ABSTRACT
Ataxia telangiectasia (A-T) is an autosomal recessive disease affecting multiple systems, including the development of the cerebellum and thymus. This results in a progressive cerebellar ataxia with onset between 1-3 years, telangiectasia occurs within the subsequent 3-5 years. We localized the A-T gene by linkage analysis to chromosome 11q22-23, between the markers D11S384, and D11S535, and constructed a series of contigs using three BACs and twelve cosmids, spanning a region of approximately 400 kb. We developed a set of sequence-tagged site (STS) markers from the ends of the BACs and cosmids. The A-T gene was isolated from within this region. It is now possible to precisely orient specific BACs, cosmids, and STSs with respect to the exons of the A-T gene (ATM). We anticipate that this information will be useful for further studies of functional domains and regulatory elements within the ATM gene, as well as for other genes in this region. In addition, these clones can be used for FISH studies of deletions, translocations and for loss of heterozygosity in various tumors.
Subject(s)
Ataxia Telangiectasia/genetics , Chromosome Mapping , Chromosomes, Human, Pair 11 , Ataxia Telangiectasia Mutated Proteins , Cell Cycle Proteins , Child, Preschool , Chromosome Aberrations/genetics , Chromosome Disorders , Cosmids , DNA-Binding Proteins , Female , Gene Expression Regulation/physiology , Gene Library , Genes, Recessive/genetics , Genetic Markers/genetics , Humans , In Situ Hybridization, Fluorescence , Infant , Male , Protein Serine-Threonine Kinases/genetics , Tumor Suppressor ProteinsABSTRACT
The metabolic role of selenium, if any, in plant systems has received little attention, as opposed to animal and other systems where many studies have been performed. Post-harvest banana (Musa sapientum) fruits treated with 1 mM solutions of sodium selenite show an increase in the rate of ripening. Visually, typical ripening changes in colour, aroma and tissue softness were observed to occur earlier in sodium selenite-treated fruits as compared to controls. These results were substantiated biochemically, enzymologically and physiologically, showing a strong relationship of this phenomenon with the oxidative changes.
