GENES ANCESTRAL TO THE THYROID/STEROID RECEPTOR FAMILY

我们小组一直在研究甲状腺/类固醇激素的成员 低等生物中的受体家族，试图分析其结构 和最原始受体的功能，更好地理解 脊椎动物中存在的无数受体的功能。我们克隆了 线虫秀丽线虫中三种这样的蛋白质的cDNA。一 其中(CHR3)与果蝇的DHR3和MHR3高度同源 在Manduca sexta。果蝇体内的这种受体是由蜕皮激素诱导的。 我们克隆的另一个受体(CNR14)也与E78A受体同源 果蝇体内可诱导的蜕皮激素。第三个受体CNR8类似 对脊椎动物的早期反应基因NAK1。受体处于发育阶段 具体如Northern分析所示。最近，我们克隆了 CHR3和CNR14基因，我们正在研究它们的启动子。我们发现 CHR3和CNR14这两个基因是反式剪接的，因此在 歌剧。而CHR3与前导序列SL2反式剪接，以及 CNR14与SL1反式剪接，CNR8似乎转录为单一 文字记录。顺式抄写给我们提供了学习的机会 从共同启动子转录而来的基因可以 共同发挥作用。我们将CHR3定位在1号染色体的中心区域 与HLH-2基因关系密切的同源框蛋白，类似于E12 蛋白质，脊椎动物MyoD的伙伴。我们确认了 粘粒上hlh-2和chr3基因的聚合酶链式反应。有趣的是，有些人 这一区域缺失的已知突变是致命的。我们目前正在 卵巢微量注射法研究CHR3和CNR14的表达 具有与DNA序列偶联的可能启动子区域的两性 编码β-半乳糖苷酶。我们还希望使用杂合子菌株 在CHR3基因缺失的区域进行基因敲除和基因敲除研究 救援队。 我们继续研究水母中的类固醇激素受体。 Cystophora三叶草。我们克隆了至少两个cdna异构体，大部分 基因。据我们所知，这是他体内唯一的这样的基因 有机体，可以代表最原始的成员 甲状腺/维甲酸亚家族。

Our group has been investigating members of thyroid/steroid hormone receptor family in lower organisms in an attempt to analyze the structure and functions of the most primitive receptors, better to understand the function of the myriad of receptors present in the vertebrata. We cloned cDNAs for three such proteins in the nematode Caenorhabditis elegans. One of them (CHR3) is highly homologous to the DHR3 in Drosophila and MHR3 in Manduca sexta. This receptor in Drosophila is induced by ecdysone. Another receptor we cloned (CNR14) is homologous to E78A receptor, also ecdysone inducible in Drosophila. The third receptor, CNR8 is similar to an early response gene in vertebrates, NAK1. The receptors are stage specific as shown by Northern analysis. More recently, we have cloned the genes for CHR3 and CNR14 and we are studying their promoters. We found that two genes, CHR3 and CNR14 are trans-spliced and so are organized in operons. While CHR3 is trans-spliced with a leader sequence SL2, and CNR14 is trans-spliced with SL1, CNR8 seems to be transcribed as single transcript. Cistronic transcription gives us the opportunity to study the genes which are transcribed from a common promoter and which could function together. We mapped CHR3 to the center region of chromosome 1 in close relation to hlh-2 gene, a homeobox protein analogous to E12 protein, the partner of MyoD in vertebrates. We confirmed the propinquity of the hlh-2 and CHR3 by PCR on a cosmid. Interestingly, some known mutants with deletion in this region are lethal. We are currently studying expression of CHR3 and CNR14 using microinjetions to the ovary of hermaphrodites with probable promoter regions coupled to DNA sequence coding for beta-galactosidase. We also hope to use heterozygotic strains with deletions in a region where CHR3 maps for a study of knock-out and rescue. We continued on the steroid hormone receptor in cubomedusan jellyfish Tripedalia cystophora. We cloned at least two cDNA isoforms and most of the gene. As far as we can tell, this is the only such gene in his organism and could represent the most primitive member of thyroid/retinoic acid subfamily.