scholarly journals Delineating the anurans axial skeleton

2020 ◽  
Vol 52 ◽  
Author(s):  
Sara Serafina Sánchez ◽  
Romel Sebastián Sánchez
Keyword(s):  
Hox Genes ◽  
Spinal Column ◽  
Morphological Difference ◽  
Axial Skeleton ◽  
The Body ◽  
Development Programs ◽  
Expression Levels ◽  
Caudal Vertebrae ◽  
Genetic Mechanisms ◽  
Structural Plan

The axial skeleton of the anurans has undergone an evolutionary reduction of its bone elements. This structural plan is strongly preserved throughout the order and would have emerged as a highly specialized anatomical adaptation to its locomotor jumping pattern. The development programs that direct the vertebral morphogenesis of the anurans are poorly described and the molecular bases that have caused their pattern to differ from other tetrapods are completely unknown. In this work, we review the ontogeny of the spinal column of the anurans and explore the genetic mechanisms that could explain the morphological difference and the maintenance of the body plan during evolution. Here we propose that the absence of caudal osseous elements, as a consequence of the inability of sclerotomes to form cartilaginous condensations in frogs, could be due to changes in both pattern and expression levels of Hox , Pax1, Pax9 and Uncx4.1 genes along the anteroposterior axis. The anteriorised expression of the Hox genes together with the reduction in the expression levels of Pax1, Pax9 and Uncx4 in the posterior somites could explain, at least partly, the loss of caudal vertebrae in the anurans during the evolution.

Functional cooperation between the non-paralogous genes Hoxa-10 and Hoxd-11 in the developing forelimb and axial skeleton

Development ◽  
1996 ◽  
Vol 122 (2) ◽  
pp. 449-460 ◽  
Author(s):  
B. Favier ◽  
F.M. Rijli ◽  
C. Fromental-Ramain ◽  
V. Fraulob ◽  
P. Chambon ◽  
...  
Keyword(s):  
Hox Genes ◽  
Expression Patterns ◽  
Axial Skeleton ◽  
Proximal Region ◽  
Mutant Mice ◽  
Phenotypic Traits ◽  
Femoral Trochlea ◽  
Preferential Expression ◽  
Caudal Vertebrae ◽  
Compound Mutation

The Abdominal B-related Hoxa-10 gene displays similar expression patterns in the differentiating forelimbs and hindlimbs of the mouse, with preferential expression around the humeral and femoral cartilages and more diffuse expression in distal regions. We found that a targeted disruption of Hoxa-10 has almost no effect in the forelimbs, while it affects the proximal hindlimb skeleton. The alterations were located along the dorsolateral side of the femur (labium laterale), with an enlargement and distal shift of the third trochanter, a misshapen lateral knee sesamoid, a supernumerary ‘ligament’ connecting these structures and an occasional duplication of the femoral trochlea. Some Hoxa-10−/− mutant mice developed severe degenerative alterations of the knee articulation upon ageing. Viable Hoxa-10/Hoxd-11 double mutant mice were produced by genetic intercrosses. The compound mutation resulted in synergistic forelimb phenotypic alterations, consisting of: (i) an exacerbation of Hoxd-11−/− phenotypic traits in the carpal and digital region, e.g. more pronounced truncations of the ulna styloid, pyramidal and pisiform bones and of some metacarpal and phalangeal bones and (ii) marked alterations in a more proximal region which is nearly unaffected in Hoxd-11−/− single mutants; the entire radius and ulna were truncated and thickened, with deformations of the ulna proximal extremity. Thus, functional redundancy can occur even between non-paralogous Abdominal B-related Hox genes. The double Hoxa-10/Hoxd-11 mutation also conferred full penetrance to the sacral and caudal vertebrae transformations which are approximately 50% penetrant in Hoxd-11−/− single mutants, revealing that functional cooperation can also occur between non-paralogous Hox gene products in axial skeleton patterning.

Cinematographic and electromyographic analysis of vertical standing jump in the dog

1979 ◽  
Vol 83 (1) ◽  
pp. 271-282
Author(s):  
M. Tokuriki
Keyword(s):  
Skeletal Muscles ◽  
Lower Extremities ◽  
Axial Skeleton ◽  
The Body ◽  
Wire Electrode ◽  
Centre Of Gravity ◽  
Electrode Method ◽  
Electromyographic Analysis ◽  
Floating Phase

The electromyograms of 37 skeletal muscles were obtained using the bipolar wire electrode method in the vertical standing jump of a dog. Their electromyographic patterns were analyzed in conjunction with cinematographic films. Co-contraction of muscles of the extremities was observed during take-off and landing. Electromyograms also revealed that the forelimbs were accelerated against the body just after take-off and that the fore quarters transferred the centre of gravity of the body in a much more complicated movement than the hind quarters. In the floating phase, the muscles of the lower extremities had no activity, apart from some proximal ones. That the muscles of the four extremities exhibited their activity just before landing indicates that the activity may have been controlled by a central programme. In the vertical standing jump, the dog brings the centre of gravity of the body near to the kicking or landing paws by skillful movement of the axial skeleton. Cinematography revealed that, in the leaping gallop gait, the dog makes a similar movement of its axial skeleton.

Genetic interactions and dosage effects of Polycomb group genes in mice

Development ◽  
1998 ◽  
Vol 125 (18) ◽  
pp. 3543-3551 ◽  
Author(s):  
S. Bel ◽  
N. Core ◽  
M. Djabali ◽  
K. Kieboom ◽  
N. Van der Lugt ◽  
...  
Keyword(s):  
Hox Genes ◽  
Expression Patterns ◽  
Axial Skeleton ◽  
Polycomb Group ◽  
Genetic Interactions ◽  
Homeotic Gene ◽  
Polycomb Group Genes ◽  
Dosage Effects ◽  
Somitic Mesoderm ◽  
Homeotic Gene Expression

In Drosophila and mouse, Polycomb group genes are involved in the maintenance of homeotic gene expression patterns throughout development. Here we report the skeletal phenotypes of compound mutants for two Polycomb group genes bmi1 and M33. We show that mice deficient for both bmi1 and M33 present stronger homeotic transformations of the axial skeleton as compared to each single Polycomb group mutant, indicating strong dosage interactions between those two genes. These skeletal transformations are accompanied with an enhanced shift of the anterior limit of expression of several Hox genes in the somitic mesoderm. Our results demonstrate that in mice the Polycomb group genes act in synergy to control the nested expression pattern of some Hox genes in somitic mesodermal tissues during development.

Mediolateral somitic origin of ribs and dermis determined by quail-chick chimeras

Development ◽  
2000 ◽  
Vol 127 (21) ◽  
pp. 4611-4617 ◽  
Author(s):  
I. Olivera-Martinez ◽  
M. Coltey ◽  
D. Dhouailly ◽  
O. Pourquie
Keyword(s):  
Skeletal Muscles ◽  
Body Wall ◽  
Primitive Streak ◽  
Axial Skeleton ◽  
Lateral Compartment ◽  
The Body ◽  
The Other ◽  
Lateral Part ◽  
Respective Contribution ◽  
Epaxial Muscles

Somites are transient mesodermal structures giving rise to all skeletal muscles of the body, the axial skeleton and the dermis of the back. Somites arise from successive segmentation of the presomitic mesoderm (PSM). They appear first as epithelial spheres that rapidly differentiate into a ventral mesenchyme, the sclerotome, and a dorsal epithelial dermomyotome. The sclerotome gives rise to vertebrae and ribs while the dermomyotome is the source of all skeletal muscles and the dorsal dermis. Quail-chick fate mapping and diI-labeling experiments have demonstrated that the epithelial somite can be further subdivided into a medial and a lateral moiety. These two subdomains are derived from different regions of the primitive streak and give rise to different sets of muscles. The lateral somitic cells migrate to form the musculature of the limbs and body wall, known as the hypaxial muscles, while the medial somite gives rise to the vertebrae and the associated epaxial muscles. The respective contribution of the medial and lateral somitic compartments to the other somitic derivatives, namely the dermis and the ribs has not been addressed and therefore remains unknown. We have created quail-chick chimeras of either the medial or lateral part of the PSM to examine the origin of the dorsal dermis and the ribs. We demonstrate that the whole dorsal dermis and the proximal ribs exclusively originates from the medial somitic compartment, whereas the distal ribs derive from the lateral compartment.

Caudofemoral musculature and the evolution of theropod locomotion

Paleobiology ◽  
1990 ◽  
Vol 16 (2) ◽  
pp. 170-186 ◽  
Author(s):  
Stephen M. Gatesy
Keyword(s):  
Knee Flexion ◽  
Hind Limb ◽  
The Body ◽  
Avian Evolution ◽  
Theropod Dinosaurs ◽  
Data Support ◽  
Caudal Vertebrae ◽  
Longus Muscle

Living crocodilians and limbed lepidosaurs have a large caudofemoralis longus muscle passing from tail to femur. Anatomical and electromyographic data support the conclusion that the caudofemoralis is the principal femoral retractor and thus serves as the primary propulsive muscle of the hind limb. Osteological evidence of both origin and insertion indicates that a substantial caudofemoralis longus was present in archosaurs primitively and was retained in the clades Dinosauria and Theropoda. Derived theropods (e.g., ornithomimids, deinonychosaurs, Archaeopteryx and birds) exhibit features that indicate a reduction in caudofemoral musculature, including fewer caudal vertebrae, diminished caudal transverse processes, distal specialization of the tail, and loss of the fourth trochanter. This trend culminates in ornithurine birds, which have greatly reduced tails and either have a minute caudofemoralis longus or lack the muscle entirely.As derived theropod dinosaurs, birds represent the best living model for reconstructing extinct nonavian theropods. Bipedal, digitigrade locomotion on fully erect limbs is an avian feature inherited from theropod ancestors. However, the primitive saurian mechanisms of balancing the body (with a large tail) and retracting the limb (with the caudofemoralis longus) were abandoned in the course of avian evolution. This strongly suggests that details of the orientation (subhorizontal femur) and movement (primarily knee flexion) of the hind limb in extant birds are more properly viewed as derived, uniquely avian conditions, rather than as retentions of an ancestral dinosaurian pattern. Although many characters often associated with extant birds appeared much earlier in theropod evolution, reconstructing the locomotion of all theropods as completely birdlike ignores a wealth of differences that characterize birds.

scholarly journals Expression levels of caspase-3 and gasdermin E and their involvement in the occurrence and prognosis of lung cancer

2021 ◽  
Author(s):  
yuanli huang ◽  
GuangHui Zhang ◽  
Qing Zhu ◽  
Xia Wu ◽  
LIGao Wu
Keyword(s):  
Lung Cancer ◽  
Caspase 3 ◽  
Clinical Stage ◽  
The Body ◽  
Caspase 8 ◽  
Survival Prognosis ◽  
Expression Levels ◽  
Protein Levels ◽  
Normal Tissues ◽  
Related Proteins

Abstract Background Pyroptosis plays a dual role in the development of cancer and malignancy, and as such, may potentially be a new target for cancer treatment. However, the inflammatory response to pyroptosis may have adverse effects on the body. The roles of gasdermin E (GSDME), caspases, and related proteins associated with pyroptosis in cancer remain controversial. This study aimed to explore whether the expression levels of caspase-3 and GSDME affect the clinical stage, pathological grade, and survival prognosis of patients with lung cancer. Methods We examined the protein levels of GSDME, caspase-3, caspase-8, and caspase-9 in lung tissues from 100 patients with lung cancer by using immunohistochemistry. Results We found that GSDME, caspase-3, and caspase-8 were more highly expressed in the tumor tissues than in the adjacent normal tissues. Moreover, we found that GSDME could serve as a prognostic factor because there was a positive correlation between its expression level and the postoperative survival rate of patients with lung cancer. Conclusions GSDME may be an independent factor affecting the prognosis of patients with lung cancer. However, the role of GSDME and its related proteins in cancer requires further research.

First remingtonocetid archaeocete (Mammalia, Cetacea) from the middle Eocene of Egypt with implications for biogeography and locomotion in early cetacean evolution

2015 ◽  
Vol 89 (5) ◽  
pp. 882-893 ◽  
Author(s):  
Ryan M. Bebej ◽  
Iyad S. Zalmout ◽  
Ahmed A. Abed El-Aziz ◽  
Mohammed Sameh M. Antar ◽  
Philip D. Gingerich
Keyword(s):  
Middle Eocene ◽  
Lumbar Vertebrae ◽  
The Body ◽  
Power Stroke ◽  
Tethys Sea ◽  
Vertebral Centra ◽  
Hind Limbs ◽  
Caudal Vertebrae ◽  
Southern Tethys

AbstractRemingtonocetidae are Eocene archaeocetes that represent a unique experiment in cetacean evolution. They possess long narrow skulls, long necks, fused sacra, and robust hind limbs. Previously described remingtonocetids are known from middle Eocene Lutetian strata in Pakistan and India. Here we describe a new remingtonocetid, Rayanistes afer, n. gen. n. sp., recovered from a middle to late Lutetian interval of the Midawara Formation in Egypt. The holotype preserves a sacrum with four vertebral centra; several lumbar and caudal vertebrae; an innominate with a complete ilium, ischium, and acetabulum; and a nearly complete femur. The ilium and ischium of Rayanistes are bladelike, rising sharply from the body of the innominate anterior and posterior to the acetabulum, and the acetabular notch is narrow. These features are diagnostic of Remingtonocetidae, but their development also shows that Rayanistes had a specialized mode of locomotion. The expanded ischium is larger than that of any other archaeocete, supporting musculature for powerful retraction of the hind limbs during swimming. Posteriorly angled neural spines on lumbar vertebrae and other features indicate increased passive flexibility of the lumbus. Rayanistes probably used its enhanced lumbar flexibility to increase the length of the power stroke during pelvic paddling. Recovery of a remingtonocetid in Egypt broadens the distribution of Remingtonocetidae and shows that protocetids were not the only semiaquatic archaeocetes capable of dispersal across the southern Tethys Sea.

UNDULATORY SWIMMING: HOW TRAVELING WAVES ARE PRODUCED AND MODULATED IN SUNFISH (LEPOMIS GIBBOSUS)

1994 ◽  
Vol 192 (1) ◽  
pp. 129-145 ◽  
Author(s):  
J Long ◽  
M Mchenry ◽  
N Boetticher
Keyword(s):  
Muscle Activation ◽  
Axial Skeleton ◽  
The Body ◽  
Lepomis Gibbosus ◽  
Axial Muscle ◽  
Locomotor Muscles ◽  
Undulatory Swimming ◽  
Swimming Kinematics ◽  
Tail Beat

We have developed an experimental procedure in which the in situ locomotor muscles of dead fishes can be electrically stimulated to generate swimming motions. This procedure gives the experimenter control of muscle activation and the mechanical properties of the body. Using pumpkinseed sunfish, Lepomis gibbosus, we investigated the mechanics of undulatory swimming by comparing the swimming kinematics of live sunfish with the kinematics of dead sunfish made to swim using electrical stimulation. In electrically stimulated sunfish, undulatory waves can be produced by alternating left­right contractions of either all the axial muscle or just the precaudal axial muscle. As judged by changes in swimming speed, most of the locomotor power is generated precaudally and transmitted to the caudal fin by way of the skin and axial skeleton. The form of the traveling undulatory wave ­ as measured by tail-beat amplitude, propulsive wavelength and maximal caudal curvature ­ can be modulated by experimental control of the body's passive stiffness, which is a property of the skin, connective tissue and axial skeleton.

Online Professional Development for Adults

2013 ◽  
pp. 171-193 ◽  
Author(s):  
J. Bernard Bradley ◽  
John Rachal ◽  
Lin Harper
Keyword(s):  
Professional Development ◽  
Empirical Studies ◽  
The Body ◽  
Online Professional Development ◽  
Development Programs ◽  
Educational Programming ◽  
Theoretical Frameworks ◽  
Learning Programs ◽  
Quasi Experimental ◽  
Definition Of

Online professional development programs for adults are increasing in frequency. Numerous scholarly articles have been written that offer polemical or anecdotal evidence supporting the effectiveness of andragogically facilitated non-formal professional development courses, including those conducted online. However, few empirical studies have been conducted to validate their usefulness, especially those offered via the Internet. Such non-formal educational programming may be most conducive to both implementing and empirically testing a more purist definition of andragogy (Pratt, 1988; Rachal, 2002; Bradley, 2011). This chapter explores the theoretical frameworks of andragogy, as well as existing experimental or quasi-experimental research studies, with a view toward creating more learner-centered non-formal educational transactions that meet the unique needs of adult learners. Lastly, suggestions for both practitioners and researchers alike are offered to help build the body of evidence-based research and extend practical advice to educators when designing and facilitating virtual learning programs for adults that emphasize professional development.

The locomotor system

2013 ◽  
Author(s):  
Martin E. Atkinson
Keyword(s):  
Vertebral Column ◽  
Cervical Vertebrae ◽  
Lumbar Vertebrae ◽  
Posterior Wall ◽  
Axial Skeleton ◽  
Intervertebral Discs ◽  
Central Canal ◽  
The Body ◽  
Thoracic Vertebrae ◽  
Locomotor System

The locomotor system comprises the skeleton, composed principally of bone and cartilage, the joints between them, and the muscles which move bones at joints. The skeleton forms a supporting framework for the body and provides the levers to which the muscles are attached to produce movement of parts of the body in relation to each other or movement of the body as a whole in relation to its environment. The skeleton also plays a crucial role in the protection of internal organs. The skeleton is shown in outline in Figure 2.1A. The skull, vertebral column, and ribs together constitute the axial skeleton. This forms, as its name implies, the axis of the body. The skull houses and protects the brain and the eyes and ears; the anatomy of the skull is absolutely fundamental to the understanding of the structure of the head and is covered in detail in Section 4. The vertebral column surrounds and protects the spinal cord which is enclosed in the spinal canal formed by a large central canal in each vertebra. The vertebral column is formed from 33 individual bones although some of these become fused together. The vertebral column and its component bones are shown from the side in Figure 2.1B. There are seven cervical vertebrae in the neck, twelve thoracic vertebrae in the posterior wall of the thorax, five lumbar vertebrae in the small of the back, five fused sacral vertebrae in the pelvis, and four coccygeal vertebrae—the vestigial remnants of a tail. Intervertebral discs separate individual vertebrae from each other and act as a cushion between the adjacent bones; the discs are absent from the fused sacral vertebrae. The cervical vertebrae are small and very mobile, allowing an extensive range of neck movements and hence changes in head position. The first two cervical vertebrae, the atlas and axis, have unusual shapes and specialized joints that allow nodding and shaking movements of the head on the neck. The thoracic vertebrae are relatively immobile. combination of thoracic vertebral column, ribs, and sternum form the thoracic cage that protects the thoracic organs, the heart, and lungs and is intimately involved in ventilation (breathing).

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