## Abstract Newts with bilaterally amputated forelimbs were exposed to either continuous light (LL), total darkness (DD), or continuous light with the dorsal head epithelium painted with an India ink and Nile blue sulfate mixture (LLβIIβNBS) that limited light penetration through the skull to the p
The effect of light on forelimb regeneration in the newt
β Scribed by Maier, C. Eberhardt ;Singer, Marcus
- Publisher
- John Wiley and Sons
- Year
- 1977
- Tongue
- English
- Weight
- 351 KB
- Volume
- 202
- Category
- Article
- ISSN
- 0022-104X
No coin nor oath required. For personal study only.
β¦ Synopsis
Abstract
The forelimb of the newt, Triturus (Notophthalamus) viridescens, was bilaterally amputated and the animals subjected to different photoperiods during the period of regeneration, namely (1) continuous light, (2) 15 hours of light/day and (3) total darkness. Animals exposed to continuous light reached the palette regeneration stage four to five days before those kept in total darkness with the 15 hours of light/day animals being intermediate. The difference in regeneration rate was first evident in the moderate early stage (blastema accumulation stage); it then increased during subsequent stages and the difference persisted during the observation period. In an attempt to determine whether the retina was the receptor of light affected, some animals were blinded at the time of amputation and subjected to continuous light. Their rate of regeneration was similar to sighted animals subjected to continuous light but greater than sighted animals in total darkness. The pineal is discussed as the likely mediator of the photo effect.
π SIMILAR VOLUMES
## Abstract A cyclic seasonal variation in forelimb regeneration in the newt, __Notophthalmus viridescens__, was noted under controlled environmental conditions at 20Β°C in previous experiments. Regeneration was enhanced in the summer months and reached its maximum linear growth rate in late springβ
## Abstract The cyclic adenosine 3β²β5β²βmonophosphate content of four regenerate stages in the forelimb of the newt, __Triturus viridescens__, was assayed using the Gilman method and compared to the content in the normal, unamputated, forelimb. The concentration was found to be highest in the earlie
## Abstract Fibroblast growth factor injected into denervated early regenerates of adult newt forelimbs promotes mitotic activity in the dedifferentiated mesodermal cells. The effect is doseβdependent and is not produced with similar doses of cytochrome c, bovine serum albumin, or growth hormone. E
The concentrations of thyroxine (TJ and triiodothyronine (T,) were determined on samples of fresh sera from adult male and female newts during the course of forelimb regeneration by means of radioimmunoassay (RIA) methods. The results show that the circulatory levels of T, and T3 in males and female