Functional Analyses in the Silkworm, Bombyx mori, Support a Role for Notch Signaling in Appendage Development But Not the Groucho-Dependent Pair-Rule Process
Article first published online: 20 AUG 2012
Copyright © 2012 Wiley Periodicals, Inc.
Journal of Experimental Zoology Part B: Molecular and Developmental Evolution
Volume 318, Issue 8, pages 651–662, December 2012
How to Cite
2012. Functional analyses in the silkworm, Bombyx mori, support a role for Notch signaling in appendage development but not the groucho-dependent pair-rule process. J. Exp. Zool. (Mol. Dev. Evol.) 318B:651–662..
- Issue published online: 30 NOV 2012
- Article first published online: 20 AUG 2012
- Manuscript Accepted: 23 JUL 2012
- Manuscript Revised: 26 APR 2012
- Manuscript Received: 7 NOV 2011
- Specialized Research Fund for the Doctoral Program of Higher Education of China. Grant Number: 20090181120050
- Youth Foundation of Sichuan University. Grant Number: 2009SCU11023
Pair-rule genes are crucial for generating dual segment periodicity for body plan patterning in Drosophila. Bombyx mori is an intermediate germband insect, in which the formation of posterior segments via sequential addition follows a different process from that in Drosophila, although it is somewhat comparable to the process that occurs in vertebrates. Notch signaling is involved in the segmentation of vertebrates, spiders, and basal insects. Groucho (Gro) participates in Notch signaling as a corepressor and plays an important role during segmentation by interacting with other pair-rule proteins. Here, we cloned a gro homolog in the silkworm and positioned it at chromosome 21 in the genetic linkage map. Functional analyses of Bmgro and Bmnotch during embryogenesis were conducted using RNA interference (RNAi). Depletion of Bmgro led to a loss of odd-numbered segments, a characteristic pair-rule phenotype. Bmnotch RNAi resulted in that paired appendages on each segment were symmetrically fused along the ventral midline. An individual segment seemed to possess only one segmental appendage when Notch signaling was compromised. Irregular segments were observed in the Bmnotch RNAi embryo. Our results show that the involvement of Bmgro during the pair-rule process is not mediated by Notch signaling in silkworm. Notch signaling remains in appendage segmentation and restriction of cell fate. J. Exp. Zool. (Mol. Dev. Evol.) 9999B:651–662, 2012. © 2012 Wiley Periodicals, Inc.