wing blister, a new Drosophila laminin alpha chain required for cell adhesion and migration during embryonic and imaginal development

Genetic control of epithelial cell polarity: lessons from Drosophila

The cell biology of polarized epithelial cells is a field of major interest to cell and developmental biologists. In addition to the study of epithelial cells in tissue culture, genetically tractable systems have been employed to examine the functional importance of individual molecules. Here I review recent progress that has been made using Drosophila as a model system to study apical-basal epithelial cell polarity. In this system, a large number of genes have been identified that are essential for the development and maintenance of the apical-basal polarity of epithelial cells in different developmental contexts. In this article, the recent progress in three models, i.e., establishment of the ectoderm and midgut epithelia during embryogenesis, epithelial polarity of imaginal discs, and epithelial development of the follicle cells during oogenesis will be discussed.

An exploration of the sequence of a 2.9-Mb region of the genome of Drosophila melanogaster: the Adh region

A contiguous sequence of nearly 3 Mb from the genome of Drosophila melanogaster has been sequenced from a series of overlapping P1 and BAC clones. This region covers 69 chromosome polytene bands on chromosome arm 2L, including the genetically well-characterized "Adh region." A computational analysis of the sequence predicts 218 protein-coding genes, 11 tRNAs, and 17 transposable element sequences. At least 38 of the protein-coding genes are arranged in clusters of from 2 to 6 closely related genes, suggesting extensive tandem duplication. The gene density is one protein-coding gene every 13 kb; the transposable element density is one element every 171 kb. Of 73 genes in this region identified by genetic analysis, 49 have been located on the sequence; P-element insertions have been mapped to 43 genes. Ninety-five (44%) of the known and predicted genes match a Drosophila EST, and 144 (66%) have clear similarities to proteins in other organisms. Genes known to have mutant phenotypes are more likely to be represented in cDNA libraries, and far more likely to have products similar to proteins of other organisms, than are genes with no known mutant phenotype. Over 650 chromosome aberration breakpoints map to this chromosome region, and their nonrandom distribution on the genetic map reflects variation in gene spacing on the DNA. This is the first large-scale analysis of the genome of D. melanogaster at the sequence level. In addition to the direct results obtained, this analysis has allowed us to develop and test methods that will be needed to interpret the complete sequence of the genome of this species. Before beginning a Hunt, it is wise to ask someone what you are looking for before you begin looking for it. Milne 1926