Microarray-Based Transcriptomic Analysis of Differences between Long-Term Gregarious and Solitarious Desert Locusts

Desert locusts (Schistocerca gregaria) show an extreme form of phenotypic plasticity and can transform between a cryptic solitarious phase and a swarming gregarious phase. The two phases differ extensively in behavior, morphology and physiology but very little is known about the molecular basis of these differences. We used our recently generated Expressed Sequence Tag (EST) database derived from S. gregaria central nervous system (CNS) to design oligonucleotide microarrays and compare the expression of thousands of genes in the CNS of long-term gregarious and solitarious adult desert locusts. This identified 214 differentially expressed genes, of which 40% have been annotated to date. These include genes encoding proteins that are associated with CNS development and modeling, sensory perception, stress response and resistance, and fundamental cellular processes. Our microarray analysis has identified genes whose altered expression may enable locusts of either phase to deal with the different challenges they face. Genes for heat shock proteins and proteins which confer protection from infection were upregulated in gregarious locusts, which may allow them to respond to acute physiological challenges. By contrast the longer-lived solitarious locusts appear to be more strongly protected from the slowly accumulating effects of ageing by an upregulation of genes related to anti-oxidant systems, detoxification and anabolic renewal. Gregarious locusts also had a greater abundance of transcripts for proteins involved in sensory processing and in nervous system development and plasticity. Gregarious locusts live in a more complex sensory environment than solitarious locusts and may require a greater turnover of proteins involved in sensory transduction, and possibly greater neuronal plasticity

A Conceptual Model for a Human Resource Center for Voluntarism

The increase in voluntary activities in both public and private sectors of the U.S.A. has begun to make it clear that information is needed concerning models for new or different ways of working with people in volunteer agencies. This study attempted to develop a model for a Human Resource Center for Voluntarism which began with three objectives. They were to: 1. stimulate and/or provide avenues for closer working relationships among existing agencies and organizations involving volunteers, 2. broaden the base of citizen participation in community services, 3. reinforce the relationship between adult education and community service by allowing for individual growth and task completion as interdependent goals. Fundamental statements underlying the purpose for developing a Model included the following: 1. Involvement of citizen volunteers is a valuable facet of the American cultural heritage, and is unique in its application. 2. An adult\u27s responsibility as a citizen is to become involved in the community to work toward improvements for all individuals. 3. Education is the principal avenue by which this can be accomplished becasue: (a) learning results in behavior change, (b) behavior change is necessary for cultural growth and progress. From this, a Model was developed which described in general terms what tones, atmosphere, and relationships were necessary to achieve the goals. In addition, a proposal was made for more specific details for the requirements of the Directing Group and its components. Data for the study was obtained from documented literature primarily from 1960 to 1970, as well as personal experiences of both the writer and many colleagues in the field of voluntary community service agencies. The writer concluded that the proposed Center could have some lasting, positive effects on a community by being both a model for other community service agencies as well as an action agency which could develop innovative and experimental ways of work

Impaired clock output by altered connectivity in the circadian network

Substantial progress has been made in elucidating the molecular processes that impart a temporal control to physiology and behavior in most eukaryotes. In Drosophila, dorsal and ventral neuronal networks act in concert to convey rhythmicity. Recently, the hierarchical organization among the different circadian clusters has been addressed, but how molecular oscillations translate into rhythmic behavior remains unclear. The small ventral lateral neurons can synchronize certain dorsal oscillators likely through the release of pigment dispersing factor (PDF), a neuropeptide central to the control of rhythmic rest-activity cycles. In the present study, we have taken advantage of flies exhibiting a distinctive arrhythmic phenotype due to mutation of the potassium channel slowpoke (slo) to examine the relevance of specific neuronal populations involved in the circadian control of behavior. We show that altered neuronal function associated with the null mutation specifically impaired PDF accumulation in the dorsal protocerebrum and, in turn, desynchronized molecular oscillations in the dorsal clusters. However, molecular oscillations in the small ventral lateral neurons are properly running in the null mutant, indicating that slo is acting downstream of these core pacemaker cells, most likely in the output pathway. Surprisingly, disrupted PDF signaling by slo dysfunction directly affects the structure of the underlying circuit. Our observations demonstrate that subtle structural changes within the circadian network are responsible for behavioral arrhythmicity

A DNA Element Regulates Drug Tolerance and Withdrawal in Drosophila

Drug tolerance and withdrawal are insidious responses to drugs of abuse; the first increases drug consumption while the second punishes abstention. Drosophila generate functional tolerance to benzyl alcohol sedation by increasing neural expression of the slo BK-type Ca(2+) activated K(+) channel gene. After drug clearance this change produces a withdrawal phenotype—increased seizure susceptibility. The drug-induced histone modification profile identified the 6b element (60 nt) as a drug responsive element. Genomic deletion of 6b produces the allele, slo (Δ6b), that reacts more strongly to the drug with increased induction, a massive increase in the duration of tolerance, and an increase in the withdrawal phenotype yet does not alter other slo-dependent behaviors. The 6b element is a homeostatic regulator of BK channel gene expression and is the first cis-acting DNA element shown to specifically affect the duration of a drug action