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11.
The objectives of this study were to determine the associations between climatic factors and production factors for returns to service of female pigs during summer and to quantify the associations between these factors and occurrences of returns to service. The factors that were assessed were as follows: maximum temperature (HT), relative humidity, age of gilts at first mating, parity, weaning-to-first-mating interval (WMI), and lactation length. The study analyzed records of 18,307 gilts in 99 herds and 78,135 parity records of 56,322 sows in 103 herds; all the females were first-serviced between June and September, 2007 to 2009. Average daily HT and relative humidity for 15 days post-service of a female were obtained from 21 local weather stations and coordinated with the performance data of the respective local herds. The returns to service were categorized into three groups: regular returns (RRs: 18–24 days), irregular returns (IRs: 25–38 days), and late returns to service (LRs: 39 days or later). Two-level mixed-effects models were applied to the data by using a herd at level 2 and an individual record at level 1. In mated gilts, the occurrences (%) of RRs, IRs, and LRs were 4.8%, 1.8%, and 5.3%, respectively. In mated sows, the respective occurrences were 3.3%, 1.8%, and 4.2%. Mean values (ranges) of HT and relative humidity were 28.4 °C (13.6 °C–39.8 °C) and 73.4% (35.0%–98.0%), respectively. In gilts, as HT increased from 25 °C to 30 °C, the occurrence of RR increased from 3.7% to 4.4% (P < 0.05). However, there was no association between the occurrence of RR and either relative humidity (P = 0.17) or age at first mating (P = 0.23). In addition, there were no associations between the occurrences of either gilt IR or LR and HT (P ≥ 0.05), relative humidity (P ≥ 0.46), or age at first mating (P ≥ 0.32). In sows, greater occurrences of RRs, IRs, and LRs were associated with higher HT, lower parity, and a WMI of 7 days or longer (P < 0.05), but they were not associated with relative humidity (P ≥ 0.62) or lactation length (P ≥ 0.13). The occurrence of RRs in sows of all WMI groups increased 1.22 (1.045) times for each 5 °C increase in HT. For sows with WMI 0 to 6 days, each 5 °C rise in HT increased the occurrence of IRs and LRs by 1.36 (1.065) and 1.27 (1.055) times, respectively. However, there was no association between increased HT and occurrences of IRs or LRs for sows with WMI 7 days or longer (P ≥ 0.38). Therefore, in order to prevent returns to service, it is recommended that producers apply cooling management for females during the post-service periods in summer.  相似文献   
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Mammalian male fertility relies on complex inter- and intracellular signaling during spermatogenesis. Here we describe three alleles of the widely expressed A-kinase anchoring protein 9 (Akap9) gene, all of which cause gametogenic failure and infertility in the absence of marked somatic phenotypes. Akap9 disruption does not affect spindle nucleation or progression of prophase I of meiosis but does inhibit maturation of Sertoli cells, which continue to express the immaturity markers anti-Mullerian hormone and thyroid hormone receptor alpha in adults and fail to express the maturation marker p27Kip1. Furthermore, gap and tight junctions essential for blood–testis barrier (BTB) organization are disrupted. Connexin43 (Cx43) and zona occludens-1 are improperly localized in Akap9 mutant testes, and Cx43 fails to compartmentalize germ cells near the BTB. These results identify and support a novel reproductive tissue-specific role for Akap9 in the coordinated regulation of Sertoli cells in the testis.  相似文献   
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DAZ家族新成员BOULE蛋白的结构与功能   总被引:5,自引:0,他引:5  
BOULE蛋白是2001年发现的DAZ家族的新成员,是人类精子发生过程中减数分裂的关键调控因子. BOULE基因表达的改变或BOULE蛋白的缺乏可引起减数分裂阻滞和精子生成障碍,从而导致无精子症并产生不育. BOULE蛋白的一级结构中含有DAZ家族的特征结构域,包括DAZ重复和RNA结合域(RBM),因此,将其列为继DAZ、DAZL之后DAZ家族的第3个成员.本文对BOULE的发现过程、结构和定位进行了总结回顾,并重点介绍了其在精子发生减数分裂中的作用及其作用机制.  相似文献   
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Recently, there are controversial opinions on the presence of Mycoplasmas/Ureaplasmas as colonizers or pathogens, and on the use of a targeted therapy. This study aimed to characterize Mycoplasmas/Ureaplasmas infections in reproductive age women, including the acquisition of sexually transmitted (ST) pathogens and poor birth outcomes. A total of 646 healthy Italian women fulfilled the inclusion criteria including 521 infertile women, 65 pregnant women, and 60 fertile women with identified risk factors and symptomatic for vaginitis/cervicitis. Multiplex and quantitative molecular techniques and direct automatic DNA sequencing were performed to assess the genome structure of Mycoplasma/Ureaplasma species and ST infected pathogens. Ureaplasma parvum serovar 3 represented the predominant colonizer of the urogenital tract of this series and the unique species significantly associated with ST pathogens coinfection (p < 0.01). U. parvum load >104 bacteria/ml, suggestive of active infection, has been measured only in asymptomatic high-risk human papillomavirus infected women (24.3%) and in 40% of women with idiopathic infertility. To note, 16% of the follicular fluid from these idiopathic women resulted infected with U. parvum. In conclusion, the present study focused the attention on U. parvum serovar 3 as emerging microorganism in sexually active women that may have the benefit of targeted therapy.  相似文献   
16.
Sex chromosome aberrations are known to cause congenital abnormalities and unexplained infertility in horses. Most of these anomalies remain undiagnosed because of the complexity of the horse karyotype and the lack of specialized laboratories that can perform such diagnoses. On the other hand, the utilization of microsatellite markers is a technique widely spread in horse breeding, mostly because of their usage in parentage tests. We studied the usage of a novel combination of diagnostic approaches in the evaluation of a very uncommon case of chromosomal abnormalities in a Spanish purebred colt, primarily detected using a commercial panel of short tandem repeat (STR) makers. Based on these results, we performed a full cytogenetic analysis using conventional and fluorescent in situ hybridization techniques with individual Equus caballus chromosome X and Equus caballus chromosome Y painting probes. We also tested the presence of two genes associated with the sexual development in horses and an extra novel panel of eight microsatellite markers specifically located in the sex chromosome pair. This is the first case report of a leukocyte chimerism between chromosomally normal (64,XY) and abnormal (63,X0) cell lines in horses. Our results indicate that the use of the short tandem repeat markers as a screening technique and as a confirmation utilizing cytogenetic techniques can be used as a very interesting, easy, and nonexpensive diagnostic approach to detect chromosomal abnormalities in the domestic horse.  相似文献   
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The clinical effect of sperm DNA damage in assisted reproduction has been a controversial topic during recent decades, leading to a variety of clinical practice recommendations. While the latest European Society of Human Reproduction and Embryology (ESHRE) position report concluded that DNA damage negatively affects assisted reproduction outcomes, the Practice Committee of the American Society for Reproductive Medicine (ASRM) does not recommend the routine testing of DNA damage for in vitro fertilization (IVF) or intracytoplasmic sperm injection (ICSI). Herein, our aim was to perform a systematic review and meta-analysis of studies investigating whether sperm DNA damage affects clinical outcomes in IVF and ICSI, in order to contribute objectively to a consistent clinical recommendation. A comprehensive systematic search was conducted according to PRISMA guidelines from the earliest available online indexing year until March 2020, using the MEDLINE-PubMed and EMBASE databases. We included studies analysing IVF and/or ICSI treatments performed in infertile couples in which sperm DNA damage was well defined and assessed. Studies also had to include information about pregnancy, implantation or live birth rates as primary outcomes. The NHLBI-NIH quality assessment tool was used to assess the quality of each study. Meta-analyses were conducted using the Mantel–Haenszel method with random-effects models to evaluate the Risk Ratio (RR) between high-DNA-damage and control groups, taking into account the 95% confidence intervals. Heterogeneity among studies was evaluated using the I2 statistic. We also conducted sensitivity analyses and post-hoc subgroup analyses according to different DNA fragmentation assessment techniques. We identified 78 articles that met our inclusion and quality criteria and were included in the qualitative analysis, representing a total of 25639 IVF/ICSI cycles. Of these, 32 articles had sufficient data to be included in the meta-analysis, comprising 12380 IVF/ICSI cycles. Meta-analysis revealed that, considering IVF and ICSI results together, implantation rate (RR = 0.74; 95% CI = 0.61–0.91; I2 = 69) and pregnancy rate (RR = 0.83; 0.73–0.94; I2 = 58) are negatively influenced by sperm DNA damage, although after adjustment for publication bias the relationship for pregnancy rate was no longer significant. The results showed a non-significant but detrimental tendency (RR = 0.78; 0.58–1.06; I2 = 72) on live birth rate. Meta-analysis also showed that IVF outcomes are negatively influenced by sperm DNA damage, with a statistically significant impact on implantation (RR = 0.68; 0.52–0.89; I2 = 50) and pregnancy rates (RR = 0.72; 0.55–0.95; I2 = 72), although the latter was no longer significant after correction for publication bias. While it did not quite meet our threshold for significance, a negative trend was also observed for live birth rate (RR = 0.48; 0.22–1.02; I2 = 79). In the case of ICSI, non-significant trends were observed for implantation (RR = 0.79; 0.60–1.04; I2 = 72) or pregnancy rates (RR = 0.89; 0.78–1.02; I2 = 44), and live birth rate (RR = 0.92; 0.67–1.27; I2 = 70). The current review provides the largest evidence to date supporting a negative association between sperm DNA damage and conventional IVF treatments, significantly reducing implantation and pregnancy rates. The routine use of sperm DNA testing is therefore justified, since it may help improve the outcomes of IVF treatments and/or allow a given couple to be advised on the most suitable treatment. Further well-designed controlled studies on a larger number of patients are required to allow us to reach more precise conclusions, especially in the case of ICSI treatments.  相似文献   
19.
Failure of epididymal spermatozoa from T/t mutant mice, but not from t/t individuals, to fertilize oocytes in vitro was partially overcome by opening a small aperture in the zona pellucida with acidified Tyrode's solution to permit direct access of the spermatozoon to the vitellus. This study provides a model system to evaluate requirements for successful zona drilling in the treatment of human infertility and further insights into the effects of the t complex on sperm fertility.  相似文献   
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