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AZFc 3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...     

男性不育症患者AZF基因与临床相关性研究

目的探讨不育症患者中无精因子基因家族（AZF）缺失类型分布及其与临床症状的关系。方法采用多重PCR技术对15个序列标记位点（STS）进行检测,判断不育患者的微缺失类型。结果运用序列标记位点在418例不育患者中检出Y染色体微缺失43例,缺失率10．3％,对照组无缺失病例检出。结论大多数AZFa区缺失临床上可表现唯支持细胞综合征,AZFb区域缺失影响精子的发育,AZFc区域缺失表现出临床症状异质性,AZFd缺失临床症状较轻或精子仅表现形态异常。     

唐氏综合征高危孕妇血浆中游离胎儿DNA的Y染色体微缺失筛查

目的 利用孕妇血浆中游离胎儿DNA在孕早期进行Y染色体微缺失筛查,诊断男性胎儿无精子症因子(AZF)缺失情况。方法 留取2013年6月～2014年8月参加产前检测的16～34孕周唐氏综合征筛查高危孕妇的外周血标本89例,提取出全血基因组DNA后利用Y染色体微缺失检测试剂盒检测AZF微缺失。结果 86例孕妇妊娠至胎儿出生,其中男胎孕妇45例,女胎孕妇41例。妊娠女性胎儿的孕妇血浆DNA仅扩增出ZFX/ZFY对照基因,而妊娠男性胎儿的孕妇血浆DNA同时扩增出SRY,ZFX/ZFY对照基因,且有3例样本检测出AZF基因微缺失。结论 通过提取孕妇血浆中游离胎儿DNA能够检测出胎儿是否伴有AZF基因微缺失,从而提前预测胎儿今后罹患生精障碍的风险。     

应用改良多重PCR筛查不育症患者Y染色体无精子症因子微缺失

目的 评价改良多重PcR筛查男性非梗阻性无精子症和严重少精子症患者Y染色体AZF缺失类型的价值.方法 在Y染色体STS常规引物序列的5'端连接一段非人类同源序列的寡核苷酸链,合成嵌合引物对.根据非人类同源序列的寡核苷酸链设计通用引物对,与嵌合引物对在同一反应体系中对人类基因组DNA进行多重PCR扩增,并用以评价筛查262例非梗阻性无精子症和严重少精子症患者中AZF a、b、c区域的微缺失状况.结果 用改良多重PCR筛查262例非梗阻性无精子症和严重少精子症患者,发现AZF微缺失33例(12.60%),其中AZF c缺失27例,AZF b+c缺失6例,与EMQN推荐方法检测的结果相比,缺失阳性符合率为100%(33/33),且未出现假阳性.改良多重PCR与EMQN推荐方法检测Y染色体多个STS的电泳结果显示,2种方法得到的sY84、sY86、sY127、sY134、sY254、sY255、SRY位点扩增产物的均一性好,扩增产物条带清晰.结论 改良多重PCR能较好地筛查出男性非梗阻性无精子症和严重少精子症患者Y染色体AZF缺失类型.     

Arrangement of DYZ1 and DYZ2 repeats on the human Y-chromosome: a case with presence of DYZ1 and absence of DYZ2.

The composition of Yq-heterochromatin is dominated by the two repetitive sequences DYZ1 (4000 copies) and DYZ2 (2000 copies). Probes derived from these sequences can be used for sex determination and the structural analysis of aberrant Y-chromosomes. Using such probes Schmid et al., have recently proposed a regular interspersion of the two sequences in a ratio of 2:1 over the entire Yq12 chromosome region. By Southern analysis we investigated the DNA of a normal male, cytogenetically negative for Yq-heterochromatin. Applying the same probes as used by Schmid et al., only a small amount of DYZ1 material could be detected. The case presented indicates the presence of DYZ1 only in the Yq11-Yq12 junction region and excludes DYZ2 from any function relevant for normal male development.     

Clinical and laboratory evaluation of idiopathic male infertility in a secondary referral center in India

The genetic basis of infertility has received increasing recognition in recent years, particularly with the advent of assisted reproductive technology. It is now becoming obvious that genetic etiology for infertility is an important cause of disrupted spermatogenesis. Y-chromosome microdeletions and abnormal karyotype are the two major causes of altered spermatogenesis. To achieve biological fatherhood, intracytoplasmic sperm injection (ICSI) is performed in cases of severe infertility with or without genetic abnormalities. There is a concern that these genetic abnormalities can be transmitted to the male progeny, who may subsequently have a more severe phenotype of infertility. A total of 200 men were recruited for clinical examinations, spermiograms, hormonal profiles, and cytogenetic and Yq microdeletion profiles. Testicular biopsy was also performed whenever possible and histologically evaluated. Genetic abnormalities were seen in 7.1% of cases, of which 4.1% had chromosomal aberrations, namely Klinefelter's mosaic (47XXY) and Robertsonian translocation, and 3.0% had Yq microdeletions, which is very low as compared to other populations. Follicle stimulating hormone (FSH) and luteinizing hormone (LH) were significantly increased in men with nonobstructive azoospermia (NOA) as compared to severe oligoasthenozoospermia (P<0.0001), whereas testosterone levels were significantly decreased in men with microdeletions as compared to men with no microdeletions (P<0.0083). Low levels of androgen in men with microdeletions indicate a need to follow-up for early andropause. Patients with microdeletions had more severe testicular histology as compared to subjects without deletions. Our studies showed a significant decrease (P<0.002) in the serum inhibin B values in men with NOA, whereas FSH was seen to be significantly higher as compared to men with severe oligoasthenozoospermia (SOAS), indicating that both the Sertoli cells as well the germ cells were significantly compromised in cases of NOA and partially affected in SOAS. Overall inhibin B in combination with serum FSH would thus be a better marker than serum FSH alone for impaired spermatogenesis. In view of the genetic and hormonal abnormalities in the group of infertile men with idiopathic severe oligozoospermia and NOA cases, who are potential candidates for ICSI, genetic testing for Y-chromosome microdeletions, karyotype, and biochemical parameters is advocated.     

Nosocomial urosepsis caused by Enterobacter kobei with aberrant phenotype

Enterobacter kobei is the species of the Enterobacter cloacae complex, which is phenotypically most closely related to the species E. cloacae. This is the first report of infection caused by a new biotype of E. kobei. A patient with a history of urinary bladder operation developed a urosepsis with an Enterobacter isolate displaying the E. cloacae phenotype. The isolate was classified to the species E. kobei by sequence analysis of the 16S-rDNA, 4 protein-coding genes and enterobacterial repetitive intergenic consensus (ERIC)-cluster analysis. E. kobei was originally described to be Voges-Proskauer (VP) negative. However, the isolates of the present case were VP-positive. After analyzing 120 biochemical tests included in the API20E and the Biotype 100 systems, 4 biochemical tests were identified potentially differentiating this new biotype from E. cloacae.     

Multilocus sequence typing and repetitive element-based polymerase chain reaction analysis of Neisseria meningitidis isolates in Brazil reveal the emergence of 11 new sequence types genetically related to the ST-32 and ST-41/44 complexes and high prevalence of strains related to hypervirulent lineages

Eighty-four strains of Neisseria meningitidis isolated from patients with meningococcal disease in 4 states of Brazil were analyzed by multilocus sequence typing and repetitive element-based polymerase chain reaction (Rep-PCR). The majority of strains analyzed (82%) belonged to 4 hypervirulent lineages, and 11 of 20 new sequence type (STs) characterized were related to hypervirulent lineages. Sequences of fetA and porA genes were analyzed, and the majority were related to profiles present in the ST-32 complex/electrophoretic type (ET)-5 complex. Rep-PCR analysis showed a unique electrophoretic pattern among strains related to hypervirulent lineages. Considering that 81% of the strains were serogroup B and strains belonging to the ST-32/ET-5 complex are genetically related to the Cuban vaccine strain used in a mass vaccination from 1990 to 1994 in Brazil, we believe that this vaccine did not confer effective herd immunity even among the age group within the vaccine showed higher efficacy. Our results once more raise the question about which strains should be used in the development of a new vaccine against N. meningitidis serogroup B.     

The DNA sequence of the structural gene of gonococcal protein III and the flanking region containing a repetitive sequence. Homology of protein III with enterobacterial OmpA proteins

The insert of a lambda gt11 clone expressing gonococcal protein III was sequenced. The deduced amino acid sequence showed a coding frame of 236 amino acids with a typical 22-amino-acid signal peptide, followed by the known NH2-terminal sequence of PIII. The mature protein has a molecular weight of 23,298. It was found that PIII had extensive and very striking homology to the carboxy-terminal portion of enterobacterial OmpA proteins. The homology encompasses the OmpA domain that is believed to be located in the periplasmic space. If the disposition of PIII across the OM is analogous, then the surface-exposed domain consists of less than 40 amino acids. These include a potential 15-amino-acid disulfide loop, a feature not found in OmpA proteins. Hybridization studies with the sequenced insert indicated that it contained a repetitive sequence that occurred at least 20 times in the genome. By additional hybridization studies the area containing the repetitive sequence was narrowed to a region of 43 bp. This region contained an exact copy of the consensus sequence of a 26-bp repetitive sequence recently described. An analogous sequence recurs in an inverted orientation 53 bp downstream.     

Effect of mibefradil on voltage-dependent gating and kinetics of T-type Ca(2+) channels in cortisol-secreting cells

We have studied the effect of the Ca(2+) antagonist mibefradil on low voltage-activated T-type Ca(2+) channels in whole-cell patch clamp recordings from bovine adrenal zona fasciculata (AZF) cells. AZF cells are distinctive in expressing only T-type Ca(2+) channels, allowing the mechanism of pharmacological agents to be explored without interference from other Ca(2+) channels. The inhibition of T-type Ca(2+) channels by mibefradil was voltage- and use-dependent. When Ca(2+) currents were activated from holding potentials of -80 and -60 mV, mibefradil inhibited currents with IC(50) values of 1.0 and 0.17 microM, respectively. When T-type Ca(2+) current (I(T)) was activated from a holding potential of -90 mV in the presence of 2 microM mibefradil, a single voltage step to -10 mV inhibited I(T) by 16.2% +/- 2.9% (n = 10). With subsequent voltage steps, applied at 10-s intervals, block reached a steady-state value of 51.9% +/- 5.0% (n = 5). Mibefradil (1 microM) produced a leftward shift of 5.7 mV (n = 4) in the voltage-dependent steady-state availability curve such that T-type Ca(2+) channels inactivated at more negative potentials, but this drug did not change the voltage-dependence of T channel opening. Mibefradil failed to alter the kinetics of T channel activation, inactivation, or deactivation, but markedly slowed T channel recovery following an inactivating prepulse. Mibefradil inhibited adrenocorticotropin-stimulated cortisol secretion from AZF cells with an IC(50) value of 3.5 microM. These results show that mibefradil is a relatively potent antagonist of T-type Ca(2+) channels in cortisol-secreting cells. The enhanced potency of mibefradil with sustained or repetitive depolarizations, its shifting of the steady-state inactivation curve, and its slowing of recovery all indicate that this drug preferentially interacts with Ca(2+) channels in the open or inactivated state. The inhibition of cortisol secretion by mibefradil at concentrations similar to those that block I(T) is consistent with a requirement for these channels in corticosteroidogenesis.     

Absence of microdeletions in the azoospermia-factor region of the Y-chromosome in viennese men seeking assisted reproduction

PURPOSE: The azoospermia-factor region of the Y-chromosome is essential for spermatogenesis in humans. In the literature, a wide range is given for the frequency of microdeletions in this region. The purpose of this study was to evaluate our own population of patients. METHODS: During a two-year period at Vienna Medical School, all male patients (n = 383) seeking assisted reproduction were screened for microdeletions. Thirty-three men had azoospermia and 154 severe oligozoospermia. Genomic DNA was prepared from peripheral lymphocytes and polymerase chain reaction analysis of the azoospermia-factor region was performed using the Promega kit. RESULTS: No case tested positive for azoospermia-factor microdeletions. In all cases amplification of 18 non-polymorphic sequence tagged sites was obtained. CONCLUSIONS: Y-chromosome microdeletions do not seem to be an important factor for male infertility in our patients. This suggests that screening should be restricted to men with azoospermia or severe oligozoospermia only.     

中国人原发无精与少精症Y染色体无精症因子区域微缺失的临床基因诊断研究

目的 建立中国人原发无精与少精症Y染色体无精症因子(AZF)区域微缺失临床基因诊断的方法并进行初步评价。方法 在完成中国人原发无精与少精症Y染色体无精症因子区域微缺失分子流行病学研究的基础上，采用盲法和多重聚合酶链反应—琼脂糖电泳检测技术，利用挑选的AZFa、AZFb、AZFc3个区域共8个序列标签位点(STS)，对100例原发无精与80例少精症患者的精液进行微缺失分析。两组患者中各有27例和16例在事先分子流行病的研究中已确认存在AZF微缺失。结果 在原发无精症患者中检出STS位点缺失27例，原发少精患者中检出AZF区STS位点缺失16例，所有试验前被确认的AZF微缺失均被检出，未发现假阳性与假阴性结果，检测的灵敏度与特异性均为100％。结论 本研究所确定的AZF区域8个STS位点缺失与中国人原发无精和严重少精密切相关，利用上述STS位点与试验设计的多重聚合酶链反应技术进行微缺失分析，可以准确、方便、快速地完成中国人原发无精与少精症AZF区域微缺失的基因诊断，适于在临床实验室中推广应用。     

严重少精子症及无精子症的遗传学分析

目的：探讨严重少精子症、无精子症与遗传学的关系。方法采用外周血细胞培养染色体检查和多重PCR 技术对142例严重少精子症和178例无精子症患者进行细胞遗传学和 Y 染色体 AZF 微缺失检测,同时对100例精液参数正常男性进行 AZF 微缺失检测作为对照。结果在严重少精子症患者中,染色体异常率为16．20％（23/142）,AZF 缺失率为9．86％（14/142）;在无精子症患者中,染色体异常率为19．66％（35/178）,AZF 缺失率为11．24％（20/178）;精液参数正常患者未检出 AZF 微缺失。在严重少精子症和无精子症患者中,染色体异常和 AZF 缺失比例均显著高于精液参数正常对照组。结论染色体异常和 AZF 微缺失是引起男性不育的重要原因,通过染色体和AZF 微缺失检测可以为优生优育提供可靠的遗传信息依据。     

上海地区原发性男性不育症患者Y染色体AZF基因微缺失的检测

目的探讨上海地区原发性男性不育症患者无精子因子(AZF)基因微缺失情况及其微缺失特点。方法运用聚合酶链反应(PCR)结合琼脂糖凝胶电泳等方法,对上海地区269例原发性男性不育症患者(无精子症38例、严重少精子症231例)以及10名已生育的正常男性进行了AZFa、AZFb和AZFc微缺失筛查。结果 269例男性不育症患者中发现18例AZF基因STS位点存在缺失,其中14例为AZFc区存在缺失、2例为AZFb+c区存在缺失、1例为AZFa+b+c均缺失、1例为AZFa区存在缺失,总缺失率为6.7%。结论 AZFc区为原发性不育症患者AZF基因筛查的主要候选基因,临床上对原发性不育患者进行AZF基因缺失筛查仍是十分必要的。     

桂西地区原发性无精子症和严重少精子症患者Y染色体无精子因子检测分析

目的探讨桂西地区原发性无精子症和严重少精子症患者Y染色体无精子因子(AZF)微缺失状况。方法采用多重聚合酶链反应技术对桂西地区56例原发无精子症、78例原发严重少精症患者及40例正常生育男性进行4个区域15个位点微缺失分析。结果 40例正常生育男性未发现Y染色体AZF微缺失,134例生精障碍患者中发现AZF微缺失14例,总缺失率为10.5%。生精障碍组与正常生育组比较Y染色体AZF微缺失率差异具有统计学意义(P<0.01)。结论 Y染色体AZF微缺失是男性原发无精、少精子症的重要原因之一,AZF微缺失检测对男性不育症患者进行遗传学诊断与筛查有一定意义。     

Metabolites of an Epac-Selective cAMP Analog Induce Cortisol Synthesis by Adrenocortical Cells through a cAMP-Independent Pathway

Adrenal zona fasciculata (AZF) cells express a cAMP-activated guanine nucleotide exchange protein (Epac2) that may function in ACTH-stimulated cortisol synthesis. Experiments were done to determine whether cAMP analogs that selectively activate Epacs could induce cortisol synthesis and the expression of genes coding for steroidogenic proteins in bovine AZF cells. Treatment of AZF cells with the Epac-selective cAMP analog (ESCA) 8CPT-2′-OMe-cAMP induced large (>100 fold), concentration-dependent, delayed increases in cortisol synthesis and the expression of mRNAs coding for the steroid hydroxylases CYP11a1, CYP17, CYP21, and the steroid acute regulatory protein (StAR). However, a non-hydrolyzable analog of this ESCA, Sp-8CPT-2′-OMe-cAMP, failed to stimulate cortisol production even at concentrations that activated Rap1, a downstream effector of Epac2. Accordingly, putative metabolites of 8CPT-2′-OMe-cAMP, including 8CPT-2′-OMe-5′AMP, 8CPT-2′-OMe-adenosine, and 8CPT-adenine all induced cortisol synthesis and steroid hydroxylase mRNA expression with a temporal pattern, potency, and effectiveness similar to the parent compound. At concentrations that markedly stimulated cortisol production, none of these metabolites significantly activated cAMP-dependent protein kinase (PKA). These results show that one or more metabolites of the ESCA 8CPT-2′-OMe-cAMP induce cortico-steroidogenesis by activating a panel of genes that code for steroidogenic proteins. The remarkable increases in cortisol synthesis observed in this study appear to be mediated by a novel cAMP-, Epac- and PKA-independent signaling pathway.