Gene copy number reduction in the azoospermia factor c (AZFc) region and its effect on total motile sperm count
Gene copy number reduction in the azoospermia factor c (AZFc) region and its effect on total motile sperm count
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DOI：
10.1093/hmg/ddr119
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发表时间：
2011-06-15
影响因子：
3.5
通讯作者：
Repping, Sjoerd
中科院分区：
文献类型：
--
作者：
Noordam, Michiel J.;Westerveld, G. Henrike;Repping, Sjoerd
无精子因子C（AZFc）区域含有在睾丸中表达的多拷贝基因。AZFc区的缺失导致这些基因的拷贝数减少。已经描述了四种（部分）AZFc缺失，其中b2/b4和gr/gr缺失影响精液质量。在大多数研究中，（部分）AZFc缺失鉴定和特点，使用加/减序列位点标签（STS）聚合酶链反应（PCR）。然而，二次重复增加基因拷贝数而不重新引入STS边界标记。因此，AZFc基因的实际拷贝数不能通过STS PCR确定。在目前的研究中，我们首先开始通过定量实时PCR确定所有AZFc基因的实际拷贝数在男性（部分）AZFc缺失的基础上STS PCR。然后，我们分析了每个AZFc基因家族的基因拷贝数减少是否与活动精子总数（TMC）减少相关，无论缺失类型如何。我们筛选了840名男性，并确定了31名无关的男性（部分）缺失的AZFc的基础上STS PCR。在这31名男性中，6名男性（19%）有一个或多个继发性重复。对于所有AZFc基因，我们发现每个AZFc基因的拷贝数减少与TMC减少之间存在关联。在gr/gr缺失的男性中，减少的基因拷贝数的恢复使他们的TMC恢复到正常值。我们的研究结果表明，AZFc区的基因内容已被保存在整个进化过程中，通过剂量效应的AZFc基因对TMC维护男性生育能力。
The azoospermia factor c (AZFc) region harbors multi-copy genes that are expressed in the testis. Deletions of the AZFc region lead to reduced copy numbers of these genes. Four (partial) AZFc deletions have been described of which the b2/b4 and gr/gr deletions affect semen quality. In most studies, (partial) AZFc deletions are identified and characterized using plus/minus sequence site tag (STS) polymerase chain reaction (PCR). However, secondary duplications increase the gene copy number without re-introducing the STS boundary marker. Consequently, the actual copy number of AZFc genes cannot be determined via STS PCR. In the current study, we first set out to determine by quantitative real-time PCR the actual copy number of all AZFc genes in men with (partial) AZFc deletions based on STS PCR. We then analyzed whether reduced gene copy numbers of each AZFc gene family were associated with reduced total motile sperm count (TMC), regardless of the type of deletion. We screened 840 men and identified 31 unrelated men with (partial) deletions of AZFc based on STS PCR. Of these 31 men, 6 men (19%) had one or more secondary duplications. For all AZFc genes, we found an association between a reduction in the copy number of each individual AZFc gene and reduced TMC. In gr/gr-deleted men, restoration of reduced gene copy numbers restored their TMC to normal values. Our findings suggest that the gene content of the AZFc region has been preserved throughout evolution through a dosage effect of the AZFc genes on TMC safeguarding male fertility.