XPERIMENTAL distributions of breaks and chromosomal recombinations in E Drosophila melanogaster have been studied by several authors in attempts to throw light on the mechanism of the origin of chromosomal rearrangement. STADLER ( 1932), BAUER, DEMEREC, and KAUFMAN (1 938), CATCHESIDE (1 938), FANO ( 1 943), KAUFMANN (1946) and many others have contributed to this literature. While there is evi...

Chromosomal translocations that results in formation and activation of fusion oncogenes are observed in numerous solid malignancies since years back. Expression of fusion kinases in these cancers drives the initiation & progression that ultimately leads to tumour development and thus comes out to be clinically imperative in terms of diagnosis and treatment of cancer. Nonetheless, molecular mech...

propranolol (pl), a non-selective beta-blocker, is a cardiovascular drug widely used to treat hypertension. the present study was concerned with assessing the cytogenetic effects of this drug on chinese hamster ovary (cho) cell line. mtt assay was then carried out to determine the cytotoxicity index (ic50) of the drug. the ic50 value of pl was 0.43±0.02 mm. to investigate the clastogenic effect...

The Mre11/Rad50/Nbs (MRN) complex and the two protein kinases ATM and ATR play critical roles in the response to DNA damage and telomere maintenance in mammalian systems. It has been previously shown that mutations in the Drosophila mre11 and rad50 genes cause both telomere fusion and chromosome breakage. Here, we have analyzed the role of the Drosophila nbs gene in telomere protection and the ...

Targeted disruption of the mouse Hus1 cell cycle checkpoint gene results in embryonic lethality and proliferative arrest in cultured cells. To investigate the essential functions of Hus1, we developed a system for the regulated inactivation of mouse Hus1 in primary fibroblasts. Inactivation of a loxP site-flanked conditional Hus1 allele by using a cre-expressing adenovirus resulted in reduced c...

Molecular karyotypes of the UC, LEM87 and LEM115 Leishmania tarentolae strains were obtained. All strains had 24-28 chromosomal bands which varied in size between 300 kb and 2.9 Mb. Several recurrent chromosomal polymorphisms occurred in LEM115 after nutrient shock or subcloning. One type of polymorphism involves the truncation of a 365-kb chromosome which contains the miniexon genes. This spec...

In response to DNA double-strand breaks (DSBs), BRCA1 forms biochemically distinct complexes with certain other DNA damage response proteins. These structures, some of which are required for homologous recombination (HR)-type DSB repair, concentrate at distinct nuclear foci that demarcate sites of genome breakage. Polyubiquitin binding by one of these structures, the RAP80/BRCA1 complex, is req...

Fanconi anaemia (FA) is an autosomal recessive inherited disorder with progressive bone marrow failure, associated congenital malformation and solid and haematological malignancies. Acute myeloid leukemia is the commonest haematological malignancy followed by myelodysplastic syndrome in children with FA. FA transformed into acute lymphoblastic leukemia (ALL) is a rare phenomenon and one of the ...

The ATM protein kinase is activated by intermolecular autophosphorylation in response to DNA damage and initiates cellular signaling pathways that facilitate cell survival and reduce chromosomal breakage. Here, we show that NBS1 and BRCA1 are required for the recruitment of previously activated ATM to the sites of DNA breaks after ionizing irradiation, and that this recruitment is required for ...

Fanconi anaemia (FA) is an autosomal recessive inherited disorder with progressive bone marrow failure, associated congenital malformation and solid and haematological malignancies. Acute myeloid leukemia is the commonest haematological malignancy followed by myelodysplastic syndrome in children with FA. FA transformed into acute lymphoblastic leukemia (ALL) is a rare phenomenon and one of the ...