刘永飞--斑马鱼的胚胎发育

StagesofEmbryonicDevelopmentoftheZebrafish,刘永飞20121902004,斑马鱼(Daniorerio)属于辐鳍亚纲(Actinop-terygii)鲤科(Cyprinidae)短担尼鱼属(Danio)的一种硬骨鱼。原产于印度东部、巴基斯坦、缅甸及孟加拉国的小溪、稻田及恒河中游地区，是一种常见的热带观赏鱼，因其体侧具有像斑马一样纵向的暗蓝与银色相间的条纹而得名。,斑马鱼的发展史,一.20世纪70年代初，利用T4噬菌体研究遗传学的美国俄勒冈大学著名遗传学家GeorgeStreisinger注意到斑马鱼的优点，从宠物店购买了斑马鱼，开始研究其养殖方法、观察其胚胎发育过程、发展一些相关的遗传学技术。二.近十年后，他的研究组于1981年在Nature上发表了第一篇具有深刻影响的论文（Productionofclonesofhomozygousdiploidzebrafish）。在这篇论文中，他们报导了斑马鱼的体外受精技术、单倍体诱导技术，建立了纯合品系，并介绍了斑马鱼的第一个自然突变体golden。,三.在其后的几年中，Streisinger和他的同事先后报导了斑马鱼的卵裂特点、不同时期胚胎中细胞的发育命运等，并发现斑马鱼脑中的许多神经元的排列简单而有规律。这些研究成果的报导，证明了斑马鱼适合用做模式动物，引起了许多发育生物学家的关注。四.20世纪90年代初，曾在果蝇上通过诱变研究阐明果蝇胚胎早期发育机理的德国发育生物学家ChristineNsslein-Volhard，以及美国哈佛大学WolfgangDrie-ver博士的研究组同时开始对斑马鱼进行大规模化学诱变研究，到1996年他们共鉴定出约4000种斑马鱼突变体，为研究脊椎动物发育的分子机理储备了丰富的遗传资源，Development专门于1996年用一期增刊发表了36篇相关论文。,斑马鱼的特点,成年鱼个体小，易于饲养发育快速、性成熟期短、繁殖力强胚胎体外发育，易于观察和操作较完善的胚胎和遗传学操作技术基因组序列的注释已经完成品系资源丰富,StagesofEmbryonicDevelopmentoftheZebrafish,0.75-2.25h,0-0.75h,2.25-5.25h,5.25-10h,10-24h,24-28h,48-72h,One:ZygotePeriod(0-0.75h),1.Thenewlyfertilizedeggisinthezygotep-erioduntilthefirstcleavageoccurs,about40minutesafterfertilization.2.Thezygoteisabout0.7mmindiameteratthetimeoffertilization.3.WeincludeonlyasinglestagecalledOne-cellstage;howevermanychangesareoccur-ring,andonecouldeasilysubdividetheperi-od.,StagesDuringtheZygotePeriod,Thezygoteperiod.A:afewminutesafterfertilization.B:about10minafterfertil-ization.,One-cellstage,Two:CleavagePeriod(0.75-2.25h),1.Afterthefirstcleavagethecells,divideatab-out15-minuteintervals.2.Thecytoplasmicdivisionsaremeroblastic;t-heyonlyincompletelyundercuttheblastodisc,andtheblastomeres,oraspecificsubsetofthemaccordingtothestageremaininterconnectedbycytoplasmicbridges.3.Thesixcleavagesthatcomprisethisperiodf-requentlyoccuratregularorientationssothato-necanseehowmanyblastomeresarepresenta-rebytheirarrangement;countingthemisunnec-cessary.,StagesDuringtheCleavagePeriod,Four-cellstage(1h),Eight-cellstage(1.25h),Sixteen-cellstage(1.5h),Thirtytwo-cellstage(1.75h),Sixtyfour-cellstage(2h),Two-cellstage(0.75h),Embryosduringthecleavageperiod.A:Two-cellstage(0.75h).8:Four-cellstage(1h).C:Eight-cellstage(1.25h).D:Sixteen-cellstage(1.5h).E:Thirty-twocellstage(1.75h).F:Sixty-fourcellstage(2h).,Three:BlastulaPeriod(2.25-5.25h),Weusethetermblastulatorefertot-heperiodwhentheblastodiscbeginstolookball-like,atthe128-cellstage,ore-ighthzygoticcellcycle,anduntiltheti-meofonsetofgastrulation,ca.cycle14.,StagesDuringtheBlastulaPeriod,128-cellstage(2.25h),256-cellstage(2.5h),512-cellstage(2.75h),Highstage(3.25h),lk-cellstage(3h),Oblongstage(3.66h),Spherestage(4h),Domestage(4.33h),30%-epibolystage(4.66h),Faceviewsofembryosduringtheblastulaperiod.A:256-cellstage(2.5h).B:Highstage(3.3h).C:Transitionbetweenthehighandoblongstages(3.5h).D:T-ransitionbetweentheoblongandspherestages(3.8h).E:Domestage(4.3h).F:30%-epibolystage(4.7h).,Four:GastrulaPeriod(5.25-10h),Themorphogeneticcellmove-mentsofinvolution,convergence,andextensionoccur,producingtheprimarygermlayersandtheembr-yonicaxis.,StagesDuringtheGastrulaPeriod,50%-epibolystage(5.25h)Germ-ringstage(5.66h)Shieldstage(6h)75%-epibolystage(8h)90%-epibolystage(9h)Budstage(10h),Developmentduringthegastrulaperiod.A:50%-epibolystage(5.25h).B:Germringsta-ge(5.7h).D:Shieldstage(6h).H:75%-epibolystage(8h).J:90%-epibolystage(9h).L:Budstage(10h).,Five:SegmentationPeriod(10-24h),1.Awonderfulvarietyofmorphogeneticmo-vementsnowoccur,thesomitesdevelop,therudimentsoftheprimaryorgansbecomevisib-le,thetailbudbecomesmoreprominentandtheembryoelongates.Thefirstcellsdifferent-iatemorphologically,andthefirstbodymovem-entsappear.2.Thetailbudappearsatthecaudalendofthelengtheningaxisduringthewholetime.,StagesDuringtheSegmentationPeriod,2-somitestage(10.7h),5-somitestage(11.7h),14-somitestage(16h),20-somitestage(19h),25-somitestage(21.5h),A:2-somitestage(10.7h)；F:5-somitestage(11.7h)；I:14-somitestage(16h)；M:20-somitestage(19h)；N:25-somitestage(21.5h).,Six:PharyngulaPeriod(24-48h),Theembryoismostevidentlynowabilaterallyorganizedcreature,enterin-gthepharyngulaperiodwithawellde-velopednotochord,andanewlycompl-etedsetofsomitesthatextendtotheendofalongpost-analtail.,StagesDuringthePharyngulaPeriod,Prim-5stage(24h),Prim-12stage(30h),Prim-25stage(36h),High-pecstage(42h),A:Prim-5stage(24h)；B:Prim-12stage(30h)；F:Prim-25stage(36h)；H:High-pecstage(42h).,Seven:HatchingPeriod(48-72h),1.Thetimeofhatchingisnotusefulasastagingindexf-orthezebrafish,incontrasttosomeothertypesofembry-os,becauseindividualswithinasingledevelopingclutchhatchsporadicallyduringthewhole3rddayofdevelopm-ent(atstandardtemperature),andoccasionallylater.2.Whetherornotanembryohashatched,itsdevelopme-ntprogresses,hourbyhour,andgenerallyindividualsth-athavespontaneouslyhatchedarenotmoredevelopment-allyadvancedthanonesremainingintheirchorions.3.Wearbitrarilycallthecreatures“embr