cki-1 links cell division and cell fate acquisition in the C. elegans somatic gonad.
The formation of a complex multicellular organism requires the precise specification of many diverse cell types at the correct time and position throughout development. This may be achieved by coordinating cell fate specification processes with progression through the cell cycle. Here, we show that the extra distal tip cells (DTCs) associated with the loss of cki-1, a Caenorhabditis elegans homologue of the cyclin-dependent kinase inhibitor p27, do not arise from duplications of pre-existing DTCs, but that they are formed from another cell type within the somatic gonad. Results from our laser microsurgery experiments suggest that the extra DTCs are caused by aberrant somatic gonadal precursor cell divisions in the absence of cki-1, resulting in abnormal daughter cell fates. cki-1(RNAi) animals also possess extra anchor cells and ectopic gonad arms with variable sheath cell numbers and positioning. In addition, cki-1(RNAi) animals display an endomitotic oocyte (Emo) phenotype. Our results uncover a novel role of this CKI in cell fate acquisition, either by directly influencing specification, or through a more conventional role in appropriately linking cell cycle phase with this process.
Department of Biology, McGill University, 1205 Avenue Docteur Penfield, Montreal, Quebec, Canada H3A 1B1.
Ivana
I
Kostić
Shaolin
S
Li
Richard
R
Roy
D000818:Animals; D017173:Caenorhabditis elegans / Q000196:embryology*; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000502:physiology*; D002455:Cell Division; D019070:Cell Lineage; D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D006066:Gonads / Q000002:abnormalities / Q000196:embryology*; D034622:RNA Interference
D029742:Caenorhabditis elegans Proteins; D018797:Cell Cycle Proteins; D050756:Cyclin-Dependent Kinase Inhibitor Proteins; C115024:cki-1 protein, C elegans