Phase Contrast Microscopy of Live Testes

This is the first technique to apply when asking the question Why are my mutant males sterile Because the key stages of spermatogenesis have a very distinctive appearance in wild-type testes (see Fig. 1), it is relatively easy to look at a squash and preliminarily classify the mutant based on the morphologies observed. Table 1 gives a key to the types of defects you may observe these give clues as to what cytological process may be affected and, therefore, will direct your future experiments....

Drosophila Cytogenetics Early Milestones

Sutton's 1903 landmark paper, The Chromosomes in Heredity (5 see also ref. 6), in which he pointed out that the behavior of chromosomes in meiosis parallels the observed patterns of inheritance of Mendelian traits, is considered to mark the beginning of the field of cytogenetics (the actual term would be coined years later). Before then, cytology with its focus on animals specimens, and genetics, which consisted of breeding experiments involving mainly plants, had been separate areas of inquiry...

Oogenesis and Development of Nurse Cells

Oogenesis Drosophila

Each of the two paired ovaries of the adult Drosophila female consists of a cluster of parallel ovarioles, where egg chambers are lying in a single-file arrangement (see Fig. 1A,B). Each egg chamber contains a branching chain of 16 interconnected cystocytes formed by mitotic division of a germarial cystoblast (2). Fifteen of the cystocytes differentiate into endopolyploid nurse cells (NCs) (see Fig. 1C). The function of these germ-line-derived cells is to synthesize RNA and protein molecules,...

References

C., and Ripoll, P. (1978) The utilization during mitotic cell division of loci controlling meiotic recombination and disjunction in Drosophila melanogaster. Genetics 90, 531-578. 2. Baker, B. S. and Smith, D. A. (1979) The effects of mutagen-sensitive mutants of Drosophila melanogaster in nonmutagenized cells. Genetics 92, 833-847. 3. Szabad, J. and Bryant, P. J. (1982) The mode of action of discless mutations in Drosophila melanogaster. Dev. Biol. 93, 240-256. 4....

Mekkara Mandaravally Madhavan and Kornath Madhavan 1 Introduction

Abdomen Cuticle Clefts Drosophila

The epidermal cells, a derivative of ectoderm during embryogenesis of insects, contribute to the distinct cuticular pattern and form of the different stages that appear during their ontogeny. The type of cuticular products is the result of gene expression of the individual epidermal cells that lie immediately underneath these outgrowths 1 . In hemimetabolous insects, the larval epidermal cells LECs present at the time of hatching from the egg and their descendants are responsible for the...