236例特发性无精子症或严重少精子症患者Y染色体微缺失检测分析

目的:研究Y染色体基因微缺失特别是DAZ基因微缺失与特发性无精子症和严重少精子症的关系. 方法:采用PCR技术,对236例无精子症及少精子症患者AZF的13个Y染色体特异序列标签位点,进行Y染色体特别是DAZ基因微缺失的检测. 结果:101例特发性无精子症患者中,Y染色体微缺失13例,发生率12.87%,其中11例发生DAZ基因微缺失,发生率为10.89%.135例严重少精子症患者中,Y染色体微缺失12例,发生率为8.89%,其中9例发生DAZ基因微缺失,发生率为6.67%.精液正常者(对照组)26例未发现Y染色体微缺失. 结论:Y染色体微缺失是造成男性精子发生障碍的常见病因之一. DAZ基因与精子发生直接有关,是AZF重要候选成分之一.     

无精症和少精子症患者的细胞遗传学和分子遗传学检测

目的:对无精症和少精子症患者进行外周血染色体及Y染色体微缺失检测,探讨生精功能障碍的遗传学机制,为临床治疗和遗传咨询提供参考。方法:运用细胞遗传学核型分析技术和多重PCR技术对133例生精功能障碍患者进行染色体核型分析和Y染色体AZF因子扩增,并以40例已生育男性作为对照组。结果:实验组中61例无精子症患者中,细胞遗传学核型数量异常13例,异常发生率21.31%,同时发现AZF微缺失6例,异常发生率9.84%;72例少精患者细胞遗传学核型异常11例,异常发生率15.28%,同时发现AZF微缺失7例,异常发生率9.72%。40例对照组Y染色体核型和AZF位点无缺失。结论:染色体异常和AZF的缺失是引起男性无精子和少精子并造成男性不育的重要原因之一,对男性不育人群进行细胞遗传学核型分析和AZF检测十分必要。     

男性原发不育患者遗传学研究

目的:寻找男性不育的遗传学依据并对男性不育患者Y染色体AZF基因进行诊断,为开展针对男性不育的辅助生殖技术提供理论依据。方法:对83例原发性无精子症及少精子症患者进行外周血淋巴细胞培养及染色体核型分析,同时采用多重PCR的方法进行Y染色体AZF区15个STS位点微缺失检测,并以30例正常生育男性为对照。结果:13例患者存在染色体异常,其中7例为无精子症,占53.8%(7/13),6例为少精子症,占46.2%(6/13),且1例存在AZFb+AZFc的微缺失。在70例染色体核型正常的无精子症和少精子症患者中8例存在AZF基因的微缺失,2例存在AZFa的微缺失,缺失构成比为25.0%(2/8);1例存在AZFb的微缺失,缺失构成比为12.5%(1/8);2例存在AZFc的微缺失,缺失构成比为25.0%(2/8);1例存在AZFb+AZFc的微缺失,缺失构成比为12.5%(1/8);1例存在AZFb+AZFc+AZFd的微缺失,缺失构成比为12.5%(1/8);1例存在AZFa+AZFb+AZFc的微缺失,缺失构成比为12.5%(1/8)。正常男性对照组染色体核型均正常并且不存在AZF基因的微缺失。实验组与正常男性对照组比较Y染色体AZF区域的微缺失率差异有统计学意义(P<0.05)。结论:男性染色体异常及Y染色体AZF区域的微缺失与男性原发性无精子症和少精子症密切相关。     

无精子症患者基因检测分析

目的:利用全外显子测序技术,筛选无精子症患者相关基因,丰富男性不育基因库。方法:抽取20例无精子症患者外周血,提取DNA,使用杂交捕获方法构建DNA文库,采用高通量测序技术检测人类全外显子组中20099个基因的外显子区及旁侧内含子区(20bp),将测序数据与人类基因组hg19参考序列进行比对,筛选变异基因,变异位点进行Sanger测序验证。结果:共计筛选出26个基因43个变异位点,排除15个常染色体隐性遗传的单个变异位点及13个与精子运动相关的变异位点,剩余11个基因的15个变异位点可能与精子发生障碍相关,其中包括FAM71B、STARD9、CLTCL1、PCBP3、S100PBP等5个在睾丸组织高表达基因,SYCE3、EFCAB6、DDX4、KDM5D、RGS22、MTL5等6个基因可能与精子发生障碍相关。结论:通过研究筛选到可能影响男性不育的基因,为男性不育的基因诊断研究提供参考。     

Y染色体微缺失与男性不育

遗传因素导致的生精障碍是引起男性不育的—个重要原因，研究发现，Y染色体长臂上无精子因子（AZF）的缺失可以导致男性生精障碍，大多表现为无精或严重少弱精。在特发性无精症、隐睾和精索静脉曲张的不育患者中均已检测到AZF的缺失。胞浆内单精子注射（ICSI）在解决男性不育问题的同时，也有可能将父代的遗传缺陷传递给男性后代．所以对无精症及严重少弱精症患者尤其是行ICSI助孕的不育男性有必要常规行AZF缺失的检测。现就Y染色体AZF微缺失的机制、与特发性男性不育及睾丸病变的关系、微缺失检测的临床意义等方面进行综述。     

Y染色体微缺失与男性不育

遗传因素导致的生精障碍是引起男性不育的一个重要原因,研究发现,Y染色体长臂上无精子因子(AZF)的缺失可以导致男性生精障碍,大多表现为无精或严重少弱精.在特发性无精症、隐睾和精索静脉曲张的不育患者中均已检测到AZF的缺失.胞浆内单精子注射(ICSI)在解决男性不育问题的同时,也有可能将父代的遗传缺陷传递给男性后代,所以对无精症及严重少弱精症患者尤其是行ICSI助孕的不育男性有必要常规行AZF缺失的检测.现就Y染色体AZF微缺失的机制、与特发性男性不育及睾丸病变的关系、微缺失检测的临床意义等方面进行综述.     

男性不育及精子发生的遗传调控

在已婚人群中不孕夫妇约占10％,其中近一半是男性的问题。男性不育越来越引起人们的重视,尤其是近几年由于环境问题及某些性激素的“失控”,男性不育的比例逐渐升高。Y染色体自然成为研究的主要目标,对SRY基因及精子生成基因或称无精子因子—AZF(azoospermic factor)的研究揭示了精子发生及产生障碍的遗传学机制。本文扼要回顾了精子发生过程中的遗传调控。     

精子生成障碍者染色体异常和无精子因子微缺失分析

目的:探讨男性精子生成障碍与染色体核型异常和Y染色体无精子因子(AZF)微缺失的相关性,为拟行IC-SI(intracytoplasmic sperm injection,ICSI)技术助孕的患者提供遗传咨询。方法:运用多重PCR检测技术,对333例男性精子生成障碍患者(242例无精子症和91例严重少精子症)Y染色体AZF区域9个序列标签位点(STS)进行扩增分析;并运用G显带技术,对患者外周血染色体核型进行分析。结果:精子生成障碍患者AZF缺失发生率为11.11%(37/333),其中无精子症组缺失率为10.33%(25/242),严重少精子症组缺失率为13.19%(12/91);外周血染色体核型分析发现染色体异常检出率为8.11%(27/333);患者总遗传缺陷发生率为19.22%。结论:染色体核型异常和Y染色体微缺失是导致无精子症和严重少精子症的重要遗传因素;在行辅助生殖治疗前,患者须行遗传学检查以避免有遗传缺陷的后代出生。     

原发性无精子症患者Y染色体AZF微缺失筛查分析

原发性无精子症是指男性不育症患者仅有精子异常,即精液检查发现无精子,其余包括细胞遗传学、生殖内分泌激素水平等情况均正常,即患者出现精子异常的原因不明.从分子水平探讨生精障碍的机制,尤其是关于Y染色体长臂AZF微缺失的研究[1],对男性原发性无精子症的诊断及治疗具有非常重要的意义,本文对24例原发性无精子症患者Y染色体AZF微缺失筛查,报告如下.     

原发性无精子症患者Y染色体AZF微缺失

原发性无精子症是指男性不育症患者仅有精子异常，即精液检查发现无精子，其余包括细胞遗传学、生殖内分泌激素水平等情况均正常，即患者出现精子异常的原因不明。从分子水平探讨生精障碍的机制，尤其是关于Y染色体长臂AZF微缺失的研究，对男性原发性无精子症的诊断及治疗具有非常重要的意义，本文对24例原发性无精子症患者Y染色体AZF微缺失筛查，报告如下。     

MOLECULAR BIOLOGY OF MALE INFERTILITY

About 15% of couples have reduced fertility and in approximately one-half of all cases the reason is male infertility, usually of genetic origin. Thus, in the context of research in genes involved in reproduction and sex determination, genetic anomalies in gametogenesis are being extensively studied. The most frequent pathogenic causes of male infertility are Y-chromosomal microdeletions (8-15%) in the long arm of the Y chromosome, which, by loss of specific DNA segments, leads to loss of vital genes for sperm production. Infertile men, who attend infertility clinics, rise to 15% among those with azoospermia or spermatogenesis problem. The new technique of intracytoplasmic sperm injection has allowed many infertile men to achieve their dreams of fatherhood. However, the spermatogenic defect is genetic anomalies, which might be a potential risk of transmitting this defect to future offspring. Therefore, genetic counseling of all couples with the diagnosis of male infertility is recommended before their enrolment in intrauterine insemination, in vitro fertilization, and intracytoplasmic sperm injection. The important role of genetic abnormalities in the causation of human male infertility is increasingly recognized. While much remains to be learned in this fast-moving field, considerable progress has been made in the clinical delineation of genetic forms of male infertility and in the characterization of the responsible genes and their mutations or deletions. This review should provide insight into the understanding of parthenogenesis of male infertility in the human.     

Y染色体微缺失及其检测方法

全世界大约有15%的夫妇不育,其中男性不育约占50%。Y染色体长臂上的AZF缺失是导致男性不育的重要因素。AZF进一步分为AZFa、AZFb和AZFc3个区域,不同区域的微缺失引起不同程度的精子发生障碍。因此Y染色体微缺失的检测对男性不育的诊治有很重要的指导意义。目前Y染色体微缺失常用的检测方法有多重定性PCR法、实时荧光PCR法、基因芯片法和荧光原位杂交法。     

抗苗勒管激素与男性生殖相关疾病的研究进展

抗苗勒管激素(anti-Mullerian hormone,AMH),又名苗勒管抑制素(Mullerian inhibiting substance,MIS),最早发现于男性胎儿,因抑制其苗勒管的发育而命名,对男性性分化具有重要作用。目前研究发现AMH在男性生殖相关领域有更加广泛的临床应用,主要体现在5个方面:(1)诊断两性畸形患者是否存在男性性腺,血清AMH比Y染色体敏感度更高,且是青春期评估睾丸功能较好的标志物;(2)与血清AMH水平比较,精浆AMH与睾丸生精功能显著相关,与精液质量呈正相关,是鉴别梗阻性、非梗阻性无精子症特异性较高的标志物;(3)精浆AMH是目前预测严重少、弱精子症患者精液冷冻-复苏率较好的指标;(4)精浆AMH水平可预测重组人卵泡刺激素(rh FSH)治疗特发性少、弱精子症的疗效;(5)对生育期需接受放化疗的男性肿瘤患者生育力的评估,精浆AMH是目前特异性最高的生物标志物。     

Genetic Risk Factors in Male Infertility

The etiopathogenesis of testicular failure remains unknown in about half of the cases and is referred to as “idiopathic infertility”. “Idiopathic” testicular failure is of probable genetic origin since the number of genes involved in human spermatogenesis is likely thousands and only a small proportion of them have been identified and screened in infertile men. In parallel with studies aimed to identify mutations with a clear cause-effect relationship in spermatogenesis candidate genes, there is an increasing interest towards genetic susceptibility factors to male infertility. Despite many efforts, only a few clinically relevant polymorphisms have been identified. This is mainly related to the multifactorial nature of male infertility and to the inappropriate study design of the majority of the studies. The most promising polymorphisms are in genes involved in the endocrine regulation of spermatogenesis and on the Y chromosome, the “gr/gr” deletions. Polymorphisms are generally considered as co-factors. Their final effect on testis function and fertility is probably modulated by the genetic background of each individual and/or by the presence of certain environmental factors. In this review, recent findings concerning some of the most widely studied polymorphisms and male infertility will be discussed.     

Emerging evidence for the role of genomic instability in male factor infertility

Male infertility is a common and complex pathology affecting about 7% of men of reproductive age. Given its complexity, the underlying etiology for male infertility is often unknown. A growing amount of evidence suggests genomic instability may be an important factor in some cases of male factor infertility. While some specific manifestations of genomic instability, such as increased sperm aneuploidy rates and increased somatic translocations and inversions in infertile men, are well established, other facets of genomic instability associated with male infertility have not been thoroughly investigated. A limited body of recent work has identified a potential association between microsatellite instability and spermatogenic failure. In addition, mutations in mismatch repair and tumor suppressor genes, which could potentially lead to genomic instability, have been identified in some infertile men and animal models. In addition, results of two epidemiologic studies suggest spermatogenic defects might be just one aspect of a more systemic problem, possibly due to increased genomic instability. In this review we discuss well-established links between genomic instability and male infertility, as well as some of the emerging but less established data to support this relationship. We also propose some important areas of future research toward a more complete understanding of the underlying mechanisms for male infertility.     

激素及其受体调节Sertoli细胞功能的研究进展

Sertoli细胞是生精小管中唯一的体细胞，对生精过程发挥着重要作用。Sertoli细胞功能受多种激素调节，如卵泡刺激素（FSH）能调节其增殖及协助细胞间通讯（intercellular communication），且有助其形成血－睾屏障；雄激素能下调抗苗勒管激素（AMH）水平以促进Sertoli细胞发育，并维持血－睾屏障完整性；雌激素在不同剂量下可诱导Sertoli细胞凋亡与存活，并可调节水通道蛋白的表达而影响血－睾屏障等。综述各种激素及其受体对Sertoli细胞结构和功能的影响及阐明具体的分子机制，这对了解哺乳动物正常精子发生过程以及临床因精子发生障碍所致的男性不育症的治疗均有重要意义。     

THE GENETICS OF MALE INFERTILITY: A FIELD OF STUDY WHOSE TIME IS NOW

Idiopathic male infertility is often associated with genetic and epigenetic abnormalities. Such abnormalities include chromosome translocations and aneuploidies, Y chromosome microdeletions, and mutations of the CFTR gene. The unraveling of the human genome and ongoing animal transgenic studies have identified numerous other genes likely to be associated with male infertility. Initial reports from human studies have identified several candidate genes, including the protamine genes, SPO11, EIF5A2, USP26, ACT, and others. In addition to gene mutations and polymorphisms, damage to the chromatin resulting in single and double strand DNA breaks affects fertility. Recent studies are highlighting the role of such abnormalities in male infertility, and point to protamine defects as one cause of DNA damage. Epigenetic abnormalities also are being investigated, including the role of residual sperm mRNA in embryogenesis, and the effects of abnormal spermatogenesis on gene imprinting. These studies are pointing to complex etiologies and clinical ramifications in many infertile men.     

Ubiquitin-specific protease activity of USP9Y,a male infertility gene on the Y chromosome

Deletions of USP9Y have been observed among infertile males with defective spermatogenesis. Therefore, the gene has been designated as a male infertility gene on the Y chromosome. However, it remains to be determined how male infertility results from deletions of this gene. In order to initiate an investigation into the cellular functions of USP9Y in male germ cell development, in the present study we characterized the enzymatic specificity of USP9Y. Our results show that both USP9Y and Fam, the mouse infertility protein Usp9x, possess a protease activity specific to ubiquitin. These results suggest that, through de-ubiquitination, USP9Y may stabilize a specific target protein that is important for male germ cell development.