The t Complex Distorter 2 Candidate Gene, Dnahc8, Encodes at Least Two Testis-Specific Axonemal Dynein Heavy Chains That Differ Extensively at Their Amino and Carboxyl Termini

Developmental Biology

Olugbemiga Ogunkua¹  Ling Hui¹  John Fossella¹  Sadhana A. Samant¹  Stephen H. Pilder¹ 

[1] Department of Anatomy and Cell Biology, Temple University School of Medicine, Philadelphia, Pennsylvania, 19140

关键词: t complex;    t haplotype;    dynein heavy chain;    stem domain;    motor domain;    sperm tail;    flagellar motility;    flagellar morphogenesis;    axoneme;    fibrous sheath;   

DOI  :  10.1006/dbio.2002.0769

学科分类：生物科学（综合）

来源: Academic Press

【 摘 要 】

Homozygosityforthethaplotypealleleofthetestis-specificallyexpressedaxonemaldyneinheavychain(axDHC)gene,Dnahc8,hasbeenlinkedtomalesterilityresultingfromaberrantspermmotility.However,thenearabsenceofDnahc8expressionhasbeenassociatedwithmalesterilityresultingfromanearlybreakdowninspermflagellardevelopment.AlthoughaxDHCsareintegralparticipantsinflagellarmotility,aroleinflagellarmorphogenesishasneverbeenattributedtoamemberofthishighlyconservedgenefamily.TogainabetterunderstandingofthispresumednovelroleforDnahc8,wehavestudiedtheorganizationandexpressionoffull-lengthDnahc8+andDnahc8ttranscripts.Ourresultsdemonstratetheexistenceofatleasttwoalternativelyspliced,testis-specificDnahc8mRNAstranscribedfromboththe+andtalleles.AhighlyexpressedisoformencodesaproteinwithsignificanthomologynearlythroughouttotheγheavychainoftheChlamydomonasaxonemalouterarmdynein,whileamorepoorlyexpressedisoformcodesforaproteinwhosesequencedivergessignificantlyfromthatofotheraxDHCsatbothitsNandCtermini.WhileinsituhybridizationstudiesdemonstratethatbothmRNAspeciesaccumulateexclusivelyinmidtolatespermatocytes,eachisoformshowsspatialindependence.Additionalexperimentsdemonstratetheexistenceofatestis-expressedmRNAwithnosignificantopenreadingframe,aportionofwhichisantisensetothe5′-untranslatedregionofthehighlydivergentDnahc8isoform.ThecumulativedataimplythatDnahc8mayhaveacquiredfunctionalplasticityinthetestisthroughthetightlycontrolledexpressionofbothtypicalandunusualisoforms.

【 授权许可】

Unknown