Although radiation effects have been extensively studied, the biological effects of low-dose radiation (LDR) are controversial. This study investigates LDR-induced alterations in locomotive behavior and gene expression profiles of Drosophila melanogaster. We measured locomotive behavior using larval pupation height and the rapid iterative negative geotaxis (RING) assay after exposure to 0.1 Gy ...

Chaser (Csr) was uncovered in a gamma mutagenesis screen to identify genes that modify the larval foraging behavior of sitters to rovers. Rover larvae have significantly longer path lengths than sitters while foraging on a yeast and water paste. This difference is influenced by one major gene, foraging (for), which has two naturally occurring alleles, forR (rover) and fors (sitter). In a mutage...

Understanding the behavior of pests targeted with Bacillus thuringiensis Berliner (Bt) crops is important to define resistance management strategies. Particularly the study of larval movement between plants is important to determine the feasibility of refuge configurations. Exposure to Bt maize, Zea mays L. (Poaceae), has been suggested to increase larval movement in lepidopteran species but fe...

The rover/sitter polymorphism in Drosophila melanogaster larval behaviour is a unique example of a genetically determined, naturally occurring behavioural polymorphism. Allelic variation at the foraging locus (for) accounts for the rover (long foraging paths) and sitter (short foraging paths) phenotypes. We previously developed lethal tagging and used deficiency mapping to place for in the 24A3...

Dispersal heterogeneity is an important process that can compensate for downstream advection, enabling aquatic organisms to persist or spread upstream. Our main focus was the effect of year-to-year variation in larval dispersal on invasion spread rate. We used the green crab, Carcinus maenas, as a case study. This species was first introduced over 200 years ago to the east coast of North Americ...

The evolution of foraging in Drosophila melanogaster (Meigen) is studied using outbred populations that had been differentiated using laboratory selection. The foraging behaviour of Drosophila larvae is measured using the foraging path length of 72-h-old larvae. The foraging path length is the distance travelled by foraging larvae over 5 min. Populations of Drosophila selected for rapid develop...

Nuclei were isolated by an aqueous detergent method from Drosophila prepupal salivary glands, and measured by integrating interference microscopy. There was a highly significant correlation between nuclear volume and dry mass. Dry masses fell into 2, 3 or 4 distinct groups corresponding to polytene replication classes; the mean of a given dry mass group was between 8 and 30% less than twice tha...

The exaggerated weapons and ornaments of sexual selection are condition-dependent traits that often grow to exaggerated proportions. The horns of male rhinoceros beetles are extremely sensitive to the larval nutritional environment and are used by rival males in combat over access to females. In contrast to horns, other parts of the body, such as wings, eyes, and legs, scale proportionally with...

In Drosophila larvae, growth and developmental timing are regulated by nutrition in a tightly coordinated fashion. The networks that couple these processes are far from understood. Here, we show that the intestine responds to nutrient availability by regulating production of a circulating lipoprotein-associated form of the signaling protein Hedgehog (Hh). Levels of circulating Hh tune the rates...