卤虫中编码DM结构域的DNA序列的克隆和初步研究(简报)

STUDY OF A DNA SEQUENCE FROM BRINE SHRIMP ARTEMIA CONTAINING A NOVEL DM DOMAIN

性别决定的分子机制复杂多样,但是处于动物性别决定的基因调控网络底部的一些调控基因具有相当高的保守性[1].doublesex(dsx)基因[2]和maleabnomal-3(mab-3)基因分别是果蝇(Drosophilamelanogaster)和线虫(Caenorhabditis elegans)性别决定调控途径末端的重要基因,对这两个基因序列的比较导致了DM结构域的发现[3],它是已知在性别发育过程中最为保守的DNA结合结构域.目前,已在包括鱼类、两栖类、爬行类、鸟类和哺乳类等多种脊椎动物的不同基因中发现了DM结构域[4,5,6,7],其中一些基因的功能已经确定与雄性发育和性别逆转相关[8,9],如人类(Homo sapiens)和小鼠的DMRTl/dmrtl(doublesex and mab3-related transcriptionfactor 1)基因[10].在脊椎动物之外,Ohbayashi等[11]和Miller等[12]分别报道了家蚕(Bombyx mori)和珊瑚(Acropora millepora)中DM结构域的序列特征.

Sex-determining mechanisms are highly variable between phyla.However,there is an apparent exception in which structurally and functionally related genes control sex determina- tion in different phyla:the sexual regulators DSX of Drosophila melanogaster and MAB-3 of Caenorhabditis elegans both containing a DNA-binding motif,DM domain.Proteins containing the domain may also play a role in sexual development of vertebrates.For examples,both the human DMRT1(doublesex and mab-3 related transcription factor 1)gene and mouse Dmrtl gene are necessary for male development.In this paper,through the degenerated PCR,a DNA fragment ADM was amplified out from genomic DNA of brine shrimp,A rtemia sinica from YunCheng Salt Lake,Shanxi,China and A rtemia parthenogenetica from GaHai,Qinghai,China,respectively.ADM encodes 47 amino acids and is highly homologous to amino acid sequence of the known DM do- mains.By comparing total of 27 DM domains in distant related species,a phylogenic tree of DM domain was constructed.In the tree,these DM domains were divided into different branches ac- cording to their subtypes.Among the DM domains that were compared,ADM is most homologous to the DM domain contained in human DMRT3 and mouse Dmrt3,which shares 83% identity be- tween them.In addition,the same length of ADM could also be amplified out from cDNA of A rtemia sinica and A rtemia parthenogenetica,which indicated that ADM was expressed and locat- ed in one exon.The DM domain in brine shrimp reported here would make it possible for cloning the full-length eDNA containing the DM domain and further elucidating their functions.