class= > 梅进
专题：Nature疟疾裂殖子一个由美英等国科学家组成的国际研究小组近日测定了两种致命疟疾寄生虫的基因组序列。这两种疟疾寄生虫分别名为Plasmodiumknowlesi和Plasmodiumvivax，其中P.knowlesi近被认为是感染人类的一个主要疟疾病原体，而P.vivax则会致人极度虚弱，甚至死亡。相关论文发表在10月9日的《自然Nature杂志上。P.knowlesi的自然宿主是kra猴，不过现在已经确定它能够感染人类。有证据表明，东南亚感染P.knowlesi的人普遍地被误诊为感染了相对更加温和的P.malariae，这导致了不恰当的治疗方式。P.knowlesi是被遗传测序的猴子疟疾寄生虫，为与新近完成的P.vivax基因组和其它已测序的疟原虫基因组进行比较提供了新的研究机会。确定疟疾寄生虫之间的相似和不同有助于挑选遗传标靶，以进行疫苗和药物的研发。此次测序的另一个疟疾寄生虫是P.vivax，它的致死率仅次于臭名昭著的P.falci
arum，75%的疟疾感染及90%的疟疾每年300万致死数都是由后者导致的。P.vivax是非洲以外疟疾的主要原因，流行于和中、南美洲潮湿的热带区域。P.vivax感染的疟疾会导致多次复发的严重失能性疾病，有时会导致死亡。P.vivax能在凉爽季节以及P.falci
arum不能耐受的更为温和的气候中传播，这使它能够影响到上一半的人口。此外，P.vivax对药物的抗性也越来越普遍，阻碍了对临床案例的管理。与P.knowlesi一样，测定P.vivax的基因组序列将会产生对其独特生物学特性的研究，而这同样有助于确定新药及疫苗开发的遗传标靶。生物谷Bioon.com生物谷原始出处：Nature，455,799-803，A.Pain，M.BerrimanThegenomeofthesimianandhumanmalaria
arasitePlasmodiumknowlesiPlasmodiumknowlesiisanintracellularmalaria
arasitewhosenaturalverteatehostisMacacafascicularisthe monkeyhowever,itisnowincreasinglyrecognizedasasignificantcauseofhumanmalaria,
articularlyinsoutheastAsia1,2.Plasmodiumknowlesiwasthefirstmalaria
arasites
eciesinwhichantigenicvariationwasdemonstrated3,andithasaclose
hylogeneticrelationshi
toPlasmodiumvivax4,thesecondmostim
ortants
eciesofhumanmalaria
arasitereviewedinref.4.Des
itetheirrelatedness,thereareim
ortant
henoty
icdifferencesbetweenthem,suchashostbloodcell
reference,absenceofadormantliverstageor inP.knowlesi,andlengthoftheasexualcyclereviewedinref.4.Herewe
resentananalysisoftheP.knowlesiHstrain,Pk1A+clone5nucleargenomesequence.Thisisthefirstmonkeymalaria
arasitegenometobedescribed,andit
rovidesano
ortunityforcom
arisonwiththerecentlycom
letedP.vivaxgenome4andothersequencedPlasmodiumgenomes6,7,8.IncontrasttootherPlasmodiumgenomes,
utativevariantantigenfiliesaredis
ersedthroughoutthegenomeandareassociatedwithintrachromosomaltelomerere
eats.Oneofthesefilies,theKIRs9,containssequencesthatcollectivelymatchoverone-halfofthehostCD99extracellulardomain,whichmayre
resentanunusualformofmolecularmimicry.Nature，455,757-763，JaneM.Carlton，ClaireM.Fraser-LiggettCom
arativegenomicsoftheneglectedhumanmalaria
arasitePlasmodiumvivaxThehumanmalaria
arasitePlasmodiumvivaxisres
onsiblefor25C40%ofthe515millionannualcasesofmalariaworldwide.Althoughseldomfatal,the
arasiteelicitssevereandinca
acitatingclinicalsym
tomsandoftencausesrela
sesmonthsaftera
rimaryinfectionhascleared.Des
iteitsim
ortanceasajorhuman
athogen,P.vivaxislittlestudiedbecauseitcannotbe
ro
agatedcontinuouslyinthelaboratoryexce
tinnon-human
rimates.WesequencedthegenomeofP.vivaxtoshedlightonitsdistinctivebiologicalfeatures,andaseanstodrivedevelo
mentofnewdrugsandvaccines.HerewedescribethesyntenyandisochorestructureofP.vivaxchromosomes,andshowthatthe
arasiteresemblesothermalaria
arasitesingenecontentandmetabolic
otential,but
ossessesnovelgenefiliesand
otentialalternativeinvasion
athwaysnotrecognized
reviously.Com
letionoftheP.vivaxgenome
rovidesthescientificcommunitywithavaluableresourcethatcanbeusedtoadvanceinvestigationintothisneglecteds
ecies.
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