Transcriptional activity of multiple copies of a subtelomerically located olfactory receptor gene that is polymorphic in number and location
Transcriptional activity of multiple copies of a subtelomerically located olfactory receptor gene that is polymorphic in number and location
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DOI：
10.1093/hmg/10.21.2373
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发表时间：
2001-10-02
影响因子：
3.5
通讯作者：
Trask, BJ
中科院分区：
文献类型：
--
作者：
Linardopoulou, E;Mefford, HC;Trask, BJ
我们在这里报告的转录活性的多个副本的亚端粒位于嗅觉受体（OR）基因，OR-A。由于最近的重复事件，OR-A的拷贝数和染色体位置在人类中各不相同。对22个个体12条染色体末端的180个拷贝的该基因的序列分析表明，除一个拷贝外，所有拷贝的主要编码外显子是一个完整的开放阅读框架，具有0-5个预测的氨基酸差异。我们检测转录的OR-A在嗅上皮和睾丸组织中使用RT-PCR扩增与计算预测的基因结构的基础上设计的引物。两个选择性剪接形式的转录本，一个编码的亚型与延长的N-末端，被发现在这两种组织。第三个转录本，来自第二个启动子，也观察到在睾丸。在所有转录本中，起始甲硫氨酸预计位于上游外显子而不是主要编码外显子，这对于大多数其他OR基因是典型的。通过检查转录本之间的序列变异，我们表明，该基因的转录发生在多个染色体位置。我们的研究结果提供了证据的想法，即OR多样性可以产生在易于重复的亚端粒区域，并表明在亚端粒区域的多态性可能会导致个体到个体的变化在OR基因的表达谱。
We report here on the transcriptional activity of multiple copies of a subtelomerically located olfactory receptor (OR) gene, OR-A. Due to recent duplication events, both the copy number and chromosomal location of OR-A vary among humans. Sequence analyses of 180 copies of this gene, derived from 12 chromosome ends in 22 individuals, show that the main coding exon of all but one copy is an intact open reading frame with 0-5 predicted amino acid differences. We detected transcription of OR-A in both olfactory epithelium and testis tissue using RT-PCR amplification with primers designed on the basis of a computationally predicted gene structure. Two alternatively spliced forms of transcripts, one encoding an isoform with an extended N-terminus, were found in both tissues. A third transcript, derived from a second promoter, was also observed in testes. The start methionine is predicted in all transcripts to lie in an upstream exon rather than the main coding exon, as is typical for most other OR genes. By examining sequence variants among transcripts, we show that transcription of this gene occurs at multiple chromosomal locations. Our results lend credence to the idea that OR diversity could be generated in rearrangement-prone subtelomeric regions and show that polymorphism in subtelomeric regions could lead to individual-to-individual variation in the expressed repertoire of OR genes.