Articles written in Proceedings – Animal Sciences
Volume 88 Issue 2 April 1979 pp 153-162
Quantitative changes in DNA, RNA and protein during the entire developmental period—including embryogenesis, larval and pupal stages — in the house-fly were determined. The development of housefly from egg to adult takes around 8·5 days at 35 ± 1° C. During the course of embryonic development toal RNA and protein decreased. On the other hand, total DNA increased and registered peak value in 4 hr old eggs. The calorific content of the developing eggs showed a decrease from 5649 cal/g dry weight to 5361 cal/g dry weight indicating the utility of energy reserves during embryonic development. Matured larvae registered high calorific content (6260 cal/g dry weight).
The ratios of DNA/DW (dry weight), RNA/DW, Protein/DW, RNA/DNA and DNA/protein were determined from the data obtained to serve as biochemical indices of changes in development. Protein/DW levels showed variations during larval and pupal stages, increased levels being correlated with the synthesis of new cuticle, etc., prior to ecdysis and the histogenesis of adult tissue prior to emergence. RNA/DW levels were highest in the young larvae but declined rapidly during development. Sharp increase was also noticed in pupal stage. DNA/DW levels were very low in the egg but reached highest level in the larvae just emerged and then declined during further development. RNA/DNA ratio was high in the egg and in the larvae between 30–60 hr of development.