An improved characterization of horse (Equus caballus, 2n=64) chromosomes by using replicating G and R banding patterns

Abstract Peripheral blood lymphocytes were cultured and treated for early- and late-BrdU incorporation to perform replicating G- and R-banding patterns, respectively. Slides were treated for GBG-, RBA- and RBG-banding techniques. Improved banded karyotypes at early- (350 bands) and pro-metaphase (500 bands) stage were performed and GBG- and RBA-banded prometaphase karyotypes were presented for the first time on this species. All chromosomes, including the small acrocentrics, show clear and distinguishable G- and R-banding patterns. Chromosome identification followed the latest chromosome standard nomenclature (ISCNH 1997). This study is also our contribution to further standard karyotype attempts at the prometaphase stage

Chromosome analyses in dairy cows exposed to dioxins and dioxin-like PCBs using the SCE test

Peripheral blood cultures were performed to study the sister chromatid exchanges (SCE) in samples from 15 cows (Valdostana x Piedmontese crossbreds) showing average milk values of dioxins+furans+PCBs higher (18.56 pg/g of fat as WHO-TEQ) than those permitted (6.0 pg/g of dioxins+furans+PCBs as WHO-TEQ) and the results were compared with samples from 16 Valdostana dairy cows (1.75 pg/g of fat as WHO-TEQ) used as control. Significant (P<0.01) higher mean number of SCE/cell (7.10±2.8) were found in cows showing higher levels of dioxins and PCB compared to those achieved in the controls (SCE/cell=5.24±2.51)

Chromosome instability in lymphocytes of Friesian cows naturally exposed to dioxins being raised close to a metallurgic factory area in southern Italy

Dioxins (PCDDs, PCDFs and DL-PCBs) are a large family of congeners that are considered highly toxic and are reported to be teratogenic, mutagenic, carcinogenic, immunotoxic and hepatotoxic, also affecting the nervous and reproductive systems. Farm animals are particularly exposed to these chemicals when they are fed with grass produced close to polluted areas such as those located in vicinity of metallurgic factories. Cytogenetic tests can be very useful to check genetic damage occurring to domestic animal cells exposed to these chemicals. Fifty-two randomly selected Italian Friesian cows (Bos taurus, 2n&nbsp;=&nbsp;60) from two farms located in the vicinity of and (as a control) far from the a metallurgic industrial area underwent cytogenetic investigations to ascertain possible differences in their chromosome fragility. One farm was under legal sequestration due to the presence in the milk mass of higher mean values of dioxins (24.78&nbsp;±&nbsp;3.19 pg&nbsp;g−1 of fat as sum of PCDD + PCDF + DL-PCBs as WHO-TEQ (World Health Organization-Toxic Equivalent Quantity), with DL-PCBs being the main chemical component) than those permitted (5.5 pg&nbsp;g−1 of fat as WHO-TEQ). Cytogenetic analyses, performed by using both the chromosome abnormality (CA) test (chromosome and chromatid breaks) and sister chromatid exchange (SCE) test, revealed a significantly (p&nbsp;&lt;&nbsp;0.01) higher chromosome fragility in cells of exposed cows (26 cows) compared to those of the control (23 cows)