Westerveld G H, Korver C M, van Pelt A M M, Leschot N J, van der Veen F, Repping S, Lombardi M P
Department of Obstetrics and Gynaecology, Center for Reproductive Medicine, Amsterdam, The Netherlands.
Hum Reprod. 2006 Dec;21(12):3178-84. doi: 10.1093/humrep/del293. Epub 2006 Aug 24.
Because of the common use of ICSI and the potential genetic aetiology of spermatogenic failure, concern has been raised about transmitting genetic disorders to ICSI offspring. However, to date, in only approximately 15% of all cases of spermatogenic failure, an underlying genetic cause can be identified. We have previously established an association between spermatogenic failure and chromosomal region 11p15. In this study, we set out to explore whether NALP14, a gene recently mapped to 11p15, has a function in spermatogenesis and whether mutations in NALP14 can cause spermatogenic failure.
We applied two different multiple tissue northern (MTN) blots to determine tissue specificity of NALP14 and performed immunohistochemistry on human testis with anti-NALP14 antiserum. To determine imprinting status of NALP14, we tested the expression pattern of two single-nucleotide polymorphisms (SNPs) in human testis. Finally, we performed a mutation screen of the NALP14 gene in 157 men with azoospermia or severe oligozoospermia by direct sequencing; 158 normospermic men served as controls.
NALP14 was, as are the three other genes in 11p15, exclusively expressed in testis. Within the testis, the NALP14 protein was mainly expressed in A dark spermatogonia, mid and late spermatocytes and spermatids. The mutation screen revealed five mutations that occurred only in the patient group. One of these unique mutations introduced an early stop codon in the NALP14 sequence, predicted to result in a severely truncated protein.
Our data suggest that NALP14 has a function in spermatogenesis and that mutations in this gene might cause spermatogenic failure.
由于卵胞浆内单精子注射(ICSI)的广泛应用以及生精功能障碍潜在的遗传病因,人们对将遗传疾病传递给ICSI后代表示担忧。然而,迄今为止,在所有生精功能障碍病例中,只有约15%能确定潜在的遗传原因。我们之前已确定生精功能障碍与染色体区域11p15之间存在关联。在本研究中,我们着手探究最近定位到11p15的NALP14基因在精子发生中是否具有功能,以及NALP14基因的突变是否会导致生精功能障碍。
我们应用两种不同的多组织Northern印迹法来确定NALP14的组织特异性,并用抗NALP14抗血清对人睾丸进行免疫组织化学分析。为了确定NALP14的印记状态,我们检测了人睾丸中两个单核苷酸多态性(SNP)的表达模式。最后,我们通过直接测序对157例无精子症或严重少精子症男性的NALP14基因进行突变筛查;158例精子正常的男性作为对照。
与11p15中的其他三个基因一样,NALP14仅在睾丸中表达。在睾丸内,NALP14蛋白主要表达于Adark精原细胞、中期和晚期精母细胞以及精子细胞。突变筛查发现五个仅在患者组中出现的突变。其中一个独特的突变在NALP14序列中引入了一个早期终止密码子,预计会导致产生严重截短的蛋白质。
我们的数据表明NALP14在精子发生中具有功能,该基因的突变可能导致生精功能障碍。