Cytogenetic studies were carried out on samples of Parapteronotus hasemani, Sternarchogiton preto and Sternarchorhamphus muelleri (Apteronotidae, Gymnotiformes) from the Amazon basin. The first two species exhibited both a 2n = 52 karyotype, but differed in their karyotypic formulae, distribution of constitutive heterochromatin, and chromosomal location of the NOR. The third species, Sternarcho...

AIM   To clinically and histopathologically evaluate the anti-inflammatory effect of 0.2% hyaluronan gel alone and with mechanical therapy on gingivitis. The argyrophilic nucleolar organizer region staining technique was attempted to routinely determine its diagnostic and prognostic dependability for periodontal lesions. METHODS   In each of the 28 gingivitis patients, the four quadrants were...

Cytogenetic analyses were performed in two Curimatidae species (Steindachnerina insculpta and Cyphocharax modesta) from the Paranapanema and Tietê Rivers (São Paulo State, Brazil), showing a karyotype composed of 54 meta-submetacentric chromosomes in both species. Silver- and chromomycyn-staining and fluorescent in situ hybridization (FISH) using a 18S rDNA probe indicated that the nucleolar or...

The epithelium of the Spemann organizer plays an important role in embryonic axis formation and transplantation experiments have shown that epithelial organizer cells have potent axis-inducing potential. Known axis-inducing molecules like noggin and chordin are not expressed in the epithelium and cannot account for its inductive properties. Xwnt-11 is expressed in the epithelium but has only po...

Argyrophilic staining of nucleolar organizer regions (AgNOR) has been considered to be useful in the diagnosis and prognostic evaluation of different cutaneous tumors. In order to evaluate the role of the AgNOR technique in discriminating aggressive from non-aggressive basal cell carcinoma (BCC), paraffin-embedded histologic sections from 30 cases of aggressive BCC (BCC2) and 30 cases of n...

Expression of the LIM homeobox gene lhx1 (lim1) is specific to the vertebrate gastrula organizer. Lhx1 functions as a transcriptional regulatory core protein to exert ;organizer' activity in Xenopus embryos. Its ancient paralog, lhx3 (lim3), is expressed around the blastopore in amphioxus and ascidian, but not vertebrate, gastrulae. These two genes are thus implicated in organizer evolution, an...

argyrophilic staining of nucleolar organizer regions (agnor) has been considered to be useful in the diagnosis and prognostic evaluation of different cutaneous tumors. in order to evaluate the role of the agnor technique in discriminating aggressive from non-aggressive basal cell carcinoma (bcc), paraffin-embedded histologic sections from 30 cases of aggressive bcc (bcc2) and 30 cases of non-ag...

In this study, we investigated the chromosomes of three species Sicarius spiders from Brazilian Caatinga, using classical and molecular cytogenetic techniques. Based on phylogenetic approach, also discussed about variation diploid number, types sex chromosome system changes in localization ribosomal genes Scytodoidea. are Synspermiata that together with genera Loxosceles Hexophthalma constitute...

Cytogenetic and molecular hybridization techniques were used to examine the arrangement of rRNA genes at the nucleolar organizer region (NOR) of maize. TB-6a stocks involving a reciprocal translocation between a B chromosome and the NOR of chromosome 6 were used. The amount of rDNA in the different stocks used varied from 1.5 to 4 NOR equivalents depending on the number of B(6) choromosomes pre...