Home | My Profile | Contact Us
Research Trends Products  |   order gateway  |   author gateway  |   editor gateway  
Register | Forgot Password

Author Resources
 Author Gateway
 Article submission guidelines

Editor Resources
 Editor/Referee Gateway

 Regional Subscription Agents/Distributors
Current Topics in Genetics   Volumes    Volume 5 
HP1 and BRCA1 proteins could enhance heterochromatin spread throughout the genome: The Ctenomys (Rodentia Ctenomydae) model
Silvia Villar, Alvaro Novello
Pages: 105 - 111
Number of pages: 7
Current Topics in Genetics
Volume 5 

Copyright © 2012 Research Trends. All rights reserved

The variation of heterochromatin amount and localization using the genus Ctenomys as a model is analyzed in this work. This genus exhibits a significant variation in heterochromatin localization that range from pericentric areas in few chromosomes to whole heterochromatic arms. Its karyotypic variation includes the occurrence of a large number of chromosomal rearrangements (2n=10 to 70; NF=16 to 80) during its evolution. The possible mechanism which generated heterochromatin variation was analyzed in the meiotic nuclei, mainly in the pachytene of Ctenomys species from Uruguay. In the pachytene stage, several bivalents merge in densely stained chromocenters that are positive for C-banding and DAPI staining. Additionally, “in situ” hybridization was used with the repetitive PvuII Ctenomys sequence (RPCS) as a probe which was also localized in the pachytene chromocenters. In order to understand the heterochromatin behaviour in the chromocenter, we applied immunolocalization for two proteins: HP1 a chromatin gene silencer which transforms euchromatin into heterochromatin and BRCA1 a double stranded break (DSB) DNA repair factor. Positive immune signals for both proteins in the pachytene chromocenters suggests that the mechanics of meiosis could break DNA in the chromocenters due to physical forces leading to metaphase I. Based on these data we propose that heterochromatin exchanges could imply double strand breaks produced by these forces that in the repairing process may conduce to the spreading of heterochromatin. This also can explain the colocalization of BRCA1 and HP1 signals.
View Full Article  


Buy this article
Buy this volume
Subscribe to this title
Shopping Cart

Quick Links
Search Products
Browse in Alphabetical Order : Journals
Browse by Subject Classification : Journals

Ordering Information Ordering Information
Downloadable forms Downloadable Forms