The Elongin Complex Antagonizes the Chromatin Factor Corto for Vein versus Intervein Cell Identity in Drosophila Wings

Abstract

Drosophila wings mainly consist of two cell types, vein and intervein cells. Acquisition of either fate depends on specific expression of genes that are controlled by several signaling pathways. The nuclear mechanisms that translate signaling into regulation of gene expression are not completely understood, but they involve chromatin factors from the Trithorax (TrxG) and Enhancers of Trithorax and Polycomb (ETP) families. One of these is the ETP Corto that participates in intervein fate through interaction with the Drosophila EGF Receptor – MAP kinase ERK pathway. Precise mechanisms and molecular targets of Corto in this process are not known. We show here that Corto interacts with the Elongin transcription elongation complex. This complex, that consists of three subunits (Elongin A, B, C), increases RNA polymerase II elongation rate in vitro by suppressing transient pausing. Analysis of phenotypes induced by EloA, B, or C deregulation as well as genetic interactions suggest that the Elongin complex might participate in vein vs intervein specification, and antagonizes corto as well as several TrxG genes in this process. Chromatin immunoprecipitation experiments indicate that Elongin C and Corto bind the vein-promoting gene rhomboid in wing imaginal discs. We propose that Corto and the Elongin complex participate together in vein vs intervein fate, possibly through tissue-specific transcriptional regulation of rhomboid.

EPOP Functionally Links Elongin and Polycomb in Pluripotent Stem Cells

“…Instead, EPOP is a scaffold protein that serves as a bridging partner between the PRC2 and Elongin BC complexes. Indeed, a protein from D. melanogaster, Corto, interacts with PcG proteins and with Elongin BC (Rougeot et al, 2013), indicating that it might have a function similar to that of EPOP, but the proteins are not homologs. In evolutionary terms, EPOP is a young protein.…”

Physical linkage and mate preference generate linkage disequilibrium for behavioral isolation in two parapatric crickets

“…In D. melanogaster , both osa and the elongin complex contribute to wing vein patterning (Terriente‐Félix and de Celis ; Rougeot et al. ). Crickets produce song by rubbing specialized structures on the forewings together and wing vein patterns control the resonant properties and thus the resulting sound (Bennet‐Clark and Ewing ; Nocke ; Bennet‐Clark ).…”