ROP, the Drosophila Sec1 homolog, interacts with syntaxin and regulates neurotransmitter release in a dosage-dependent manner.

The Sec1 family of proteins is thought to function in both non-neuronal and neuronal secretion, although the precise role of this protein family has not been defined. Here, we study the function of ROP, the Drosophila Sec1 homolog, in neurotransmitter release. Electrophysiological analyses of transgenic lines overexpressing ROP and syntaxin, a presynaptic membrane protein, indicate that ROP interacts with syntaxin in vivo. Characterization of four point mutations in ROP shows that they fall into two phenotypic classes. Two mutations cause a dramatic reduction in both evoked and spontaneous neurotransmitter release. In contrast, the other two mutations reveal an increase in evoked neurotransmission. Our data further show that neurotransmission is highly sensitive to the levels of ROP function. Studies on heterozygote animals indicate that half the amount of wild-type ROP results in a dramatic decrease in evoked and spontaneous exocytosis. Taken together, these results suggest that ROP interacts with syntaxin in vivo and is a rate-limiting regulator of exocytosis that performs both positive and inhibitory functions in neurotransmission.     

Haloalkane dehalogenases: Biotechnological applications

Haloalkane dehalogenases (EC 3.8.1.5, HLDs) are α/β-hydrolases which act to cleave carbon-halogen bonds. Due to their unique catalytic mechanism, broad substrate specificity and high robustness, the members of this enzyme family have been employed in several practical applications: (i) biocatalytic preparation of optically pure building-blocks for organic synthesis; (ii) recycling of by-products from chemical processes; (iii) bioremediation of toxic environmental pollutants; (iv) decontamination of warfare agents; (v) biosensing of environmental pollutants; and (vi) protein tagging for cell imaging and protein analysis. This review discusses the application of HLDs in the context of the biochemical properties of individual enzymes. Further extension of HLD uses within the field of biotechnology will require currently limiting factors – such as low expression, product inhibition, insufficient enzyme selectivity, low affinity and catalytic efficiency towards selected substrates, and instability in the presence of organic co-solvents – to be overcome. We propose that strategies based on protein engineering and isolation of novel HLDs from extremophilic microorganisms may offer solutions.     

Blood group H like activity in crude preparations of bovine lung galactan.

In crude preparations of bovine lung galactan blood group H-like activity, which does not occur on bovine red cells, has been detected with heterophile anti-H-like reagents from different origin. These H-like receptors, associated with pneumococcus type XIV cross-reactivity, belong to a glycoprotein fraction and not to the galactan itself.     

Yeast SCP from ethanol: Measurements,modeling, and parameter estimatin in a batch system

The production of single-cell protein (SCP) from ethanol by different imcroorganisms is briefly reviewed. The trends in modeling the SCP production are outlined with a stress on the need to incorporate metabolic and engineering considerations into the pertinent models. Data on batch yeast growth on ethanol are analyzed, a metabolic model involving design parameters is suggested, parameters values are estimated, and their significance is discussed. The model essentially describes the response of a system to disturbances (substrate, metabolites, oxygen, etc.). An effective numerical integration procedure is necessary in the solution of the model which has “stiff” character.     

Molecular phylogeny of African hinged and helmeted terrapins (Testudines: Pelomedusidae: Pelusios and Pelomedusa)

Fritz, U., Branch, W. R., Hofmeyr, M. D., Maran, J., Prokop, H., Schleicher, A., ?iroký, P., Stuckas, H., Vargas‐Ramírez, M., Vences, M. & Hundsdörfer, A. K. (2010). Molecular phylogeny of African hinged and helmeted terrapins (Testudines: Pelomedusidae: Pelusios and Pelomedusa). —Zoologica Scripta, 40, 115–125. With 18 currently recognised species, Pelusios is one of the most speciose chelonian genera worldwide, even though the taxonomy of some species is contentious. Recent investigations suggested that the closely related, but morphologically distinct genus Pelomedusa is paraphyletic with respect to Pelusios, and that Pelomedusa consists of nine deeply divergent lineages. Using three mitochondrial and three nuclear DNA fragments (2054 bp mtDNA, 2025 bp nDNA), we examined for the first time the phylogeny of Pelusios by molecular means. Our analyses included all Pelusios species, except the probably extinct P. seychellensis, as well as the nine Pelomedusa lineages. The results showed that Pelusios and Pelomedusa are reciprocally monophyletic. Limited sampling of Pelusios species and homoplasy introduced by remote outgroups most likely explain the paraphyly of Pelomedusa in previous studies. The distinctiveness of most Pelusios species was confirmed, but none of the currently recognised species groups within Pelusios was monophyletic. In Pelusios rhodesianus and P. sinuatus distinct genetic lineages were discovered, suggestive of cryptic taxa. In contrast, the recognition of the weakly differentiated P. castaneus and P. chapini as full species is doubtful, as is the validity of the Malagasy and Seychellois subspecies of P. castanoides. GenBank sequences of P. williamsi were nested within P. castaneus, but the morphological distinctiveness of the two species makes it likely that the GenBank sequences (derived from a turtle from the pet trade) are misidentified. Divergence among the distinct genetic lineages of Pelomedusa equals or exceeds the differences among Pelusios species, supporting the view that Pelomedusa is a species complex.     

Knowledge and Perceptions of,and Attitudes to,Bats by People Living around Arabuko-Sokoke Forest,Malindi-Kenya

Bat populations continue to decline worldwide because of myriad human activities. To enhance bat conservation, human behavior needs to change. Such change can occur, in part, through an understanding of what motivates human actions toward bats. We used a Bat Attitude Questionnaire (BAQ) to investigate attitudes toward bats in people (n = 394) living around Arabuko-Sokoke Forest (ASF), Kenya. Belief in myths seemed to prevail among those surveyed and that these myths were significantly associated with low tolerance of bats (ordinal regression, p < 0.05). Older and more educated people reported more positive attitudes toward bats than others. Multiple linear regression revealed that females showed more negative attitudes toward, and more belief in, myths about bats than males (both p < 0.01). Ordinal regression showed that hostile behavior toward bats was more common among males (p < 0.001). Nearly one-third of the respondents reported actively killing bats or destroying bat roosts. A similar proportion did not see any benefits of bats to humans, while the majority of respondents associated bats with the destruction of farmers’ fruits. To address prevailing negative attitudes about bats, we recommend conducting evening school-based bat study tours, specifically targeting youths in schools around the forest, to examine whether physical contacts with bats would help positively influence human attitudes toward bats. Additionally, since mango (Mangifera indica) farming is an important source of income to people around ASF, an assessment of the quantity of mangoes destroyed by bats would be important to determine whether there is a need for controlling bat access to crops through appropriate schemes.