Identification and expression analysis of genes induced by 20-hydroxyecdysone in the larval brain of the silkworm, Bombyx mori (CBX249). unidentified

To understand the molecular mechanism of the 20E control of the PTTH-producing neurosecretory cells, we performed a screening of genes induced by 20-hydroxyecdysone (20E) using DNA microarray with brains of day-2 fifth instar silkworm larvae. DNA microarray, constructed with 16K expression sequence tag (EST) clusters from the silkworm EST project were used to analyze RNA samples (20E-injected V2 ?~ Ringer-injected V2) to identify the 20E-regulated genes in the larval brain. Total RNA was extracted from brains and used as RNA sample. 20E-injected and Ringer-injected samples were both independently labelled with Cyanine 3-CTP (Cy3) and Cyanine 5-CTP (Cy5). Two array slides were used for each sample: one for 20E-injected Cy3 and Ringer-injected Cy5 and the other for 20E-injected Cy5 and Ringer-injected Cy3. Dye swap design were used in the comparison. Additionally, common reference design were used for the second replicate samples to determine the difference of the experimental design.