P50 <i>Perk^+/−</i> mice exhibit higher β-cell number due to elevated β-cell proliferation.

<p>A. Gene expression levels of islets or whole pancreata from P50 <i>Perk^+/−</i> mice relative to <i>Perk^+/+</i> control. Shown are means ± SEM. Below the bar graph shows the estimated fold-increase of β-cell number of P50 <i>Perk^+/−</i> mice relative to <i>Perk^+/+</i> control using each β-cell specific gene (islet data: n = 3, 4; pancreas data: n = 6, 4. *P<0.05). B. Daily BrdU incorporation rate of β-cells in mice at various ages. Shown are means ± SEM (n for <i>Perk ^+/−, Perk^+/+</i> = 5, 5 (P5); 3, 4 (P17); 10, 10 (P30); 4, 4 (P50); 3, 3 (P70). *P<0.05).