Selection for increased tibia length in mice alters skull shape through parallel changes in developmental mechanisms
- University of Calgary, Canada
Abstract
Bones in the vertebrate cranial base and limb skeleton grow by endochondral ossification, under the control of growth plates. Mechanisms of endochondral ossification are conserved across growth plates, which increases covariation in size and shape among bones, and in turn may lead to correlated changes in skeletal traits not under direct selection. We used micro-CT and geometric morphometrics to characterize shape changes in the cranium of the Longshanks mouse, which was selectively bred for longer tibiae. We show that Longshanks skulls became longer, flatter, and narrower in a stepwise process. Moreover, we show that these morphological changes likely resulted from developmental changes in the growth plates of the Longshanks cranial base, mirroring changes observed in its tibia. Thus, indirect and non-adaptive morphological changes can occur due to developmental overlap among distant skeletal elements, with important implications for interpreting the evolutionary history of vertebrate skeletal form.
Data availability
All data generated or analysed during this study are included in the manuscript and supporting Source Data files.
Article and author information
Author details
Funding
Natural Sciences and Engineering Research Council of Canada (Discovery Grant 4181932)
- Campbell Rolian
University of Calgary (Faculty of Veterinary Medicine)
- Campbell Rolian
Natural Sciences and Engineering Research Council of Canada (Canada Graduate Scholarship - Masters)
- Colton Michael Unger
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: All animal procedures were approved by the Health Sciences Animal Care Committee at the University of Calgary (Protocols AC13-0077 and AC17-0026) and performed in accordance with best practices outlined by the Canadian Council on Animal Care.
Copyright
© 2021, Unger et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 1,481
- views
-
- 160
- downloads
-
- 12
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
A two-part list of links to download the article, or parts of the article, in various formats.
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Selection for increased tibia length in mice alters skull shape through parallel changes in developmental mechanisms
eLife 10:e67612.
https://doi.org/10.7554/eLife.67612
Further reading
-
- Developmental Biology
Mammalian sperm delve into the female reproductive tract to fertilize the female gamete. The available information about how sperm regulate their motility during the final journey to the fertilization site is extremely limited. In this work, we investigated the structural and functional changes in the sperm flagellum after acrosomal exocytosis (AE) and during the interaction with the eggs. The evidence demonstrates that the double helix actin network surrounding the mitochondrial sheath of the midpiece undergoes structural changes prior to the motility cessation. This structural modification is accompanied by a decrease in diameter of the midpiece and is driven by intracellular calcium changes that occur concomitant with a reorganization of the actin helicoidal cortex. Midpiece contraction occurs in a subset of cells that undergo AE, and live-cell imaging during in vitro fertilization showed that the midpiece contraction is required for motility cessation after fusion is initiated. These findings provide the first evidence of the F-actin network’s role in regulating sperm motility, adapting its function to meet specific cellular requirements during fertilization, and highlighting the broader significance of understanding sperm motility.
-
- Developmental Biology
New research shows that the neural circuit responsible for stabilising gaze can develop in the absence of motor neurons, contrary to a long-standing model in the field.
