Cloning of actin genes from a genomic library of the newt, Notophthalmus viridescens

The regenerating urodele limb is a useful model system in which to study, in vivo, the controls of cell proliferation and differentiation. Techniques are available which enable one to experimentally manipulate mitogenic influences upon the blastema, as well the morphogenesis of the regenerating 11mb. Although classical regeneration studies have generated a wealth of knowledge concerning tissue interactions, little 1s known about the process at the level of gene expression. The aim of this project was to clone potentially developmentally regulated genes from a newt genomic library for use in future studies of gene expression during limb regeneration. We decided to clone the cytoskeletal actin gene for the following reasons: 1. its expression reflects the proliferative and differentiatlve states of cells in other systems 2. the high copy number of cytoplasmic actin pseudogenes in other vertebrates and the high degree of evolutionary sequence conservation among actin genes increased the chance of cloning one of the newt cytoplasmic actin genes. 3. Preliminary experiments indicated that a newt actin could probably be identified using an available chick ~-actln gene for a molecular probe. Two independent recombinant phage clones, containing actin homologous inserts, were isolated from a newt genomic library by hybridization with the chick actin probe. Restriction mapping identified actin homologous sequences within the newt DNA inserts which were subcloned into the plasmid pTZ19R. The recombinant plasmids were transformed into the Escherichia coli strain, DHsa. Detailed restriction maps were produced of the 5.7Kb and 3.1Kb newt DNA inserts in the plasmids, designated pTNAl and pTNA2. The short «1.3 Kb) length of the actin homologous sequence in pTNA2 indicated that it was possibly a reverse transcript pseudogene. Problems associated with molecular cloning of DNA sequences from N. viridescens are discussed with respect to the large genome size and abundant highly repetitive DNA sequences.

Message from the President of the United States, to both Houses of Congress, at the commencement of the third session of the thirteenth Congress. --

Document no. 1 in U.S. 13th Congress, 3d session, 1814-1815. House.

Message from the President of the United States to both Houses of Congress at the commencement of the second session of the twelfth Congress. --

November 4, 1812. Read, and ordered to be printed.

Resolutions reported by the Military Committee, expressive of the thanks of Congress to Major General Jackson, and the troops under his command, for their gallantry and good conduct, in the defence of New Orleans.--

February 13, 1815. Printed by order of the Senate of the United States.

Message from the President of the United States to both Houses of Congress at the commencement of the second session of the twelfth Congress

November 4, 1812. Read, and ordered to be printed. Includes Documents accompanying the Message of the President of the United States to the two Houses of Congress, at the opening of the second session of the twelfth Congress United States. 12th Congress, 2nd session, 1812-1813. House.; United States. 12th Congress, 2nd session, 1812-1813. Senate.; United States. Congress. House.; United States. Congress. Senate. Printed by A. and C. Way

Message from the President of the United States, to both Houses of Congress, at the commencement of the third session of the thirteenth Congress

Document no. 1 in U.S. 13th Congress, 3d session, 1814-1815. House. September 20, 1814. Read and committed to a committee of the whole House on the State of the Union. Printed by Roger C. Weightman

Resolutions reported by the Military Committee, expressive of the thanks of Congress to Major General Jackson, and the troops under his command, for their gallantry and good conduct, in the defence of New Orleans

February 13, 1815. Printed by order of the Senate of the United States. Printed by Roger C. Weightman