The C. elegans MELK ortholog PIG-1 regulates cell size asymmetry and daughter cell fate in asymmetric neuroblast divisions.
In the nematode Caenorhabditis elegans, neurons are generated from asymmetric divisions in which a mother cell divides to produce daughters that differ in fate. Here, we demonstrate that the gene pig-1 regulates the asymmetric divisions of neuroblasts that divide to produce an apoptotic cell and either a neural precursor or a neuron. In pig-1 mutants, these neuroblasts divide to produce daughters that are more equal in size, and their apoptotic daughters are transformed into their sisters, leading to the production of extra neurons. PIG-1 is orthologous to MELK, a conserved member of the polarity-regulating PAR-1/Kin1/SAD-1 family of serine/threonine kinases. Although MELK has been implicated in regulating the cell cycle, our data suggest that PIG-1, like other PAR-1 family members, regulates cell polarity.
Cordes
Shaun
S
Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA.
Frank
C Andrew
CA
Garriga
Gian
G
D000818:Animals; D030801:Animals, Genetically Modified; D017209:Apoptosis; D017173:Caenorhabditis elegans / Q000166:cytology / Q000196:embryology; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division / Q000502:physiology*; D019070:Cell Lineage; D016764:Cell Polarity; D048430:Cell Shape; D006801:Humans; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism; D009474:Neurons / Q000166:cytology / Q000502:physiology; D010802:Phylogeny; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*
D029742:Caenorhabditis elegans Proteins; C103072:HAM-1 protein, C elegans; D009419:Nerve Tissue Proteins; C513437:PIG-1 protein, C elegans; D017346:Protein Serine-Threonine Kinases