Sperm chromosome segregation of rob(4;16) and rob(4;16)inv(4) in the brown brocket deer (Mazama gouazoubira).

The genus Mazama stands out among the Neotropical deer due to their wide intra and interspecific karyotypic diversification, which is associated with an accentuated chromosomal fragility. There are reports of heterozygous Robertsonian translocation (RT) carriers in a free-range population of Mazama gouazoubira (brown brocket deer), as well as in captive animals of this and other species of the genus. To analyze possible negative impacts of heterozygous chromosome rearrangements on reproductive fitness of the carriers, we performed an analysis of sperm meiotic segregation in four brown brocket bucks, carriers of a rob(4;16), and compared the results with those of a normal buck. We established a reliable FISH and sperm-FISH protocol for the brown brocket deer using bovine (Bos taurus; diploid number, 2n = 60) whole chromosome painting (WCP) and BAC probes. Using BAC probes, we revealed the presence of a paracentric inversion (PAI) of the fused chromosome 4 in two of the four analyzed RT carriers. The mean frequency of normal/balanced sperm in the translocation carriers was significantly lower than in the normal buck (94.78% vs 98.40%). The mean value of total unbalanced spermatozoa was almost doubled in the RT/PAI carriers (6.68%) when compared to RT carriers (3.76%), but the difference was not statistically significant. This study demonstrated the efficiency of FISH with bovine WCP and BAC probes in the characterization of chromosome rearrangements and gametic segregation patterns in brown brocket deer. Our results indicate a low to moderate increase in the rates of unbalanced meiotic segregation products in brown brocket bucks heterozygous for RT and RT/PAIs.

Different chromosome damage in lymphocytes of newly diagnosed gastrointestinal and breast cancer patients.

Structural chromosome aberrations are a predictive biomarker of cancer risk. Conventional chromosome analysis widely used for these purposes detects unstable chromosome aberrations that are eliminated during cell division. Stable aberrations that may persist in the body and tend to accumulate during a lifetime can be detected by fluorescence in situ hybridization (FISH). The aim of the study was to investigate the level of chromosome damage in newly diagnosed cancer patients and control subjects by FISH. Both groups of untreated cancer patients had increased frequency of aberrant cells. However, chromosome damage affected different cytogenetic endpoints. Stable translocations and cells with complex rearrangements were elevated in breast cancer patients whereas unstable chromosome aberrations (dicentric chromosomes and acentric fragments) were elevated in gastrointestinal cancer patients. These associations observed in nonsmokers were typically not pronounced in smokers (with the exception of dicentric chromosomes in gastrointestinal patients). Exposure to tobacco smoke increased aberrations in healthy controls but not in the cancer patients. Our study suggests an association between cancer and stable chromosomal rearrangements in breast cancer patients. Unstable aberrations elevated in gastrointestinal cancer patients may be at least partly ascribed to the exposure to diagnostic X-rays.

[Biomonitoring of Work with Genotoxic Substances and Factors in a Cancer Treatment Facility]. / Biomonitoring práce s genotoxickými látkami a faktory v onkologickém zdravotnickém zarízení.

BACKGROUND: A long-term occupational exposure of healthcare staff to cytostatics and ionizing radiation is associated with a possible manifestation of their genotoxic, carcinogenic and teratogenic effects. MATERIAL AND METHODS: A total number of 101 employees working with cytostatics or ionizing radiation were examined (some of them repeatedly) in a cancer treatment facility. The control group consisted of 119 persons excluded from the risk exposure. Fluorescence in situ hybridization with three pairs of whole-chromosomal probes and a pancrossomeric probe was used and the translocation frequency was determined. RESULTS: The total number of chromosomal rearrangements of healthcare professionals and control group correlates with age. Taking into account the age dependence, an increased level of chromosomal reconstruction was found in the case of 11 individuals, 10 of which were female, working on the positions of pharmacist, general nurse, physician. A total of 9 of those case involved the work with cytostatics. Five of these cases were re-examined two years later and the observed levels dropped to the control level. CONCLUSION: The results of biomonitoring should be evaluated on a group basis and individually, taking into account the personal history and possible non-professional effects on individuals - in particular those related to specific environmental measurement results.Key words: preventive medicine - occupational exposure - cytostatic agents - chromosome aberrations - in situ hybridization - fluorescence The authors declare they have no potential conflicts of interest concern ing drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. This work was supported by project of Ministry of Health Czech Republic. reg. No. 15-33968A.Submitted: 12. 4. 2018Accepted: 16. 4. 2018.