Frequent deletion of the CDKN2A locus in chordoma: analysis of chromosomal imbalances using array comparative genomic hybridisation

The initiating somatic genetic events in chordoma development have not yet been identified. Most cytogenetically investigated chordomas have displayed near-diploid or moderately hypodiploid karyotypes, with several numerical and structural rearrangements. However, no consistent structural chromosome aberration has been reported. This is the first array-based study characterising DNA copy number changes in chordoma. Array comparative genomic hybridisation (aCGH) identified copy number alterations in all samples and imbalances affecting 5 or more out of the 21 investigated tumours were seen on all chromosomes. In general, deletions were more common than gains and no high-level amplification was found, supporting previous findings of primarily losses of large chromosomal regions as an important mechanism in chordoma development. Although small imbalances were commonly found, the vast majority of these were detected in single cases; no small deletion affecting all tumours could be discerned. However, the CDKN2A and CDKN2B loci in 9p21 were homo- or heterozygously lost in 70% of the tumours, a finding corroborated by fluorescence in situ hybridisation, suggesting that inactivation of these genes constitute an important step in chordoma development

Zmiany histopatologiczne w mięśniu piersiowym powierzchniowym bażantów ( Phasinus colchicus ; Phasinus c. Mongolicus)

The aim of investigation was the frequency of histopathological changes of the m. pectoralis superficialis of game and Mongolian pheasants of different ages. The samples for analyze from pectoral muscle were taken after bird slaughter immediately at 12, 16 and 20 weeks of age. Then with from the samples made the histological slides and stained with H + E coloring method to visualize of the muscle tissue structure. The muscle structure analysis was conducted per area 1.5 mm2 with the following histopathological changes: atrophy, shape changes, giant fibers, necrosis, hyaline degeneration, splitting, connective tissue hypertrophy and inflammatory. There was a small frequency of histopathological changes in both pheasant varieties. The most histopathological changes ware observed atrophy and changes of fiber shape. Other changes were sporadic. The connective tissue hypertrophy and inflammatory infiltration were not observed in any individuals. Mongolian pheasants found slightly higher frequency of histopathological changes, but these differences were not statistically significant. Considering the above facts, it can be stated that m. pectoralis superficialis both varieties of pheasants because of the small number of histopathological changes observed in their structure and their nutritional value are valuable raw materials for the high-quality food production

Structure of the cohesin loader Scc2

The functions of cohesin are central to genome integrity, chromosome organization and transcription regulation through its prevention of premature sister-chromatid separation and the formation of DNA loops. The loading of cohesin onto chromatin depends on the Scc2–Scc4 complex; however, little is known about how it stimulates the cohesion-loading activity. Here we determine the large ‘hook' structure of Scc2 responsible for catalysing cohesin loading. We identify key Scc2 surfaces that are crucial for cohesin loading in vivo. With the aid of previously determined structures and homology modelling, we derive a pseudo-atomic structure of the full-length Scc2–Scc4 complex. Finally, using recombinantly purified Scc2–Scc4 and cohesin, we performed crosslinking mass spectrometry and interaction assays that suggest Scc2–Scc4 uses its modular structure to make multiple contacts with cohesin