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1、安徽农业大学学报,2007,34(3):440-445JournalofAnhuiAgriculturalUniversity真菌核心组蛋白基因的分子特点与进化动力学模式¹*鞠建峰,赵国焓,许晓风(南京师范大学生命科学学院,南京210097)摘要:统计了不同真菌36个核心组蛋白基因的核苷酸组成与分布特点及密码子适应指数(CAI),分类计算了这些基因在种内及种间同义位点差异(pS)和非同义位点差异(pN)。结果发现:1)真菌H2A、H2B、H3、H4基因的平均GC%含量依次为:4212、4317、4313和4217,第3位密码子G
2、C%含量依次为:3417、4216、3210和3019,平均CAI依次为:01698、01745、01699和01745;2)真菌4种组蛋白基因的pS和pN表现不同,其中H3和H4表现为pSmpN,符合birth-and-death进化模式,H2A和H2B表现为pSUpN,不符合birth-and-death进化模式;3)酵母的H2A和H2B甚至表现出了pNmpS的情形,与协调进化相一致。真菌组蛋白基因的这些分子特点与进化动力学模式和其它生物组蛋白基因的明显不同。关键词:真菌组蛋白;分子进化;进化模式中图分类号:Q755文献标识
3、码:A文章编号:1672-352X(2007)03-0440-06Molecularcharactersandlong-termevolutionarypatternoffungicscorehistonemultigenesJUJian-feng,ZHAOGuo-han,XUXiao-feng(CollegeofLifeScience,NanjingNormalUniversity,Nanjing210097)Abstract:Inthisstudy,weexaminedboththemolecularcharactersan
4、dlong-termevolutionarypatternoffungicscorehistonemultigenefamily1Weanalyzedthenucleotidecomposition,nucleotidedistributionandcodonadaptationindex(CAI)of36corehistonemultigenesfrom9speciesoffung,iandcalculatedtheirproportionofsyn-onymousnucleotidedifferences(pS)andnon
5、synonymousnucleotidedifferences(pN)bothwithinandbetweenspe-ciestodeterminewhetherconcertedevolutionorpurifyingselectionwasthemajorfactorfortheevolutionofthesemultigenes.Theresultsareasfollows:1)fungicsH2A,H2B,H3andH4multigenesallhavealowGC%contentandalowGC3s%withthev
6、alueof4212,4317,4313,4217,and3417,4216,3210,3019respectively;TheiraverageCAIvaluesare01698,01745,01699and01745;2)theirpSandpNbehaviorsbothwithinandbetweenspeciesarequitedifferentwiththeH2AcsandH2BcsshowingpSUpNandH3csandH4csshowingpSmpN,indicatingthattheH3andH4areacc
7、ordingthebirth-and-deathmodelofevolutionunderstrongpurifyingselectionwhiletheH2AandH2Bno;t3)yeastcsH2AandH2Bareveryspecia,lfortheirpSandpNbehavedaspNmpSbothwithinandbe-tweenspecies,whichindicatesthattheconcertedevolutionisthemajorevolutionarypatternforthesetwokindsof
8、histonegenes.Keywords:fung;iyeas;tcorehistonegenes;evolutionarydynamicpattern构成核小体八聚体的4种组蛋白(H2A、H2B、核生物共有的重要功能蛋白,它们不仅是染色质的H3、H4)家族是