Printer Friendly

'Precancer' gene localized in embryo, sperm.

"Precancer' gene localized in embryo, sperm

During the past five years, it has becomeclear to scientists that certain proto-oncogenes --those genes involved in tumor growth following activation by cancer-causing viruses--also play a regulatory role in normal embryo development. Based on evidence that proto-oncogenes can code for growth factors and control cell differentiation, research groups have searched for products of the genes in embryonic tissues. Two of those groups independently report in the July 3 CELL that the product coded for by the proto-oncogene called int-1 is restricted in the embryo to specific cells in the developing brain and spinal cord.

Using radioactive int-1 DNA as aprobe, scientists at the National Institute for Medical Research in London assayed sections of mouse embryos for expression of int-1, which also is found in mammary tumors in mice. David G. Wilkinson, Juliet A. Bailes and Andrew P. McMahon compiled data from embryos of different ages and used computers to reconstruct three-dimensional models of int-1 distribution in embryonic neural tissue (see photos). The figure on the left shows a 10 1/2-day embryo; that on the right shows a 14 1/2-day embryo. Neural tissue is indicated in green. The pink, red and blue regions mark int-1 expression in various regions of the embryonic brain; the yellow represents int-1 expression in the spinal cord.

Gregory M. Shackleford and Harold E.Varmus at the University of California at San Francisco also report that expression of the int-1 gene is restricted to specific regions in the developing central nervous system of embryos 11 to 15 days after conception. In addition, they say that int-1 is expressed in adult mouse testes only in the immediate precursors of mature sperm. Shackleford and Varmus note that this "severely restricted pattern of expression' is unusual among proto-on-cogenes. Although these results suggest that int-1 is important in early development of the central nervous system and in spermatogenesis, both the British and U.S. research groups say the mechanism of int-1's influence is unknown.
COPYRIGHT 1987 Science Service, Inc.
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 1987, Gale Group. All rights reserved. Gale Group is a Thomson Corporation Company.

Article Details
Printer friendly Cite/link Email Feedback
Publication:Science News
Date:Aug 1, 1987
Previous Article:More momentum for Mars - and Martians.
Next Article:Animal patent debate heats up.

Related Articles
Sexually transmitted anticancer drugs.
A genetic gender gap.
Embryonic machismo.
Test-tube diagnosis: analyzing embryos for genetic flaws.
Unraveling the role of the breast cancer gene.
Two egg cells make fatherless mouse.
Trash to treasure: junk DNA influences eggs, early embryos.
Polyethylenimine promotes sperm-mediated transgene and oligonucleotide delivery in abalone Haliotis discus hannai.
Cells' root: adult stem cells have a master gene.
Egg shell game: chicks' sex isn't just a matter of chance.

Terms of use | Copyright © 2017 Farlex, Inc. | Feedback | For webmasters