The centipede Strigamia maritima possesses a large complement of Wnt genes with diverse expression patterns

Area of Science:

• Developmental Biology
• Evolutionary Biology
• Genetics

Background:

• Wnt genes are crucial for animal development, particularly in arthropods for posterior development and segmentation.
• Secondary loss of Wnt genes is frequent in Arthropoda, making exceptions noteworthy.
• Strigamia maritima, a centipede, uniquely retains a large Wnt gene set (11 genes).

Purpose of the Study:

• To investigate the embryonic expression patterns of all 11 Wnt genes in Strigamia maritima.
• To understand the functional relationships and potential redundancy among Wnt genes in this species.
• To evaluate existing models of Wnt signaling in light of the observed expression data.

Main Methods:

• Examining the expression of each of the 11 Wnt genes.
• Analyzing expression across various embryonic developmental stages.
• Mapping gene expression patterns in the trunk, head, and proctodeum.

Main Results:

• Wnt gene expression in Strigamia maritima is highly variable.
• Most Wnt genes show expression in segmental stripes, the head region, and near the proctodeum.
• Specific expression differences exist among the Wnt genes despite broad similarities.

Conclusions:

• The observed Wnt gene expression patterns in Strigamia maritima are consistent with the combinatorial model of Wnt activity.
• This model suggests that regional identity is determined by the specific combination of Wnt ligands present.
• Findings provide insights for reconstructing the evolutionary history of Wnt signaling in arthropods.