Role of the mod(mdg4) common region in homolog segregation in Drosophila male meiosis
| Autor: | Louisa Villeneuve, Kierstyn Schwartz, Morvarid Soltani-Bejnood, Chia-sin Hong, Bruce D. McKee, Sharon E. Thomas |
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| Rok vydání: | 2007 |
| Předmět: |
Male
X Chromosome Recombinant Fusion Proteins Molecular Sequence Data Nuclear Localization Signals Biology Investigations Chromosomal crossover Chromosome segregation Meiosis Nondisjunction Genetic Chromosomal Instability Chromosome Segregation Y Chromosome Genetics Homologous chromosome Animals Drosophila Proteins Amino Acid Sequence RNA Messenger Alleles Anaphase Genetic Complementation Test Chromosome Breakage Chiasma Alternative Splicing Chromosome Pairing Drosophila melanogaster Phenotype Nondisjunction Amino Acid Substitution Chromosome breakage Transcription Factors |
| Zdroj: | Genetics. 176(1) |
| ISSN: | 0016-6731 |
| Popis: | Homologous chromosomes must pair and establish stable connections during prophase I of meiosis to segregate reliably from each other at anaphase I. In most organisms, the stable connections, called chiasmata, arise from crossovers. In Drosophila males, homologs pair and segregate without crossing over. Chiasmata are replaced by a homolog conjunction complex that includes the Stromalin in Meiosis (SNM) and Modifier of Mdg4 in Meiosis (MNM) proteins. MNM is one of 31 alternative splice products of mod(mdg4), all of which share a common 402-amino-acid N terminus and differ at their C termini. Previous data demonstrated that an MNM-specific exon is required for homolog conjunction, but did not address whether the N-terminal common region, which includes a BTB domain that can mediate coalescence of protein-DNA complexes, is also required. Here we describe a mutation in the common region of mod(mdg4), Z3-3401, that causes qualitatively similar phenotypes as the MNM-specific alleles but disrupts X–Y segregation much more drastically than autosomal segregation. The mutant MNM protein in Z3-3401 is expressed throughout prophase I in spermatocytes but the protein is confined to the cytoplasm, suggesting that the Z3-3401 mutation disrupts a signal required for nuclear localization or retention. Z3-3401 fails to complement a large battery of lethal and semilethal alleles in the common region for meiotic nondisjunction, including an allele containing an amino acid substitution at a conserved residue in the BTB/POZ domain, consistent with a general requirement for the mod(mdg4) common region in homolog segregation. |
| Databáze: | OpenAIRE |
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