Kidd V J, Saunders G F
J Biol Chem. 1982 Sep 25;257(18):10673-80.
Human placental lactogen (hPL) and growth hormone (hGH) are two hormones thought to have evolved from a common ancestral gene (along with prolactin), yet they have quite different functions and specificities. The nucleic acid sequences of the respective cDNAs of the two genes share considerable homology, as well as the existence of multiple forms of each gene within the genome. In this study we report on the linkage arrangement of several genes from this group. Two hPL-like genes as well as an hGH gene are shown to be linked within a 38-kilobase pair region of DNA. Linkage between a variant hGH gene and an hPL gene is also shown. The orientation and structural organization of these genes was previously established using 5'- and 3'-specific probes from a placental lactogen cDNA clone and detailed restriction endonuclease mapping. Restriction fragments from the overlapping clones were verified by comparison to digests of high molecular weight genomic DNA. In addition, the location of a specific class of repetitive DNA sequences, the Alu family, was mapped on these clones using the recombinant clone BLUR 8. All members of this multigene family have Alu repeat sequences either immediately flanking their 3' or 5' untranslated regions or within their intervening sequences.
人胎盘催乳素（hPL）和生长激素（hGH）是两种被认为由共同祖先基因（与催乳素一起）进化而来的激素，但它们具有截然不同的功能和特异性。这两个基因各自的cDNA的核酸序列具有相当大的同源性，并且基因组中每个基因都存在多种形式。在本研究中，我们报告了该基因家族中几个基因的连锁排列。两个hPL样基因以及一个hGH基因被证明在一个38千碱基对的DNA区域内连锁。还显示了一个变异的hGH基因与一个hPL基因之间的连锁。这些基因的方向和结构组织先前是使用来自胎盘催乳素cDNA克隆的5'和3'特异性探针以及详细的限制性内切酶图谱确定的。通过与高分子量基因组DNA的消化产物进行比较，验证了重叠克隆的限制性片段。此外，使用重组克隆BLUR 8将一类特定的重复DNA序列，即Alu家族，定位在这些克隆上。这个多基因家族的所有成员在其3'或5'非翻译区紧邻处或其间隔序列内都有Alu重复序列。
