简介:Inthispaper,wediscussasimplifiedmodelofmitosisinfrogeggsproposedbyM.T.BorisukandJ.J.Tysonin[1].Byusingrigorousqualitativeanalysis,weprovetheexistenceoftheperiodicsolutionsonalargescaleandpresentthespaceregionoftheperiodicsolutionsandtheparameterregioncorespondingtotheperiodicsolution.Wealsopresentthespaceregionandtheparameterregionwheretherearenoperiodicsolutions.Theresultsareinaccordancewiththenumericalresultsin[1]uptothequalitativeproperty.
简介:World’sLargestHatcheryofDinosaurEggsFossiltreasuresthathadlainformillionsofyearsunderthegroundinHenanfinallycametolightlastge...
简介:摘要:从Ganzhou,江西省和他们忍受的胚胎的骨骼的上面的白垩纪的二个elongatoolithid恐龙鸡蛋被描述。他们在中国与胚胎的骨骼代表第一个oviraptorosaurian鸡蛋并且提供oospecies能被相关到某些恐龙taxon/taxa的第一个例子。二颗卵与在从在卵壳的宏观结构和微观结构的一样的区域的一样的地平线的一个女oviraptorosaurian骨盆内的卵的对一样,并且能被指oospecies,Macroolithusyaotunensis赵,1975。胚胎的骨骼的保存部分的形态学显示他们可能被oviraptorid,从广东省的Heyuanniahuangi或密切相关的oviraptorosaurian生了,它也可能在迟了的白垩纪在Ganzhou区域被过了。二个鸡蛋的胚胎的骨骼不在一样的发展中阶段。在鸡蛋之一,保存vertebrae的Heyuanniahuangi很好被骨化,显示它就被孵。
简介:Themethodforcollectingeggsofthestripedstemborer.Chilosuppressalisusingplasticbagswasstudiedincomparisonwithusingcagedriceplants.TherewasnosignificantdifferenceinfecundityofC.suppressalisat279eggs/mothandinpercentageofhatchedeggsat95%betweeninplasticbagsandonriceplants.Moreeggmasseswerecollectedonplasticbagsthanonriceplants,whereasmoresmallereggmasses(lessthan100eggspermass)inplasticbagsthanonriceplants.TheadvantagesincollectingeggsofC.suppressalisandotherinsectsbyusingplasticbagswerealsodiscussed.
简介:TheregionbetweenthepreexistingandnascentmembranesofacleavingRanaeggisadenseprotrusionregionofnearly40μmwideat180°stage.Later,thisregiondifferentiate,intoanupperpart,astripwithlong,branchedandrandomlydistributedprotrusionswhicharederivedlargelyfromthepreexistingmembrane,andalowerpart,abandwithmicrovilli.During4-and8-cel1stages,thestripisalmostvanishedandmicrovilliinthebandisshortened.Thenascentmembraneissmoothatthe180°stage,thenaroughareaappearsbelowthesmoothregionandquicklyexpands.Wheatgermagglutininwhichcanbindtopreexistingmembraneinterruptsthedevelopmentoftheregionbetweenthepreexistingandnascentmembranes.Detergent,Brij,havingthepropertytoincreasetheareaofnascentmembrane,doesnotinterruptthedevelopmentoftheregionbetweenthepreexistingandnascentmembranes.
简介:IncubationofdinoflagellateCrythecodiniumcohniichromosomesincytoplasmicextractsofunfertilizedXenopuslaeviseggsresultedinchromosomesdecondensationandrecondensation,nuclearenvelopeassembly,andnuclearreconstitution.DinoflagellateCrythecodiniumcohniiisakindofprimitiveeukaryotewhichpossessesnumerouspermanentlycondensedchromosomesanddiscontinuousdouble-layerednuclearmembranethroughoutthecellcycle.Theassemblednuclei,beingsurroundedbyacontinuousdoublemembranecontainingnuclearporesandtheuniformlydispersedchromatinfibersaremorphologicallydistinguishablefromthatofDinoflagellateCrythecodiniumcohnii.However,incubationofdinoflagellateCyrthecodiniumcohniichromosomesintheextractsfromdinoflagellateCrythecodiniumcohniicellsdoesnotinducenuclearreconstitution.
简介:ToinvestigatethechangesofthebiochemicalcompositionofAmericanshad(Alosasapidissima)eggsandlarvaeatembryonicandearlylarvalstages,sampleswerecollectedatdifferentdevelopmentstagesfromartificialfertilizationtotheendofyolkabsorptionincluding2h,12hand30hafterfertilizationandnewlyhatchedlarvaeincluding1and3daysafterhatching.Thecompositionoflipid,fattyacids,proteinandaminoacidswereanalyzed.Thecontentoftotalproteinexhibitedadecreasingtrendduringembryogenesisandlarvaldevelopment,andasignificantreductionwasdetectedafterhatching(P<0.05).Thetotallipidcontentremainedrelativestable.Asignificantreductionwasdetectedinalmostallaminoacidsafterhatchingexceptforglycine(P<0.05),whileasignificantdecreasewasfoundinthecontentofcysteine,proline,tyrosine,valine,isoleucine,leucineandphenylalanineduringtheyolk-sacphase(P<0.05).Ontheotherhand,allthegroupsoffattyacidsremainedstableduringtheperiodofembryogenesis.Butafterhatching,asignificantdecreasewasfoundinthecontentofC18:2n-6,C18:3n-6,SFAandratioofEPA/ARA(P<0.05),whileasignificantincreasewasfoundinthecontentofC18:3n-3,C20:4n-6,C22:6n-3andratioofn-3/n-6(P<0.05).Inconclusion,thecombineddatasuggestedthatAmericanshadutilizestheproteincontentaspreferentialenergysubstratesduringembryonicandearlylarvaldevelopmentswithsomespecificityintheconsumptionofdifferentaminoacids.