Dietary restriction shapes intergenerational ribosome abundance and early growth of Caenorhabditis elegans offspring.

Cells adjust their proteome to their environment. Most prominently, ribosome expression often scales near linearly with the cellular growth rate to provide sufficient translational capacity while preventing metabolically wasteful ribosomal excess. In microbes, such proteome adjustments can passively perpetuate through symmetric cell division. However, in animals, a passive propagation is hindered by the separation between soma and germline. This separation raises the question whether the proteome of animals is reset at every generation or can be propagated from parent to offspring across this barrier. We addressed this question for the intergenerational effects of dietary restriction in Caenorhabditis elegans, combining proteomics and live imaging. Under ad libitum feeding, the offspring of dietarily restricted mothers grew more slowly than progeny of well-fed mothers. However, this growth disparity was attenuated when mTORC1 signaling in the progeny was inhibited, creating conditions in which the protein-synthesis capacity at hatching is less limiting. Maternal inhibition of mTORC1 signaling, either ubiquitously or specifically in the pharynx, similarly reduced growth and ribosomal protein levels in offspring, whereas other growth-reducing perturbations, such as reduced insulin signaling or mTORC1 inhibition in the epidermis, did not reduce progeny ribosomal protein levels. We conclude that maternal physiology shapes ribosomal protein provisioning across the soma-germline boundary, thereby modulating early offspring growth in accordance with post-hatching ribosome demand.