Gap junctions in the alimentary tract regulate reproductive span in C. elegans

Abstract

Aging does not occur uniformly throughout an organism but is instead differentially regulated across distinct physiological systems. In particular, reproductive aging is often temporally distinct from somatic aging and exhibits species-specific trajectories, suggesting that different physiological functions may age independently. Here we show that mutation of inx-20, an innexin family gene encoding a gap junction component, markedly extends reproductive span, with only a minor increase in overall lifespan. Furthermore, this extension of reproductive span persists in a feminized genetic background, thereby precluding the possibility that it is driven by altered sperm dynamics. inx-20 is expressed in a specific subset of cells within the alimentary tract, and its expression is selectively repressed in a fraction of these cells during dauer diapause, suggesting a role in nutrient responses. Genetic analyses suggest that inx-20 operates via a distinct mechanism that does not intersect with the TGF-{beta} and IIS-FOXO pathways, which are established regulators of reproductive span. Collectively, our results suggest that gap junctions in the alimentary tract are a selective determinant of reproductive span, capable of extending it substantially without a commensurate effect on lifespan.