Cartilaginous Process Research Articles

The ciliary protein C2cd3 is required for mandibular musculoskeletal tissue patterning

The mandible is composed of several musculoskeletal tissues including bone, cartilage, and tendon that require precise patterning to ensure structural and functional integrity. Interestingly, most of these tissues are derived from one multipotent cell population called cranial neural crest cells (CNCCs). How CNCCs are properly instructed to differentiate into various tissue types remains nebulous. To better understand the mechanisms necessary for the patterning of mandibular musculoskeletal tissues we utilized the avian mutant talpid2 (ta2) which presents with several malformations of the facial skeleton including dysplastic tendons, mispatterned musculature, and bilateral ectopic cartilaginous processes extending off Meckel's cartilage. We found an ectopic epithelial BMP signaling domain in the ta2 mandibular prominence (MNP) that correlated with the subsequent expansion of SOX9+ cartilage precursors. These findings were validated with conditional murine models suggesting an evolutionarily conserved mechanism for CNCC-derived musculoskeletal patterning. Collectively, these data support a model in which cilia are required to define epithelial signal centers essential for proper musculoskeletal patterning of CNCC-derived mesenchyme.

Anatomical and morphometric studies on the axial skeleton of ostrich (Struthio camelus)

The present study showed a descriptive anatomical study of the parts of the axial skeleton in the ostrich (Struthio camelus) in addition to a morphometric study of each bone. We studied 7 male ostriches aged from 1 to 3 years with an average weight of 120.00 kg. The cranium exhibited two vast orbits supported by a sclerotic ring. Hyoid apparatus was fine delicate horseshoe-shaped and comprised Basihyale, Urohyale, and Cornu branchiale. Cornu branchiale were paired and long rod-shaped, consisting of a proximal bony part Ceratobranchiale and slightly curved distal cartilaginous process, the Epibranchiale located on either side of the hyoid apparatus. The whole vertebral column comprised 54 vertebrae, including 18 cervical vertebrae, 7 separated thoracic vertebrae, a synsacrum, and 9 separated caudal vertebrae. Atlas had a butterfly-shape with a narrow width and large vertebral foramen. Axis had a protruded dens with a rounded tip that arose from the cranial surface of the body for articulation with the Incisura fossae of atlas. Several Pneumatic foramina were found in the cervical vertebrae. The transverse foramen was found in all the cervical vertebrae except atlas. The ribs were nine pairs in number, the sternal ribs extended from the third to the seventh rib while the rest were asternal floating ribs. The sternum was a broad quadrilateral extensive bone, lacking the keel bone. It had dorsally several Pneumatic foramina.

Association between the developing sphenoid and adult morphology: A study using sagittal sections of the skull base from human embryos and fetuses.

The developing sphenoid is regarded as a median cartilage mass (basisphenoid [BS]) with three cartilaginous processes (orbitosphenoid [OS], ala temporalis [AT], and alar process [AP]). The relationships of this initial configuration with the adult morphology are difficult to determine because of extensive membranous ossification along the cartilaginous elements. The purpose of this study was therefore to evaluate the anatomical connections between each element of the fetal sphenoid and adult morphology. Sagittal sections from 25 embryos and fetuses of gestational age 6-34weeks and crown-rump length 12-295mm were therefore examined and compared with horizontal and frontal sections from the other 25late-term fetuses (217-340mm). The OS was identified as a set of three mutually attached cartilage bars in early fetuses. At all stages, the OS-post was continuous with the anterolateral part of the BS. The BS included the notochord and Rathke's pouch remnant in embryos and early fetuses. The dorsum sellae was absent from embryos, but it protruded from the BS in early fetuses before a fossa for the hypophysis became evident. Although not higher than the hypophysis at midterm, the dorsum sellae elongated superiorly after gestational age 25weeks. In early fetuses, the AP was located on the side immediately anterior to the otic capsule. The AT developed on the side immediately posterior to the extraocular rectus muscles. At late term, the greater wing was formed by membranous bones from the AT and AP. The AT and AP formed a complex bridge between the BS and the greater wing. A small cartilage, future medial pterygoid process (PTmed) was located inferior to the AT in early fetuses. At midterm, one endochondral bone and multiple membranous bones formed the PTmed. The lateral pterygoid process (PTlat) was formed by a single membranous bone plate. Therefore, we connected fetal elements and the adult morphology as follows. (1) Derivative of the OS makes not only the lesser wing but also the anterior margin of the body of the sphenoid. (2) Derivatives of the BS are the body of the sphenoid including the sella turcica and the dorsum sellae. (3) Most of the greater wing including the foramen rotundum and the foramen oval originate from the AT and AP and multiple membranous bones. (4) The PTmed originate from endochondral bones and multiple membranous bones, while the PTlat derive from a single membranous bone.

Attenuation of Post-Traumatic Osteoarthritis After Anterior Cruciate Ligament Injury Via Inhibition of Hedgehog Signaling.

We aimed to investigate whether post-traumatic osteoarthritis (PTOA) progression is appropriately represented by a PTOA mouse model using a unique climbing cage to add mechanical loading after anterior cruciate ligament (ACL) transection and to determine how Hedgehog signaling inhibition prevents PTOA progression by observing time-dependent morphological changes. This controlled laboratory study histologically compared mice with surgically-induced ACL transection (ACLT) and those with voluntary increased activity in a climbing cage from 1 week postoperatively (ACLT + climbing). We generated conditional knockout (cKO) mice with a deleted Smoothened (Smo) gene. Time-dependent histopathological, immunohistochemical, and gene expression analyses were performed. The ACLT + climbing group showed more severe cartilage defects and massive osteophyte formation than the ACLT group. Smo deletion significantly suppressed PTOA progression. The time-dependent assessment revealed cartilaginous processes of equivalent size at the posterior tibial margin in the Smo cKO and control mice at 4 weeks postoperatively. However, at 8 weeks postoperatively, mature ossifying lesions were detected in the controls but not in Smo cKO mice. In the articular cartilage, ADAMTS5 and RUNX2 expression were observed in hypertrophic chondrocytes near the defective cartilage in controls but not in Smo cKO mice. Climbing exercise after ACLT accelerated PTOA progression more severely not only through increasing joint instability induced by ACLT but also through mechanical loading force induced by climbing exercise. Hedgehog signaling inhibition attenuated PTOA progression by suppressing chondrocyte hypertrophy induced by mechanical loads, to which ACL-deficient athletes are usually exposed. Thus, Hedgehog signaling inhibition may be a therapeutic option to prevent arthritic changes in athletes. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:609-619, 2020.

First Record of the Black Snoek Thyrsitoides marleyi (Pisces: Gempylidae) from Korea

A single specimen of Thyrsitoides marleyi (818 mm in standard length), belonging to the family Gempylidae, was collected for the first time in Korea from the coastal waters off Busan, Korea using longline with hooks on 27 January 2012. This species is characterized by the following morphological traits: palate with three fangs, dark dorsal spine membrane, ending part of soft dorsal and anal fin rays finlet-like, and tip of the jaw with a cartilaginous process. We suggest a new Korean name Gal-chi-ggo-chi for T. marleyi.

Early osteological development of the fins in the hatchery-reared red porgy,Pagrus pagrus(L. 1758)

Summary The present study was undertaken to establish the normal, healthy features of morphological structures at various developmental stages as achieved under well-defined environmental culture conditions (temperature between 16 and 21°C, salinity 36 ppt, pH around 7.6, and oxygen saturation over 95%) common in aquaculture of the species. The pectoral fin supports began to develop at 2.90 mm total length (TL), followed by those of dorsal fins at 5.5 mm TL, caudal fins at 5.6 mm TL, pelvic fins at 5.9 mm TL and anal fins at 6.0 mm TL. The pelvic fins appeared fully at 7.4 mm TL. Development of dorsal lepidotrichia was first observed at 6.9 mm TL, attaining their final number at 7.6 mm TL. The dorsal spines first appeared at 6.5 mm TL and were complete at 7.4 mm TL. The anal lepidotrichia appeared during the development phase from 6.8 to 8.6 mm TL. At 5.6 mm TL, the upward flexion of the urostyle was initiated. The caudal lepidotrichia formed within the primordial fin at 5.6 mm TL and reached the final count at 7.4 mm TL. The caudal dermatotrichia first appeared at 7.3 mm TL and all forms were observed by 15.5 mm TL. The development pattern of fin supports found in Pagrus pagrus is quite similar to that described for other Sparid species.

A Novel Technique for Experimental Stellate Ganglion Block in Rats

A stellate ganglion block (SGB) is routinely performed in a clinical setting for the treatment of sympathetically maintained pain syndromes. However, the cardiovascular effects of SGB have not been well defined. The purpose of the present study was to develop a new technique of SGB in a rat model. Our new technique of SGB is a posterior percutaneous approach and uses the cartilaginous process of the C7 spinous process as a landmark. Twenty-six Sprague-Dawley female rats were divided into six groups. Group I (n = 4) underwent right sided SGB, Group II (n = 5) underwent left-sided SGB, and Group III (n = 5) underwent bilateral SGB using bupivacaine 0.25%. Three additional sham groups (n = 4 in each group) served as controls to each of the three treatment groups. Ipsilateral eyelid droop (ptosis) was observed in all animals that underwent SGB with bupivacaine. Heart rate decreased significantly for up to 45 min after bilateral SGB compared with control groups. However, this value did not change in rats after unilateral SGB. In 9 additional rats, we evaluated the accuracy of SGB by injecting methylene blue to stain the right (n = 3), left (n = 3), and bilateral SGB (n = 3). At autopsy, 11 of 12 SG were stained post-methylene blue injection. We conclude from our study that our new approach, posterior percutaneous SGB is a reliable technique that can be used for further studies. We describe a new technique for stellate ganglion block in rats that may be used in future studies to investigate the role of cervical sympathetic nervous system (especially the stellate ganglion) in regulating sympathetically maintained pain and myocardial function.

Runx2-deficient mice lack mandibular condylar cartilage and have deformed Meckel's cartilage.

Runx2 (runt-related transcription factor 2) deficient mice lacked the mandibular condylar cartilage and the mandibular bone. The anlage of the condylar process consisted of mesenchymal condensation, which expressed Type I collagen mRNA and alkaline phosphatase activity, but not Type II collagen and aggrecan mRNAs. Therefore, the differentiation of the mandibular condylar cartilage stopped at the preosteoblast (skeletoblast) stage. The lateral pterygoid muscle was attached to this anlage, and relatively abundant mesenchymal condensations were also formed at the muscle-attaching sites, e.g. the anlage of the mandibular body, the angular and coronoid processes. Three-dimensional reconstruction models showed that each mesenchymal condensation was connected to one another, and roughly outlined the shape of the mandible. Meckel's cartilage in the Runx2-deficient mice had two ectopic cartilaginous processes to which the digastric and myohyoid muscles were attached. These findings indicate that Runx2 is essential for the formation of the mandibular condylar cartilage, as well as for normal development of Meckel's cartilage and that muscle tissues influence mandible morphology.

On the development of the shoulder girdle in Crocidura russula (Soricidae) and other placental mammals: evolutionary and functional aspects.

The development of the shoulder girdle was studied in embryonic stages and a neonate of Crocidura russula using histological sections and 3-D reconstructions. Neonatal stages of Suncus etruscus and Mesocricetus auratus, both altricial placentals, were also studied. The earliest stage of C russula, in which the scapula is still partially blastematous, has already a supraspinous fossa. The dorsal portion of the scapular spine does not develop from the anterior margin of the scapula. Its mode of development varies among the placentals studied to date. In some it is completely appositional bone, in others it consists of bone formed mostly by endochondral ossification of a dorsal cartilaginous process stemming from the acromium. During development the supraspinatus muscle increases in size in proportion to the infraspinatus muscle and the humeral head increases in size in relation to the glenoid fossa. Placentals have secondary cartilage in the sternal and acromial ends of the clavicle, a derived feature absent in Marsupialia. Even the most altricial placentals have a more developed shoulder girdle at birth than any newborn marsupial studied to date.

The Chondrocranium of the Mexican Burrowing Toad, Rhinophrynus dorsalis

-The chondrocranium of Rhinophrynus dorsalis is described and illustrated. Autapomorphies of R. dorsalis are the presence of the symplectic cartilage and a cartilaginous process on the ascending process of the palatoquadrate. Synapomorphies of Rhinophrynus shared with the Pipidae are: (1) early formation of the lower jaw and (2) presence of a suprarostral plate. Alternative developmental pathways for the formation of the suprarostral plate are considered. Histological data indicates that the suprarostral plate forms from: (1) the early fusion of the cornua trabeculae with the suprarostral cartilages, (2) an anterior growth of the ethmoid plate, and (3) subsequent fusion of the cornua trabeculae and the anterior process of the ethmoid plate. The larval crista parotica of R. dorsalis resembles the one described for microhylid taxa. Taylor (1942) described pipid-like anuran larvae from a sample of tadpoles collected in Guerrero, Mexico. However, these larvae remained unidentified until the tadpole of Rhinophrynus dorsalis was described by Orton (1943). Orton's description included a few chondrocranial characteristics, particularly focusing on the jaw apparatus. She noted the early formation of the lower jaw and suggested that this early development may be correlated with a macrophagous diet. Subsequently, Sokol (1977, 1981) made references to the chondrocranial anatomy for Rhinophrynus dorsalis larvae while evaluating the use of larval characteristics in systematics. The sequence of cranial ossification for Rhinophrynus larvae was described by Trueb, 1985. Description of adult osteology has been previously described (Trueb, 1973; Trueb and Cannatella, 1982). Hay et al. (1995) placed Rhinophrynus as the sister group to Pipidae based on 12S and 16S rRNA sequence data. Previous morphological studies suggested the following synapomorphies for the Pipoidea: absence of mentomeckelian bones, lack of parasphenoid alae, presence of a single frontoparietal, greatly enlarged otic capsules, and larvae with paired spiracles and lacking comified beaks and denticles (Ford and Cannatella, 1993). Of the approximately 28 species of the Pipoidea, the chondrocranium has been described thoroughly for Xenopus laevis (Trueb and Hanken, 1992) and partially for Rhinophrynus dorsalis, Pipa carvalhoi, and Xenopus tropicalis (Sokol, 1975). Herein we provide a complete description and illustration of the chondrocranium of Rhinophrynus dorsalis. 1 Corresponding Author. MATERIALS AND METHODS Thirty tadpoles of the Mexican Burrowing Toad, Rhinophrynus dorsalis, representing Neiuwkoop and Faber (1956) stages 48-62 were cleared and double-stained for bone and cartilage using standard procedures. Drawings were obtained with the help of a Wild M3C stereomicroscope with camera lucida attachment. Collection localities of specimens used in this study are: Guanacaste, Costa Rica (USNM 515945515958); and Aguacate Lagoon, Cayo District, Belize (USNM 515959-515974). Collection numbers, measurements, and stages of material examined are given in Table 1. Nieuwkoop and Faber's (1956) staging table for Xenopus was used to stage Rhinophrynus tadpoles. The similarity of external morphology of Xenopus and Rhinophrynus during development makes this table preferable to the Gosner's (1960) staging table. Chondrocranial terminology follows De Jongh (1968), Haas (1995), and Trueb and Hanken (1992).

Ossification of the human fetal ilium.

Ossification of the ilium is similar to that of a long bone. It possesses three cartilaginous epiphyses and one cartilaginous process. Moreover, it undergoes peculiar osteoclastic resorption, comparable with that of the cranium bones. Asymmetrical ossification of the ilium, haversian bone remodelling and apposition of chondroid tissue posterosuperiorly to the acetabulum most probably emphasize the importance of mechanical factors in the morphogenesis of the hip bone during fetal life.

Tarsal development in birds: evidence for homology with the theropod condition

Theropod dinosaurs and birds share a specialized ankle joint in which the proximal tarsal series. the astragalus and calcaneum is braced against the tibia by an ascending process. This feature has been used since T. H. Huxley's time (1870) to support the proposal that birds evolved from dinosaurs. However, according to Martin, Stewart & Whetstone (1980), the avian tarsus is not homologous with that of theropods. They argue that while the ascending process in theropods is continuous with the astragalus in Archaeopteryx and all later birds, it is an independent ossification associated primarily with the calcaneum. A preliminary study of tarsal ontogeny in birds (McGowan, 1984), undertaken to resolve this problem, revealed two developmental pathways, one exemplified in ratites and the other in carinates. The ratite condition corresponded to that of theropods, the bony ascending process being part of the astragalus, while in carinates the corresponding process was part of the calcaneum. The present study, based on more extensive material, reveals that, although the carinate process becomes associated with the calcaneum during later development, there is evidence that it originates as a cartilaginous process from the astragalus and is therefore homologous with the ratite condition. As the avian tarsus is homologous with that of theropods, and of Archaeopteryx, it may be used to support a close phylogenetic relationship among them.

THE COMPARATIVE MORPHOLOGY OF THE AXIAL SKELETON IN THE AUSTRALIAN GEKKONIDAE

Summary 1 The systematic position of Gekkonidae is considered, and the need for careful assessment of basic criteria such as amphicoely and procoely is stressed. 2 The procoelous centra of Phyllurus milii and Sphaerodactylv parkeri are similar to one another and to those of amphicoelous geckos in possessing a continuous notochord, interrupted only at the atlanto-occipital joint, and the full complement of inter centra, but differing from amphicoelous forms in that they bear a rounded condyle posteriorly. 3 Tables of vertebral counts made on 151 geckos, representing 20 genera and 31 species are given. 4 The laterally projecting processes on the atlantal neurapophyses are considered to be serially homologous with the postzygapophyses of following vertebrae; the low processes on the arch pedicels are regarded as parapophyses. 5 The axial neurapophyses bear parapophyses and reduced prezygapophyses. 6 Rudimentary ribs may occur on the third cervical vertebra. The ribs of the fourth, fifth and sixth vertebrae usually bear cartilaginous processes inappropriately termed ‘uncinate processes’. The triangular bony process on the proximal portion of the ribs of the seventh vertebra of some genera, also inappropriately termed an ‘uncinate process’, is considered to represent a state transitional between the ribs typical of the cervical and dorsal series. Presence of sacral and caudal ribs is confirmed. 7 Ribs normally arc attached to the vertebra by means of an articulation between rib head and parapophysis of neural arch, and two ligaments, one above and one below the articulation. Dorsal ligament is considered to be homologous with the tuberculum, and rib head with capitulum. 8 In most geckos fracture planes occur in all postpygal vertebrae. Geckos with a distinct constriction in the tail at junction of pygal and postpygal series, have fracture planes only in this region; Nephrurus asper has no fracture planes at all. Last two conditions may be regarded as specialized. 9 In geckos with a constricted tail, the last pygal neural spine is enlarged, and the two chevrons immediately preceding the first fracture plane are joined together by a bridge of cartilage. 10 No great morphological change is required for transition from amphicoely to procoely in geckos, and amphicoely is regarded as ancestral to procoely. Procoelous vertebrae of Phyllurus milii and Sphaerodactylus parkeri are only slightly removed from the amphicoelous condition. There is no evidence of degeneracy in the vertebral column of amphicoelous geckos; living Gekkonidae as a whole are regarded as an ancient lacertilian group. 11 Procoely is considered to have arisen at least three times in the Gekkonidae– first, in ancestors of Coleonyx and related forms; second, in the series leading to Sphaerodactylus; and third in the Australian species Phyllurus milii. Probable course of evolution of procoely in geckos is described. 12 Arguments are presented against placing all procoelous geckos in one subgroup, the Eublepharidae, regardless of affinities with amphicoelous forms. Nevertheless amphicoely, in relation to geckos as a whole, is considered to retain the palaeotelic weight ascribed to it by Camp (1923).

On the Innervation of the Snout and the Nasal Cavity of Cat in the Last Fetal Stage

The snout is already in nearly full formation in the last fetal stage, but shows some infantility. Its mucous membrane is covered by a stratified flat epithelium far thinner than in fetal cattle (ABE) and has epithelial sulci on its surface. At the bottom of these sulci are formed distinct cristae limitantes. Between these cristae, papillae are found developed. In the submucosa, neither snout glands nor sinus hairs can be discovered.The vestibula nasi have a catilaginous plate corresponding in shape to the inner vestibular moulding. The nasal septal cartilage stands on the median line and a semilunar cartilaginous arch extends on either side of it. A cartilaginous process juts out from a point somewhat lower than the mid-point of either arch. This closed cartilage is lined with a mucous membrane on its inside, the epithelium is a a stratified flat one far thinner than that of the snout and forms no epithelial sulci. Conspicuous papillae, however, are still in formation in the foremost part adjacent to the snout. Nasal glands are well developed in the areas where the mucous membrane is thick but absent in the areas where it is thin, in the deep parts of the vestibulum. The backmost part of the vestibule is covered by a stratified cylindrical epithelium.The pars respiratoria of the nasal cavity is under a ciliated epithelium and nasal glands and venous plexus are in very good development in the submucosa beneath, but no smooth muscle fibres are found among the veins.The snout of fetal cat of last stage is already richly supplied with sensory fibres. Very uumerous thick sensory fibres are found in the submucosal and the proprial plexus. Most of the sensory fibres run toward the epithelial cristae and a fewer toward the papillae. A small part of the former end subepithelially in branched terminations, but the larger part run further into the cristae to end similarly. These are already rather complexly constructed, their terminal fibres are thick and mostly show frequent change in size in their short and peculiar winding courses before ending sharply. Fibres that run up in rather long courses close to the superficial layer of the epithelium are not rare either. It is of interest that such terminations were found in all the cristae examined. The sensory terminations in the papillae are very scanty, and these few are nothing more complex than the simplest unbranched terminations.Arterio-venous anastomoses were often found in the submucosa of the snout and the foremost part of the vestibulum nasi of my cat's fetus. These are not only very richly provided with terminations of vegetative fibres (STOHR's terminal reticula), but also contain a comparatively large number of terminations of thick sensory fibres. Their terminal fibres show frequent change in size and often penetrate into the epitheloid cell layer before ending.Sensory nerve fibres are found also rather numerous in the vestibulum nasi, and most of them are found in the parts adjoining the snout. As the deeper part of the vestibulum is reached, the number of sensory fibres decreases very rapidly, especially in the area where the mucous membrane is thin.The mucous membrane covered by a thick papillae-containing epithelium in the part of the vestibulum nasi adjoining the snout also contains many sensory fibres, though not so many as in the snout. These usually enter the cristae to form intraepithelial branched terminations. The terminal fibres of these also show marked change in size and peculiar looped courses. A small number of unbranched and simple branched terminations are found in the papillae as well.In the parts of mucous membrane outside the areas provided with epitelial cristae and papillae in the vestibulum, the formation of proprial plexus is feeble, so that sensory fibres are also limited in number; these few sensory fibres end subepithelially in unbranched and simple branched terminations.

The Baculum of the Peromyscus truei Species Group

Several subgenera of Peromyscus are easily distinguished from each other by their characteristic types of bacula (Blair, Jour. Mamm., 23: 196–204, 1942), but differences have not been found with this character between certain species or even species groups of this genus. Although Sprague (Trans. Kans. Acad. Sci., 42: 495–497, 1939) readily separated species of the P. leucopus and P. maniculatus groups on the length of this structure, Blair ( op. cit .) could not separate bacula of the P. boylei and P. truei species groups. Likewise the species P. boylei and P. pectoralis of the P. boylei species group were not distinguishable by Clark (Ph.D. dissertation, Univ. Texas, 1952) with this character. His examination of the cartilaginous processes of these two species, however, did reveal indicative characters not observed previously. The cartilage tip of the baculum of Peromyscus had not been reported in the literature prior to his work, and …