PT  - JOURNAL ARTICLE
AU  - Russell, Steven R. H.
AU  - Heimbeck, Gertrud
AU  - Goddard, Catherine M.
AU  - Carpenter, Adelaide T. C.
AU  - Ashburner, Michael
TI  - The Drosophila <em>Eip78C</em> Gene Is Not Vital But Has a Role in Regulating Chromosome Puffs
DP  - 1996 Sep 01
TA  - Genetics
PG  - 159--170
VI  - 144
IP  - 1
4099  - http://www.genetics.org/content/144/1/159.short
4100  - http://www.genetics.org/content/144/1/159.full
SO  - Genetics1996 Sep 01; 144
AB  - We have generated a number of chromosomal aberrations that disrupt the early-late ecdysone-induced 78C puff gene (Eip78C, ecdysone-induced protein, FlyBase name for the E78 gene of Stone and Thummel 1993), which encodes the two members of the nuclear hormone receptor superfamily Eip78C-A and Eip78C-B. The aberrations include deletions of the ligand-binding/dimeriization domain of both, inversions that split Eip78C-A but retain residual Eip78C-B expression, and a small deletion specific for Eip78C-B. We find that wild-type Eip78C functions are completely dispensable for normal development under laboratory conditions. However, we show that Eip78C-B is required for the maximal puffing activity of a subset of late puffs (63E and 82F) since these puffs are reduced in size in Eip78C-B mutant backgrounds. Paradoxically the same late puffs are reduced, as well as at least one other, when the Eip78C-B cDNA is overexpressed from a heat shock promoter. These data indicate either that Eip78C function is redundant or that it plays a subtle modulating role in the regulation of chromosome puffing.