Effects of retinoic acid on ribosomal RNA gene expression during limb regeneration

Genomic DNA and total RNA was isolated from blastemas of control and retinoic acid (RA) treated animals during the following limb regeneration stages: initial dedifferentiation (ID), medium bud (MB), notch (N), and 3-finger bud (3-FB). Xenopus nuclear rDNA and axolotl 16S mitochondrial rDNA fragments were used to detect rDNA and rRNA during regeneration. Nuclear rDNA was amplified during the MB stage of regeneration in the absence of RA. The amplified rDNA did not appear to be contributing to the 18S and 28S rRNA pools of MB blastemal cells, at least not in direct proportion to the number of copies of amplified rDHA sequences. RA reduced the level of the amplified sequence in MB blastemas and extended its presence through the N stage of regeneration. The 5.4 kb rDNA signal tended to be stronger in blastemas from RA-treated animals. The levels of both 18S and 28S rRNA tended to be higher in ID and MB blastemas from RA- treated animals. A cloned sequence from an axolotl blastemal cDNA library was almost identical to a region of the bovine 16S mitochondrial rDHA sequence and was inferred to be derived from the axolotl mitochondrial 165 rRNA gene. Both axolotl mitochondrial rDNA and 16S rRNA exhibited relatively little variation among regeneration stages between control and RA-treated samples from corresponding stages. RA, within the limits of these experiments, has a more pronounced effect upon nuclear rRNA gene expression than upon the corresponding mitochondrial rRNA gene expression.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Biology

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2011

Author dc:creator

• Cho, Young-Lan

Contributors dc:contributor

• Daniel, William L.

• Biology, Molecular

Statement dc:rights

• Copyright 1990 Cho, Young-Lan

Language dc:language

eng

Identifier

AAI9114203
(UMI)AAI9114203

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/19534