It has been suggested that delayed DNA replication underlies fragility at common human fragile sites, but specific sequences responsible for expression of these inducible fragile sites have not been identified. One approach to identify such cis-acting sequences within the large nonexonic regions of fragile sites would be to identify conserved functional elements within orthologous fragile sites...

Heat stress is an effective factor on immune responses, body weight, egg production and egg quality of chickens. The major effect of heat stress is due to decreased food intake and alteration in acid-base balance. During the recent years, efforts to improve laying performance at high temperatures have been relatively successful. Supplementation of the diet or drinking water with special nutrien...

  Mild anaemia among patients with hyperthyroidism, reduction in intracranial zinc content of erythrocytes and anti- haemolysis of whole blood of patients with Graves, disease under laboratory Condition are the facts which indicate that although erythrocytes are devoid of receptors for thyroid hormones, they are affected by the excess of these hormones. In order to find out the reasons for suc...

Fragile X syndrome, the most common form of inherited mental retardation and leading genetic cause of autism, is caused by transcriptional silencing of the Fmr1 gene. The fragile X mental retardation protein (FMRP), the gene product of Fmr1, is an RNA binding protein that negatively regulates translation in neurons. The Fmr1 knock-out mouse, a model of fragile X syndrome, exhibits cognitive def...

Fragile sites /Chromosomal aberrations play a role in the etiology of mental retardation and other associated complications. Since Down syndrome is the most common genetic cause of mental retardation, the present study was done to evaluate the effect of fragile sites on sys-temic diseases and growth and developmental pattern among them. Human lymphocyte cell culture with folate free medium show...

Genetic recombination near the fragile X locus (Xq27.3) has frequently been a problem in linkage studies of families in which the fragile X is segregating. This case report illustrates the resolution of a difficult situation in a fragile X family for whom cytogenetic studies were inconclusive and where recombination had twice confounded attempts at prenatal DNA diagnosis by RFLP analysis. Using...

Aphidicolin-induced common fragile sites are site-specific gaps or breaks seen on metaphase chromosomes after partial inhibition of DNA synthesis. These fragile sites were first recognized during the early studies of the fragile X syndrome and are induced by the same conditions of folate or thymidylate stress used to induce the fragile X site. Common fragile sites are normally stable in culture...

The common fragile site, FRA3B, has been shown to be a site of frequent homozygous deletions in some cancers, resulting in loss of expression of the associated FHIT gene. It has been proposed that FHIT is a tumor suppressor gene that is inactivated as a result of the instability of FRA3B in tumorigenesis. More recently, deletions at other common fragile sites, FRA7G and FRA16D, have been identi...