MEL-47, a novel protein required for early cell divisions in the nematode Caenorhabditis elegans.
In the early Caenorhabditis elegans embryo, a rapid succession of cell divisions, many of them asymmetric, form blastomeres that differ in size, cell cycle duration and developmental potential. These early cell cycles are highly regulated and controlled by maternally contributed products. We describe here a novel gene, mel-47, that is required maternally for the proper execution of the early cell cycles. mel-47(yt2) mutants arrest as completely disorganized embryos with 50-80 cells of variable size. The earliest defects we found are changes in the absolute and relative duration of the very early embryonic cell cycles. In particular, the posterior cell of the two-cell embryo divides late compared with its anterior sister. Frequently the daughter cells remain connected through chromatin bridges after the early cleavage divisions indicating that the chromosomes do not segregate properly. The cell cycle delay can be suppressed by knocking down a DNA replication check point. Therefore we propose that mel-47 is required for proper DNA replication in the early embryo.
Minasaki
Ryuji
R
Max Planck Institute for Developmental Biology, Spemannstrasse 37, 72076, Tübingen, Germany.
Streit
Adrian
A
D000818:Animals; D030801:Animals, Genetically Modified; D001483:Base Sequence; D017173:Caenorhabditis elegans / Q000166:cytology / Q000196:embryology* / Q000235:genetics* / Q000378:metabolism; D029742:Caenorhabditis elegans Proteins / Q000235:genetics* / Q000502:physiology; D002453:Cell Cycle / Q000235:genetics; D002455:Cell Division / Q000235:genetics / Q000502:physiology; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D004261:DNA Replication / Q000235:genetics; D018509:DNA, Helminth / Q000096:biosynthesis / Q000235:genetics; D018507:Gene Expression Regulation, Developmental; D017238:Genes, Helminth; D005816:Genetic Complementation Test; D016296:Mutagenesis; D034622:RNA Interference
D029742:Caenorhabditis elegans Proteins; D017931:DNA Primers; D018509:DNA, Helminth