HIGH-EFFICIENCY GENE-TRANSFER INTO THE EMBRYONIC CHICKEN CNS USING B-SUBGROUP RETROVIRUSES

Attempts to use replication-competent retroviruses to target genes to the chick CNS have met with limited success for injections performed p rior to stage 14 using A- or E-subgroup viruses, This study was aimed at improving CNS infection by varying the stage of injection, viral en velope subgroup, viral titer, and the presence or absence of a transge ne and/or the polycation polybrene in the inoculum. RCASBP vectors wer e injected into the neural tube of stages 3-13 embryos and protein exp ression was determined 9-48 hr later for forebrain, hindbrain, retina, and inner ear, Optimal injection parameters were defined which balanc ed good survival rates with high levels of transgene expression at ear ly stages, The results demonstrate nearly complete expression of virus -mediated transgenes in neural tissues at stages 15-21 following injec tion of B-envelope RCASBP with polybrene at stages 7.5-12, This techni que can now be applied to study the roles of genes in cell-autonomous events such as cell connectivity, physiology, and differentiation, as well as neural patterning and regional identity. (C) 1996 Wiley-Liss, Inc.