Alan John Kingsman

Efficient production of germline transgenic chickens using lentiviral vectors

An effective method for genetic modification of chickens has yet to be developed. An efficient technology, enabling production of transgenic birds at high frequency and with reliable expression of transgenes, will have many applications, both in basic research and in biotechnology. We investigated the efficiency with which lentiviral vectors could transduce the chicken germ line and examined the expression of introduced reporter transgenes. Ten founder cockerels transmitted the vector to between 4% and 45% of their offspring and stable transmission to the G2 generation was demonstrated. Analysis of expression of reporter gene constructs in several transgenic lines showed a conserved expression profile between individuals that was maintained after transmission through the germ line. These data demonstrate that lentiviral vectors can be used to generate transgenic lines with an efficiency in the order of 100‐fold higher than any previously published method, with no detectable silencing of transgene expression between generations.

Retinoic acid receptor |[beta]|2 promotes functional regeneration of sensory axons in the spinal cord

The embryonic CNS readily undergoes regeneration, unlike the adult CNS, which has limited axonal repair after injury. Here we tested the hypothesis that retinoic acid receptor β2 (RARβ2), critical in development for neuronal growth, may enable adult neurons to grow in an inhibitory environment. Overexpression of RARβ2 in adult rat dorsal root ganglion cultures increased intracellular levels of cyclic AMP and stimulated neurite outgrowth. Stable RARβ2 expression in DRG neurons in vitro and in vivo enabled their axons to regenerate across the inhibitory dorsal root entry zone and project into the gray matter of the spinal cord. The regenerated neurons enhanced second-order neuronal activity in the spinal cord, and RARβ2-treated rats showed highly significant improvement in sensorimotor tasks. These findings show that RARβ2 induces axonal regeneration programs within injured neurons and may thus offer new therapeutic opportunities for CNS regeneration.