Coevolution of the glucose dehydrogenase gene and the ejaculatory duct in the genus Drosophila

The glucose dehydrogenase gene (Gld) in Drosophila melanogaster exhibits a unique spatial and temporal pattern of expression. GLD expression switches from a non-sex-limited state at the pupal stage to a male-limited state at the adult stage. At the adult stage, the enzyme is restricted to the ejaculatory duct. Within the genus Drosophila, the ejaculatory duct has undergone a simple morphological divergence. In order to determine whether correlated changes in GLD expression had occurred, GLD activity during the pupal and adult stages was determined for several Drosophila species. It was found that virtually all of the species exhibit pupal GLD activity, whereas only those species with an expanded ejaculatory duct express male-limited GLD. The results of interspecific genital imaginal disc transplantation experiments indicate that the expanded morphology and GLD expression do not require any species- or sex-specific diffusible factors. An apparent regulatory polymorphism exists within the D. takahashii species with respect to male-limited GLD expression.      

A report on methods to reduce,refine and replace animal testing in industrial toxicology laboratories

The Committee to Promote Principles of Reduction, Refinement and Replacement of Animal Testing in Industrial Toxicology Laboratories was established in 1987 to work toward industrywide improvements in laboratory animal testing methods. The committee's goals are to gather information about effective nonanimal testing techniques and other methods of conserving and improving the care of laboratory animals, to work toward the systematic validation of nonanimal alternatives, and to disseminate useful information about progressive programs and policies throughout the industrial toxicology community. This is the first in a continuing series of reports the committee plans to produce as part of an ongoing program to promote communication among industrial toxicologists about successful methods of reducing, refining and replacing animal testing. Here are some of the report's major findings: (1) Animal care and use committees charged with the oversight of laboratory animal use are a universal practice at the companies surveyed. (2) Significant reductions in the number of animals used for acute toxicity testing have taken place at all the companies during the last 5- to 10-year period. (3) Structure-activity relationships (predicting a test compound's properties based on the known properties of familiar chemicals with similar structures) are widely used to minimize, but not replace, the use of animals. (4) Tissue and organ culture systems are being used with increasing frequency for screening and mechanistic studies, but are not completely replacing animal evaluations as a final step. (5) There is a pressing need for the systematic and scientifically sound validation of nonanimal alternative techniques to reduce the use of animals in toxicology testing while satisfying requirements for the protection of public safety.     

Deconstructing fatalism: ethnographic perspectives on women's decision making about cancer prevention and treatment

Researchers have long held that fatalism (the belief in a lack of personal power or control over destiny or fate) constitutes a major barrier to participation in positive health behaviors and, subsequently, adversely affects health outcomes. In this article, we present two in-depth, ethnographic studies of rural women's health decisions surrounding cancer treatments to illustrate the complexity and contestability of the long-established fatalism construct. Narrative analyses suggest that for these women, numerous and complex factors--including inadequate access to health services, a legacy of self-reliance, insufficient privacy, combined with a culturally acceptable idiom of fatalism--foster the use of, but not necessarily a rigid conviction in, the notion of fatalism.     

Regulation of cytoplasmic mRNA decay

Discoveries made over the past 20 years highlight the importance of mRNA decay as a means of modulating gene expression and thereby protein production. Up until recently, studies largely focused on identifying cis-acting sequences that serve as mRNA stability or instability elements, the proteins that bind these elements, how the process of translation influences mRNA decay and the ribonucleases that catalyse decay. Now, current studies have begun to elucidate how the decay process is regulated. This Review examines our current understanding of how mammalian cell mRNA decay is controlled by different signalling pathways and lays out a framework for future research.