Experimental Studies on the Duration of Life. X. The Duration of Life of Drosophila melanogaster in the Complete Absence of Food

1924 ◽  
Vol 58 (656) ◽  
pp. 193-218 ◽  
Author(s):  
Raymond Pearl ◽  
Sylvia L. Parker
Keyword(s):  
Drosophila Melanogaster ◽  
Experimental Studies

scholarly journals Sexual selection favours good or bad genes for pathogen resistance depending on males' pathogen exposure

2019 ◽  
Vol 286 (1902) ◽  
pp. 20190226 ◽  
Author(s):  
Patrick Joye ◽  
Tadeusz J. Kawecki
Keyword(s):  
Drosophila Melanogaster ◽  
Sexual Selection ◽  
Female Choice ◽  
Experimental Studies ◽  
Pathogen Resistance ◽  
Condition Dependence ◽  
Indirect Benefit ◽  
Intestinal Pathogen ◽  
Sexual Traits ◽  
Pathogen Exposure

Resistance to pathogens is often invoked as an indirect benefit of female choice, but experimental evidence for links between father's sexual success and offspring resistance is scarce and equivocal. Two proposed mechanisms might generate such links. Under the first, heritable resistance to diverse pathogens depends on general immunocompetence; owing to shared condition dependence, male sexual traits indicate immunocompetence independently of the male's pathogen exposure. By contrast, other hypotheses (e.g. Hamilton–Zuk) assume that sexual traits only reveal heritable resistance if the males have been exposed to the pathogen. The distinction between the two mechanisms has been neglected by experimental studies. We show that Drosophila melanogaster males that are successful in mating contests (one female with two males) sire sons that are substantially more resistant to the intestinal pathogen Pseudomonas entomophila —but only if the males have themselves been exposed to the pathogen before the mating contest. By contrast, sons of males sexually successful in the absence of pathogen exposure are less resistant than sons of unsuccessful males. We detected no differences in daughters’ resistance. Thus, while sexual selection may have considerable consequences for offspring resistance, these consequences may be sex-specific. Furthermore, contrary to the ‘general immunocompetence’ hypothesis, these consequences can be positive or negative depending on the epidemiological context under which sexual selection operates.

Experimental studies on development in Drosophila melanogaster. II. Regulation in the early egg

1936 ◽  
Vol 73 (1) ◽  
pp. 109-125 ◽  
Author(s):  
R. B. Howland ◽  
B. P. Sonnenblick
Keyword(s):  
Drosophila Melanogaster ◽  
Experimental Studies

scholarly journals Manipulating the Patterns of Mechanical Forces That Shape Multicellular Tissues

Physiology ◽  
2019 ◽  
Vol 34 (6) ◽  
pp. 381-391 ◽  
Author(s):  
R. Marisol Herrera-Perez ◽  
Karen E. Kasza
Keyword(s):  
Drosophila Melanogaster ◽  
Embryonic Development ◽  
Experimental Studies ◽  
Model Organism ◽  
Temporal Patterns ◽  
Epithelial Tissue ◽  
Mechanical Forces ◽  
Spatial And Temporal Patterns ◽  
Functional Tissue ◽  
Unstructured Groups

During embryonic development, spatial and temporal patterns of mechanical forces help to transform unstructured groups of cells into complex, functional tissue architectures. Here, we review emerging approaches to manipulate these patterns of forces to investigate the mechanical mechanisms that shape multicellular tissues, with a focus on recent experimental studies of epithelial tissue sheets in the embryo of the model organism Drosophila melanogaster.

A Theoretical Model for the Regulation of Sex-lethal, a Gene That Controls Sex Determination and Dosage Compensation in Drosophila melanogaster

Genetics ◽  
2003 ◽  
Vol 165 (3) ◽  
pp. 1355-1384
Author(s):  
Matthieu Louis ◽  
Liisa Holm ◽  
Lucas Sánchez ◽  
Marcelle Kaufman
Keyword(s):  
Drosophila Melanogaster ◽  
Theoretical Model ◽  
Sex Determination ◽  
Numerical Simulations ◽  
Cell Fate ◽  
Regulatory Gene ◽  
Experimental Studies ◽  
Formal Basis ◽  
Sex Lethal ◽  
Specific Regulation

Abstract Cell fate commitment relies upon making a choice between different developmental pathways and subsequently remembering that choice. Experimental studies have thoroughly investigated this central theme in biology for sex determination. In the somatic cells of Drosophila melanogaster, Sex-lethal (Sxl) is the master regulatory gene that specifies sexual identity. We have developed a theoretical model for the initial sex-specific regulation of Sxl expression. The model is based on the well-documented molecular details of the system and uses a stochastic formulation of transcription. Numerical simulations allow quantitative assessment of the role of different regulatory mechanisms in achieving a robust switch. We establish on a formal basis that the autoregulatory loop involved in the alternative splicing of Sxl primary transcripts generates an all-or-none bistable behavior and constitutes an efficient stabilization and memorization device. The model indicates that production of a small amount of early Sxl proteins leaves the autoregulatory loop in its off state. Numerical simulations of mutant genotypes enable us to reproduce and explain the phenotypic effects of perturbations induced in the dosage of genes whose products participate in the early Sxl promoter activation.

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