dMi-2, a Hunchback-Interacting Protein That Functions in Polycomb Repression

Abstract

Early in Drosophila embryogenesis, gap gene products directly repress transcription of homeotic (HOX) genes and thereby delimit HOX expression domains. Subsequently, Polycomb-group proteins maintain this repression. Currently, there is no known molecular link between gap and Polycomb-group proteins. Here, dMi-2 is identified as a protein that binds to a domain in the gap protein Hunchback that is specifically required for the repression of HOX genes. Genetic analyses show that dMi-2 participates in both Hunchback and Polycomb repression in vivo. Hence, recruitment of dMi-2 may serve as a link between repression of HOX genes by Hunchback and Polycomb proteins.

Parental RNA interference of genes involved in embryonic development of the western corn rootworm, Diabrotica virgifera virgifera LeConte

“…Since the functions of chromatin remodelers confer epigenetic effects that lead to stable changes in gene expression, short-term exposure to dsRNA in the ovary or in the embryo may lead to long-lasting RNAi-induced phenotype. Mutations in other members of the chromatin remodeler gene group are known to have gametogenic and/or embryonic effects in fruit flies (Daubresse et al, 1999;Deuring et al, 2000;Kehle et al, 1998;McDaniel et al, 2008); it remains to be seen if these genes would also serve as efficacious pRNAi targets for pest insect control. The ability of western corn rootworm to develop resistance to crop protection chemistries (Gray et al, 2009;Narva et al, 2013) and transgenic insect resistance traits based on Bt proteins (Gassmann et al, 2011) creates the need for new approaches to corn rootworm control to combine with existing technology.…”

Use of chromatin remodeling ATPases as RNAi targets for parental control of western corn rootworm (Diabrotica virgifera virgifera) and Neotropical brown stink bug (Euschistus heros)

“…In Drosophila, chromatin remodeling ATPases are known to have roles in both oogenesis and development. The Drosophila chromatin remodeling ATPases that are essential for oogenesis include Iswi (Deuring et al, 2000), Chd1 (McDaniel et al, 2008), Mi-2 (Kehle et al, 1998), and possibly Brm (He et al, 2014). In addition to oviposition defects, it was reported that the lack of maternal iswi leads to developmental arrest in an early stage of oogenesis (Deuring et al, 2000).…”

Interplay between chromatin remodelers and protein arginine methyltransferases

“…In Drosophila, CHD mutants arrest in the first or second larval stage of development, suggesting that CHD ATPases are essential for normal fly development (Khattak et al, 2002). Genetic studies have established a link between the Drosophila Mi-2 complex and hunchback, which can repress HOX gene expression (Kehle et al, 1998). Similarly, in C. elegans CHD proteins, LET-418 and CHD-3, play a crucial role during vulval development by antagonizing RAS signaling and preventing a multiple vulva phenotype, while in humans CHD4 has been shown to be important for normal T cell development (von Zelewsky et al, 2000;Williams et al, 2004).…”