Differential expression analysis in the Drosophila melanogaster midgut from virgin and mated female flies

One striking example of such plasticity is the intestine: its length is diet-sensitive in many animals, and it elongates further in females during reproduction. Our current understanding of organ-scale remodelling is centred around the dynamics of epithelial stem cells and their progeny.

Here, we show that intestinal muscles resize the entire adult organ. In Drosophila, we find that intestinal muscles differ in their size and structure between the sexes and grow in females during reproduction. Mechanistically, intrinsic sex determinants control myofibril width within muscle cells, whereas hormone-driven changes lead to sarcomere elongation in females during reproduction.