Using Genetic Tools to Track Desert Bighorn Sheep Colonizations

ABSTRACT Understanding colonization is vital for managing fragmented populations. We employed mitochondrial DNA haplotypes and 14 microsatellite (nuclear DNA) markers to infer the origins of newly established populations of desert bighorn sheep (Ovis canadensis nelsoni) and to assess loss of genetic diversity during natural colonizations. We used haplotype distribution, F-statistics, Bayesian population clustering, and assignment tests to infer source populations for 3 recent colonies and identified a previously undetected colonization from multiple source populations. Allelic richness declined in 3 of 4 colonies in comparison to the primary source populations, but not as much as has been reported for translocated populations. Heterozygosity declined in only one colony. We also demonstrated that both native and translocated desert bighorn sheep have naturally recolonized empty habitats and suggest that colonization may partially offset population extinction in the region as long as connectivity is maintained. Genetic techniques and mitochondrial DNA haplotypes we described will allow managers to determine the origins of future colonizations by bighorn sheep in California, USA, and prioritize protection of linkages between known sources and colonies.     

Properties of Extracellular Enzymes from Aphanomyces astaci and Their Relevance in the Penetration Process of Crayfish Cuticle

In culture filtrates from the crayfish plague parasite, Aphanomyces astaci, protease and a low level of hyaluronidase activity were found. The hyaluronidase activity was highest at pH 6.5 or above and at about 23°C. The protease activity had a broad pH-optimum, between pH 7 and at least pH 10, and was partially denatured at 30°C. However, when incubated for 30 min with the substrate, casein, the activity increased logarithmically up to about 35–40°C and had an apparent optimum at 45–50°C. The proteases from the parasitic as well as from two less proteolytic, saprophytic Aphanomyces species were predominantly constitutive and were excreted mainly by the older mycelia. Proteases from the parasite and a saprophyte did not reach full activity until 10–30 min after substrate addition. No lipase activity was found in the case of the mycelium of the parasitic species. However, esterase was apparently present inside germinating zoospores. The native enzymes of A. astaci could degrade freeze-dried soft cuticle from crayfish. The relevance of the different enzymes of A. astaci for the penetration process within the cuticle of crayfish is discussed.     

Sex-reversed XY females with campomelic dysplasia are H-Y negative

Summary Three families with infants affected with campomelic dysplasia, a genetically determined mesenchymal disease frequently associated with sex reversal were studied. Two XY famales with ovarian gonadal differentiation and typical clinical features of campomelic dysplasia could be tested for H-Y antigen and were found to be H-Y negative.     

Nutraceutical Effect of Trace Elements as Additional Injectable Doses to Modulate Oxidant and Antioxidant Status,and Improves the Quality of Lamb Meat

Our study aimed to evaluate whether zinc, copper, selenium, and manganese subcutaneous mineral application (trace elements) reduced mortality, improved performance, and modulated oxidant and antioxidant balance in lamb meat, thereby improving its quality. We divided the 110 newborn Lacaune lambs into two groups: non-treated (control), and treated (application of minerals) with three doses of 0.33 mL/kg of body weight mineral complex on days of life 1, 30, and 60. All animals were weighed on day of life 1, 30, 60, 90, and 150. At the end of the experiment, 12 animals were slaughtered for physical and chemical analysis of meat, oxidant, and antioxidant status, and for allometric analysis. Mineral-application animals had greater live-weight (P < 0.05) on days of life 60 and 90. There was an increase in fat thickness (P = 0.004); pH levels (P = 0.002) were lower in mineral-application animal meat than in that of the control group. Meat was paler (according to lightness (L color)) in the control group (P = 0.04). Weight loss from cooking was greater in control animals (P = 0.004). Shear strength values were lower in the meat of treated lambs (P = 0.008) suggesting that mineral application was associated with increased meat tenderness. In addition, catalase and superoxide dismutase activities were higher (P = 0.01) in mineral-treated animals, associated with a reduction in reactive oxygen species levels (P < 0.01), and lipid peroxidation products (P = 0.02). These data suggest that mineral application modulated oxidant and antioxidant status, reflecting better meat quality.