|
If you are seeing this message, you may be experiencing temporary network problems. Please wait a few minutes and refresh the page. If the problem persists, you may wish to report it to your local Network Manager.
It is also possible that your web browser is not configured or not able to display style sheets. In this case, although the visual presentation will be degraded, the site should continue to be functional. We recommend using the latest version of Microsoft or Mozilla web browser to help minimise these problems.
Wiley InterScience | ||||||||||||||||||||
  Evolution & DevelopmentVolume 5 Issue 2, Pages 198 - 207 Published Online: 5 Mar 2003 © 2010 Wiley Periodicals Sponsored by the Society for Integrative and Comparative Biology
Abstract | References | Full Text: HTML, PDF (Size: 1878K) | Related Articles | Citation Tracking  The pattern of segment formation, as revealed by engrailed expression, in a centipede with a variable number of segments Copyright 2003 Blackwell Science, Inc. SUMMARY
SUMMARYArthropods vary enormously in segment number, from less than 20 to more than 200. This between-species variation must have originated, in evolution, through divergent selection operating in ancestral arthropod species with variable segment numbers. Although most present-day arthropod species are invariant in this respect, some are variable and so can serve as model systems. Here, we describe a study based on one such species, the coastal geophilomorph centipede Strigamia maritima. We investigate the way in which segments are formed using in situ hybridization to demonstrate the expression pattern of the engrailed gene during embryogenesis. We also analyze segment number data in mother–offspring broods and thereby demonstrate a significant heritable component of the variation. We consider how natural selection might act on this intraspecific developmental variation, and we discuss the similarities and differences in segment formation between the geophilomorphs and their phylogenetic sister-group. | 
|
