Spieth J, Denison K, Kirtland S, Cane J, Blumenthal T
Nucleic Acids Res. 1985 Jul 25;13(14):5283-95. doi: 10.1093/nar/13.14.5283.
The nematode Caenorhabditis elegans contains a small family of vitellogenin genes which is expressed abundantly, but only in the intestine of the adult hermaphrodite worm. In order to identify possible regulatory elements, we have sequenced the DNA surrounding the 5' ends of five of the six genes. Contained within regions which have largely diverged from one another, two different heptameric sequences are found repeated within the first 200 bp upstream of each of the genes. The first sequence, TGTCAAT, is present as a perfect heptamer at least once upstream of each gene. It is repeated in both orientations four to six times in each 5' flanking region, allowing a one-base mismatch. The second sequence, CTGATAA, is also present as a perfect heptamer in a restricted region upstream of each gene. These two sequence elements may be involved in regulation of the vitellogenin genes. Remarkably, the CTGATAA sequence is present in a similar location in the promoter regions of vertebrate vitellogenin genes. In fact, our data reveal a surprising degree of similarity between the nematode and vertebrate vitellogenins.
线虫秀丽隐杆线虫含有一个小的卵黄蛋白原基因家族，该家族表达丰富，但仅在成年雌雄同体线虫的肠道中表达。为了鉴定可能的调控元件，我们对六个基因中五个基因的5'端周围的DNA进行了测序。在彼此差异很大的区域内，在每个基因上游的前200 bp内发现了两种不同的七聚体序列重复出现。第一个序列TGTCAAT，在每个基因上游至少有一次以完美的七聚体形式存在。它在每个5'侧翼区域以两种方向重复四到六次，允许一个碱基错配。第二个序列CTGATAA，在每个基因上游的一个受限区域内也以完美的七聚体形式存在。这两个序列元件可能参与卵黄蛋白原基因的调控。值得注意的是，CTGATAA序列在脊椎动物卵黄蛋白原基因的启动子区域中位于相似的位置。事实上，我们的数据揭示了线虫和脊椎动物卵黄蛋白原之间惊人的相似程度。
