0000000000280154
AUTHOR
L. M. Botella
Analysis of male recombination in third chromosomes of Drosophila melanogaster
Data on male recombination in twenty third-chromosomal lines of Drosophila melanogaster are presented. Frequencies of female and male recombination have been calculated in seven intervals along the third chromosome. The influence on male recombination (M.R.) exercised by different factors such as population origin (cellar, vineyard), the presence of heterozygous inversions and recessive lethal chromosomes, is analyzed. The results obtained lead to the main conclusion that M.R. is not affected by the presence of heterozygous inversions which reduce female recombination in the same lines. In the light of this effect, the possible mechanism operating on male recombination is discussed. Lethal …
Larva-to-adult and pupa-to-adult mortality dynamics in crowded cultures ofDrosophila melanogaster
Pupal mortality is shown here to bear the main responsibility for total mortality duringDrosophila melanogaster development in crowded conditions. The dynamics of the pupa-to-adult and larva-to-adult processes of mortality follows a S-shaped logistic model, like survival in density-dependent processes. Data given here confirm to some extent Wallace's suggestion that pupal mortality is a density-dependent process.
Effect of conditioned media on three genotypes ofDrosophila melanogaster: Physical, chemical, and biological aspects
The uric acid contents in larvae, pupae, and culture media were studied during larval and pupal development in three genotypes of Drosophila melanogaster reared in both crowded and noncrowded conditions. The uric acid content and the response of genotypes in media supplemented with 10 and 15 mg/ml of uric acid were correlated with the outcome obtained in conditioned media. In addition, the behavior of genotypes in conditioned media is explained in terms of the physicochemical properties of the conditioned media, which include uric acid content, the amount of food ingested, the degree of free water, the physical disturbance within the cultures, and the particular response of each genotype to…
Larval Arrest in Development of Tribolium castaneum (Coleoptera: Tenebrionidae)
Arrested larval development (in the last larval instar) of part of the total larval population has been detected in moderately crowded situations (40 larvae in 2 g food) in Tribolium castaneum (Herbst) cultures This phenomenon is the same found previously in highly crowded cultures of Drosophila melanogaster (Meigen) and other related species. The arrest may be viewed as a mechanism of physiological adaptation of organisms to competitive situations.