Characterization and developmental expression of a Drosophila ras oncogene

Area of Science:

• Molecular Biology
• Genetics
• Developmental Biology

Background:

• Ras genes are crucial proto-oncogenes involved in cell signaling pathways across eukaryotes.
• Understanding ras gene evolution and function in model organisms like Drosophila melanogaster provides insights into conserved biological processes.

Purpose of the Study:

• To clone and characterize a Drosophila melanogaster ras gene (Dmras64B) based on homology to the Harvey murine sarcoma virus ras oncogene.
• To investigate the genetic location, sequence homology, and expression patterns of Dmras64B.

Main Methods:

• Gene cloning using homology to a known ras oncogene.
• Chromosomal mapping to determine gene location.
• DNA sequencing to analyze the gene's coding region and intron-exon structure.
• RNA analysis to identify and quantify expressed transcripts.

Main Results:

• The Drosophila melanogaster ras gene, Dmras64B, was successfully cloned and mapped to chromosomal position 64B.
• Dmras64B exhibits extensive amino acid homology with human and Saccharomyces cerevisiae ras proteins.
• The gene contains two introns, differently positioned compared to its human homolog.
• Dmras64B encodes three distinct RNA transcripts (1.6, 2.1, and 2.6 kb) that are constitutively expressed during fly development.

Conclusions:

• Dmras64B is a conserved ras gene in Drosophila melanogaster with structural similarities to mammalian and yeast counterparts.
• The constitutive expression of Dmras64B throughout development suggests a fundamental role in essential cellular functions in flies.