HEAT-SHOCK ACTIVATION OF TELOMERIC SEQUENCES IN DIFFERENT TISSUES OF CHIRONOMUS-THUMMI

The heat shock transcription factor (HSF) has been found by immunocyto chemistry using the Drosophila HSF antibody at T-BRIII, a telomeric he at shock-induced puff in polytene chromosomes of Chironomus thummi sal ivary glands. Other heat shock-activated loci were also positively sta ined by the antibody. Neither the telomeres nor other heat shock loci were labeled under control conditions. These results support the prese nce of a heat shock gene at T-BRIII despite its peculiar location and molecular organization, different from other well-characterized heat s hock genes in Diptera. This locus is similarly induced and transcribed under heat shock in Malpighian tubules, another larval polytenic tiss ue. Transcription from telomeric-associated sequences has also been fo und in control polytenic and diploid tissues. The meaning of transcrip tion and heat shock activation of telomeric sequences is discussed in relation to the organization of telomeres and compared to possible equ ivalents in other known heat shock loci. (C) 1994 Academic Press, Inc.