ผลต่างระหว่างรุ่นของ "หน้าหลัก"
ล |
ล |
||
แถว 1: | แถว 1: | ||
− | + | E protein product is present within the nucleus but fails to | |
− | + | E protein product is present in the nucleus but fails to localize to chromosomes.81 Thus the C2H2 motif is most likely the major determinant of chromosome localization, but no matter if it functions by binding to DNA, to another protein or something else remains to be determined. SNM can also be intriguing. It really is a paralog of your cohesin protein SA/Stromalin, the protein that's not a part of the cohesin ring.64 This raises the possibility that homolog conjunction has something in frequent with cohesion, a possibility that's under active investigation. The taxonomic distribution of SNM is often a potentially exciting challenge. Achiasmate male meiosis seems to become universal inside the genus Drosophila as well as extends to some "higher Dipterans" (but not mosquitoes). We've got discovered SNM homologs in all sequenced Drosophila genomes but not within the Anopheles genome.64 We predict it will be present in genomes of dipterans with achiasmate male meiosis but not in these with chiasmate meiosis. Homolog Segregation Two current reports have described mutations that impair segregation of homologs at anaphase I without the need of disturbing homolog conjunction. Two with the affected genes, Cap-D3 and Cap-H2, encode non-SMC elements in the condensin II complex, a conserved complicated with roles in chromatin condensation and chromosome resolution and also other processes during each mitosis and meiosis.82-87 The third is dtopors, which encodes a conserved ubiquitin/SUMO ligase which has been shown to interact with a selection of chromosomal proteins.88-Condensin II. All robust condensin II alleles have been fully sterile86 and exhibited severely defective chromosome condensation. The DNA was smeared uniformly throughout the nucleus through prophase I and condensed bivalents had been totally absent through S6-prometaphase I. Remarkably, even so, the chromosomes sooner or later condensed and congressed to type reasonably typical metaphase I and anaphase I figures, except that 30?0 from the anaphase I cells exhibited chromatin bridges, some amongst homologs and other folks amongst non-homologs. Intriguingly, teflon mutants partially suppressed both the homologous and heterologous bridges, suggesting that condensin II may function in opposition to homolog conjunction in some way. A single possibility is the fact that condensin II is necessary to release the inter-homolog connections that the conjunction complex creates or preserves. A role as an anti-pairing aspect is constant with studies that show condensin II to be responsible for the suppression of polyteny in nurse cells in stage 6?0 egg chambers.49 A connected suggestion is the fact that inter-homolog connections may take the type of DNA entanglements, probably generated throughout the early prophase intimate pairing period.42 These tangles may be preserved (by, e.g., SNM and MNM) till anaphase I and after that removed by the combined action of condensin and topoisomerase II. This suggestion has not been pursued but perhaps ought to be, particularly in light from the failure to locate any steady autosomal pairing web pages. A part of condensin II in removing DNA tangles is undoubtedly constant with its established enzyme activities and its interaction with topoisomerase II.85 dTopors. As opposed to the condensin II mutants, all of the dtopors alleles, even null alleles, were fertile, albeit weakly so, and NDJ frequencies were high for all chromosomes, approaching 50 for the sex and 4th chromosome pairs, constant with random assortment.90 Interestingly, chromatin bridges have been observed in practically 100 of an. |
รุ่นแก้ไขเมื่อ 17:34, 4 สิงหาคม 2564
E protein product is present within the nucleus but fails to E protein product is present in the nucleus but fails to localize to chromosomes.81 Thus the C2H2 motif is most likely the major determinant of chromosome localization, but no matter if it functions by binding to DNA, to another protein or something else remains to be determined. SNM can also be intriguing. It really is a paralog of your cohesin protein SA/Stromalin, the protein that's not a part of the cohesin ring.64 This raises the possibility that homolog conjunction has something in frequent with cohesion, a possibility that's under active investigation. The taxonomic distribution of SNM is often a potentially exciting challenge. Achiasmate male meiosis seems to become universal inside the genus Drosophila as well as extends to some "higher Dipterans" (but not mosquitoes). We've got discovered SNM homologs in all sequenced Drosophila genomes but not within the Anopheles genome.64 We predict it will be present in genomes of dipterans with achiasmate male meiosis but not in these with chiasmate meiosis. Homolog Segregation Two current reports have described mutations that impair segregation of homologs at anaphase I without the need of disturbing homolog conjunction. Two with the affected genes, Cap-D3 and Cap-H2, encode non-SMC elements in the condensin II complex, a conserved complicated with roles in chromatin condensation and chromosome resolution and also other processes during each mitosis and meiosis.82-87 The third is dtopors, which encodes a conserved ubiquitin/SUMO ligase which has been shown to interact with a selection of chromosomal proteins.88-Condensin II. All robust condensin II alleles have been fully sterile86 and exhibited severely defective chromosome condensation. The DNA was smeared uniformly throughout the nucleus through prophase I and condensed bivalents had been totally absent through S6-prometaphase I. Remarkably, even so, the chromosomes sooner or later condensed and congressed to type reasonably typical metaphase I and anaphase I figures, except that 30?0 from the anaphase I cells exhibited chromatin bridges, some amongst homologs and other folks amongst non-homologs. Intriguingly, teflon mutants partially suppressed both the homologous and heterologous bridges, suggesting that condensin II may function in opposition to homolog conjunction in some way. A single possibility is the fact that condensin II is necessary to release the inter-homolog connections that the conjunction complex creates or preserves. A role as an anti-pairing aspect is constant with studies that show condensin II to be responsible for the suppression of polyteny in nurse cells in stage 6?0 egg chambers.49 A connected suggestion is the fact that inter-homolog connections may take the type of DNA entanglements, probably generated throughout the early prophase intimate pairing period.42 These tangles may be preserved (by, e.g., SNM and MNM) till anaphase I and after that removed by the combined action of condensin and topoisomerase II. This suggestion has not been pursued but perhaps ought to be, particularly in light from the failure to locate any steady autosomal pairing web pages. A part of condensin II in removing DNA tangles is undoubtedly constant with its established enzyme activities and its interaction with topoisomerase II.85 dTopors. As opposed to the condensin II mutants, all of the dtopors alleles, even null alleles, were fertile, albeit weakly so, and NDJ frequencies were high for all chromosomes, approaching 50 for the sex and 4th chromosome pairs, constant with random assortment.90 Interestingly, chromatin bridges have been observed in practically 100 of an.