A specific stain for α-glucosidases in isoelectric focusing gels

The separation of the four diastereomers of β,γ-bidentate Cr · ATP using reverse-phase HPLC techniques is described. This technique provides complete resolution of the diastereomers within 10 min and relies on the use of methanesulfonic acid (in the ionized form) as an ion-pairing agent. To identify the screw sense of these resolved isomers, the CD spectra of each isomer were done, and substrate and inhibition specificities were examined using hexokinase. The results were then correlated with the isomeric assignments made by D. Dunaway-Mariano and W. W. Cleland (1980, Biochemistry19, 1506–1515). Further studies included the monitoring of isomer interconversion at pH 6.2 to an equilibrium concentration of all four, and specific rotation measurements of the pure isomers at pH 2.5, 23°C, and 546 nm.     

Modeling problems in conservation genetics using captive Drosophila populations: Improvement of reproductive fitness due to immigration of one individual into small partially inbred populations

Immigration into small isolated captive and wild populations is recommended to alleviate inbreeding depression. The effects on reproductive fitness of introducing one immigrant into 10 small partially inbred captive populations of D. melanogaster were evaluated. The relative reproductive fitness of the immigrant populations (0.628) was approximately double that of the isolated populations (0.294) and about halfway between the isolated populations and the outbred base population (1.00). Every replicate population increased in fitness following the introduction of an immigrant. The improvements in reproductive fitness shown by the immigrant populations were not due to F₁ hybrid vigor, as the experimental populations underwent three generations of random mating prior to the fitness tests. These results indicate substantial benefits can be gained by the translocation of as few as a single animal between small, partially inbred populations. © 1992 Wiley-Liss, Inc.     

Fatal toxoplasmosis in koalas (Phascolarctos cinereus)

Toxoplasma gondii-like organisms were seen in the heart, kidney, liver, lung, lymph node, spleen, small intestine, and stomach from 2 koalas that died suddenly in a fauna park in Sydney, Australia. Diagnosis was confirmed by immunohistochemical staining. This is the first confirmed report of toxoplasmosis in an arboreal marsupial.