Cortex, a Drosophila gene required to complete oocyte meiosis, is a member of the Cdc20/fizzy protein family.
Mutations in cortex and grauzone cause abnormal arrest in Drosophila female meiosis. cortex was mapped to a 14 kb interval in 26F-27A by the male recombination mapping method. While these experiments mapped the gene accurately, they also illustrated some complexities of this method. Rescue results showed that a 2.8 kb genomic fragment from this interval was able to fully rescue the cortex phenotype. The 2.8 kb rescuing fragment contains a single open reading frame. The predicted amino acid sequence indicates that cortex encodes a WD-repeat protein and is a distant member of the Cdc20 protein family. Results from a developmental Northern analysis showed that the cortex transcript is expressed at high levels during oogenesis and early embryogenesis. Interestingly, the meiotic metaphase-anaphase II arrest defect in embryos laid by cortex homozygous females resembles the mitotic metaphase-anaphase defects observed in yeast cdc20 mutants. The predicted nature of the Cortex protein, together with the observed meiotic phenotype in cortex mutants, suggest that a similar pathway to the cdc20 dependent APC-mediated proteolysis pathway, which governs the metaphase-anaphase transition in mitosis, is also important in regulating oocyte meiosis.
Chu
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T
Department of Pharmacology, Program in Molecular Biology and Biochemistry, University at Stony Brook, Stony Brook, New York, USA.
Henrion
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G
Haegeli
V
V
Strickland
S
S
D000483:Alleles; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D064199:Cdc20 Proteins; D018797:Cell Cycle Proteins / Q000235:genetics* / Q000378:metabolism; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D004330:Drosophila / Q000235:genetics*; D029721:Drosophila Proteins; D005260:Female; D015870:Gene Expression; D017344:Genes, Insect / Q000502:physiology*; D017403:In Situ Hybridization / Q000379:methods; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008540:Meiosis / Q000502:physiology*; D008969:Molecular Sequence Data; D016296:Mutagenesis; D009865:Oocytes / Q000502:physiology; D010053:Ovary / Q000378:metabolism; D011506:Proteins / Q000235:genetics; D012333:RNA, Messenger; D017386:Sequence Homology, Amino Acid
D064199:Cdc20 Proteins; D018797:Cell Cycle Proteins; D029721:Drosophila Proteins; D019476:Insect Proteins; D011506:Proteins; D012333:RNA, Messenger; C577503:cort protein, Drosophila; C577502:fzy protein, Drosophila; C577488:CDC20 protein, human