ABSTRACT
The Drosophila system has been invaluable in providing important insights into mesoderm specification, muscle specification, myoblast fusion, muscle differentiation, and myofibril assembly. Here, we present a series of Drosophila protocols that enable the researcher to visualize muscle precursors and differentiated muscles, at all stages of development. In doing so, we also highlight the variety of techniques that are used to create these findings. These protocols are directly used for the Drosophila system, and are provided with explanatory detail to enable the researcher to apply them to other systems.
Subject(s)
Drosophila melanogaster/embryology , Drosophila melanogaster/growth & development , Muscle Development , Muscle, Skeletal/embryology , Muscle, Skeletal/growth & development , Animals , Body Patterning/physiology , Embryo, Nonmammalian/metabolism , Genes, Reporter/genetics , Immunohistochemistry/methods , In Situ Hybridization/methods , Larva/metabolism , Microscopy, Fluorescence , Staining and LabelingABSTRACT
College males completed a survey that asked open-ended questions concerning instances in which they might have been tempted to use force to obtain sexual contact with another person. Participants also completed Malamuth's (1989a, 1989b) Attraction to Sexual Aggression scale, Mosher and Sirkin's (1984) Hypermasculinity Inventory. and Burt's (1980) Rape Myth Acceptance and Adversarial Sexual Beliefs scales. Of the 83 participants, 22 (27%) reported that they had been tempted to use force. Participants that indicated they had been tempted to use force scored significantly higher on attraction to sexual aggression and hypermasculinity than those who were never tempted. Reasons for temptation, circumstances of the tempting situations, and possible ties to sexual coercion were explored.
Subject(s)
Aggression/psychology , Coercion , Dominance-Subordination , Rape/psychology , Sexual Partners/psychology , Adult , Coitus/psychology , Courtship , Humans , Interpersonal Relations , Male , Midwestern United States , Risk Factors , Surveys and Questionnaires , Young AdultABSTRACT
A complex regulatory cascade is required for normal cardiac development, and many aspects of this network are conserved from Drosophila to mammals. In Drosophila, the seven-up (svp) gene, an ortholog of the vertebrate chick ovalbumin upstream promoter transcription factors (COUP-TFI and II), is initially activated in the cardiac mesoderm and is subsequently restricted to cells forming the cardiac inflow tracts. Here, we investigate svp regulation in the developing cardiac tube. Using bioinformatics, we identify a 1007-bp enhancer of svp which recapitulates its entire expression in the embryonic heart and other mesodermal derivatives, and we show that this enhancer is initially activated by the NK homeodomain factor Tinman (Tin) via two conserved Tin binding sites. Mutation of the Tin binding sites significantly reduces enhancer activity both during normal development and in response to ectopic Tin. This is the first identification of an enhancer for the complex svp gene, demonstrating the effectiveness of bioinformatics tools in assisting in unraveling transcriptional regulatory networks. Our studies define a critical component of the svp regulatory cascade and place gene regulatory events in direct apposition to the formation of critical cardiac structures.
Subject(s)
DNA-Binding Proteins/physiology , Drosophila Proteins/physiology , Drosophila/metabolism , Enhancer Elements, Genetic , Receptors, Steroid/physiology , Repressor Proteins/physiology , Trans-Activators/physiology , Transcriptional Activation , Animals , Base Sequence , Cardiovascular System/embryology , DNA-Binding Proteins/genetics , Drosophila/embryology , Drosophila/genetics , Drosophila Proteins/genetics , Mesoderm/metabolism , Molecular Sequence Data , Mutation , Receptors, Steroid/genetics , Repressor Proteins/genetics , Trans-Activators/geneticsABSTRACT
The linear cardiac tube of Drosophila, the dorsal vessel, is an important model organ for the study of cardiac specification and patterning in vertebrates. In Drosophila, the Hox segmentation gene abdominal-A (abd-A) is required for the specification of a functionally distinct heart region at the posterior of the dorsal vessel, from which blood is pumped anteriorly through a tube termed the aorta. Since we have previously shown that the posterior part of the aorta is specified during embryogenesis to form the adult heart during metamorphosis, we determined if the embryonic aorta is also patterned by the function of Hox segmentation genes. Using gain- and loss-of-function experiments, we demonstrate that the three Hox genes expressed in the posterior aorta and heart are sufficient to confer heart or posterior aorta fate throughout the dorsal vessel. Additionally, we demonstrate that Ultrabithorax and abd-A, but not Antennapedia, function to control cell number in the dorsal vessel. These studies add robustness to the model that homeotic selector genes pattern the Drosophila dorsal vessel, and further extend our understanding of how the cardiac tube is patterned in animal models.
