男性不育与Y染色体

目的：观察精子数目异常与小Y染色体及内分泌性腺激素水平。方法：对262名少精及无精症患者检测染色体,并对其中11例小Y染色体及随机抽取的15例Y染色体正常的患者运用磁性分离酶免疫测定法分别检测性腺激素。结果：小Y染色体检出率为4.19％（11／262）,其内分泌性腺激素均呈高卵泡刺激素、高黄体生成素和低睾酮水平,与Y染色体正常的无精及少精症患者相比较．差异有显著性（P〈0．05）。而小Y染色体不同精子数组各内分泌性腺激素比较,差异无显著性（P〉0．05）。结论：精子数目畀常可能与小Y染色体有关,小Y染色体基因改变可能是导致其内分泌性腺激素的变化因素。     

人类X染色体与Y染色体是否为同源染色体

对同源染色体的概念及人类X染色体与Y染色体的来源、形态结构、功能以及减数分裂中的行为等进行了讨论.X染色体与Y染色体虽然在形态、大小以及所含的基因等方面有差别,但从综合分析看,二者属于同源染色体,或者属于特殊的同源染色体.     

QF-PCR筛查男性不育患者Y染色体无精子症因子微缺失

为评估定量荧光PCR(Quantitative fluorescent polymerase chain reaction, QF-PCR)技术在快速筛查无精子症因子(Azoospermia factor, AZF)微缺失中的应用, 文章对1218例非梗阻性无精子症、少精子症的男性不育患者, 采用多重QF-PCR结合毛细管电泳技术, 检测Y染色体长臂AZF区9个序列标签位点(Sequence tagged site, STS)以及性染色体短臂的AMEL(Amelogenin)和SRY(Sex-determining region of Y chromosome)位点, 辅以常规染色体G显带方法进行核型分析。结果显示, 1218例患者中105例可见AZF区微缺失(8.62%), 其中AZFc区缺失(67.62%)最常见, 其次为AZFb,c区缺失(20.95%); AZFb区缺失(7.62%)和AZFa区缺失(3.81%)则较少见; 另有5例患者为AZFa,b,c区缺失合并AMEL-Y缺失, 提示可能缺少Y染色体, 经核型分析验证为46,XX(性反转)。105例AZF区微缺失患者的染色体核型分析显示染色体异常16例, 其中“Yqh-”12例。根据AMEL-X/AMEL-Y比值, 可见1218例患者中86例可能存在性染色体异常, 经核型分析验证, 68例为性染色体非整倍体。多重QF-PCR技术, 一个反应即能检测样本的多个位点, 并可提示性染色体是否存在异常, 有助于男性不育患者尽早明确病因, 也为后续的检查和治疗提供依据。     

Y染色体的分子结构和多态性研究与应用

人类Y染色体是最小的近端着丝粒染色体,作为男性所特有的染色体,在减数分裂的过程中几乎不与X染色体发生交换重组,故呈现出单倍型遗传,而Y特异区DNA序列的改变构成了人类Y染色体的多态性.其异常通常会导致各种遗传效应.综述了Y染色体的分子结构及其遗传多态性的最新研究和应用.     

无精子症和严重少精子症患者Y染色体微缺失研究

目的：研究Y染色体微缺失与男性不育的关系。方法：采用多重PCR技术,研究正常男性、无精子症和严重少精子症男性不育患者Y染色体无精子因子（AZF）区域3个序列标志位点（STS）的缺失情况。结果：在93例无精子症或严重少精子症患者中,15例有Y染色体微缺失,缺失率为16%。其中,42例无精子症患者中,6例为AZFc区SY255位点缺失,2例为AZFb区SY134位点缺失;51例严重少精子症患者中,7例为AZFc区SY255位点缺失。40例正常男性无Y染色体微缺失。结论：多重PCR技术是简便而有效的对男性不育患者进行Y染色体微缺失筛查的方法;Y染色体微缺失是造成男性不育的一个重要原因,对男性不育患者进行辅助生育技术治疗前应常规进行Y染色体微缺失的检测。     

Y染色体的回文结构与男性生育

Y染色体的回文结构对男性的生殖能力至关重要.其左右臂对应碱基具有很高的互补性,借助于基因转变,维持了男性性别决定基因的稳定性.探讨回文结构的形成机制对于更深入地理解其结构和功能的关系具有重要意义.在导致男性不育的AZFc区的删除中,涉及一种借助于扩增子家族的重组而形成回文结构的机制,这有助于深入地认识形成回文的原初动力.     

Y染色质

Ｙ染色质的发现是萤光染色技术发明的结果,Ｙ染色质作为Ｙ染色体长臂的一部分,在人类男性各种间期细胞代表Ｙ染色体。Ｙ染色质观察在临床性别鉴定,Ｙ染色体数量异常诊断和遗传优生方面得到广泛的应用。     

人类Y染色体DNA多态性及其应用

Y染色体的大部分区域为Y特异区,呈严格的父系遗传,因此Y染色体上的DNA多态性在人类进化、法医学等领域具有特殊的应用价值。     

男性不育与染色体畸变

男性不育症愈来愈引起社会和医学生物界的关注。据统计,因各种各样原因引起男性不育的患者约占育龄夫妇的5—8％,也就是说,全国每年如有100万对育龄夫妇的话,就有5至8万对夫妇因男性不育而陷入痛苦与焦虑之中。男性不育的病因很多,本文重点谈谈男性不育的细胞遗传学有关问题,即男性不育与染色体畸变的关系。 (一)男性不育的细胞遗传学基础男性的精子都是单倍性。由于男性的性染色体是XY,故有X精子和Y精子两种,它们与卵子结合的机会都是随机的。精子的发生是由一个精原细胞经过减数分裂后形成四个精子,它的发生是每时每刻在进行     

中国林蛙性腺的发育及温度对其性别分化的影响

为探讨幼蛙性别分化与温度的关系,在恒温和变温条件下培养中国林蛙（Rana chensinensis)受精卵至变态完成,结果表明：（1）胚胎发育到24期时生殖嵴开始出现,25期个别原始生殖细胞（PGCs)已迁移到生殖嵴中,生殖细胞与生殖嵴共同发育成生殖腺;（2）胚胎发育到31期生殖腺出现性别分化,卵巢分化初期较易识别,而精巢分化不明显;…（3）卵巢分化完成于37期,精巢分化完成于变态之后,两侧生殖腺等大;（4）胚胎发育从30期开始,性别分化对温度较为敏感,低温利于雌性化,高温利于雄性化;（5）15－25℃为变温培养时性比发生变化的敏感温度区,缓慢升温雄性比较显著增加,缓慢降温雌性比例显著增加。     

甲壳动物胰岛素样促雄腺激素功能及 作用机制的研究进展

甲壳动物的雄性性别分化主要由其促雄腺（AG）分泌的胰岛素样促雄腺激素（IAG）负责调控。在罗氏沼虾（Macrobrachium rosenbergii）中,通过单个IAG的操作可以成功性反转,进而实现全雄养殖。因此,基于IAG的性别调控技术具有良好的应用潜力。目前,IAG在许多经济甲壳动物中得到研究报道,发现其表达不仅局限于促雄腺,功能也更加广泛。此外,随着RNA干扰技术在水产动物中的广泛运用,基因功能的研究更易实现,IAG如何执行其生理作用的信号机制及上游的调控网络逐渐成为学者们探究的热点。本文综述了近年来有关IAG研究的进展,从IAG的分子特征、生理功能、作用机制及上游调控机理等方面展开探讨,为深入阐明IAG的生理功能及作用机制提供基础。     

Abundance and Characterization of Perfect Microsatellites on the Cattle Y Chromosome

Microsatellites or simple sequence repeats (SSRs) are found in most organisms and play an important role in genomic organization and function. To characterize the abundance of SSRs (1-6 base-pairs [bp]) on the cattle Y chromsome, the relative frequency and density of perfect or uninterrupted SSRs based on the published Y chromosome sequence were examined. A total of 17,273 perfect SSRs were found, with total length of 324.78?kb, indicating that approximately 0.75% of the cattle Y chromosome sequence (43.30?Mb) comprises perfect SSRs, with an average length of 18.80?bp. The relative frequency and density were 398.92?loci/Mb and 7500.62?bp/Mb, respectively. The proportions of the six classes of perfect SSRs were highly variable on the cattle Y chromosome. Mononucleotide repeats had a total number of 8073 (46.74%) and an average length of 15.45?bp, and were the most abundant SSRs class, while the percentages of di-, tetra-, tri-, penta-, and hexa-nucleotide repeats were 22.86%, 11.98%, 11.58%, 6.65%, and 0.19%, respectively. Different classes of SSRs varied in their repeat number, with the highest being 42 for dinucleotides. Results reveal that repeat categories A, AC, AT, AAC, AGC, GTTT, CTTT, ATTT, and AACTG predominate on the Y chromosome. This study provides insight into the organization of cattle Y chromosome repetitive DNA, as well as information useful for developing more polymorphic cattle Y-chromosome-specific SSRs.     

Estimating Tempo and Mode of Y Chromosome Turnover: Explaining Y Chromosome Loss With the Fragile Y Hypothesis

Chromosomal sex determination is phylogenetically widespread, having arisen independently in many lineages. Decades of theoretical work provide predictions about sex chromosome differentiation that are well supported by observations in both XY and ZW systems. However, the phylogenetic scope of previous work gives us a limited understanding of the pace of sex chromosome gain and loss and why Y or W chromosomes are more often lost in some lineages than others, creating XO or ZO systems. To gain phylogenetic breadth we therefore assembled a database of 4724 beetle species’ karyotypes and found substantial variation in sex chromosome systems. We used the data to estimate rates of Y chromosome gain and loss across a phylogeny of 1126 taxa estimated from seven genes. Contrary to our initial expectations, we find that highly degenerated Y chromosomes of many members of the suborder Polyphaga are rarely lost, and that cases of Y chromosome loss are strongly associated with chiasmatic segregation during male meiosis. We propose the “fragile Y” hypothesis, that recurrent selection to reduce recombination between the X and Y chromosome leads to the evolution of a small pseudoautosomal region (PAR), which, in taxa that require XY chiasmata for proper segregation during meiosis, increases the probability of aneuploid gamete production, with Y chromosome loss. This hypothesis predicts that taxa that evolve achiasmatic segregation during male meiosis will rarely lose the Y chromosome. We discuss data from mammals, which are consistent with our prediction.     

立体定向放疗联合内分泌治疗对转移性激素敏感性前列腺癌患者免疫功能和生活质量的影响

摘要 目的：探讨立体定向放疗（SBRT）联合内分泌治疗对转移性激素敏感性前列腺癌患者生活质量、免疫功能的影响。方法：选取我院2015年2月~2017年2月期间收治的转移性激素敏感性前列腺癌患者100例,根据信封抽签法将患者分为对照组（50例）和放疗组（50例）,对照组给予内分泌治疗,放疗组在对照组的基础上联合SBRT治疗。对比两组前列腺特异性抗原（PSA）进展时间、PSA缓解率、治疗期间不良反应状况、3年生存率、免疫功能（CD3⁺、CD4⁺、CD8⁺、CD4⁺/CD8⁺）和扩展性前列腺癌复合指数量表（EPIC）各项评分。结果：随访3年,对照组有2例失访、放疗组有3例失访,放疗组的PSA进展时间长于对照组（P<0.05）,放疗组的3年生存率高于对照组（P<0.05）。治疗后,两组CD3⁺、CD4⁺/CD8⁺、CD4⁺均下降,但放疗组较对照组升高（P<0.05）,两组治疗后CD8⁺均升高,但放疗组较对照组降低（P<0.05）。治疗后6个月,放疗组性功能、激素功能、泌尿功能、肠道功能领域评分均高于对照组（P<0.05）。两组不良反应总发生率、PSA缓解率组间对比无差异（P>0.05）。结论：SBRT联合内分泌治疗转移性激素敏感性前列腺癌患者,可延长患者PSA进展时间,减轻免疫抑制,提高患者生活质量,同时还可改善患者的预后,患者耐受性良好。     

No signature of Y chromosomal resemblance between possible descendants of the Cimbri in Denmark and Northern Italy

Two European populations are believed to be related to the ancient Germanic tribe Cimbri: one living in Northern Italy, the other living in Jutland, Denmark. The people called Cimbri are documented in the ancient Roman historical record. Arriving from the far north their movements can be tracked from successive battles with the Romans. The Cimbri finally entered Italy from the northeast and were defeated at Vercellae (present day Vercelli) in 101 BC by Gaius Marius and his professional legions. Classical sources from the first centuries AD relate the homeland of the Cimbri to the coasts around the Elb estuary (northern Germany) or specifically towards the north (Himmerland in northern Jutland). In the alpine parts of Veneto, northeast of the historical battlefield, local traditions dating back to late medieval time, identify a local population as Cimbri living in Terra dei Cimbri. They are considered the descendents of the Germanic combatants that fled the battlefield at Vercelli. As the defeated Cimbri that possibly fled to the mountains of Northern Italy most likely would have been male (warriors), the present study investigated the possible Y chromosomal diversity of the two present populations using microsatellite markers and single nucleotide polymorphisms. While Cimbri from Himmerland resembled their geographical neighbors from Denmark for the Y-chromosome markers, Cimbri from Italy were significantly differentiated both from Cimbri from Himmerland and from Danes. Therefore, we were not able to show any biological relationship for uniparentally transmitted markers.     

The Activation Mechanism of Glycoprotein Hormone Receptors with Implications in the Cause and Therapy of Endocrine Diseases

Glycoprotein hormones (GPHs) are the main regulators of the pituitary-thyroid and pituitary-gonadal axes. Selective interaction between GPHs and their cognate G protein-coupled receptors ensure specificity in GPH signaling. The mechanisms of how these hormones activate glycoprotein hormone receptors (GPHRs) or how mutations and autoantibodies can alter receptor function were unclear. Based on the hypothesis that GPHRs contain an internal agonist, we systematically screened peptide libraries derived from the ectodomain for agonistic activity on the receptors. We show that a peptide (p10) derived from a conserved sequence in the C-terminal part of the extracellular N terminus can activate all GPHRs in vitro and in GPHR-expressing tissues. Inactivating mutations in this conserved region or in p10 can inhibit activation of the thyroid-stimulating hormone receptor by autoantibodies. Our data suggest an activation mechanism where, upon extracellular ligand binding, this intramolecular agonist isomerizes and induces structural changes in the 7-transmembrane helix domain, triggering G protein activation. This mechanism can explain the pathophysiology of activating autoantibodies and several mutations causing endocrine dysfunctions such as Graves disease and hypo- and hyperthyroidism. Our findings highlight an evolutionarily conserved activation mechanism of GPHRs and will further promote the development of specific ligands useful to treat Graves disease and other dysfunctions of GPHRs.