Patterns of puffing activity in the salivary gland polytene chromosomes ofthe medfly Ceratitis capitata, during larval and prepupal development

The patterns of puffing activity in the salivary gland polytene chromosomes have been studied during the late larval and prepupal stages of the medfly Ceratitis capitata. A total of 128 loci, with significant changes in puffi ng activity during this developmental period, were assigned to the five aut osomes of the medfly. Two waves of puffing activity were observed, the firs t during the late larval stage and the second during the prepupal developme nt. Overall puffing activity can be divided into four groups, group-IV acti vity being most conspicuous with 58 active loci. The major changes in puffi ng activity take place around jumping, a characteristic event occurring abo ut 6 h before puparium formation, at puparium formation, and during midprep upal development. The overall puffing activity shows a positive correlation to the ecdysone titer in the hemolymph, suggesting that most of the change s in the activity of the puffs during the late larval and prepupal stages o f the medfly may be regulated by ecdysone.