scholarly journals Development of the turtle plastron, the order-defining skeletal structure

2016 ◽  
Vol 113 (19) ◽  
pp. 5317-5322 ◽  
Author(s):  
Ritva Rice ◽  
Aki Kallonen ◽  
Judith Cebra-Thomas ◽  
Scott F. Gilbert
Keyword(s):  
Developmental Stage ◽  
Cell Fate ◽  
Bone Development ◽  
Trachemys Scripta ◽  
Skeletal Structure ◽  
Evolutionary Development ◽  
Extinct Species ◽  
Know How ◽  
Cartilage Development ◽  
Dermal Bones

The dorsal and ventral aspects of the turtle shell, the carapace and the plastron, are developmentally different entities. The carapace contains axial endochondral skeletal elements and exoskeletal dermal bones. The exoskeletal plastron is found in all extant and extinct species of crown turtles found to date and is synaptomorphic of the order Testudines. However, paleontological reconstructed transition forms lack a fully developed carapace and show a progression of bony elements ancestral to the plastron. To understand the evolutionary development of the plastron, it is essential to know how it has formed. Here we studied the molecular development and patterning of plastron bones in a cryptodire turtleTrachemys scripta. We show that plastron development begins at developmental stage 15 when osteochondrogenic mesenchyme forms condensates for each plastron bone at the lateral edges of the ventral mesenchyme. These condensations commit to an osteogenic identity and suppress chondrogenesis. Their development overlaps with that of sternal cartilage development in chicks and mice. Thus, we suggest that in turtles, the sternal morphogenesis is prevented in the ventral mesenchyme by the concomitant induction of osteogenesis and the suppression of chondrogenesis. The osteogenic subroutines later direct the growth and patterning of plastron bones in an autonomous manner. The initiation of plastron bone development coincides with that of carapacial ridge formation, suggesting that the development of dorsal and ventral shells are coordinated from the start and that adopting an osteogenesis-inducing and chondrogenesis-suppressing cell fate in the ventral mesenchyme has permitted turtles to develop their order-specific ventral morphology.

scholarly journals Cranial bone histology ofMetoposaurus krasiejowensis(Amphibia, Temnospondyli) from the Late Triassic of Poland

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2685 ◽  
Author(s):  
Kamil Gruntmejer ◽  
Dorota Konietzko-Meier ◽  
Adam Bodzioch
Keyword(s):  
Bone Development ◽  
Cranial Bone ◽  
Late Triassic ◽  
Cranial Development ◽  
Biomechanical Loading ◽  
Calcified Cartilage ◽  
Single Bone ◽  
Occipital Condyles ◽  
Dermal Bones ◽  
Metoposaurus Krasiejowensis

In this study, 21 skull bones ofMetoposaurus krasiejowensisfrom the Late Triassic of Poland were investigated histologically. Dermal bones show a diploë structure, with an ornamented external surface. The ridges consist of mostly well vascularized parallel-fibered bone; the valleys are built of an avascular layer of lamellar bone. The thick middle region consists of cancellous bone, with varying porosity. The thin and less vascularized internal cortex consists of parallel-fibered bone. The numerous Sharpey’s fibers and ISF are present in all bones. The cyclicity of growth is manifested as an alternation of thick, avascular annuli and high vascularized zones as well as a sequence of resting lines. The detailed histological framework of dermal bones varies even within a single bone; this seems to be related to the local biomechanical loading of the particular part of the skull. The dynamic processes observed during the ornamentation creation indicate that the positions of the ridges and grooves change during growth and could be a specific adaptation to changing biomechanical conditions and stress distribution during bone development. In the supratemporal, the cementing lines show that the remodeling process could be involved in the creations of sculpture. The common occurrence of ISF suggests that metaplastic ossification plays an important role during cranial development. Endochondral bones preserved the numerous remains of calcified cartilage. This indicates that ossification follows a pattern known for stereospondyl intercentra, with relatively slow ossification of the trabecular part and late development of the periosteal cortex. The large accumulation of Sharpey’s fibers in the occipital condyles indicates the presence of strong muscles and ligaments connecting the skull to the vertebral column.

scholarly journals Transitional B Cell Fate Is Associated with Developmental Stage-Specific Regulation of Diacylglycerol and Calcium Signaling upon B Cell Receptor Engagement

2006 ◽  
Vol 177 (8) ◽  
pp. 5405-5413 ◽  
Author(s):  
Kristen L. Hoek ◽  
Pierre Antony ◽  
John Lowe ◽  
Nicholas Shinners ◽  
Bhaskarjyoti Sarmah ◽  
...  
Keyword(s):  
Calcium Signaling ◽  
B Cell ◽  
Developmental Stage ◽  
Cell Fate ◽  
Cell Receptor ◽  
B Cell Receptor ◽  
Specific Regulation ◽  
Transitional B Cell

scholarly journals Recent Advances in Single-Cell View of Mesenchymal Stem Cell in Osteogenesis

2022 ◽  
Vol 9 ◽  
Author(s):  
Fangyuan Shen ◽  
Yu Shi
Keyword(s):  
Stem Cell ◽  
Single Cell ◽  
Cell Fate ◽  
Progenitor Cell ◽  
Bone Development ◽  
Lineage Tracing ◽  
Research Progress ◽  
Bone Homeostasis ◽  
Differentiation Potential ◽  
Cell Technology

Osteoblasts continuously replenished by osteoblast progenitor cells form the basis of bone development, maintenance, and regeneration. Mesenchymal stem cells (MSCs) from various tissues can differentiate into the progenitor cell of osteogenic lineage and serve as the main source of osteoblasts. They also respond flexibly to regenerative and anabolic signals emitted by the surrounding microenvironment, thereby maintaining bone homeostasis and participating in bone remodeling. However, MSCs exhibit heterogeneity at multiple levels including different tissue sources and subpopulations which exhibit diversified gene expression and differentiation capacity, and surface markers used to predict cell differentiation potential remain to be further elucidated. The rapid advancement of lineage tracing methods and single-cell technology has made substantial progress in the characterization of osteogenic stem/progenitor cell populations in MSCs. Here, we reviewed the research progress of scRNA-seq technology in the identification of osteogenic markers and differentiation pathways, MSC-related new insights drawn from single-cell technology combined with experimental technology, and recent findings regarding the interaction between stem cell fate and niche in homeostasis and pathological process.

Assessing the Credibility of Young Children's Allegations of Sexual Abuse: Clinical Issues*

1987 ◽  
Vol 32 (7) ◽  
pp. 610-614 ◽  
Author(s):  
Halina Klajner-Diamond ◽  
William Wehrspann ◽  
Paul Steinhauer
Keyword(s):  
Decision Making ◽  
Sexual Abuse ◽  
Developmental Stage ◽  
Decision Making Process ◽  
Clinical Issues ◽  
Know How

In assessing the credibility of young children's (ages 2–7) allegations of sexual abuse clinicians need to know how dynamics of sexual abuse affect disclosure, what situations are most commonly associated with fictitious allegations and how the child's developmental stage affects disclosures. Understanding these issues allows for clear decision making. A clear decision making process flows naturally from an understanding of these issues.

scholarly journals Identification of mRNAs Related to Tibial Cartilage Development of Yorkshire Piglets

2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Shuaifei Feng ◽  
Xiaoyong Du ◽  
Chao Wang ◽  
Dengdeng Ye ◽  
Guanjun Ma ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Transcriptome Analysis ◽  
Molecular Mechanisms ◽  
Comparison Group ◽  
Bone Development ◽  
Expression Patterns ◽  
Osteoclast Differentiation ◽  
Economic Losses ◽  
Mineral Absorption ◽  
Cartilage Development

Cartilage dysplasia is one of the important reasons for the weakness of pig limbs and hooves. Porcine rickets with weak limbs and hooves bring huge economic losses to the pig industry. However, research on the development of pig cartilage is lacking. This study investigated the key genes and molecular mechanisms involved in cartilage development via an RNA-seq technique. Samples of proximal tibia cartilage were collected from three normal piglets with 1 day, 14 days, and 28 days of age, respectively, and then these samples were divided into two comparison groups (1-day vs. 14-day group, 14-day vs. 28-day group). Through the transcriptome analysis, 108 differentially expressed genes (DEGs), such as FORL2, were obtained from 1-day vs. 14-day comparison group, and 3602 DEGs were obtained from 14-day vs. 28-day comparison group, including SOX9, BMP6, and MMP13. The gene ontology (GO) functional and KEGG pathway enrichment revealed that many functions of DEGs were related to bone development. The pathways of DEGs from Day 1 vs. Day 14 were mainly enriched in mineral absorption, but the DEGs of Day 14 vs. Day 28 were enriched in osteoclast differentiation. Then, the expression patterns of six candidate genes were verified via qPCR. In conclusion, candidate genes affecting cartilage development in Yorkshire pigs were obtained by transcriptome analysis, and the clues showed that Day 14 to Day 28 is a more active and extensive period in cartilage developments, which played a key role in revealing the molecular mechanism of pig cartilage development basis, also compensating for vacancies in cartilage research.

scholarly journals Designing Topographically Textured Microparticles for Induction and Modulation of Osteogenesis in Mesenchymal Stem Cell Engineering

2020 ◽  
Author(s):  
Mahetab H. Amer ◽  
Marta Alvarez-Paino ◽  
Jane McLaren ◽  
Francesco Pappalardo ◽  
Sara Trujillo ◽  
...  
Keyword(s):  
Stem Cell ◽  
Mesenchymal Stem Cell ◽  
Cell Fate ◽  
Cell Attachment ◽  
Bone Development ◽  
Human Mesenchymal Stem Cell ◽  
Stem Cell Engineering ◽  
Osteogenic Response ◽  
Altered Gene

AbstractMesenchymal stem cells have been the focus of intense research in bone development and regeneration. We demonstrate the potential of microparticles as modulating moieties of osteogenic response by utilizing their architectural features. Topographically textured microparticles of varying microscale features were produced by exploiting phase-separation of a readily-soluble sacrificial component from polylactic acid. The influence of varying topographical features on primary human mesenchymal stem cell attachment, proliferation and markers of osteogenesis was investigated. In the absence of osteoinductive supplements, cells cultured on textured microparticles exhibited notably increased expression of osteogenic markers relative to conventional smooth microparticles. They also exhibited varying morphological, attachment and proliferation responses. Significantly altered gene expression and metabolic profiles were observed, with varying histological characteristics in vivo. This study highlights how tailoring topographical design offers cell-instructive 3D microenvironments which allow manipulation of stem cell fate by eliciting the desired downstream response without use of exogenous osteoinductive factors.

Delta-1 negatively regulates the transition from prehypertrophic to hypertrophic chondrocytes during cartilage formation

Development ◽  
1999 ◽  
Vol 126 (5) ◽  
pp. 987-998 ◽  
Author(s):  
R. Crowe ◽  
J. Zikherman ◽  
L. Niswander
Keyword(s):  
Notch Signaling ◽  
Cell Fate ◽  
Bone Development ◽  
Hypertrophic Chondrocytes ◽  
Signaling System ◽  
Endochondral Bone ◽  
Cell Fate Decisions ◽  
Cartilage Formation ◽  
Chondrocyte Maturation

Endochondral bone development begins with the formation of a cartilage template. Chondrocytes within this template undergo a progressive program of maturation from proliferative to prehypertrophic chondrocytes to hypertrophic chondrocytes. The progression of cells through these steps of differentiation must be carefully controlled to ensure coordinated growth. Because the Delta/Notch signaling system is known to regulate cell fate choices, we sought to determine if these molecules might be involved in the progressive cell fate decisions that chondocytes undergo. Here we demonstrate in the chick that Delta/Notch signaling negatively regulates progression from the prehypertrophic to hypertrophic state of differentiation. Delta-1 is expressed specifically in the hypertrophic chondrocytes while Notch-2 is expressed in chondrocytes at all stages. Misexpression of Delta-1 using a replication-competent retrovirus blocks chondrocyte maturation. Prehypertrophic cells form normally but do not undergo differentiation to hypertrophic cells, resulting in shortened skeletal elements that lack ossification. We conclude that Delta-1 acts during chondrogenesis to inhibit the transition from prehypertrophic chondrocytes to hypertrophic chondrocytes, thus defining a novel mechanism for the regulation of the chondrocyte maturation program. In addition, these results reveal a new role for Delta/Notch signaling in regulating the progression to a terminally differentiated state.

Reclassification of velvet antler portions following transcriptomic analysis

2020 ◽  
Vol 60 (10) ◽  
pp. 1364
Author(s):  
Tao Qin ◽  
Guanning Wei ◽  
Haiping Zhao ◽  
Yong Li ◽  
Hengxing Ba ◽  
...  
Keyword(s):  
Sika Deer ◽  
Bone Development ◽  
Longitudinal Axis ◽  
New Classification ◽  
Traditional Methods ◽  
Illumina Hiseq ◽  
Cartilage Development ◽  
Velvet Antler ◽  
Traditional Classification ◽  
Highly Expressed Genes

Context Commercially, velvet antlers along the longitudinal axis are divided into four portions, namely, wax-like (WL), blood-colour (BC), honeycomb-like (HL) and bone (B) slices from the top to the base. However, there is no evidence at a molecular level showing the accuracy of this classification. Aims The aim of the present study was to take transcriptional approach to assess the accuracy of the traditional classification for these four portions of velvet antler, and to link the expressed mRNAs of each portion with possible functions by using bioinformatics analysis. Methods Three sticks of three-branched velvet antlers of sika deer were harvested from three anaesthetised 4-year-old sika deer. On the basis of the traditional methods used commercially, the velvet antler sticks were divided into the four portions of WL, BC, HL and B. Transcriptome sequencing was performed using Illumina HiSeq × Ten at BGI (Shenzheng, China). Key results In total, 5647 genes were obtained from the four portions. Spearman correlation analysis grouped these four portions into three clusters (WL, BC, HL+B). C-means analysis further confirmed a similar trend, indicating the accuracy of the new classification based on transcriptome analysis. Further functional analysis showed that highly expressed genes in WL, BC and HL+B were mainly related to cell cycle, cartilage development, and bone development respectively. Conclusions Four-portion classification based on traditional methods should be replaced by three-portion classification based on the mRNA expression levels. Implications We believe that this new classification can contribute to velvet antler industry, providing more accuracy in the use of velvet antlers as pharmaceuticals.

scholarly journals Omics Profiling of S2P Mutant Fibroblasts as a Mean to Unravel the Pathomechanism and Molecular Signatures of X-Linked MBTPS2 Osteogenesis Imperfecta

2021 ◽  
Vol 12 ◽  
Author(s):  
Pei Jin Lim ◽  
Severin Marfurt ◽  
Uschi Lindert ◽  
Lennart Opitz ◽  
Timothée Ndarugendamwo ◽  
...  
Keyword(s):  
Transcription Factors ◽  
Osteogenesis Imperfecta ◽  
Er Stress ◽  
Bone Development ◽  
Differentially Expressed ◽  
Single Amino Acid ◽  
Missense Mutations ◽  
Cartilage Development ◽  
Molecular Features

Osteogenesis imperfecta (OI) is an inherited skeletal dysplasia characterized by low bone density, bone fragility and recurrent fractures. The characterization of its heterogeneous genetic basis has allowed the identification of novel players in bone development. In 2016, we described the first X-linked recessive form of OI caused by hemizygous MBTPS2 missense variants resulting in moderate to severe phenotypes. MBTPS2 encodes site-2 protease (S2P), which activates transcription factors involved in bone (OASIS) and cartilage development (BBF2H7), ER stress response (ATF6) and lipid metabolism (SREBP) via regulated intramembrane proteolysis. In times of ER stress or sterol deficiency, the aforementioned transcription factors are sequentially cleaved by site-1 protease (S1P) and S2P. Their N-terminal fragments shuttle to the nucleus to activate gene transcription. Intriguingly, missense mutations at other positions of MBTPS2 cause the dermatological spectrum condition Ichthyosis Follicularis, Atrichia and Photophobia (IFAP) and Keratosis Follicularis Spinulosa Decalvans (KFSD) without clinical overlap with OI despite the proximity of some of the pathogenic variants. To understand how single amino acid substitutions in S2P can lead to non-overlapping phenotypes, we aimed to compare the molecular features of MBTPS2-OI and MBTPS2-IFAP/KFSD, with the ultimate goal to unravel the pathomechanisms underlying MBTPS2-OI. RNA-sequencing-based transcriptome profiling of primary skin fibroblasts from healthy controls (n = 4), MBTPS2-OI (n = 3), and MBTPS2-IFAP/KFSD (n = 2) patients was performed to identify genes that are differentially expressed in MBTPS2-OI and MBTPS2-IFAP/KFSD individuals compared to controls. We observed that SREBP-dependent genes are more downregulated in OI than in IFAP/KFSD. This is coupled to alterations in the relative abundance of fatty acids in MBTPS2-OI fibroblasts in vitro, while no consistent alterations in the sterol profile were observed. Few OASIS-dependent genes are suppressed in MBTPS2-OI, while BBF2H7- and ATF6-dependent genes are comparable between OI and IFAP/KFSD patients and control fibroblasts. Importantly, we identified genes involved in cartilage physiology that are differentially expressed in MBTPS2-OI but not in MBTPS2-IFAP/KFSD fibroblasts. In conclusion, our data provide clues to how pathogenic MBTPS2 mutations cause skeletal deformities via altered fatty acid metabolism or cartilage development that may affect bone development, mineralization and endochondral ossification.

Beam-radiation effects on wool in the ESEM

1986 ◽  
Vol 44 ◽  
pp. 674-675
Author(s):  
G.D. Danilatos
Keyword(s):  
Electron Beam ◽  
Radiation Effects ◽  
Research Work ◽  
Beam Radiation ◽  
Liquid Environment ◽  
Know How ◽  
Environmental Sem

The advent of the environmental SEM (ESEM) has made possible the examination of uncoated and untreated specimen surfaces in the presence of a gaseous or liquid environment. However, the question arises as to what degree the examined surface remains unaffected by the action of the electron beam. It is reasonable to assume that the beam invariably affects all specimens but the type and degree of effect may be totally unimportant for one class of applications and totally unacceptable for another; yet, for a third class, it is imperative to know how our observations are modified by the presence of the beam. The aim of this report is to create an awareness of the need to initiate research work in various fields in order to determine the guiding rules of the limitations (or even advantages) due to irradiation.

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