Increased frequencies of both chromosome abnormalities and SCEs in two sheep flocks exposed to high dioxin levels during pasturage

Abstract

During the past four years several livestock farms (sheep, cattle and river buffalo) in the provinces of Naples and Caserta (southern Italy) have been unable to sell their milk and other dairy products due to the levels of dioxins (17 different types) present in the milk mass exceeding the value permitted [3 pg/g of fat, as human WHO 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD or dioxin) equivalent]. While some farms, especially those showing relatively low levels of dioxins, have managed to reduce the dioxins in the milk below the permitted threshold by changing the diet, many, especially sheep farms, have failed to do so. Indeed, about 12,000 head of cattle, river buffaloes and sheep have so far been culled. In the present study, 34 and 42 sheep from two herds raised in the province of Naples (Acerra municipality) and where high levels of dioxins (50.65 and 39.51 pg/g of fat, respectively) were found in the milk mass, were cytogenetically investigated and compared with 20 sheep (control) raised 80 km away from the exposed area. Increases of both chromosome abnormalities (gap, chromosome and chromatid breaks) (17 and 8 times higher in the two exposed herds, respectively) and sister chromatid exchanges (SCEs) were found in both herds when compared with the control, and the differences were highly significant (P<0.001). No statistical differences were found when comparing the frequencies of aneuploid cells of exposed animals (16.4 and 17.8%) and control (17.9%). Furthermore, high levels of mortality and abnormal foetuses were recorded in one of the two farms when compared with the control.

Analysis of plasma indices of redox homeostasis in dairy cows reared in polluted areas of Piedmont (northern Italy)

“…In particular, dioxin pollution has occurred in Italy, especially in Campania and in industrial areas of Piedmont, Lombardy, Tuscany and Puglia (Biasioli and Ajmone-Marsan, 2007;Ingelido et al, 2009;Turrio-Baldassarri et al, 2009), leading to contamination of dairy milk in sheep, cattle and river buffaloes (Iannuzzi et al, 2004;Perucatti et al, 2006;Cirillo et al, 2008;Esposito et al, 2009). Dioxins are polyhalogenated aromatic hydrocarbons, highly toxic and persistent, present at low level in air, soil, water, feed as well as in foods such as dairy products (Matsumura, 2003).…”

Adaptación de la Técnica de Cultivo de Linfocitos de Alpacas y Llamas para el Análisis de Intercambio de Cromátides Hermanas

“…Con base a lo anterior, se tomó de referencia la incorporación de 5-BrdU (10 µg/ mL) en el cultivo de la sangre de CSA a las 42 h de iniciado el cultivo de linfocitos en ovejas (Perucatti et al, 2006) hasta completar las 72 h de cultivo, observando un 20% de cromátides hermanas sin coloración diferencial de SCE. Esto es consecuencia de la presencia de 5-BrdU en más de dos ciclos celulares durante la replicación del ADN, es decir más de 30 h. Como referencia a la anterior experiencia, se incorporó 5-BrdU (10 µg/ ml) a las 46 h de iniciado el cultivo de linfocitos de los camélidoshasta finalizar las 72 h de cultivo, resultando la visualización de SCE en un 95%; es decir, la presencia de 5-BrdU estuvo presente durante dos ciclos celulares con un total de 26 h del cultivo de linfocitos, sugiriendo que cada ciclo celular es aproximadamente de 13 h en los CSA.…”

“…Se utilizó el Giemsa (solución stock) al 3% diluido en buffer fosfato a pH 6.8, el cual permitió observar los intercambios entre las cromátides hermanas en microscopio con luz incorporada, sin necesidad de requerir un microscopio de fluorescencia para observar el SCE, tal como reporta Perucatti et al (2006) en su técnica de coloración con naranja de acridina. Una ventaja adicional de la coloración Giemsa es que se puede observar la lámina por un largo periodo, en comparación con las láminas coloreadas con naranja de acridina que tienen un tiempo de vida útil corto para observarlas, fotografiarlas y analizarlas en el microscopio de fluorescencia (Dutrillaux, 1981).…”

“…1). Perucatti et al (2006) describen la coloración con naranja de acridina, proceso que permite observar la coloración diferencial de las SCE en microscopio de fluorescencia por un tiempo limitado.…”

Fluorescence in situ hybridization mapping of six loci containing genes involved in the dioxin metabolism of domestic bovids

“…Due to their high persistence, they are considered to be among the main causes of food chain and environmental pollution. Indeed, analyses performed to check dioxin levels in milk mass samples of bovids revealed higher values of dioxins than those legally permitted in several farms and this originated enormous economic damages to the farmers who were unable to sell milk or their derivative products for a long time (reviewed in Perucatti et al 2006;Di Meo et al 2010). Thus, the physical organization of genes involved in the dioxin metabolism can be of such interest to increase our knowledge on bovid genomes.…”