Nuclear reorganization and homologous chromosome pairing during meiotic prophase require C. elegans chk-2
AUTOR(ES)
MacQueen, Amy J.
FONTE
Cold Spring Harbor Laboratory Press
RESUMO
Analysis of mutants defective in meiotic chromosome pairing has uncovered a role for Caenorhabditis elegans chk-2 in initial establishment of pairing between homologous chromosomes during early meiotic prophase. chk-2 is also required for the major spatial reorganization of nuclei that normally accompanies the onset of pairing, suggesting a mechanistic coupling of these two events. Despite failures in pairing, nuclear reorganization, and crossover recombination, chk-2 mutants undergo many other aspects of meiotic chromosome morphogenesis and complete gametogenesis. Although chk-2 encodes a C. elegans ortholog of the Cds1/Chk2 checkpoint protein kinases, germ-line nuclei in chk-2 mutants are competent to arrest proliferation in response to replication inhibition and to trigger DNA damage checkpoint responses to ionizing radiation. However, chk-2 mutants are defective in triggering the pachytene DNA damage checkpoint in response to an intermediate block in the meiotic recombination pathway, suggesting that chk-2 is required either for initiation of meiotic recombination or for monitoring a specific subset of DNA damage lesions. We propose that chk-2 functions during premeiotic S phase to enable chromosomes to become competent for subsequent meiotic prophase events and/or to coordinate replication with entry into prophase.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=312723Documentos Relacionados
- Synapsis-dependent and -independent mechanisms stabilize homolog pairing during meiotic prophase in C. elegans
- A Caenorhabditis elegans cohesion protein with functions in meiotic chromosome pairing and disjunction
- Two Types of Sites Required for Meiotic Chromosome Pairing in Caenorhabditis Elegans
- Somatic cAMP signaling regulates MSP-dependent oocyte growth and meiotic maturation in C. elegans
- C. elegans condensin promotes mitotic chromosome architecture, centromere organization, and sister chromatid segregation during mitosis and meiosis