Genes specifically expressed in the otic vesicle that are responsive to Pax2/8 over-expression. Lateral views of medaka embryos. Anterior is towards the left. Developmental stages (Stg) are indicated for each embryo. (a, b) Normal expression patterns of pax2/5/8 genes (a), and pax2/5/8 target candidates (b) during otic vesicle development. The ccdc102a transcript is absent in the otic vesicle until stage 29; at this stage it was detected in the medioventral part of the otic vesicle (dashed line). The metrnl transcript could be found weakly at stage 32 (dashed line), whereas sec31l mRNA was detected from early otic vesicle development in the epithelium and later in the medial part of the otic vesicle. The cldn7 gene exhibits a broad expression during otic development from the otic placode stage (data not shown) till stage 33 where the expression is restricted to the medial cristae. brn2 expression is restricted to the medial part of the otic vesicle. (c) Overexpression of pax2 and pax8 leads to ectopic (all except for brn2) expression or repression (brn2) of the candidate genes. At stage 24, ccdc102a is overexpressed in the dorsal epithelium (arrows).