. "\"A swelling at a site along the length of a polytene chromosome, thought to be the site of active transcription.\" [GOC:bf, ISBN:0120649012]" . . "polytene chromosome puff" . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .