Controversies surrounding segments and parasegments in onychophora: insights from the expression patterns of four "segment polarity genes" in the peripatopsid Euperipatoides rowelli.

ABSTRACT: Arthropods typically show two types of segmentation: the embryonic parasegments and the adult segments that lie out of register with each other. Such a dual nature of body segmentation has not been described from Onychophora, one of the closest arthropod relatives. Hence, it is unclear whether onychophorans have segments, parasegments, or both, and which of these features was present in the last common ancestor of Onychophora and Arthropoda. To address this issue, we analysed the expression patterns of the "segment polarity genes" engrailed, cubitus interruptus, wingless and hedgehog in embryos of the onychophoran Euperipatoides rowelli. Our data revealed that these genes are expressed in repeated sets with a specific anterior-to-posterior order along the body in embryos of E. rowelli. In

SUBMITTER: Franke FA 

PROVIDER: S-EPMC4255022 | biostudies-literature | 2014

REPOSITORIES: biostudies-literature