Regulation of aging by unc-13 and sbt-1 in Caenorhabditis elegans is temperature-dependent.
OBJECTIVE
To investigate the role of environmental factor-temperature in the regulation of aging process by unc-13 and sbt-1 in Caenorhabditis elegans.


METHODS
The lifespan, the speed of pharynx pumping, and the intestinal autofluorescence of unc-13 and sbt-1 mutants were examined at different temperature conditions. In addition, to exclude the possible influences from other factors in unc-13 and sbt-1 mutants, the dauer formation, the thermotaxis, the brood size and the population percentage of the mutants expressing hsp16.2-gfp were further investigated.


RESULTS
Mutations of unc-13 and sbt-1 significantly increased the mean and the maximum lifespans of nematodes cultured at 20 degrees C and 25 degrees C, while no noticeable increase was found at 15 degrees C in either the mean or the maximum lifespan. Investigations on the speed of pharynx pumping and the intestinal autofluorescence suggested that at 20 degrees C and 25 degrees C, mutations of unc-13 and sbt-1 could slow the aging process and delay the accumulation of aging-related cellular damage. Meanwhile, mutations of unc-13 or sbt-1 did not affect the dauer formation or the thermotaxis to different temperatures in nematodes. In contrast, at 20 degrees C and 25 degrees C conditions, mutations of unc-13 and sbt-1 significantly decreased the brood size and the percentage of nematodes expressing hsp16.2-gfp, while no such differences were detected at 15 degrees C. Moreover, the thermotolerance of unc-13 and sbt-1 mutants could be greatly strengthened after the 16-h heat shock at 35 degrees C.


CONCLUSIONS
The regulation of aging by unc-13 and sbt-1 is temperature-dependent. And the alterations in reproduction capability and stress response may be associated with the formation of this temperature-dependent property.
He
Ke-Wen
KW
Key Laboratory of Developmental Genes and Human Disease in Ministry of Education, Department of Genetics and Developmental Biology, Southeast University Medical School, Nanjing, China.
Shen
Lu-Lu
LL
Zhou
Wen-Wen
WW
Wang
Da-Yong
DY
D000375:Aging / Q000235:genetics / Q000502:physiology*; D000818:Animals; D030801:Animals, Genetically Modified; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D002352:Carrier Proteins; D052284:Clutch Size / Q000502:physiology; D005453:Fluorescence; D006360:Heat-Shock Proteins / Q000378:metabolism; D007422:Intestines / Q000502:physiology; D008136:Longevity / Q000235:genetics / Q000502:physiology; D009154:Mutation; D010614:Pharynx / Q000502:physiology; D013312:Stress, Physiological / Q000235:genetics / Q000502:physiology*; D013696:Temperature
D029742:Caenorhabditis elegans Proteins; D002352:Carrier Proteins; D006360:Heat-Shock Proteins; C108431:hsp-16.2 protein, C elegans; C083141:phorbol ester binding protein