Genetic analysis of maternal information in Drosophila

Abstract

EMBRYONIC development is controlled by the information carried by the gametes of the zygote's parents. However, although the chromosomal information is similar in both gametes the oocyte also provides a structural frame (determining embryonic axes), determinants in the cortex and a metabolic pool to support early embryonic events (see ref. 1). The active transcription of thousands of DNA loops in the lampbrush chromosomes of amphibian oocytes suggests that the egg contains transcripts of a large fraction of the genome2. In sea urchin oocytes the mRNA complexity might account for the synthesis of several thousands of different protein species3,4. Genetic analysis should help to establish the functional meaning of the information present in the oocytes for embryonic development. In this study we have analysed the effect of chromosome deletions on the development of Drosophila embryos. The results indicate that the products of a large proportion of the maternal genome, present in the oocyte, are sufficient and necessary for epidermal morphogenesis and differentiation in the embryo.