Expression of Irx6 during mouse morphogenesis

Iroquois (Irx) proteins comprise a family of homeodomain-containing transcr iption factors involved in patterning and regionalization of embryonic tiss ues in both vertebrates and invertebrates. The six murine Irx genes are org anized in two clusters. each consisting of three genes. Irx1, Irx2 and Irx4 belong to the IrxA cluster on chromosome 13, whereas Irx3. Irx5 and Irx6, comprising the IrxB cluster, are located on chromosome 8 (Peters et al., Ge nome Res. 10(2000) 1453). Developmental expression patterns have so far onl y been reported for five Irx genes. Here, we investigated the expression pa ttern of Irx6 during mouse morphogenesis and early organogenesis. The patte rn was found to be much more restricted compared to the other five Irx gene s, and its level of expression was much lower. (C) 2001 Elsevier Science Ir eland Ltd. All rights reserved.