Figure 2. Pax6-deficiency reduces the proportion of MafB⁺ and PDX-1⁺ cells that express insulin.

Quantification of immunostained E15.5 embryonic pancreatic sections from wild type and Sey^Neu/Sey^Neu embryos (n = 6 each). (A) Total number of Nkx6.1⁺, MafB⁺ and MafA⁺ cells in wild type and Sey^Neu/Sey^Neu embryonic pancreas were determined along with the number of insulin⁺ cells in the same sections. In Sey^Neu/Sey^Neu embryonic pancreas, the numbers of MafB⁺, MafA⁺ and insulin⁺ cells were significantly reduced (p = 0.03, 0.01 and 0.01 respectively), while the number of Nkx6.1⁺ cells remained unchanged (p = 0.46). (B) The ability of transcription factor expressing cells to express insulin was determined by quantifying the proportion of transcription factor⁺ insulin⁺ cells per total number of transcription factor⁺ cells, as represented by cells in green circle in adjacent Venn diagram. Proportions of MafB⁺Ins⁺ cells / total MafB⁺ cells and PDX-1⁺Ins⁺ cells / total PDX-1⁺ cells in Sey^Neu/Sey^Neu pancreas were significantly less than the wild-type (p = 0.005 and 0.01 respectively), while all of the MafA⁺ cells express insulin. (C) To determine the ability of insulin⁺ cells to undergo further maturation in the absence of Pax6 function, the proportion of insulin⁺ cells expressing these transcription factors was quantified, as represented by cells in red circle in adjacent Venn diagram. The proportion of MafB⁺ Ins⁺, PDX-1⁺Ins⁺ and MafA⁺Ins⁺ cells to the total Ins⁺ cells was not significantly different between wild type and Sey^Neu/Sey^Neu mice.