Vellard M, Soret J, Viegas-Pequignot E, Galibert F, Nguyen V C, Dutrillaux B, Perbal B
Institut Curie, Centre Universitaire, Orsay, France.
Oncogene. 1991 Apr;6(4):505-14.
We have characterized a novel chicken c-myb exon whose sequences are specifically expressed in thymic cells. In situ hybridization experiments indicate that this thymus-specific coding exon is localized on a small chromosome, distinct from the large acrocentric chromosome 3 on which we recently mapped the bulk of 15 exons, common to the c-myb mRNA species expressed in hematopoietic cells of both B and T lineages. These observations indicate that intermolecular recombination is required for the tissue-specific expression of the c-myb proto-oncogene. We also show that these thymus-specific sequences are conserved in human DNA and lie on chromosome 17q25, whereas the human c-myb locus is localized on chromosome 6q22-23. Sequencing data obtained from genomic DNA and PCR analyses performed with c-myb mRNA species expressed in chicken thymic cells strongly suggest that a repeated decameric sequence plays a key role in the recombination process.
我们鉴定了一个新的鸡源c-myb外显子，其序列在胸腺细胞中特异性表达。原位杂交实验表明，这个胸腺特异性编码外显子定位于一条小染色体上，与大的近端着丝粒染色体3不同，我们最近在该染色体3上定位了大部分15个外显子，这些外显子是B和T谱系造血细胞中表达的c-myb mRNA种类所共有的。这些观察结果表明，分子间重组是c-myb原癌基因组织特异性表达所必需的。我们还表明，这些胸腺特异性序列在人类DNA中是保守的，位于染色体17q25上，而人类c-myb基因座定位于染色体6q22 - 23。从基因组DNA获得的测序数据以及对鸡胸腺细胞中表达的c-myb mRNA种类进行的PCR分析强烈表明，一个重复的十聚体序列在重组过程中起关键作用。
