molecular interaction of cocaine and its metabolites with germ cells. Full article