Developmental Biology | |
The Second Meiosis Occurs in Cytochalasin D-Treated Eggs of Corbicula leana Even Though It Is Not Observed in Control Androgenetic Eggs because the Maternal Chromosomes and Centrosomes Are Extruded at First Meiosis | |
K. Ookubo1  A. Komaru1  R. Ishibashi1  M. Kiyomoto1  | |
[1] Faculty of Bioresources, Mie University, Tsu, Mie, 514-8507, Japan | |
关键词: bivalvia; androgenesis; cytochalasin D; second meiosis; tubulin; centrosomes; spindle; pronuclei; | |
DOI : 10.1006/dbio.2002.0590 | |
学科分类:生物科学(综合) | |
来源: Academic Press | |
【 摘 要 】
ThehermaphroditicfreshwaterclamCorbiculaleanareproducesbyandrogenesis.Inthecontrol(androgeneticdevelopment),allmaternalchromosomesandmaternalcentrosomesatthemeioticpoleswereextrudedasthetwofirstpolarbodies,andsubsequently,secondmeiosisdidnotoccur.But,inC.leanaeggstreatedwithcytochalasinD(CD)toinhibitpolarbodyextrusion,thesecondmeiosisoccurred.Atmetaphase-I,thespindleshowedthetypicalbipolarstructureandtwospheroidcentrosomeswerelocatedatitspoles.Allthematernalchromosomesweredividedatanaphase-I,buttheywerenotextrudedaspolarbodiesduetotheeffectsofCD.Aftercompletionoffirstmeiosis,thematernalcentrosomessplitintofour.Atthesecondmeiosis,twinortetrapolarspindleswereformedandtwogroupsofmaternalchromosomesdividedintofoursetsofchromosomes.Afterthesecondmeiosis,thespindledisassociatedandthefourmaternalcentrosomesdisappeared.Fourgroupsofmaternalchromosomestransformedintothefourfemalepronuclei.Maleandfemalepronucleibecamemetaphasechromosomesofthefirstmitosis.ThepresentstudyclearlyindicatesthattypicalmeiosissystemsstillproceedinandrogenetictriploidC.leana.Weconcludethattheandrogeneticformmayhavearisenfromthemeioticform.
【 授权许可】
Unknown
【 预 览 】
Files | Size | Format | View |
---|---|---|---|
RO201912090729110ZK.pdf | 73KB | download |