Centromeres, telomeres, and ribosomal gene clusters consist of repetitive DNA sequences. To assess their contributions to the spatial organization of the interphase genome, their interactions with the nucleoskeleton were examined in quiescent and activated human lymphocytes. The nucleoskeletons were prepared using "physiological" conditions. The resulting structures were probed for specific DNA...

This study examined the sequences of the two rRNA (rrn) operons of pathogenic non-cultivable treponemes, comprising 11 strains of T. pallidum ssp. pallidum (TPA), five strains of T. pallidum ssp. pertenue (TPE), two strains of T. pallidum ssp. endemicum (TEN), a simian Fribourg-Blanc strain and a rabbit T. paraluiscuniculi (TPc) strain. PCR was used to determine the type of 16S-23S ribosomal in...

In Drosophila melanogaster males, X-Y meiotic chromosome pairing is mediated by the nucleolus organizers (NOs) which are located in the X heterochromatin (Xh) and near the Y centromere. Deficiencies for Xh disrupt X-Y meiotic pairing and cause high frequencies of X-Y nondisjunction. Insertion of cloned rRNA genes on an Xh- chromosome partially restores normal X-Y pairing and disjunction. To map...

Accurate estimation of divergence times of soil bacteria that form nitrogen-fixing associations with most leguminous plants is challenging because of a limited fossil record and complexities associated with molecular clocks and phylogenetic diversity of root nodule bacteria, collectively called rhizobia. To overcome the lack of fossil record in bacteria, divergence times of host legumes were us...

In this study we used and evaluated three rapid molecular typing methods for the identification of three frequent, clinically significant Salmonella serovars on the basis of the ease, simplicity and reproducibility of the chosen methods. We determined the genetic diversity among several isolates of Salmonella enteritidis, S. typhimiurium and S. virchow, and compared them with other enterobacter...

Pleurostoma richardsiae is associated with host trunk diseases, known to cause dieback, cankers and wilting of woody trees, human infections. This fungus was isolated from wood tissues declining olive trees grapevines showing esca disease symptoms, in the Apulia region Italy. Fungus detection has been based on morphological molecular features, which are time-consuming identify require well-trai...