Alterations in cell lineage following laser ablation of cells in the somatic gonad of Caenorhabditis elegans☆

[摘要] ThepostembryoniccelllineageofthesomaticgonadisessentiallyinvariantinCaenorhabditiselegans(J.E.KimbleandD.Hirsh,1979,Develop.Biol.70,396–417).Thetwoexceptionstothisruleofinvarianceinvolveanaturalambiguityintheancestryofcertaincellssuchthateachoftwoprecursorcellsassumesoneoftwoalternativefatesinagivenanimal.Inthispaper,experimentsarereportedinwhichlasermicrosurgeryisusedtokillindividualcellsinthedevelopingsomaticgonad.Suchinterventionperturbsthenormalenvironmentoftheremainingcells;achangeobservedintheexpectedbehaviorofthesecellssuggeststhatextrinsiccuesmaynormallyplayaroleincontrollingthatbehavior.Severaldifferentlineagealterationshavebeenobservedafterlasermicrosurgeryinthesomaticgonad.Theseincludeswitchesinthetypeoflineagefollowedbyagivenprecursorcell,reversalsinlineagepolarity,duplicationsofalineage,andalteratiionsinthenumberofcellsproducedinthelineage.Theonlycasesinwhichcellsswitchfromonelineagetypetoanotherinvolvepairsofcellswhichexhibitnaturalambiguity.Inmostcases,theinteractionsinferredfromthesechangesseemtooccurbetweenneighboringsomaticgonadalcells.Inonecase,inductionofthevulva,theinteractionoccursbetweenasinglesomaticgonadalcell,theanchorcell,andtheprecursorstothevulvainaneighboringtissue,thehypodermis.Therolesofintrinsicandextrinsiccuesincontrollingnormallyinvariantcelllineagesarediscussed.

[学科分类] 生物科学（综合）