ISSN:
1550-7408
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Biology
Notes:
SYNOPSIS. The regeneration of three species of Blepharisma—americanum, undulans and japonicum (grown in conslant yellow light in a constant-temperature room at 25d̀C) from specimens of which the hypostome had been removed, was studied under a variety of conditions. The reliability of the methods was checked by an extensive series of experiments with B. americanum and B. japonicum under normal conditions. The time of regeneration of 50% of the individuals was taken as a convenient means for comparing action of various agents. No diurnal rhythm of rate of regeneration was observed. Regeneration is readily affected by the state of nutrition of the cells, starved ones regenerating more slowly than well-fed ones. Regeneration is accelerated by maintaining the cells at 30d̀ but retarded at 35d̀. Even brief exposures to 40d̀ may retard regeneration. Regeneration is slowed by maintenance at temperatures below 25d̀, and stopped at 10d̀. Cut Blepharisma placed at 5d̀ lose pigment in a “shock” reaction and many die. The injury is more marked in lettuce medium than in balanced salt solution. Between 13 and 30d̀ the rate of regeneration increases with rise in temperature, the Q10′s for the ranges 13 to 18d̀, 18 to 25d̀ and 25 to 30d̀ being, respectively, 6.92, 3.93 and 1.56. The effect of temperature upon division of Blepharisma was found to be similarly sensitive to temperature, the Q10's for the ranges 13 to 18d̀, 18 to 25d̀ and 25 to 30d̀ being 3.87, 2.92 and 1.59, respectively. High and low temperature limits for division were also found to be similar to those for regeneration. Preliminary evidence indicates some degree of thermal adaptation in Blepharisma to both higher and lower temperatures than those usually tolerated. The studies indicate a general similarity in sensitivity of regeneration and division to environmental influences in the various races of the species studied, with some individual variations.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1550-7408.1963.tb01658.x
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