DNA matchmaking in captive facilities: a case study with tigers.

BACKGROUND: Genetics driven interventions if adopted in conservation breeding projects may enhance the overall success by prioritizing breeding among genetically most competent individuals and delaying or completely diminishing the ill effects of inbreeding. METHODS AND RESULTS: In the present study, we investigated genetic make-up of 15 tigers housed at five different captive facilities of West Bengal in India and report the moderate level of genetic variation. We identified five tigers based on individual genetic attributes that may be prioritized for future breeding or animal exchange programmes. The occurrence of first and second order related individuals in captivity require management attention and they should be paired considering their immediate genetic background. CONCLUSION: Considering tiger as a case study, we highlight the use of genetic assessment and necessity to validate the studbook records in formulating adaptive management strategies for long-term conservation and management of species of interest.

Oxidative stress responses of two different ecophysiological species of earthworms (Eutyphoeus waltoni and Eisenia fetida) exposed to Cd-contaminated soil.

The aim of this study was to assess the biomarkers of oxidative stress [reduced glutathione (GSH), glutathione-S-transferase (GST), superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione reductase (GR), aldehyde dehydrogenase (ALDH) and lipid peroxidation (LPO)] in earthworms of different ecological categories [epigeic Eisenia fetida (E. fetida) and anecic Eutyphoeus waltoni (E. waltoni)] exposed to cadmium (Cd)-polluted soil (30, 60 and 120 mg kg-1) for 28 days. Cd accumulation in earthworms increased significantly with increasing exposure dose and duration. However, E. fetida showed a relatively higher level of Cd accumulation until day 21; thereafter, depletion in the Cd level was recorded for the highest exposure dose. In E. waltoni, the detoxification enzymes and GSH level increased significantly with increasing exposure dose and Cd accumulation for 14 days (acute phase). In contrast, in E. fetida, acute exposure to Cd increased detoxification enzymes with decrease in GSH levels. For both species, sub-chronic exposures (28 days) increased lipid peroxidation with decrease in detoxification enzymes. GPx and ALDH responses of Cd-exposed earthworms showed a similar trend. Thus, these enzymes can be used as general biomarkers in these two species. The consistent variations in GST, GPx and ALDH activities suggest that E. waltoni may be used as a bioindicator species; this further signifies the use of endemic earthworms as a bioindicator to assess the risk of soil contamination. The present investigation indicates that Cd accumulation and biomarker responses in earthworms depend on dose and duration of exposure and on the concerned species.

Antioxidant responses in the earthworm Aporrectodea caliginosa of eastern Slovakia: application of principal component analysis as a tool to identify metal contaminated areas.

The soil of Slovak Republic is severely contaminated with heavy metals, creating hazards to soil health. In order to assess the current status with the prospect of selecting the appropriate treatment methods and land use, this investigation aimed to determine a panel of complementary and ecologically relevant biomarkers that reflect adverse biological responses towards terrestrial pollutants. To attain this objective, the concentration of reduced glutathione and enzymes of glutathione antioxidant system were assessed in clitellate earthworm, Aporrectodea caliginosa sampled from selected sites of eastern Slovakia along with the pH and total metal concentration (As, Cd, Pb, Cr, Hg, Mn, Fe, Co, Ni, Cu, Zn) of soils. Positive, significant (p < 0.05) induction of glutathione peroxidase, glutathione reductase, and glutathione-S-transferase activities and depletion of reduced glutathione level (negative correlation) were associated with the increased soil metal concentrations. Metal interference was found in the detoxification process and antioxidant defense mechanism does not efficiently counteract the oxidative stress induced by chronic metal exposure. The tested biomarkers confirmed sensitive and affective response to the pollution of soil contaminants, in this case metals. This has a potential use in ecotoxicological field monitoring. The proposed principal component analysis is a multivariate model of data analysis that represents a cost-effective approach to differentiate metalliferous soils of eastern Slovakia with different health status.

Metallothionein response in earthworms Lampito mauritii (Kinberg) exposed to fly ash.

Among pollutants, the coal fly ash occupies a significant position in industrial wastes. The fly ash matrix is a complex mixture of various organic (polyhalogenated compounds) and inorganic (Si, Al, Fe, As, Cd, Bi, Hg, etc.) chemicals. The application of fly ash for agricultural purposes and as landfills may lead to the contamination of the land with some of the toxic chemical compounds present in fly ash. Thus prior to the application of fly ash for developmental activities, it requires bio-monitoring and risk characterization. In order to achieve this objective adult Lampito mauritii were exposed to different proportions of fly ash in soil for 30 d and the concentrations of metallothionein in earthworm were assessed. The results revealed that up to 50% of fly ash amendment does not apparently harm the earthworm in respect of their survival and growth. A significant increase in tissue metallothionein level was recorded in L. mauritii exposed to fly ash amended soil without tissue metal accumulation indicating that metallothionein is involved in scavenging of free radicals and reactive oxygen species metabolites. It is concluded that this biochemical response observed in L. mauritii exposed to fly ash amended soil could be used in ecotoxicological field monitoring.

The role of earthworm Lampito mauritii (Kinberg) in amending lead and zinc treated soil.

A laboratory experiment was carried out to determine the effect of earthworm (Lampito mauritii) activity on mobility of Pb2+ and Zn2+ in the soil (DTPA-extractable) and its composting potential in presence of these metals. Well clitellate earthworms collected from an uncontaminated site were exposed to different concentrations (75, 150, 300mgkg(-1)) of Pb2+ and Zn2+ separately for 30 days. It was observed that the metal burden in the earthworm tissue increased with the increase in metal treatment. L. mauritii elevated the soil pH of all the metal treated beds and lowered the soil C/N ratio in the cast by reducing the organic carbon and fixing additional nitrogen. Earthworm activity significantly increased the availability of phosphorous, potassium and decreased the amount of DTPA-extractable Pb2+ and Zn2+ in the cast, which implies the immobilization of metals in soils. These findings suggest the use of L. mauritii in amelioration of metal contaminated soil.

Antioxidant responses of the earthworm Lampito mauritii exposed to Pb and Zn contaminated soil.

The aim of this study was to provide fundamental data on the biochemical analysis of antioxidant defences in the earthworm exposed to low levels (75, 150, 300 mg kg(-1) soil) of Pb and Zn. In order to attain this objective, adult Lampito mauritii were exposed to different doses of Pb and Zn separately for 28 days and the concentrations of oxidized and reduced glutathione, activities of glutathione-S-transferase, glutathione peroxidase and glutathione reductase were assessed. Dose-dependent perturbations were observed in the glutathione-glutathione-S-transferase system and other antioxidant enzymes during the early phase of the exposure to Pb. In the Zn exposed earthworm, the glutathione-glutathione-S-transferase system remained stable and the stimulation of glutathione peroxidase and glutathione reductase activities occurred significantly only on day 14 at 300 mg Zn kg(-1). It is concluded that the antioxidants are directly involved in the adaptive response of Lampito mauritii for survival in metal contaminated soil.