The eukaryotic ribonucleoprotein reverse transcriptase (RT) telomerase uses a template within its integral RNA subunit to extend chromosome ends by synthesis of single-stranded telomeric repeats. Telomerase is adapted to its unique cellular role by an ability to release product DNA in single-stranded form, regenerating free template from the product-template hybrid. Furthermore, by retaining a ...

The macronucleus of the protozoan Oxytricha fallax is generated from a micronucleus following conjugation. While the micronucleus contains high molecular weight DNA, the macronucleus contains only short linear DNA molecules which all end in the same 20 bp inverted terminal repeat (Ma-ITR). The Ma-ITR was radioactively labeled and purified for use as a probe in hybridizations to micronuclear and...

DNA methylation of CpG dinucleotides is essential for mammalian development, X inactivation, genomic imprinting, and may also be involved in immobilization of transposons and the control of tissue-specific gene expression (Bird & Wolffe, 1999). The common theme in each of these processes is gene silencing. Therefore, gene silencing is a major biological consequence of DNA methylation. As such, ...

A 14 kb maize DNA fragment carrying nuclear rRNA genes and spacer regions was isolated and characterised by restriction enzyme mapping. A complete 3020 bp long external spacer region was sequenced and revealed 9 tandemly arranged 200 bp long repeat units with high homology. The repeat units lie upstream from two prominent S1 mapping signals. The sequence of a typical repeat unit is compared to ...

Background: The lengths of CAG repeats in two spinocerebellar ataxia genes, SCA1 and SCA3, were analyzed to determine whether such repeats exist in higher numbers in infertile males. Materials and Methods: Blood samples were collected from healthy controls, oligozoospermia patients, and azoospermia patients. DNA fragments containing target CAG repeats were amplified by PCR with template DNA pur...