Characterizing how intermittent and single periods of fasting affect age-related reproductive decline in Caenorhabditis elegans
Date
2022
Authors
Motkoski, Saige
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Abstract
The physiological decline associate with aging is observed relatively early in the reproductive system. The initial stage of age-related reproductive decline is partly due to oocyte deterioration, and may provide insights into aging on a broader scale. Nutrient-sensing signaling pathways are crucial for adjusting somatic and reproductive tissue growth and maintenance during natural variations in food availability. Dietary restriction (DR) approaches such as intermittent fasting (IF) or a single period of fasting (SPF) can induce lifespan extension in the nematode Caenorhabditis elegans. However, it is not known if IF or SPF will similarly delay C. elegans reproductive decline. Interestingly, it has previously been found that hedgehog-related gene wrt-10 is upregulated in response to fasting, and a separate study showed that wrt-10 overexpression can delay phenotypes of reproductive aging. It is not yet known if wrt-10 acts to mediate IFinduced lifespan extension, or plays a role in regulating reproductive function under fasting conditions. To characterize the impacts of fasting on reproductive aging and clarify the mechanism of IF-induced lifespan extension, I subjected worms with and without functional wrt-10 to IF or SPF nutrient conditions. I unexpectantly found that IF does not significantly extend lifespan under the experimental conditions used here. Instead, I found that IF and SPF can have detrimental consequences for behaviour, physiology, and reproductive capacity. These detrimental consequences highlight that reproductive decline should remain an integral aspect of
aging research. Worms with non-functional wrt-10 had a survival advantage in late adulthood and conversely accelerated reproductive decline, suggesting that wrt-10 may play alternative roles in somatic or reproductive tissue maintenance. These key findings contribute to an understanding of the interplay between nutrition, longevity, and reproductive decline.