<i>Sox10</i> is required by LPP melanocytes postnatally.

Abstract

<p>(A) Number of KIT⁺ LPP melanocytes within hairs from <i>Sox10^fl/fl</i> (<i>fl/fl; +/+</i>) and <i>Sox10^fl/fl; Tyr::CreERT2</i> (<i>fl/fl; Cre/+</i>) mice. P0–3/P10 indicates skins harvested from pups on P10 that were maintained by lactating mothers that were IP injected with TAM on P0–3. 0–3dpp/7dpp indicates skins harvested from adult mice on 7dpp after IP injections of TAM on 0–3dpp. (B) White hairs remain visible in adult <i>Sox10^fl/fl; Tyr::CreERT2</i> mice that were treated with TAM by IP injection on 0–3dpp, allowed for complete hair regeneration, replucked and allowed for a second round of hair regrowth (brackets indicate plucked/replucked region, lower image is a magnification of plucked region; mouse in 2E and 3B are the same, imaged prior to and after replucking). (C) Number of PAX3⁺ bulb melanocytes within hairs from <i>Sox10^fl/fl</i> and <i>Sox10^fl/fl; Tyr::CreERT2</i> mice treated as described in B but harvested on 7dpp after replucking (0–3dpp/7dpp repluck). (D) Distribution of melanocytes double-labeled for PAX3 and SOX10 within pigmented (gray) and non-pigmented (white) hair bulbs in skins from <i>Sox10^fl/fl</i> (n = 3) and <i>Sox10^fl/fl; Tyr::CreERT2</i> (n = 3) mice treated as described in B but harvested on 7dpp after replucking (*p<0.002). (E) Persistent hair graying is visible in <i>Sox10^fl/fl; Tyr::CreERT2</i> mice treated with IP TAM for pulse of five days beginning at five weeks old and imaged at one and two years old.</p