Editors' ChoiceDevelopmental Biology

Lasers for Discrete Gene Manipulation

Science's STKE  11 Apr 2000:
Vol. 2000, Issue 27, pp. tw5
DOI: 10.1126/stke.2000.27.tw5

The transgenic (Tg) expression of ectopic genes in organisms allows researchers to observe developmental outcomes that deviate from those of the wild-type organism. However, Tg expression in single organs is sometimes desired to determine protein function outside the context of other organs, or when organismic expression is lethal. Halloran et al. use laser-induced gene expression to track development within and surrounding one cell. Tg zebrafish were made containing the green fluorescent protein (GFP) gene cloned under the control of the heat shock protein (Hsp) 70 promoter. Tg fish subjected to heated water exhibited no morphological defects, had normal axonal development, and reproduced successfully, indicating that heat induction of GFP did not have any deleterious developmental effects. Laser-induced heating of individual cells in GFP Tg fish induced GFP production in 24-94% of the cells treated, depending on the cell type. The laser heat did not damage the cells. The authors then created fish containing a fusion of the Hsp70 promoter and semaphorin 3A1, a gene whose product causes repulsion of motor neurons and inhibition of growth cone extension. Laser excitation of one muscle cell led to the inhibition of motor neuron extension at only that muscle cell. Thus, laser-induced gene expression in single cells may give investigators the ability to trace cell lineages and very detailed fate maps in vertebrates.

Halloran, M.C., Sato-Maeda, M., Warren, J.T., Su, F., Lele, Z., Krone, P.H., Kuwada, J.Y., and Shoji, W. (2000). Laser-induced gene expression in specific cells of transgenic zebrafish. Development 127: 1953-1960 [Online Journal]