INTERACTIVE MODELFIELD NOTECELL BIOLOGY
The Kleptosome Bench
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The paper reports two things happening to the same organelle at different times: while food is available the kleptosome keeps a stolen chloroplast working, and once it runs out the same compartment digests that chloroplast for calories. Drag the week slider below and watch both phases happen to the same organelle. Then use the second model to see how much of the slug's oxygen output rides on a single ion channel.
Model 1. The starvation clock
Move the slider forward in weeks without food. The chloroplast inside the kleptosome stays green and productive at first, dims and turns amber around the point the paper reports chlorophyll loss and a drop in the photosystem gene psbB, and the animal itself survives only as long as the paper reports for whichever species you have selected. Nothing here is measured continuously between the paper's reported checkpoints; the fade is the club's own interpolation between them.
Checkpoints are the paper's own: week 1, mTOR pathway markers already inactivated; around week 6, chloroplasts visibly dimmer, the slug turning orange, and psbB expression down (p = 0.003); close to week 17, death for Elysia crispata. Aplysia californica, run through the identical protocol with no chloroplasts to draw on, dies at 3–4 weeks. The smooth fade between checkpoints is our interpolation, not a continuous measurement.
Model 2. The P2X4 dial
The paper's electrophysiology measured exactly one channel-activity contrast directly: fully working versus blocked with the antagonist 5-BDBD, a 62% drop in net photosynthetic oxygen output. The dial below treats those two conditions as the two ends of a straight line and lets you slide between them. The paper did not measure intermediate channel activities, so every point on this line except the two ends is the club's own illustrative interpolation, not a reported value.
Endpoints only are from the paper: control output defined as 100%, and output at 38% (a 62% reduction, p = 0.0250) when the channel is blocked with 5-BDBD. The straight line between them is an assumption we made to draw a dial, not a claim about the channel's real dose-response curve.
What to take from pushing the sliders
Two things tend to land harder here than in prose. The first is how much calendar time the same organelle spends doing two completely different jobs: for most of the clock it is life support, and only in the last stretch does it become a pantry. The second is how much of this animal's entire solar income depends on one gate: drag the P2X4 dial from 100 down to 0 and watch nearly two-thirds of the output disappear, from blocking a single kind of channel out of everything else in the cell.
Neither model reproduces the paper's own methods. Allard and colleagues used fluorescence imaging, gene-expression assays, proteomics and patch-clamp electrophysiology to reach these numbers. What is here is the shape of their two headline results, built only from the checkpoints they reported, with the interpolation between checkpoints left visible rather than hidden.