In vivo analysis of morphogenesis of choroid plexus in transgenic zebrafish

Abstract

Materials and methods We generated a range of random transgenics by means of enhancer trapping using the Tol2 transposon that carries the EGFP gene controlled by a partial keratin8 promoter. It inserts randomly and reveals activity of enhancers in tissue-specific manner in stable transgenic lines. (Parinov et al., 2004; Choo et al.2006). One of these lines, ET33 expressed GFP in the roof plate, dorsal interneurons and meninx. The injection of the transposase mRNA into ET33 embryos resulted in transposition of Tol2 in germ cells and many novel transgenic lines including ET33E20 (Gateways) were generated. Gateways embryos demonstrate the GFP expression pattern mainly restricted to the brain and spinal cord, similar to that of several genes located close to the insertion site that we cloned in an attempt to define which genes expression is recapitulated by GFP expression in Gateways. Interestingly, the early GFP expression is localized to sites, where several cranial blood vessels develop later on. GFP also appears in the roof plate and in groups of cells at the midline in contact with brain ventricles, including the choroid plexus. Using the enhancer trap lines we studied the morphogenesis of the choroid plexus of IV ventricle using a combination of histology, immunohistochemistry and in vivo analysis during normal development.