Hirashima M, Ono T, Nakao M, Nishi H, Kimura A, Nomiyama H, Hamada F, Yoshida M C, Shimada K
Molecular Genetic Laboratory, Chemo-Sero-Therapeutic Research Institute, Kumamoto, Japan.
DNA Seq. 1992;3(4):203-12. doi: 10.3109/10425179209034019.
Cytokine LD78 is a member of a newly identified cytokine superfamily. We cloned the third human gene for the LD78, termed LD78 gamma and the sequence analysis showed that it is a 5'-truncated pseudogene. Exons 2 and 3 and the intron between them are highly homologous to those of the LD78 beta gene, hence, the gamma gene was probably derived from the beta gene. Southern blot analysis of human x mouse somatic hybrid cell DNAs and in situ hybridization experiments mapped all the three gene loci on human chromosome 17q21.1-q21.3. Analysis of DNAs from family members supports our previous finding that the beta and gamma genes on each of the paired chromosome 17 vary in copy number and that the LD78 alpha gene is presumably a single copy. In our analyses of cosmid clones, the LD78 beta gene and the second gene for AT744, which is also a member of the superfamily are closely linked in a head-to-head arrangement. The mechanism of generation of the three LD78 genes is discussed.
细胞因子LD78是新发现的细胞因子超家族的成员。我们克隆了人类LD78的第三个基因，命名为LD78γ，序列分析表明它是一个5'端截短的假基因。外显子2和3以及它们之间的内含子与LD78β基因的外显子2和3以及它们之间的内含子高度同源，因此，γ基因可能起源于β基因。对人×小鼠体细胞杂交细胞DNA的Southern印迹分析和原位杂交实验将所有三个基因座定位在人类染色体17q21.1 - q21.3上。对家庭成员DNA的分析支持了我们之前的发现，即每对17号染色体上的β和γ基因拷贝数不同，并且LD78α基因可能是单拷贝。在我们对黏粒克隆的分析中，LD78β基因和AT744的第二个基因（AT744也是该超家族的成员）以头对头的排列紧密相连。文中讨论了三个LD78基因的产生机制。
