DNA种类分析和总结.docx

一、脱氧核糖核酸

cDNA:互补DNA（ComplementaryDNA，cDNA）是一种利用逆转录酶，以RNA（通常是mRNA）为模板作成的复制品，经常用来将真核生物的基因（以mRNA形式）复制到原核生物细胞中。若一个cDNA含有许多来自不同基因的mRNA，称为cDNA基因库（cDNAlibrary）。另外也可制成只含单一mRNA的cDNA。(fromwiki)

cpDNA:叶绿体基因组也叫叶绿体DNA（cpDNA)，双链环状，每个叶绿体中约含12个cpDNA分子。叶绿体具有独立基因组，被认为是内共生起源的细胞器。叶绿体基因组主要用于编码与光合作用密切相关的一些蛋白和一些核糖体蛋白。叶绿体基因表达调控是在不同水平上进行的，光和细胞分裂素对叶绿体基因的表达也起着重要的调节作用。

gDNA:GenomicDNA.是区别与染色体之外的DNA，如质粒DNA等。gDNA可以遗传给后代。

msDNA：Multicopysingle-strandedDNA(msDNA)isatypeofextrachromosomalsatelliteDNAthatconsistsofasingle-strandedDNAmoleculecovalentlylinkedviaa2-5phosphodiesterbondtoaninternalguanosineofanRNAmolecule.TheresultantDNA/RNAchimerapossessestwostem-loopsjoinedbyabranchsimilartothebranchesfoundinRNAsplicingintermediates.ThecodingregionformsDNA,calledaretron,alsoencodesatypeofreversetranscriptase,whichisessentialformsDNAsynthesis.[2]

mtDNA：MitochondrialDNA(mtDNAormDNA[2])istheDNAlocatedinorganellescalledmitochondria,structureswithineukaryoticcellsthatconvertthechemicalenergyfromfoodintoaformthatcellscanuse,adenosinetriphosphate(ATP).Most otherDNApresentineukaryoticorganismsisfoundinthecellnucleus.mtDNA是母系遗传的。

rDNA:RibosomalDNA(rDNA)codesforribosomalRNA.Theribosomeisanintracellularmacromoleculethatproducesproteinsorpolypeptidechains.TheribosomeitselfconsistsofacompositeofproteinsandRNA.Asshowninthe figure,rDNAconsistsofatandemrepeatofaunitsegment,anoperon,composedofNTS,ETS,18S,ITS1,5.8S,ITS2,and28Stracts.rDNAhasanothergene,codingfor5SrRNA,locatedinthegenomeinmosteukaryotes.[1]5SrDNAisalsopresentintandemrepeatsasinDrosophila.[1]Inthe nucleus,the rDNAregionofthechromosomeisvisualizedasanucleoluswhichformsexpandedchromosomalloopswithrDNA.TheserDNAregionsarealsocallednucleolusorganizerregions,astheygiverisetothenucleolus.I