Figure 1. Mating increases ISC proliferation and gut size.

(A, A′) Using the esgReDDM tracer (Antonello et al., 2015), intestinal progenitors (intestinal stem cells (ISCs) and enteroblasts) are labelled with GFP and RFP, whereas the postmitotic progeny (enterocytes (ECs) and enteroendocrine cells) that these progenitors give rise to in a defined time window is labelled with RFP only (see Supplemental Information for additional details). At 3 days after mating, the posterior midgut of mated flies contains more newly generated postmitotic progeny (A) compared to age-matched virgins (A′). It has also become visibly larger (B, B′). At this time point, these guts also have a higher number of nuclei marked by the mitotic marker pH3 in both w¹¹¹⁸ and OregonR backgrounds (C, p = 0.008, and E, p < 0.001, negative binomial GLM), although the proliferation increase is transient (data not shown). The size increase is quantified in the posterior midgut by measuring midgut diameter (D, p < 0.001, t-test) and counting the number of cells labelled by the EC marker caudal-Gal4 (F, p = 0.02, t-test). See Table 1 for full genotypes.

DOI: http://dx.doi.org/10.7554/eLife.06930.003

Figure 1—figure supplement 1. Mating re-sizes the Drosophila gut.

The increase in gut size at 3 days after mating is also measurable (A, A′) and significant (B, p < 0.001, t-test) in the OregonR background. The esgReDDM tracing system reveals that mated guts contain more cells generated in the last 7 days if the fly had been mated in that time (C, p < 0.001, t-test) than if it had not. The size increase is not due to stretching of the tissue, as the density of nuclei in the posterior midgut remains the same (D, p = 0.77, t-test). See Table 1 for full genotypes.

DOI: http://dx.doi.org/10.7554/eLife.06930.004