In Drosophila melanogaster , an increase in ecdysone concentration induces the expression of genes coding for proteins that the larva requires .
Increase causes chromosome puffs ( sites of high expression ) to form in polytene chromosomes .
In Drosophila melanogaster , an increase in ecdysone concentration induces the expression of genes coding for proteins that the larva requires , and it causes chromosome puffs ( sites of high expression ) to form in polytene chromosomes .