Figure 11
From: Hox gene expression during postlarval development of the polychaete Alitta virens
Changes in Hox gene expression profile in the postlarval segment during worm growth. As an example, the expression of two Hox genes is shown in one particular segment (highlighted in green). The expression gradient with two maxima of Nvi-Hox4 is shown in red. The posterior-to-anterior gradient of Nvi-Post2 is shown in purple. (A) The nascent postlarval segment of the small worm is the most posterior. In this case, both Nvi-Post2 and Nvi-Hox4 are strongly expressed in this segment. (B) As the worm grows and new segments are added, the highlighted segment moves to the central part of the body. Now, both Nvi-Post2 and Nvi-Hox4 expression is weak (for Nvi-Hox4 this is a local minimum of expression level). (C) At the later stage, the highlighted segment is in the anterior part of the body. Nvi-Post2 is no longer expressed in this segment, while for Nvi-Hox4 this position corresponds to the anterior expression maximum.