Simulation of the Emergence of the Endochondral Ossification Process in Evolution

2011 ◽  
Author(s):  
Hanifeh Khayyeri ◽  
Patrick J. Prendergast
Keyword(s):  
Endochondral Ossification ◽  
Structural Genes ◽  
Reasonable Accuracy ◽  
Local Conditions ◽  
Remarkable Feature ◽  
Mechanical Environment ◽  
Bone Differentiation ◽  
Early Vertebrates ◽  
Cartilaginous Fishes ◽  
Ossification Process

The ability of tissues to adapt to the mechanical environment is a remarkable feature of the skeleton. Although the mechano-regulation process is very complex, several mechano-regulation theories for musculo-skeletal tissues have successfully predicted the tissue differentiation and remodelling process in various scenarios with reasonable accuracy (1,2); but how did mechano-regulated bone differentiation emerge in evolution? Early vertebrates, like cartilaginous fishes, could modulate their tissues to the mechanical environment and it is likely that evolution worked with the regulatory genes for skeletal tissues, rather than changes in structural genes, i.e. adapting skeletal tissues to the local conditions rather than involving major changes in cells or tissue types (3).

Diversity and Evolution of Mineralized Skeletal Tissues in Chondrichthyans

2021 ◽  
Vol 9 ◽  
Author(s):  
Fidji Berio ◽  
Morgane Broyon ◽  
Sébastien Enault ◽  
Nelly Pirot ◽  
Faviel A. López-Romero ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Phylogenetic Relationships ◽  
Current Knowledge ◽  
Neural Arch ◽  
Fossil Species ◽  
Fibrous Matrix ◽  
Cartilaginous Matrix ◽  
Mineralized Tissues ◽  
Early Vertebrates ◽  
Cartilaginous Fishes

The diversity of skeletal tissues in extant vertebrates includes mineralized and unmineralized structures made of bone, cartilage, or tissues of intermediate nature. This variability, together with the diverse nature of skeletal tissues in fossil species question the origin of skeletonization in early vertebrates. In particular, the study of skeletal tissues in cartilaginous fishes is currently mostly restrained to tessellated cartilage, a derived form of mineralized cartilage that evolved at the origin of this group. In this work, we describe the architectural and histological diversity of neural arch mineralization in cartilaginous fishes. The observed variations in the architecture include tessellated cartilage, with or without more massive sites of mineralization, and continuously mineralized neural arches devoid of tesserae. The histology of these various architectures always includes globular mineralization that takes place in the cartilaginous matrix. In many instances, the mineralized structures also include a fibrous component that seems to emerge from the perichondrium and they may display intermediate features, ranging from partly cartilaginous to mostly fibrous matrix, similar to fibrocartilage. Among these perichondrial mineralized tissues is also found, in few species, a lamellar arrangement of the mineralized extracellular matrix. The evolution of the mineralized tissues in cartilaginous fishes is discussed in light of current knowledge of their phylogenetic relationships.

scholarly journals Combinatorial morphogenetic and mechanical cues to mimic bone development for defect repair

2019 ◽  
Author(s):  
S. Herberg ◽  
A. M. McDermott ◽  
P. N. Dang ◽  
D. S. Alt ◽  
R. Tang ◽  
...  
Keyword(s):  
Stem Cell ◽  
Bone Formation ◽  
Mechanical Loading ◽  
Endochondral Ossification ◽  
Bone Development ◽  
Human Mesenchymal Stem Cell ◽  
Bone Defects ◽  
Mechanical Environment ◽  
Tgf Β1

AbstractEndochondral ossification during long bone development and natural fracture healing initiates by mesenchymal cell condensation and is directed by local morphogen signals and mechanical cues. Here, we aimed to mimic these developmental conditions for regeneration of large bone defects. We hypothesized that engineered human mesenchymal stem cell (hMSC) condensations with in situ presentation of transforming growth factor-β1 (TGF-β1) and/or bone morphogenetic protein-2 (BMP-2) from encapsulated microparticles would promote endochondral regeneration of critical-sized rat femoral bone defects in a manner dependent on the in vivo mechanical environment. Mesenchymal condensations induced bone formation dependent on morphogen presentation, with dual BMP-2 + TGF-β1 fully restoring mechanical bone function by week 12. In vivo ambulatory mechanical loading, initiated at week 4 by delayed unlocking of compliant fixation plates, significantly enhanced the bone formation rate in the four weeks after load initiation in the dual morphogen group. In vitro, local presentation of either BMP-2 alone or BMP-2 + TGF-β1 initiated endochondral lineage commitment of mesenchymal condensations, inducing both chondrogenic and osteogenic gene expression through SMAD3 and SMAD5 signaling. In vivo, however, endochondral cartilage formation was evident only in the BMP-2 + TGF-β1 group and was enhanced by mechanical loading. The degree of bone formation was comparable to BMP-2 soaked on collagen but without the ectopic bone formation that limits the clinical efficacy of BMP-2/collagen. In contrast, mechanical loading had no effect on autograft-mediated repair. Together, this study demonstrates a biomimetic template for recapitulating developmental morphogenic and mechanical cues in vivo for tissue engineering.One Sentence SummaryMimicking aspects of the cellular, biochemical, and mechanical environment during early limb development, chondrogenically-primed human mesenchymal stem cell condensations promoted functional healing of critical-sized femoral defects via endochondral ossification, and healing rate and extent was a function of the in vivo mechanical environment.

scholarly journals Empirical Modeling of Stream Nutrients for Countries without Robust Water Quality Monitoring Systems

Environments ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 129
Author(s):  
Ismael Díaz ◽  
Paula Levrini ◽  
Marcel Achkar ◽  
Carolina Crisci ◽  
Camila Fernández Nion ◽  
...  
Keyword(s):  
Water Quality ◽  
Land Use ◽  
Planning Process ◽  
Significant Risk ◽  
Sustainable Land Use ◽  
Empirical Modeling ◽  
Geographical Information ◽  
Local Conditions ◽  
Remarkable Feature ◽  
The Impact

Water quality models are useful tools to understand and mitigate eutrophication processes. However, gaining access to high-resolution data and fitting models to local conditions can interfere with their implementation. This paper analyzes whether it is possible to create a spatial model of nutrient water level at a local scale that is applicable in different geophysical and land-use conditions. The total nitrogen and phosphorus concentrations were modeled by integrating Geographical Information Systems, Remote Sensing, and Generalized Additive and Land-Use Changes Modeling. The research was based on two case studies, which included 204 drainage basins, with nutrient and limnological data collected during two seasons. The models performed well under local conditions, with small errors calculated from the independent samples. The recorded and predicted concentrations of nutrients indicated a significant risk of water eutrophication in both areas, showing the impact of agricultural intensification and population growth on water quality. The models are a contribution to the sustainable land-use planning process, which can help to prevent or promote land-use transformation and new practices in agricultural production and urban design. The ability to implement models using secondary information, which is easily collected at a low cost, is the most remarkable feature of this approach.

scholarly journals The evolution of early vertebrate photoreceptors

2009 ◽  
Vol 364 (1531) ◽  
pp. 2925-2940 ◽  
Author(s):  
Shaun P. Collin ◽  
Wayne L. Davies ◽  
Nathan S. Hart ◽  
David M. Hunt
Keyword(s):  
Common Ancestor ◽  
Sampling Strategy ◽  
Rods And Cones ◽  
Eye Evolution ◽  
Living Fossils ◽  
The Common ◽  
Early Vertebrates ◽  
Cartilaginous Fishes ◽  
Dim Light ◽  
Aquatic Landscape

Meeting the challenge of sampling an ancient aquatic landscape by the early vertebrates was crucial to their survival and would establish a retinal bauplan to be used by all subsequent vertebrate descendents. Image-forming eyes were under tremendous selection pressure and the ability to identify suitable prey and detect potential predators was thought to be one of the major drivers of speciation in the Early Cambrian. Based on the fossil record, we know that hagfishes, lampreys, holocephalans, elasmobranchs and lungfishes occupy critical stages in vertebrate evolution, having remained relatively unchanged over hundreds of millions of years. Now using extant representatives of these ‘living fossils’, we are able to piece together the evolution of vertebrate photoreception. While photoreception in hagfishes appears to be based on light detection and controlling circadian rhythms, rather than image formation, the photoreceptors of lampreys fall into five distinct classes and represent a critical stage in the dichotomy of rods and cones. At least four types of retinal cones sample the visual environment in lampreys mediating photopic (and potentially colour) vision, a sampling strategy retained by lungfishes, some modern teleosts, reptiles and birds. Trichromacy is retained in cartilaginous fishes (at least in batoids and holocephalans), where it is predicted that true scotopic (dim light) vision evolved in the common ancestor of all living gnathostomes. The capacity to discriminate colour and balance the tradeoff between resolution and sensitivity in the early vertebrates was an important driver of eye evolution, where many of the ocular features evolved were retained as vertebrates progressed on to land.

The Origin of Jaws and Paired Fins

2019 ◽  
pp. 125-195
Author(s):  
Georg F. Striedter ◽  
R. Glenn Northcutt
Keyword(s):  
Olfactory Receptor ◽  
Mass Extinction ◽  
Sensory Information ◽  
Brain Regions ◽  
Vestibular Apparatus ◽  
Olfactory Information ◽  
Vomeronasal Receptors ◽  
Early Vertebrates ◽  
Cartilaginous Fishes ◽  
Olfactory Receptor Genes

Between 450 and 500 million years ago, some vertebrates evolved paired fins and jaws, which made them more efficient swimmers and fiercer predators. These jawed vertebrates (i.e., gnathostomes) diversified in the Devonian period, but most died out during the end-Devonian mass extinction. The surviving gnathostomes had a more complex vestibular apparatus than their jawless ancestors, an expanded set of olfactory receptor genes, and vomeronasal receptors. A major innovation in the brains of gnathostomes was the emergence of a cerebellum that is distinct from the cerebellum-like areas found in all vertebrates. The telencephalon of early vertebrates processed primarily olfactory information, but this olfactory dominance was independently reduced in three later lineages, namely in cartilaginous fishes, ray-finned fishes, and tetrapods. In concert with the reduction in olfactory dominance, these lineages enlarged their telencephalon, relative to other brain regions, and evolved a telencephalic “dorsal pallium” that receives non-olfactory sensory information from the diencephalon.

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