mirror, a Drosophila homeobox gene in the iroquois complex, is required for sensory organ and alula formation

Abstract

The Drosophila notum, the dorsal body wall of the thorax, is subdivided genetically into longitudinal domains (Calleja, M., Moreno, E., Pelaz, S. and Morata, G. (1996) Science 274, 252–255). Two homeobox genes clustered in the iroquois complex, araucan and caupolican, regulate proneural genes and are required for development of sensory bristles in the lateral notum (Gomez-Skarmeta, J. L., del Corral, R. D., de la Calle-Mustienes, E., Ferres-Marco, D. and Modolell, J. (1996) Cell 85, 95–105). An iroquois-related homeobox gene, mirror, was recently isolated and is localized close to the iroquois complex region (McNeil, H., Yang, C.-H., Brodsky, M., Ungos, J. and Simon, M. A. (1997) Genes and Development 11, 1073–1082; this study). We show that mirror is required for the formation of the alula and a subset of sensory bristles in the lateral domain of the notum. Genetic analysis suggests that mirror and the other iroquois genes interact to form the alula as well as the sensory organs. Based on similarities between mirror and the iroquois genes in their genetic map positions, expression, protein structure and function, mirror is considered a new member of the iroquois complex and is involved in prepatterning sensory precursor cells in the lateral notum.

A hierarchical transcription factor cascade regulates enteroendocrine cell diversity and plasticity in Drosophila

“…Mirr is a regulator for all class II subtypes, and a putative Pros binding region was found at about 1 kb upstream of the TSS site, close to the previously reported mirr B1-B12 -lacZ enhancer trap insertion site (Fig. 2m ) 26 . This reporter was specifically expressed in Tk + EEs, and similarly, its expression was readily abolished upon pros depletion (Fig.…”

mirrordetermines the far posterior domain in butterfly wings

“…1 (D) mirror RNAi knockdowns result in highly specific loss of the alula in D. melanogaster . 2 (E) Snodgrass’ model of the archetypal insect wing specifies three major domains along the anteroposterior axis: the remigium, the vannus, and the jugum. Homologies of these domains with the features of the dipteran wing (C), or butterfly wing pattern boundaries (A), has remained unclear.…”

“…We initially identified the transcription factor mirror as a potential candidate gene based on previous mRNA-seq studies, 12 coupled with D. melanogaster work showing that mirror specifies the alula – a small membranous lobe at the posterior base of the wing in some dipterans (Figure 1C,D). 2,13 We used in situ hybridization to visualize mirror mRNA localization in the last-instar imaginal discs of the common buckeye butterfly, Junonia coenia , and observed mirror expression throughout the wing domain posterior to the 2A vein boundary (Figures 2A and S1). This expression precisely marks the vannus, or anal region (Figure 1E), of the butterfly wing – a distinct posterior field of the wing blade populated by the anal (A) veins, and bordered anteriorly by the claval fold between the cubital (Cu) and A veins in the hindwing.…”

Correction: The Iroquois Complex Is Required in the Dorsal Mesoderm to Ensure Normal Heart Development in Drosophila

“…In the present study we wanted to determine the impact of the loss of Iro-C on heart development. We initially analyzed embryos that contain a deletion on the third chromosome (Df(3L)iro-2) that eliminates all three members of the Iro-C (ara, caup and mirr) [20,52,53]. The phenotypes of an additional deficiency line that lacks ara, caup and mirr (iro DFM3 ) [36] are shown in Figure S2.…”

“…The phenotypes of an additional deficiency line that lacks ara, caup and mirr (iro DFM3 ) [36] are shown in Figure S2. Since Ara and Caup have been indicated to act redundantly in different tissues, we chose a second mutant that lacks ara and caup but still expresses mirr (iro DFM1 ) [20,53,54]. To validate the contribution of ara and caup to the observed heart phenotypes we analyzed embryos with the genetic background Df(3L)iro-2/iro DFM1 .…”