@article {45730, title = {Preparation and mounting of adult Drosophila structures in Canada balsam.}, journal = {Cold Spring Harb Protoc}, volume = {2012}, year = {2012}, month = {2012 Mar}, pages = {373-5}, abstract = {

The Drosophila cuticle carries a rich array of morphological details. Thus, cuticle examination has had a central role in the history of genetics. To prepare fine "museum-quality," permanent slides, it is best to mount specimens in Canada Balsam. It is difficult to give precise recipes for Canada Balsam, because every user seems to prefer a slightly different viscosity. Dilute solutions spread easily and do not dry too rapidly while mounting specimens. The disadvantage is that there is actually less Balsam in a "drop" of the solution, and when dried, it can contract from the sides of the coverslip, sometimes disturbing the specimen. Unfortunately, there is no substitute for experience when using Canada Balsam. This protocol describes a procedure for mounting adult cuticles in Canada Balsam.

}, keywords = {Animals, Balsams, Drosophila, Microscopy, Preservation, Biological, Specimen Handling}, issn = {1559-6095}, doi = {10.1101/pdb.prot067389}, author = {Stern, David L and Sucena, Elio} } @article {45731, title = {Rapid mounting of adult Drosophila structures in Hoyer{\textquoteright}s medium.}, journal = {Cold Spring Harb Protoc}, volume = {2012}, year = {2012}, month = {2012 Jan}, pages = {107-9}, abstract = {

The Drosophila cuticle carries a rich array of morphological details. Thus, cuticle examination has had a central role in the history of genetics. This protocol describes a procedure for mounting adult cuticles in Hoyer{\textquoteright}s medium, a useful mountant for both larval and adult cuticles. The medium digests soft tissues rapidly, leaving the cuticle cleared for observation. In addition, samples can be transferred directly from water to Hoyer{\textquoteright}s medium. However, specimens mounted in Hoyer{\textquoteright}s medium degrade over time. For example, the fine denticles on the larval dorsum are best observed soon after mounting; they begin to fade after 1 week, and can disappear completely after several months. More robust features, such as the ventral denticle belts, will persist for a longer period of time. Because adults cannot profitably be mounted whole in Hoyer{\textquoteright}s medium, some dissection is necessary.

}, keywords = {Animals, Drosophila, Integumentary System, Specimen Handling}, issn = {1559-6095}, doi = {10.1101/pdb.prot067371}, author = {Stern, David L and Sucena, Elio} } @article {45732, title = {Preparation of cuticles from feeding Drosophila larvae.}, journal = {Cold Spring Harb Protoc}, volume = {2011}, year = {2011}, month = {2011 Nov}, pages = {1394-8}, abstract = {

The Drosophila cuticle carries a rich array of morphological details. Thus, cuticle examination has had a central role in the history of genetics. Studies of the Drosophila cuticle have focused mainly on first-instar larvae and adult cuticular morphology. Although the cuticles of second- and third-instar larvae are strikingly different from those of the first instar, these differences have been poorly studied. This protocol describes three methods for preparing cuticles from fed larvae. One commonly used procedure involves manually pricking the larvae. A simpler method for preparing larval cuticles is to burst the larvae once they have been mounted. This method is used for first- and second-instar larvae and does not require pricking; it removes the gut contents by "popping" the rear of the embryo using pressure from the coverslip. If just the right amount of medium is used, the coverslip will be pulled toward the slide, applying pressure on the samples. The larvae usually burst from their posterior ends. Also presented is an alternative procedure designed specifically for the use with third-instar larvae, although the "pricking" method can be used at this stage.

}, keywords = {Animals, Dissection, Drosophila, Entomology, Female, Integumentary System, Larva}, issn = {1559-6095}, doi = {10.1101/pdb.prot066498}, author = {Stern, David L and Sucena, Elio} } @article {45733, title = {Preparation of cuticles from unhatched first-instar Drosophila larvae.}, journal = {Cold Spring Harb Protoc}, volume = {2011}, year = {2011}, month = {2011 Sep}, abstract = {

The finely sculpted cuticle of Drosophila carries a rich array of morphological details. Thus, cuticle examination has had a central role in the history of genetics. Studies of the Drosophila cuticle have focused mainly on first-instar larvae and adult cuticular morphology. This protocol describes the preparation of cuticles from larvae that have not yet hatched from the egg. It is designed for sampling all eggs laid by one or more females. This can be particularly useful, for example, when a mutation produces embryos that are unable to hatch from the egg.

}, keywords = {Animals, Drosophila, Entomology, Female, Integumentary System, Larva}, issn = {1559-6095}, doi = {10.1101/pdb.prot065532}, author = {Stern, David L and Sucena, Elio} } @article {45762, title = {Regulatory evolution of shavenbaby/ovo underlies multiple cases of morphological parallelism.}, journal = {Nature}, volume = {424}, year = {2003}, month = {2003 Aug 21}, pages = {935-8}, abstract = {

Cases of convergent evolution that involve changes in the same developmental pathway, called parallelism, provide evidence that a limited number of developmental changes are available to evolve a particular phenotype. To our knowledge, in no case are the genetic changes underlying morphological convergence understood. However, morphological convergence is not generally assumed to imply developmental parallelism. Here we investigate a case of convergence of larval morphology in insects and show that the loss of particular trichomes, observed in one species of the Drosophila melanogaster species group, has independently evolved multiple times in the distantly related D. virilis species group. We present genetic and gene expression data showing that regulatory changes of the shavenbaby/ovo (svb/ovo) gene underlie all independent cases of this morphological convergence. Our results indicate that some developmental regulators might preferentially accumulate evolutionary changes and that morphological parallelism might therefore be more common than previously appreciated.

}, keywords = {Animals, Biological Evolution, DNA-Binding Proteins, Drosophila, Drosophila Proteins, Gene Expression Regulation, Developmental, Genes, Insect, Larva, Molecular Sequence Data, Morphogenesis, Phylogeny, RNA, Messenger, Transcription Factors}, issn = {1476-4687}, doi = {10.1038/nature01768}, author = {Sucena, Elio and Delon, Isabelle and Jones, Isaac and Payre, Fran{\c c}ois and Stern, David L} }