Abstract
The homeobox transcription factor Caudal has conserved roles in all Bilateria in defining the posterior pole and in controlling posterior elongation. These roles are seemingly similar and are difficult to disentangle. We have carried out a detailed analysis of the expression, function and interactions of the caudal ortholog of the milkweed bug, Oncopeltus fasciatus, a hemimetabolous insect with a conservative early development process, in order to understand its different functions throughout development. In Oncopeltus, caudal is not maternally deposited, but has a sequence of roles in the posterior of the embryos throughout early development. It defines and maintains a posterior-anterior gradient in the blastoderm and modulates the activity of segmentation genes in simultaneous segmentation during the blastoderm stage. It later defines the invagination site and the posterior segment addition zone (SAZ) in the germband. It maintains the posterior SAZ cells in an undifferentiated proliferative state, while promoting dynamic expression of segmentation genes in the anterior SAZ. We show that rather than being a simple posterior determinant, Caudal is involved in several distinct regulatory networks, each with a distinct developmental role.
Original language | American English |
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Pages (from-to) | 66-76 |
Number of pages | 11 |
Journal | Developmental Biology |
Volume | 467 |
Issue number | 1-2 |
DOIs | |
State | Published - 1 Nov 2020 |
Bibliographical note
Funding Information:This work was funded by Israel Science Foundation grants #120/16 and #75/11 , by an NSF-BSF (IOS) grant #2012763 and by an Einsten Stifftung Berlin grant ( HUJ #030-8573 ). Work by OO and EG was done through undergraduate research fellowships funded in part by the Silberman Institute of Life Sciences. We thank Miriam Rosenberg for critical comments on an early draft of this manuscript. Oren Lev re-imaged some of the embryos shown in the figures.
Funding Information:
This work was funded by Israel Science Foundation grants #120/16 and #75/11, by an NSF-BSF (IOS) grant #2012763 and by an Einsten Stifftung Berlin grant (HUJ #030-8573). Work by OO and EG was done through undergraduate research fellowships funded in part by the Silberman Institute of Life Sciences. We thank Miriam Rosenberg for critical comments on an early draft of this manuscript. Oren Lev re-imaged some of the embryos shown in the figures.
Publisher Copyright:
© 2020 Elsevier Inc.
Keywords
- Axis elongation
- Axis formation
- GRN
- Transcription factor
- evo-devo