The effect of camphor on bacterial bioluminescence

Summary The inhibitory effect of camphor on bioluminescence of both bacteria and bacterial luciferase has been examined. The camphor has been shown to be a substrate of cytochrome P-450 of the luminous bacteria Photobacterium fischeri. The inhibition of the luminescence reaction provided evidence for the competitive nature of the interaction of camphor and aliphatic aldehyde at the binding site for luciferase. Camphor is also supposed to interact with P-450. The findings indicate that the hydroxylation process of camphor affects the kinetics of the luminescence.     

Aldolases of the lactic acid bacteria

Reciprocal qualitative and quantitative immunological experiments employing an anti-Pediococcus cerevisiae aldolase serum confirmed many of the interspecific relationships demonstrated previously among lactic acid bacteria with antisera prepared against the Streptococcus faecalis fructose diphosphate aldolase. The extent of immunological relatedness observed between the Lactobacillus and Pediococcus aldolases was markedly greater than that noted between Pediococcus and Streptococcus aldolases indicating that the pediococci share closer phylogenetic ties with the rod-shaped lactobacilli than with their spherical counterparts in the streptococci. In addition to confirming the existence of definitive, but distant, relationships between the lactic acid bacteria and certain gram positive nonsporeforming anaerobes, immunological cross-reactivity was also demonstrated between the pediococcal aldolases and those of Aerococcus viridans.This paper is dedicated with deepest appreciation to Prof. Roger Y. Stanier on the occasion of his 60th birthday in token of what his friendship and guidance have meant to me. — J. L.     

Cycloheximide resistance in Chinese hamster cells. II. Induction of Chm resistance in Chinese hamster cells by N-nitrosomethylurea.

Mutant Chinese hamster ovarian (CHO) cells with a resistance to 7-10(-7) and 8-10(-7) M cycloheximide (CHM) were induced at mutation rates of 1.9-5.2-10(-3) and 1.6-1.8-10(-3) respectively after treatment with N-nitrosomethylurea (NMU) at 100 mug/ml. The induced mutation rates differed by two orders of magnitude from the spontaneous rate of mutation to CHM resistance.     

Construction of a fusion protein carrying antigenic determinants of enteric clostridial toxins

Clostridium difficile and Clostridium perfringens type A are infectious agents of enteric diseases. The main virulence factors of these microorganisms include toxins A and B of C. difficile (ToxA and ToxB) and enterotoxin of C. perfringens (Cpe). In this study genetic constructions have been created for the expression of ToxA, ToxB and Cpe fragments either as individual components or as a hybrid multidomain (ToxA-ToxB-Cpe) protein. Rabbit monospecific sera raised against individual peptides reacted with the chimeric product indicating that the corresponding antigenic determinants were correctly expressed on the hybrid molecule. Furthermore, mice immunized with the fusion protein produced antibodies specific to each of the three separate components. These data suggest that the constructed three-domain molecule could be used in future studies for development of a vaccine against enteric clostridial diseases.     

Evaluating the effectiveness of road mitigation measures

The last 20 years have seen a dramatic increase in efforts to mitigate the negative effects of roads and traffic on wildlife, including fencing to prevent wildlife-vehicle collisions and wildlife crossing structures to facilitate landscape connectivity. While not necessarily explicitly articulated, the fundamental drivers behind road mitigation are human safety, animal welfare, and/or wildlife conservation. Concomitant with the increased effort to mitigate has been a focus on evaluating road mitigation. So far, research has mainly focussed on assessing the use of wildlife crossing structures, demonstrating that a broad range of species use them. However, this research has done little to address the question of the effectiveness of crossing structures, because use of a wildlife crossing structure does not necessarily equate to its effectiveness. The paucity of studies directly examining the effectiveness of crossing structures is exacerbated by the fact that such studies are often poorly designed, which limits the level of inference that can be made. Without well performed evaluations of the effectiveness of road mitigation measures, we may endanger the viability of wildlife populations and inefficiently use financial resources by installing structures that are not as effective as we think they are. In this paper we outline the essential elements of a good experimental design for such assessments and prioritize the parameters to be measured. The framework we propose will facilitate collaboration between road agencies and scientists to undertake research programs that fully evaluate effectiveness of road mitigation measures. We discuss the added value of road mitigation evaluations for policy makers and transportation agencies and provide recommendations on how to incorporate such evaluations in road planning practices.     

Genetic and potential non-genetic benefits increase offspring fitness of polyandrous females in non-resource based mating system

Background  

The adaptive significance of female polyandry is currently under considerable debate. In non-resource based mating systems, indirect, i.e. genetic benefits have been proposed to be responsible for the fitness gain from polyandry. We studied the benefits of polyandry in the Arctic charr (Salvelinus alpinus) using an experimental design in which the material investments by the sires and maternal environmental effects were controlled.