Drosophila グライコーム: ショウジョウバエを用いた糖鎖機能解析へのアプローチ

抄録

Elucidation of the biological role of glycan is one of the most important subjects to be resolved following the genome project. Glycosylation of proteins and lipids is performed in the Golgi apparatus by glycosyltransferases, which are responsible for synthesizing the huge diversity of complex oligosaccharides attached to glycoproteins and glycolipids. Our molecular evolutionary study showed that a prototype of each glycosyltransferase was conserved in Drosophila, suggesting common roles of glycans in humans and Drosophila.
RNA interference (RNAi) was first reported in 1998 as a biological response of C. elegans to exogeneous double-strand RNA (dsRNA), which induces sequence-specific gene silencing. It is a multi-step process including the generation of active small interfering RNA (siRNA) by reaction with an RNase III endonuclease, Dicer. The resulting 21- to 23-nt siRNA mediates degeneration of the complementary homologous RNA. RNAi has recently emerged as a powerful reverse genetics tool for studying gene function in many model organisms, including Drosophila.
To analyze the basic physiological functions of glycans, we established the Drosophila RNAi knock down system of glycosyltransferases and verified the system using the Drosophila proteoglycan UDP-galactose: β-xylose β1, 4galactosyltransferase I (dβ4GalTI). The expression of the target gene was disrupted specifically and the degree of interference was correlated with the phenotype. This study was the first to use reverse genetics, RNA interference, to study Drosophila glycosyltransferase systematically. The inducible glycosyltransferase RNAi knock down fly obtained using the GAL4-UAS system will open a new way for the analysis of the biological role of glycans.