Schematic drawing of the test building and training tanks.

<p>Distances are to scale (the scale is indicated above the black line). Circles indicate the position of the training tanks. Details of the training tanks show the location of the water inflow (cylinders) and the directions eels were taken out of the training tanks.</p

Schematic of the test tank and funnel insert.

<p>Once the release device is lowered into the tank, the eel is able to come out in any direction. Its escape direction (where it touches the water surface along the slopes of the funnel) is recorded as a bearing.</p

Orientation of <i>Anguilla anguilla</i> under four artificial magnetic conditions at temperatures between 6 and 17

<p>°<b>C.</b> Eels taken from training tank 1 are represented by diamonds and eels taken from training tank 2 are denoted by circles. Bearings (relative to magnetic North) were standardized relative to the direction of displacement. The triangular symbol represents the direction of displacement. The center arrow shows the mean angle of the group weighed by r (scaled 0–1) and the 95% confidence interval. The inner circle represents a significance level of 5% for the Rayleigh test. A and B are bearings standardized to the direction of the magnetic field; C and D are topographical bearings (relative to geographic north). A and C: Tests carried out at temperatures <12°. B and D: Tests carried out at temperatures >12°. Bearings on B have been doubled as they displayed significant bimodal distribution.</p

Niche-independent high-purity cultures of Lgr5+ intestinal stem cells and their progeny

Although Lgr5(+) intestinal stem cells have been expanded in vitro as organoids, homogeneous culture of these cells has not been possible thus far. Here we show that two small molecules, CHIR99021 and valproic acid, synergistically maintain self-renewal of mouse Lgr5(+) intestinal stem cells, resulting in nearly homogeneous cultures. The colony-forming efficiency of cells from these cultures is ~100-fold greater than that of cells cultured in the absence of CHIR99021 and valproic acid, and multilineage differentiation ability is preserved. We made use of these homogeneous cultures to identify conditions employing simultaneous modulation of Wnt and Notch signaling to direct lineage differentiation into mature enterocytes, goblet cells and Paneth cells. Expansion in these culture conditions may be feasible for Lgr5(+) cells from the mouse stomach and colon and from the human small intestine. These methods provide new tools for the study and application of multiple intestinal epithelial cell types