background and objectives: uterine smooth muscle tumors are the most common human neoplasm .they are divided clinically as benign and malignant but there is  another group of  lesions which is difficult to place in these two categories ,so-called smooth  muscle tumors of uncertain malignant potential (stump) and differentiation  of these tumors on the basis of h&e staining is impossible . t...

In mouse testis, the diploid Sertoli cell displays one large nucleolus flanked symmetrically by two heterochromatic masses. The hybridization in situ with [3H]rRNA confirmed that the ribosomal cistrons are localized with in the central nucleolar mass. At the ultrastructural level this nucleolar mass appears to be reticulated and contains numerous fibrillar centres. These fibrillar centres are s...

Non-coding RNAs play a key role in organizing the nucleus into functional subcompartments. By combining fluorescence microscopy and RNA deep-sequencing-based analysis, we found that RNA polymerase II transcripts originating from intronic Alu elements (aluRNAs) were enriched in the nucleolus. Antisense-oligo-mediated depletion of aluRNAs or drug-induced inhibition of RNA polymerase II activity d...

We describe the karyotype, location of nucleolus-organizing regions (NORs) and heterochromatin composition and distribution in Lepidochitona caprearum (Scacchi, 1836). The examined specimens had 2n=24 chromosomes; the elements of pairs 1-4 were metacentric, subtelocentric those of the fifth pair, telocentric the elements of other pairs. NOR-FISH, Ag-NOR- and CMA3 banding showed NORs localized o...

The architecture of the nucleolus in Allium porum and Triticum vulgare meristematic cells has been investigated by means of digestions with various enzymes. After staining with azure B at pH4, plant nucleoli exhibit lighter regions which, under electron microscopy, correspond to the fibrillar zones characterizing these organelles. Evidence is presented indicating that these latter zones contain...

The genus Odontophrynus, composed of ten species, is found in practically the entire south South America. Odontophrynus americanus was first vertebrate registered to present natural polyploidy, considering that most individuals have 2N = 4x 44 chromosomes, although having 2x 22 chromosomes considered ancestral condition for all genera family Odontophrynidae. study aimed analyze karyotype O. ame...

The physical location of the rDNA repeating units (25 S, 18 S and 5.8 S rRNA genes and the intergenic spacer sequences) was investigated in rye (Secale cereale L.) and wheat (Triticum aestivum L.) root tip meristematic cells by in situ hybridization using light and electron microscopy. The rDNA sequences are organized differently in the two related and intercrossable species. In rye (2n = 14, o...