Fmr1基因敲除小鼠脏器重量和脏器系数的比较分析

目的通过对Fmr1基因敲除小鼠雌雄两性和FVB小鼠的脏器重量和脏器系数进行比较分析,了解其脏器重量的差异,探讨Fmr1基因对动物生长发育等方面的影响。方法分别测定Fmr1基因敲除小鼠雌雄两性和FVB小鼠内脏器官的绝对重量和脏器系数,并进行统计学处理和分析。结果相同年龄的Fmr1基因敲除小鼠雄性的体重、心、肺、肝和肾的绝对重量均极显著的大于雌性（P〈0.01）。雌雄间脏器系数除肾脏（P〈0.05）和脑（P〈0.01）外,其余无显著差异。与FVB小鼠比较,Fmr1基因敲除小鼠心脏较轻（P〈0.01）,肾脏（P〈0.01）、体重和脑较重（P〈0.05）。脏器系数肾脏较大（P〈0.01）,心脏（P〈0.01）、脑和脾（P〈0.05）较小。结论Fmr1基因可影响动物的某些脏器重量和脏器系数。     

不同周龄Balb／c小鼠脏器质量及其变化趋势分析

目的：测定不同周龄Balb／c小鼠主要脏器质量、脏器系数,并进行比较。方法：取120只3周龄、5周龄、7周龄的Balb／c小鼠,雌雄各半,精确测量小鼠体重和主要脏器质量,计算脏器系数。结果：①雌性与雄性Balb／c小鼠脏器质量相比较：3周龄时肝、脾有显著差异（P〈0．05）;5周龄时肝有非常显著差异（P〈0．01）,脾、肺有显著差异（P〈0．05）;7周龄时肝、肺及双肾有非常显著差异（P〈0．01）,心、脾有显著差异（P〈0．05）。②雌性与雄性Balb／c小鼠脏器系数相比较：3周龄时肝、脾有显著差异（P〈0．05）;5周龄时肝、脾有非常显著差异（P〈0．01）,膀胱有显著差异（P〈0．05）;7周龄时肺、双肾有非常显著差异（P〈0．01）,脾、膀胱有显著差异（P〈0．05）。结论：随着周龄的增长,Balb／c雌、雄性小鼠之间,存在差异的脏器也在增多。     

不同周龄Balb/c小鼠脏器质量及其变化趋势分析

目的:测定不同周龄Balb/c小鼠主要脏器质量、脏器系数,并进行比较。方法:取120只3周龄、5周龄、7周龄的Balb/c小鼠,雌雄各半,精确测量小鼠体重和主要脏器质量,计算脏器系数。结果:①雌性与雄性Balb/c小鼠脏器质量相比较:3周龄时肝、脾有显著差异(P0.05);5周龄时肝有非常显著差异(P0.01),脾、肺有显著差异(P0.05);7周龄时肝、肺及双肾有非常显著差异(P0.01),心、脾有显著差异(P0.05)。②雌性与雄性Balb/c小鼠脏器系数相比较:3周龄时肝、脾有显著差异(P0.05);5周龄时肝、脾有非常显著差异(P0.01),膀胱有显著差异(P0.05);7周龄时肺、双肾有非常显著差异(P0.01),脾、膀胱有显著差异(P0.05)。结论:随着周龄的增长,Balb/c雌、雄性小鼠之间,存在差异的脏器也在增多。     

合欢皮总皂苷对雄性小鼠的抗生育作用研究

目的探讨合欢皮总皂苷对雄性小鼠的抗生育作用。方法将60只健康的雄性性成熟昆明小鼠随机分成3个试验组和1个对照组,各试验组小鼠灌胃540 mg·(kg·d)-1,270 mg·(kg·d)-1和135 mg·(kg·d)-1的合欢皮总皂苷水溶液,对照组自由饮水,灌胃1周后按雌雄比2∶1合笼,继续对雄鼠灌胃至19 d,采集雄性小鼠的血液并测定血液生化指标,剖检灌胃雌性小鼠,统计雌性小鼠的怀孕率,测定雄性小鼠睾丸与附睾的脏器系数及附睾精子活力,并固定睾丸和附睾,研究其组织学变化。结果与对照组相比较,雄性小鼠灌胃合欢皮总皂苷后,导致雌性小鼠的怀孕率降低,睾丸脏器系数和附睾精子活率极显著降低(P<0.01),精子畸形率极显著升高(P<0.01)。光学显微镜下,试验组小鼠睾丸和附睾均有一定程度的损失,睾丸生精细胞排列疏松,间质减少,可见曲细精管内有多核巨噬细胞浸润,各级生精细胞脱落。附睾具正常的管腔结构,但能明显观察到管腔内精子几乎消失。结论合欢皮总皂苷对雄性小鼠具有抗生育作用,主要通过影响精子的生成及破坏生精组织而达到。     

薄荷油对雄性小鼠的抗生育作用研究

目的探讨薄荷油对雄性小鼠的抗生育作用。方法将60只健康的雄性性成熟昆明小鼠随机分成3个试验组和1个对照组,各试验组小鼠灌胃0.135 g/(kg·d),0.27 g/(kg·d)和0.54 g/(kg·d)的薄荷油0.5%羧甲基纤维素钠(sodium carboxymethylcellulose,CMC)混悬液,对照组灌胃0.5%羧甲基纤维素钠溶液,灌胃1周后按雌雄比2∶1合笼,继续对雄鼠灌胃至19 d,采集雄性小鼠的血液并测定血液生化指标,剖检灌胃雌雄小鼠,统计雌性小鼠的怀孕率,测定雄性小鼠睾丸与附睾的脏器系数及附睾精子活力,并固定睾丸和附睾,研究其组织学变化。结果与对照组相比较,雄性小鼠灌胃薄荷油后,导致雌性小鼠的怀孕率降低,睾丸脏器系数和附睾精子活率极显著降低(P<0.01),精子畸形率极显著升高(P<0.01)。光学显微镜下,试验组小鼠睾丸和附睾均有一定程度的损伤,睾丸间质减少,睾丸各级生精细胞排列疏松,曲细精管内有多核巨噬细胞浸润。附睾具正常的管腔结构,但能明显观察到管腔内精子减少。结论薄荷油对雄性小鼠具有抗生育作用,且主要通过影响精子的生成及破坏生精组织而达到,具有实际应用价值,可进一步开发成环境友好型鼠类抗生育药剂。     

黄芩苷通过增强抗氧化和抑制细胞凋亡减轻哮喘小鼠雄性生殖损伤

生殖健康是人口与健康领域的重要议题。作为全球最常见的呼吸道疾病哮喘会影响男性生殖功能,但相关机制鲜有报道。本文研究了黄酮类化合物黄芩苷(baicalin,BA)对哮喘小鼠睾丸损伤的干预作用及相关机制。选择雄性BALB/c小鼠随机分为对照组(CK组)、卵清蛋白(ovalbumin,OVA)致敏的哮喘组(OVA组)和黄芩苷干预哮喘组(OVA+BA组)。结果发现,3组小鼠体重无明显差异。OVA组小鼠睾丸系数和精子数量显著降低(P < 0.05),精子畸形率显著增加(P < 0.05);黄芩苷干预组小鼠睾丸系数显著增加(P < 0.05),精子畸形率显著降低(P < 0.05)。HE染色观察到OVA组小鼠睾丸组织生精小管结构损伤,精子发生异常,生精细胞减少,Johnson得分显著降低;BA干预组生精小管直径及生精上皮细胞高度显著增加,生精小管基膜结构较完整,Johnson得分显著提高(P < 0.05);试剂盒法检测氧化还原指标发现,OVA组睾丸组织过氧化氢(H₂O₂)和丙二醛(MDA)含量显著增加(P < 0.05),总超氧化物歧化酶(T-SOD)活性和谷胱甘肽(GSH)含量显著降低(P < 0.05);OVA+BA组睾丸组织H₂O₂和MDA含量显著降低(P < 0.05),T-SOD活性显著增加(P < 0.05);实时荧光定量RT-PCR检测发现,OVA组睾丸组织中促凋亡基因p53、Casp-3转录上调,抗凋亡基因Bcl2转录显著下调,胱天蛋白酶3(caspase-3)活性显著增加(P < 0.05);OVA+BA组p53和Casp-3转录下调,Bcl2转录上调,胱天蛋白酶3活性显著降低(P < 0.05)。结果表明,哮喘小鼠睾丸组织发生了氧化应激和结构损伤,细胞凋亡途径被激活,BA干预可有效减轻哮喘小鼠睾丸组织的氧化胁迫,抑制凋亡通路,保护睾丸组织的功能和结构。结果提示,黄芩苷能缓解哮喘小鼠的生殖毒性,该效应与机体抗氧化能力提高、细胞凋亡途径抑制有关。     

复方辣木颗粒剂影响雄性小鼠性功能的实验研究

目的观察复方辣木颗粒剂对雄性小鼠性功能的影响。方法建立醋酸铅致雄性小鼠生精障碍模型。将60只实验小鼠分为正常组、模型组、阳性对照组和复方辣木颗粒剂高、中、低剂量组,每组10只。给药后,观察小鼠体重、脏器指数、附睾精子活力、精子活率及睾丸的病理形态等。结果复方辣木颗粒剂对醋酸铅致少弱精子症小鼠体重无明显影响,各给药组小鼠附睾系数、睾丸系数、精子活力、精子活率均有所上升,生精细胞和间质细胞数量增多、排列更紧密。各剂量间比较,高剂量效果更显著(均P0.05)。结论复方辣木颗粒剂可显著改善小鼠性功能,为临床合理应用提供有利参考。     

中国大鲵肌肉蛋白肽对BPA诱导小鼠精子发生障碍的治疗作用及其机制研究

摘要 目的：研究中国大鲵肌肉蛋白肽（The protein and peptide extracts from muscles of Chinese giant salamanders,SP）对双酚A（bisphenol A,BPA）诱导的小鼠生精障碍的保护作用,并初步探讨其作用机制。方法：40只C57BL/6 雄性小鼠分为四组,分别为Control组、BPA组、BPA+CS（Compound Substance）组、BPA+SP组。BPA组使用50 mg/kg/d的BPA腹腔注射,BPA溶解于玉米油;Control组只腹腔注射玉米油。BPA+CS组灌胃其他有利于生精壮阳的复合物用作对照,复合物溶解于生理盐水中;BPA+SP组灌胃上述复合物联合大鲵肌肉蛋白肽,以上灌胃剂量均4 g/kg/d。连续造模28天,期间每周测定小鼠体重,造模结束后测定睾丸体积、睾体比,取附睾精子使用CASA计算机辅助分析系统测定精子数目、精子活力,ELISA法测定血清睾酮含量,HE染色、TUNEL染色分析睾丸组织病理学,最后采用免疫荧光染色及Western blotting分析转移相关基因2（MTA2）的表达情况、油红O染色观察支持细胞体内、体外吞噬作用。结果：与对照组比较,BPA组睾丸体积（P<0.05）、睾丸重量（P<0.05）、睾体比（P<0.05）、精子数目（P<0.05）、精子活力（P<0.05）、睾酮含量（P<0.01）均显著降低,睾丸组织形态受损（P<0.05）、生精细胞凋亡增多（P<0.01）、MTA2表达量降低（P<0.01）、支持细胞吞噬功能减弱（P<0.01）;BPA+CS组较BPA组无明显变化,BPA+SP组以上变化显著改善（P<0.05）。结论：大鲵肌肉蛋白肽对BPA诱导的小鼠生精功能障碍有明显的保护作用,作用机制可能与干预MTA2表达进而增强支持细胞的吞噬作用相关。     

ERα基因敲除小鼠的繁育及子代小鼠基因型的鉴定

目的探讨雌激素受体α(ERα)基因敲除小鼠的优化繁育方法及ERα基因敲除小鼠子代鼠的鉴定方法,建立ERα基因敲除小鼠模型,为进一步研究ERα蛋白的功能奠定基础。方法用4种不同的交配方式观察子代鼠的各表型比率及雌、雄性ERα基因突变纯合子小鼠的繁殖能力;从子鼠鼠尾中提取基因组DNA,用PCR方法扩增ERα基因片段,琼脂糖凝胶电泳后观察结果。HE染色观察雌、雄性ERα-/-小鼠生殖系统表型变化。结果 WT、ERα+/-、ERα-/-各表型小鼠互交繁殖结果基本符合孟德尔遗传规律,且雌、雄性ERα-/-小鼠无繁殖能力。与WT比较,雄性ERα-/-小鼠睾丸脏器系数降低,睾丸病理变化表现为生精小管管腔膨胀,生精细胞层变薄,且排列不规则;雌性ERα-/-小鼠子宫脏器系数降低,子宫和卵巢病变明显,表现为:子宫浆膜、肌层、内膜层细胞排列不规则,卵巢有囊性病变、充血,无黄体。结论雌、雄性ERα+/-小鼠交配是繁育ERα-/-小鼠的较好方法;实验所用PCR方法能够精确鉴定ERα-/-小鼠,ERα-/-小鼠的获得为ERα蛋白功能的实验研究提供了较理想的动物模型。     

EERα基因敲除小鼠的繁育及子代小鼠基因型的鉴定

目的 探讨雌激素受体α(ERα)基因敲除小鼠的优化繁育方法及ERα基因敲除小鼠子代鼠的鉴定方法,建立ERα基因敲除小鼠模型,为进一步研究ERα蛋白的功能奠定基础.方法 用4种不同的交配方式观察子代鼠的各表型比率及雌、雄性ERα基因突变纯合子小鼠的繁殖能力;从子鼠鼠尾中提取基因组DNA,用PCR方法扩增ERα基因片段,琼脂糖凝胶电泳后观察结果.HE染色观察雌、雄性ERα<'-/->小鼠生殖系统表型变化.结果 WT、ERα<'+/->、ERα<'-/->各表型小鼠互交繁殖结果基本符合孟德尔遗传规律,且雌、雄性ERα<'-/->小鼠无繁殖能力.与WT比较,雄性ERα<'-/->小鼠睾丸脏器系数降低,睾丸病理变化表现为生精小管管腔膨胀,生精细胞层变薄,且排列不规则;雌性ERα<'-/->小鼠子宫脏器系数降低,子宫和卵巢病变明显,表现为:子宫浆膜、肌层、内膜层细胞排列不规则,卵巢有囊性病变、充血,无黄体.结论 雌、雄性ERα<'+/->小鼠交配是繁育ERα<'-/->小鼠的较好方法;实验所用PCR方法能够精确鉴定ERα<'-/->小鼠,ERα<'-/->小鼠的获得为ERα蛋白功能的实验研究提供了较理想的动物模型.     

Hereditary haemochromatosis gene (HFE) H63D mutation shows an association with abnormal sperm motility

The aim of this study was to screen infertile men for HFE H63D mutation in correlation with clinical characteristics of infertile men (sperm concentration, sperm motility, morphology, testicular volume, Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH) and total Testosterone levels) and find out if the HFE H63D mutation has an effect on male infertility. After excluding hormonal treatment, any scrotal pathology, having any systemic diseases such as diabetes mellitus, sickle cell anemia and microdeletions of the Y chromosome, a total of 148 infertile men with age range between 17 and 52-years-old (average age 29.6 ± 7.2) were enrolled into the study. Our analysis indicates that the mean FSH levels are significantly higher (6.3 ± 4.6 mIU/ml, P = 0.03), whereas sperm motility is significantly lower (36.6 ± 28.1%, P = 0.01) in the infertile men with the HFE H63D mutation compared with subjects lacking this mutation. Comparison of allele frequencies of the infertile men with Ts < 50% versus the infertile men with Ts > 50% revealed a significant difference as expected (P = 0.001, OR = 0.14, %95 CI = 0.04–0.44). Comparison of allele frequencies of infertile men with abnormal sperm motility versus infertile men with normal sperm motility revealed a highly significant difference (P = 0.005, OR = 3.11, %95 CI = 1.41–6.86). Thus, the HFE H63D mutation seems to be an important risk factor for impaired sperm motility and is clinically associated with male infertility.     

Interplay between p53 and Ink4c in spermatogenesis and fertility

The tumor suppressor p53, and the cyclin-dependent kinase inhibitor Ink4c, have been both implicated in spermatogenesis control. Both p53-/- and Ink4c-/- single knockout male mice are fertile, despite testicular hypertrophy, Leydig cell differentiation defect, and increased sperm count in Ink4c-/- males. To investigate their collaborative roles, we studied p53-/- Ink4c-/- dual knockout animals, and found that male p53-/- Ink4c-/- mice have profoundly reduced fertility. Dual knockout male mice show a marked decrease in sperm count, abnormal sperm morphology and motility, prolongation of spermatozoa proliferation and delay of meiosis entry, and accumulation of DNA damage. Genetic studies showed that the effects of p53 loss on fertility are independent of its downstream effector Cdkn1a. Absence of p53 also partially reverses the hyperplasia seen upon Ink4c loss, and normalizes the Leydig cell differentiation defect. These results implicate p53 in mitigating both the delayed entry into meiosis and the secondary apoptotic response that occur in the absence of Ink4c. We conclude that the cell cycle genes p53 and Ink4c collaborate in sperm cell development and differentiation, and may be important candidates to investigate in human male infertility conditions.     

Mechanisms of damage to sperm structure in mice on the zinc-deficient diet

BackgroundZinc (Zn)is an essential trace element for spermatogenesis and its deficiency causes abnormal spermatogenesis.ObjectiveThe present study was conducted to examine the mechanisms by which Zn-deficient diet impairs sperm morphology and its reversibility.Methods30 SPF grade male Kunming (KM) mice were randomly divided into three groups, 10 mice per group. Zn-normal diet group (ZN group) was given Zn-normal diet（Zn content= 30 mg/kg）for 8 weeks. Zn-deficienct diet group (ZD group) was given Zn-deficienct diet（Zn content< 1 mg/kg）for 8 weeks. Zn-deficient and Zn-normal diet group（ZDN group）was given 4 weeks Zn-deficienct diet followed by 4 weeks Zn-normal diet. After 8 weeks, the overnight fasted mice were sacrificed, and blood and organs were collected for further analysis.ResultsThe experimental results showed that Zn-deficienct diet leads to increased abnormal morphology sperm and testicular oxidative stress.The rate of abnormal morphology sperm, chromomycin A3(CMA3), DNA fragmentation index (DFI), malondialdehyde (MDA) were significantly increased, and a-kinase anchor protein 4(AKAP4), dynein axonemal heavy chain 1(DNAH1), sperm associated antigen 6(SPAG6), cilia and flagella associated protein 44(CFAP44), glutathione peroxidase (GSH-PX), superoxide dismutase (SOD), total antioxidant capacity (T-AOC), nuclear factor erythroid 2-related factor (NRF2), NAD(P)H:quinone oxidoreductase 1(NQO1)and heme oxygenase 1(HO1) were significantly decreased in the ZD group mice. While the changes in above indicators caused by Zn-deficient diet were significantly alleviated in the ZDN group.ConclusionIt was concluded that Zn-deficient diet causes abnormal morphology sperm and testicular oxidative stress in male mice. Abnormal morphology sperm caused by Zn-deficient diet are reversible, and Zn-normal diet can alleviate them.     

Mouse aldehyde dehydrogenase genetics: Positioning of Ahd-1 on chromosome 4

Electrophoretic variants of mitochondrial aldehyde dehydrogenase (AHD-A₂) are widely distributed among inbred strains of Mus musculus and have been used to localize the gene encoding AHD-A₂(Ahd-1) at the non-centromeric end of chromosome 4. In the mouse (Mus musculus), aldehyde dehydrogenase (AHD; E.C.1.2.1.3) exists as at least three isozymes which are differentially distributed in liver subcellular fractions (designated A₂, B₄ and Cy* for the mitochondrial, soluble and microsomal isozymes respectively) and in various tissues of this animal (Holmes, 1978a; 1978b; Timms & Holmes, 1981). Electrophoretic variants have been previously reported for the A₂ and B₄ isozymes among inbred strains of mice, and the genetic loci (designated Ahd-1 and Ahd-2) have been localized on chromosomes 4 and 19 respectively (Holmes, 1978b; Timms & Holmes, 1980). This paper describes further genetic analyses of AHD-A₂ enabling Ahd-1 to be positioned at the non-centromeric end of chromosome 4. Forty-three inbred strains of Mus musculus were used in these studies (Table 1). Two series of matings were carried out. 1) Female SM/J mice and male NZC/B1 mice were mated to obtain F, female offspring which were backcrossed to male NZC/B1 mice. These progeny were used to examine the segregation and linkage relationship of b (brown), Pgm-2 (encoding phosphoglucomutase B) and Ahd-1 (Table 2). 2) Female C57BL/6J mice and male SM/J. mice were mated to obtain F, female offspring which were backcrossed to male SM/J mice. The segregation and linkage relationship of Pgm-2, Gpd-1 (encoding the liver and kidney isozyme of hexose-6 phosphate dehydrogenase) and Ahd-1 were examined for these backcross progeny (Table 3). Methods for preparing liver and kidney extracts and the cellulose acetate electrophoresis procedure for typing Ahd-1, Pgm-2 and Gpd-1 have been previously described (Holmes, 1978b). A previous study has described the electrophoretic patterns for allelic variants for mitochondria1 AHD and of the hybrid phenotype for this enzyme (Holmes, 1978b). The three-allelic isozyme pattern for hybrid animals was consistent with a dimeric subunit structure: AHD-A¹A², AHD-A¹A² and AHD-3, with the A1 and A2 subunits being encoded by separate alleles at a single locus, designated Ahd-1 (Ahd-1^oand Ahd-1^brespectively). The distribution of these alleles among 43 inbred strains of mice is given in Table 1. The allelic variants were approximately equally distributed among the inbred strains examined and no divergence of phenotype was observed among the 6 substrains of C57BL mice (Ahd-1^aallele) and 5 substrains of BALB/c (Ahd-1^ballele) mice examined. Genetic variants for phosphoglucomutase-B (PGM-B) have been reported by Shows, Ruddle and Roderick (1969) and the gene (Pgm-2) was subsequently localized on chromosome 4 near b (brown) by Chapman, Ruddle and Roderick (1970). Table 2 illustrates the results of a three-point cross between b, Pgm-2 and Ahd-1. Variation from the expected 1:1:1:1:1:1 ratio for unlinked loci was significant(x²= 73.15; 7 df; P < 1 × 10^-5), indicating that the three loci are linked. Recombination frequency data are consistent with the gene order: b - Pgm-2 - Ahd-1 The second cross examined the segregation of Pgm-2, Ahd-1 and Gpd-1 loci (Table 3). The latter locus has been previously positioned on chromosome 4 (linkage group VIII) by Hutton & Roderick (1970) and Chapman (1975), and has been used to localize Ahd-1 in this region (Ahd-1 and Gpd-1 exhibit a recombination frequency of 10.3 ± 3.7 %) (Holmes, 1978b). The data from Table 3 is consistent with a gene order of Pgm-2 - Ahd-1 - Gpd-1. The recombination frequency data of Ahd-1 with Gpd-1, Pgm-2 and b also supports the proposal that Ahd-1 is localized between Pgm-2 and Gpd-1 (Tables 2 and 3; Holmes, 1978b). Recent metabolic studies have indicated that mitochondria1 aldehyde dehydrogenase (AHD) plays a very important role in the metabolism of acetaldehyde derived from ethanol, ensuring a low concentration of acetaldehyde in the blood leaving the liver (Grunnet, 1973; Parilla et al., 1974; Corral1 et al., 1976). Moreover, genetic variation of this isozyme in human livers has been recently reported (Harada et al., 1978), and this polymorphism has been proposed as the molecular basis for individual and racial differences in alcohol sensitivity (Goedde et al., 1979). Consequently, genetic analyses of mitochondria1 AHD are of particular significance to studies on the genetic control of alcohol metabolism in mammals. In summary, this report confirms previous studies which demonstrated that the genetic locus encoding mitochondrial aldehyde dehydrogenase in the mouse (Ahd-1) is on chromosome 4 (Holmes, 1978b), and positions the gene with respect to b (brown), Pgrn-2 (encoding phosphoglucomutase B) and Gpd-1 (encoding the liver and kidney isozyme of hexose-6-phosphate dehydrogenase). In addition, the distribution of the 2-allelic phenotypes for this isozyme has been examined among 43 in- bred strains of mice.     

Reducing endogenous estrogen during prepuberal life does not affect boar libido or sperm fertilizing potential

Increasing sperm production per breeding male has economic significance with increasing use of artificial insemination. Manipulations to increase sperm production in livestock will only be useful if libido and sperm fertilizing capacity are not adversely affected. Reducing endogenous estrogens in the postnatal interval increases the number of Sertoli cells and hence testicular sperm production capacity. These experiments were designed to evaluate the effects of reducing endogenous estrogens on libido and sperm fertilizing capacity. Boars were treated with an aromatase inhibitor, letrozole, to reduce testicular estrogen production between 1 and 6 weeks of age or between 11 and 16 weeks of age, and the littermates to these boars were treated with the canola oil vehicle. Letrozole treatment did not affect time to first mount at 22 weeks of age, regardless of whether the treatment occurred from 1 to 6 weeks of age (118 seconds vs. 233 seconds, SEM = 161 for letrozole-treated and vehicle-treated boars, respectively) or from 11 to 16 weeks of age (107 seconds vs. 67 seconds, SEM = 63 for letrozole-treated and vehicle-treated boars, respectively). Similarly, sperm fertilizing ability and in vivo fertility were equivalent in letrozole-treated boars and their vehicle-treated littermates. Surprisingly, the increase in Sertoli cell numbers observed in the letrozole-treated boars at 20 weeks of age (5.8 vs. 4.3 billion, SEM = 0.5; P < 0.05) was not maintained to 40 weeks of age in their letrozole-treated littermates. Reducing endogenous estrogen production neonatally or prepuberally had no detectable adverse effect on libido or sperm fertilizing capacity.     

Generation of floxed Spag6l mice and disruption of the gene by crossing to a Hprt-Cre line

Mouse sperm-associated antigen 6 like (SPAG6L) is an axoneme central apparatus protein, essential for the normal function of the ependymal cell and lung cilia, and sperm flagella. Accumulated evidence has disclosed multiple biological functions of SPAG6L, including ciliary/flagellar biogenesis and polarization, neurogenesis, and neuronal migration. Conventional Spag6l knockout mice died of hydrocephalus, which impedes further investigation of the function of the gene in vivo. To overcome the limitation of the short lifespan of conventional knockout mice, we developed a conditional allele by inserting two loxP sites in the genome flanking exon 3 of the Spag6l gene. By crossing the floxed Spag6l mice to a Hrpt-Cre line which expresses Cre recombinase ubiquitously in vivo, mutant mice that are missing SPAG6L globally were obtained. Homozygous mutant Spag6l mice showed normal appearance within the first week after birth, but reduced body size was observed after 1 week, and all developed hydrocephalus and died within 4 weeks of age. The phenotype mirrored that of the conventional Spag6l knockout mice. The newly established floxed Spag6l model provides a powerful tool to further investigate the role of the Spag6l gene in individual cell types and tissues.     

The testis‐specific gene 1700102P08Rik is essential for male fertility

Male infertility is a rising problem around the world. Often the cause of male infertility is unclear, and this hampers diagnosis and treatment. Spermatogenesis is a complex process under sophisticated regulation by many testis‐specific genes. Here, we report the testis‐specific gene 1700102P08Rik is conserved in both the human and mouse and highly expressed in spermatocytes. To investigate the role of 1700102P08Rik in male fertility, knockout mice were generated by CRISPR‐Cas9. 1700102P08Rik knockout male mice were infertile with smaller testis and epididymis, but female knockout mice retained normal fertility. Spermatogenesis in the 1700102P08Rik knockout male mouse was arrested at the spermatocyte stage, and no sperm were found in the epididymis. The deletion of 1700102P08Rik causes apoptosis in the testis but did not affect the serum concentration of testosterone, luteinizing hormone, and follicle‐stimulating hormone or the synapsis and recombination of homologous chromosomes. We also found that 1700102P08Rik is downregulated in spermatocyte arrest in men. Together, these results indicate that the 1700102P08Rik gene is essential for spermatogenesis and its dysfunction leads to male infertility.     

Testicular Size,Mating System,and Maturation Schedules in Wild Anubis and Hamadryas Baboons

We report body mass and testicular size in 258 anubis (Papio anubis or P. hamadryas anubis) and 59 hamadryas (P. hamadryas or P. h. hamadryas) baboons, live-trapped in Ethiopia. As predicted by theories of sexual selection by sperm competition, among hamadryas baboons, which are monandrous, fully adult males have absolutely and relatively smaller testes than those of comparable males among anubis baboons, which are polyandrous. Male hamadryas are also ca. 10% smaller in bodily mass as adults. The intertaxonal difference in adults is due entirely to the fact that in male anubis baboons, testicular and bodily mass continue to grow up to full adulthood–the age at which most males emigrate from their natal troop and initiate a confrontational breeding strategy among unrelated animals. By contrast, male hamadryas baboons, which are usually philopatric, attain adult body mass and testicular size as subadults. In both species, juveniles experience rapid testicular growth peaking in rate at ca. 12kg body mass, but testicular descent and growth starts earlier in hamadryas than in anubis baboons. Juvenile hamadryas baboons have relatively larger testes than their anubis equivalents, perhaps because male philopatry allows the mating strategy of male hamadryas baboons to be initiated during juvenile life and therefore permits some sperm competition between juveniles and adults.