Population genetics of soluble glutamic-pyruvic-transaminase in North Germans (Lübeck)

Summary The soluble glutamic-pyruvate-transaminase activity in 103 mother-child combinations and 374 randomly selected individuals from a North German population was examined. The frequency of GPT¹ was found to be slightly higher than that of GPT², but this is in accordance with the various other German population groups. Investigation of mother-child combinations supports the assumption that GPT¹ and GPT² are dimers, i.e. each being composed of two identical subunits.

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Zusammenfassung Es wurde die Aktivität der löslichen Glutamat-Pyruvat-Transaminase bei 103 Mutter-Kind-Kombinationen und 374 auslesefrei gewonnenen Individuen einer norddeutschen Bevölkerung untersucht. Die Häufigkeit von GPT¹ ist etwas größer als die von GPT²; das stimmt mit den übrigen bisher untersuchten deutschen Bevölkerungsstichproben überein. Die Mutter-Kind-Kombinationen unterstützen die Auffassung, GPT¹ und GPT² seien Dimere, d. h. jeweils aus zwei identischen Untereinheiten zusammengesetzt.

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This study was carried out in 1972/73 during the author's tenure at the Medizinische Hochschule in Lübeck, West Germany.     

Effects of scale on interpreting life-history characteristics of ungulates and carnivores

Many life-history characteristics of large mammals are scale sensitive. We provide examples where varying temporal and spatial scales can affect interpretation of data concerning life-history characteristics in large herbivores and carnivores and offer recommendations for selecting the most appropriate sampling scale or scales. We also document that some animals make decisions concerning their spatial distribution at scales well beyond the size of the home range. Conversely, other decisions involving sexual segregation of sexes, or where to give birth, may be made at scales below the level of the habitat patch. Such differences in behaviour affect our understanding of habitat selection in large herbivores, and interpreting tradeoffs between acquiring essential resources and avoiding predators. Moreover, some landscape attributes may be selected at one scale, whereas other characteristics of the environment may be selected at another. We argue that even sophisticated models for explaining the ecology and behaviour of mammals benefit from framing specific hypotheses that are related to the to the life-history characteristics of those animals. We also believe that the failure to consider and select the most appropriate scale, or suite of scales, may lead to the mismanagement of critical natural resources. We forge relationships among scale, life-history characteristics of mammals, and biodiversity. Finally, we synthesize the literature on scale for large mammals and make recommendations for future research.     

Wild bacterial probiotics fed to larvae of mass‐reared Queensland fruit fly [Bactrocera tryoni (Froggatt)] do not impact long‐term survival,mate selection,or locomotor activity

Queensland fruit fly [Bactrocera tryoni (Froggatt), Diptera, Tephritidae] is the most devastating insect pest impacting Australian horticulture. The Sterile Insect Technique (SIT) is an important component of tephritid pest management programs. However, mass‐rearing and irradiation (to render insects sterile) may reduce the fitness and performance of the insect, including the ability of sterile males to successfully compete for wild females. Manipulation of the gut microbiome, including the supplementation with bacterial probiotics shows promise for enhancing the quality of mass‐reared sterile flies, however there are fewer published studies targeting the larval stage. In this study, we supplemented the larval stage of mass‐reared B. tryoni with bacterial probiotics. We tested several individual bacteria that had been previously isolated and characterized from the gut of wild B. tryoni larvae including Asaia sp., Enterobacter sp., Lactobacillus sp., Leuconostoc sp. We also tested a consortium of all four of these bacterial isolates. The fitness parameters tested included adult survival in field cages, laboratory mate selection of bacteria supplemented males by bacteria nonsupplemented females, and laboratory locomotor activity of adult flies. None of the bacterial probiotic treatments in the current study was significantly different to the control for field survival, mate selection or locomotor activity of adult B. tryoni, which agree with some of the other studies regarding bacterial probiotics fed to the larval stage of tephritids. Future work is needed to determine if feeding the same, and/or other probiotics to adults, as opposed to larvae can positively impact survival, mating performance, mating competitiveness and locomotor activity of B. tryoni. The bacterial group(s) and function of bacterial species that increase fitness and competitiveness is also of interest to tephritid mass‐rearing programs.     

A specific defect in the proliferative capacity of B cells from old mice stimulated with autoreactive T cells

B lymphocytes from aged mice were found to be defective in their ability to proliferate in response to stimulation with an autoreactive T cell clone D1.4. The differentiative response leading to antibody secretion was also impaired in the auto D1.4 T cell-stimulated B cells from old mice in comparison to similarly stimulated B cells from young mice. The B cells from old mice were competent in activating the autoreactive T cells such that the T cells were induced to proliferate. The B cell defect appears to be restricted to a certain phase of B cell activation, since old mouse B cells responded to the auto D1.4 T cells by increasing cell surface Ia as well as size, but failed to incorporate tritiated thymidine. The responsiveness to interleukin-4 was found to be similar between B cells from young and old mice. It appeared that the B cells from old mice are specifically defective in progressing from the G0 phase of cell cycle into the S phase when stimulated with the auto D1.4 T cells.