RESUMO
HMGB-like proteins are architectural chromatin factors, and their function is heavily dependent on their ability to interact with DNA (especially non-canonical DNA structures). HMGB1 is involved in many DNA processes, and dysregulation of HMGB protein expression has profound effects on cellular transcription, resulting in severe developmental defects as well as cancer. During DNA replication, elements that form the origin are still not well defined in metazoans. Sites with A (adenine) or T (thymine) repeats cause intrinsic curvatures in the DNA and are described to be involved in the replication machinery by providing binding sites to replication proteins. As a result, the DNA molecule shows intrinsically bent DNA sites, caused by periodic repeats of 2 or more As/Ts (dA/dT) as well as intrinsically non-bent DNA sites (INBDs), due to a succession of curvatures that cancel each other. In the present study, we mapped 11 INBDSs present in the AMPD2 gene that are related to each replication origin (oriGNAI3, oriC, oriB, and oriA). Following characterization of INBDSs, we tested the ability of HMGB1 to bind to the bent (b1, b2, b4a, b4b, b5, b6, b7, and b8) and non-bent DNA fragments (nb7, nb11, nb1, nb2, nb4, and nb5) via electrophoretic mobility shift assays. All fragments showed efficient binding to HMGB1. However, the non-bent DNA fragments nb2, nb4, and nb5 showed slightly reduced binding efficiency.
Assuntos
AMP Desaminase/genética , Replicação do DNA/genética , Proteínas de Ligação a DNA/genética , Proteína HMGB1/genética , AMP Desaminase/química , Animais , Sítios de Ligação , Cromatina/química , Cromatina/genética , Cricetulus/genética , DNA/química , DNA/genética , Proteínas de Ligação a DNA/química , Proteína HMGB1/química , Conformação de Ácido Nucleico , Ligação Proteica , Origem de Replicação/genéticaRESUMO
Diatraea saccharalis is an insect that causes considerable losses in the sugar cane crop. Our aim was to contribute to the knowledge of the biology of D. saccharalis, with the report of DNA fragments involved in the differentiation between the male and female of this species using the RAPD sex molecular marker GyakuU-13, which is specific for the W chromosome of Bombyx mori. Another point evaluated in this study was the genetic diversity of a D. saccharalis population maintained by inbreeding in a laboratory culture. The profile of sex-specific fragments was analyzed, and the genetic variability of this population was estimated. An analysis of the molecular markers showed only one fragment, of approximately 700 bp, that could be considered as a female sex marker in D. saccharalis.