Fig. 1.

hoxa13b is expressed from early stages. (A) Expression of the five posteriorly expressed Hox13 genes at the 18-somite stage. The embryos were allowed to develop for different lengths of time to optimally show expression of each of the genes and do not reflect the relative levels of expression. (B) Expression of hoxa13b from the end of gastrulation (bud stage) until the 24-somite stage (24 s). Embryos from 8 s to 24 s were developed for the same length of time. Embryos from bud to 6 s were developed 50% longer.