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.
Conclusion: 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.
目的: 研究环境因素—温度对秀丽线虫 unc-13 和 sbt-1 基因调控衰老作用的影响。
方法: 在不同培养温度下,测定 unc-13 和 sbt-1 突变线虫的寿命、 咽泵运动速率和肠道荧光。 此外, 为排除其他可能的影响因素, 对 unc-13 和 sbt-1 突变体的永久性幼虫形成率、 对培养温度的趋向性、 子代数目以及表达 hsp16.2-gfp 线虫在群体中的比例进行了测定。
结果: 在20 °C 和25 °C 培养条件下, unc-13 和 sbt-1 突变能显著提高线虫的平均寿命和最高寿命; 然而在15 °C 条件下, unc-13 和 sbt-1 突变体的平均寿命和最高寿命与野生型相似。 咽泵运动速率和肠道脂褐质自发荧光分析进一步验证了在20 °C 和25 °C 培养条件下, unc-13 和 sbt-1 突变可以减慢线虫衰老或延缓衰老相关的细胞损伤累积。 同时, unc-13 和 sbt-1 突变不影响永久性幼虫发生率以及动物对不同温度的趋向性。 相反, 在20 °C和25 °C 培养条件下, unc-13 和 sbt-1 突变能显著降低秀丽线虫的子代数目和群体中表达 hsp16.2-gfp 的线虫比率, 而在15 °C 条件下未出现此种差异。 此外, unc-13 和 sbt-1 突变体经35 °C 热激16 h 后, 其耐热性得到增强。
结论: unc-13 和 sbt-1 对衰老的调节具有温度依赖性。 unc-13 和 sbt-1 突变体的生殖功能和应激反应的改变可能与此温度依赖性的形成有关。