scholarly journals Early Palaeozoic dentine and patterned scales in the embryonic catshark tail

2007 ◽  
Vol 4 (1) ◽  
pp. 87-90 ◽  
Author(s):  
Zerina Johanson ◽  
Mikiko Tanaka ◽  
Natalie Chaplin ◽  
Moya Smith
Keyword(s):  
Scale Development ◽  
Sonic Hedgehog ◽  
The Body ◽  
Iterative Sequence ◽  
Histological Structure ◽  
Scyliorhinus Canicula ◽  
Pulp Cavity ◽  
Early Palaeozoic ◽  
Hedgehog Signal ◽  
Modular Nature

Regular scale patterning, restricted to the caudalmost tail and organized into two opposing rows on each side of the tail, is observed in few chondrichthyans. These evenly spaced scales, in dorsal and ventral rows, develop in an iterative sequence from the caudal tip, either side of the notochord. They are subsequently lost as a scattered pattern of placoid scales develops on the body and fins. An identical organized pattern is observed in tail scales of Scyliorhinus canicula (catshark), where the expression of sonic hedgehog signal is restricted to the epithelium of developing scales and remains localized to the scale pocket. Regulation of iterative scale position by sonic hedgehog is deeply conserved in vertebrate phylogeny. These scales also reveal an archaic histological structure of a dentine type found in the oldest known shark scales from the Ordovician and Silurian. This combination of regulated pattern and ancient dentine occurs only in the tail, representing the primary scalation. Scattered body scales in elasmobranchs such as S. canicula originate secondarily from differently regulated development, one with typical orthodentine around a central pulp cavity. These observations emphasize the modular nature of chondrichthyan scale development and illustrate previously undetected variation as an atavism in extant chondrichthyan dentine.

scholarly journals Thyroid hormone-induced sonic hedgehog signal up-regulates its own pathway in a paracrine manner in theXenopus laevisintestine during metamorphosis

2011 ◽  
Vol 241 (2) ◽  
pp. 403-414 ◽  
Author(s):  
Takashi Hasebe ◽  
Mitsuko Kajita ◽  
Liezhen Fu ◽  
Yun-Bo Shi ◽  
Atsuko Ishizuya-Oka
Keyword(s):  
Thyroid Hormone ◽  
Sonic Hedgehog ◽  
Hedgehog Signal

ENCAPSULATION OF RHABDITOID NEMATODES IN MOSQUITOES

1962 ◽  
Vol 40 (7) ◽  
pp. 1269-1275 ◽  
Author(s):  
Joan F. Bronskill
Keyword(s):  
Aedes Aegypti ◽  
Endemic Species ◽  
Body Cavity ◽  
Fourth Instar ◽  
The Body ◽  
Histological Structure ◽  
Adult Tissue ◽  
Defence Reaction ◽  
Blood Sinus

In third and fourth instar larvae of Aedes aegypti (L.), juveniles of the rhabditoid, DD136, penetrate the blood sinus and cardial epithelium of the proventriculus to enter the body cavity of the host, where they complete their development. By 5 hours, a thick capsule developed about many of the ensheathed immature adults of DD136 within the body cavity of A. aegypti larvae. This rapid defence reaction of the mosquito to DD136, which has both a melanin and a cellular manifestation, occurs both in the exotic mosquito A. aegypti and in the two endemic species tested, Aedes stimulans (Walker) and Aedes trichurus (Dyar). The resistance of A. stimulans to an endemic rhabditoid, possibly of the Diplogasteridae, is also similar. The histological structure of the capsule is not affected during metamorphosis in A. aegypti; however, during histogenesis of adult tissue displacement and (or) distortion of some tissues and organs may be caused by the presence of the capsule within the host's body cavity. The activity of the adult A. aegypti is normal when this distortion or displacement is minor. Though usually encapsulated DD136 are retained within the body cavity of A. aegypti during metamorphosis, sometimes they are partially or completely expelled from the host's body cavity at the time of molting.

The Body Image Psychological Inflexibility Scale: Development and psychometric properties

2015 ◽  
Vol 226 (1) ◽  
pp. 45-52 ◽  
Author(s):  
Glenn M. Callaghan ◽  
Emily K. Sandoz ◽  
Sabrina M. Darrow ◽  
Timothy K. Feeney
Keyword(s):  
Body Image ◽  
Scale Development ◽  
Psychometric Properties ◽  
The Body ◽  
Psychological Inflexibility

Imaging of the Ciliary Cholesterol Underlying the Sonic Hedgehog Signal Transduction

2021 ◽  
pp. 49-57
Author(s):  
Tatsuo Miyamoto ◽  
Kosuke Hosoba ◽  
Silvia Natsuko Akutsu ◽  
Shinya Matsuura
Keyword(s):  
Signal Transduction ◽  
Sonic Hedgehog ◽  
Hedgehog Signal Transduction ◽  
Hedgehog Signal

Breathing Movements in Entobdella Soleae (Trematoda, Monogenea) from the Skin of the Common Sole

1962 ◽  
Vol 42 (1) ◽  
pp. 93-104 ◽  
Author(s):  
G. C. Kearn
Keyword(s):  
Oxygen Content ◽  
Sea Water ◽  
The Body ◽  
Scyliorhinus Canicula ◽  
Solea Solea ◽  
Flat Fish ◽  
The Common ◽  
The Relationship ◽  
Common Sole

An undulating movement of the body was observed in Entobdella soleae, a monogenean found on the blind surface of a mud-dwelling flat-fish, Solea solea, at Plymouth. The movement is described and shown to have a breathing function, the rate of undulation increasing with decreasing oxygen content of the ambient sea water and vice versa.The relationship between the movement and micro-habitat is discussed and the phenomenon is compared with breathing movements in other muddwelling animals.A similar movement was noted in three other skin-parasitic monogeneans: Acanthocotyle sp. from Raia clavata, Pseudocotyle squatinae from Squatina squatina and Leptocotyle minor from Scyliorhinus canicula.

scholarly journals Requirement of Smurf-mediated endocytosis of Patched1 in sonic hedgehog signal reception

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Shen Yue ◽  
Liu-Ya Tang ◽  
Ying Tang ◽  
Yi Tang ◽  
Qiu-Hong Shen ◽  
...  
Keyword(s):  
Sonic Hedgehog ◽  
Feedback Loop ◽  
Hect Domain ◽  
E3 Ligases ◽  
Caveolin 1 ◽  
Shh Pathway ◽  
Sorting Signals ◽  
Pathway Activation ◽  
Endocytic Sorting ◽  
Hedgehog Signal

Cell surface reception of Sonic hedgehog (Shh) must ensure that the graded morphogenic signal is interpreted accordingly in neighboring cells to specify tissue patterns during development. Here, we report endocytic sorting signals for the receptor Patched1 (Ptch1), comprising two ‘PPXY’ motifs, that direct it to degradation in lysosomes. These signals are recognized by two HECT-domain ubiquitin E3 ligases, Smurf1 and Smurf2, which are induced by Shh and become enriched in Caveolin-1 lipid rafts in association with Ptch1. Smurf-mediated endocytic turnover of Ptch1 is essential for its clearance from the primary cilium and pathway activation. Removal of both Smurfs completely abolishes the ability of Shh to sustain the proliferation of postnatal granule cell precursors in the cerebellum. These findings reveal a novel step in the Shh pathway activation as part of the Ptch1 negative feedback loop that precisely controls the signaling output in response to Shh gradient signal.

scholarly journals Anatomical and histological structure of the cavy’s teeth as a basis for diagnosis of dental diseases

2021 ◽  
Vol 77 (01) ◽  
pp. 6500-2021
Author(s):  
JUSTYNA DZIECH ◽  
TOMASZ PIASECKI
Keyword(s):  
Histological Structure ◽  
Dental Cementum ◽  
Pulp Cavity ◽  
Apical Bud ◽  
Dental Diseases ◽  
Acellular Cementum ◽  
And Cartilage ◽  
Tooth Growth ◽  
Periodontal Ligaments

The cavy’s dentition can be shortly described as diphyodont, heterodont, and hypselodont. Histologically, each tooth consists of enamel formed of 4 layers of cells, which together form an apical bud, dentin formed by odontoblasts, and dental cementum. The facies lingualis of incisors is covered with classical acellular cementum, whereas a few circular islands of cementum pearls occur on facies labialis. There are 3 types of cementum in cheek teeth: acellular cementum, cementum pearls, and cartilage-like cementum. Constant tooth growth is ensured by an open pulp cavity within the apex. Periodontal ligaments that are part of the desmodontium are responsible for anchoring teeth in the alveolus.

scholarly journals The effect of different doses of probiotic feed additives on hematologic indices and morphological structure of individual pig internal organs

2020 ◽  
Vol 3 (1) ◽  
pp. 13-20
Author(s):  
M. Zhyla ◽  
N. Shkodyak ◽  
G. Kotsyumbas ◽  
Y. Stronskyi ◽  
O. Sobodosh ◽  
...  
Keyword(s):  
Clinical Trials ◽  
Feed Additives ◽  
The Body ◽  
Feed Additive ◽  
Control Group ◽  
Histological Structure ◽  
Metabolic Processes ◽  
Morphological Studies ◽  
Significant Difference ◽  
White Breed

In order to improve the digestibility and absorption of feed, metabolic processes, growth and development of animals, increase the resistance of the body immunomodulatory agents, probiotics, prebiotics, combined enzyme-probiotic feed additives are widely used. The purpose of our work was to conduct comparative clinical trials of the effectiveness of the probiotic feed additive Probion-forte in terms of productivity, blood indices and histological structure of individual internal  pigs organs during fattening. The researches were carried out on 120 piglets of big white breed at the age of 28 days, which were divided into 4 groups with 30 units in each one. The probiotics were added to feed in different concentrations in order to determine their efficiency and examine influence on piglets organism: the first group was given probiotic Probion-forte in dose of 1.0 g/kg (10 weeks); the second one – Probion in dose of 1.0 g/kg (6 weeks) and 0.5 g/kg (4 weeks); the third one was given probiotic Bio Plus 2B in dose of 0.4 g/kg for 10 weeks; and the fourth one was a control group. The compound feed was provided according to norms recommended for big white breed taking into account age. On the 42nd day (6 weeks) and on the 70th day of test 10 units were selected for haematological, pathomorphological and microbiological tests. The productivity of animals of all studied groups was evaluated by the average daily gains, safety, feed conversion and slaughter output. The stabilized with EDTA piglets’ blood was used for morphological studies, and blood serum – for biochemical studies. The clinical trials have shown that the application of Probion-forte, as a feed additive for fattening of piglets within 10 weeks after weaning, did not cause adverse reactions, was well tolerated by animals and contributed to the improvement of the processes of erythropoiesis and leucopoiesis, increased of serum total protein content. The increasing activity of serum transaminases indicated more intense metabolic processes in experimental animals’ organism, which was confirmed by increase in average daily weight gains and slaughter output compared to control. In the microscopic examination of the thymus, spleen, lymph nodes, intestines, liver, the characteristic histological structure of the organs was preserved and indicated their active morphofunctional state throughout the study period. Morphometrically the increase in the height of the villi in the duodenum and the size of the thymus lobes in piglets, which were fed with probiotic feed additives was established. The efficiency and appropriateness of the application of these products was confirmed in the first and second experimental groups. However, the most significant difference was observed in piglets fed with Probion-forte for 10 weeks at a dose of 1.0 g/kg of feed.

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