Ontogeny of the Electroreceptive System of The Platypus.

1998 ◽  
Vol 20 (2) ◽  
pp. 309
Author(s):  
P.R. Manger ◽  
R. Collins ◽  
J.D. Pettigrew
Keyword(s):  
Histological Examination ◽  
Developmental Stages ◽  
Developmental Profile ◽  
Adult Pattern ◽  
Poorly Differentiated ◽  
Sensory Structures

A series of developmental stages of the platypus were examined in order to obtain an anatomical description of the development of the periphery of the electroreceptive system. Putative electroreceptors, composed of modified mucous glands, were observed to appear at I0 days post hatching (p.h.). The typical striped arrangement of peripheral electroreceptors in the platypus was seen at 12 days p.h. The arrangement of the stripes was modified during development with a range of additions and divisions of stripes occurring until the adult pattern is obtained, approximately 6 months p.h. After appearing at 10 days p.h. the number of electroreceptors increases rapidly until sometime between 24 and 28 days p.h. when there is massive death of electroreceptors, the number present at 28 days p.h. being 60% of the number present at 24 days p.h. This massive death of receptors is coincident with the appearance of other sensory structures in the epidermis of the bill skin, the push-rod mechanoreceptors and the sensory serous glands. Histological examination of a range of developmental stages demonstrated poorly differentiated innervation at 28 days p.h. which became differentiated and reached the adult configuration between 11 weeks p.h. and 6 months p.h. Lamination of the cells lining the duct of the electroreceptors showed a similar developmental profile. This study indicates that the electroreceptive system of the developing platypus is not functional, in a similar manner to the adult, until around the time the platypus leaves the nesting burrow. However, the system may be functional in the developing platypus, and speculatively may be used in the location o f the mammary region for suckling.

scholarly journals The development of the electroreceptors of the platypus ( Ornithorhynchus anatinus )

1998 ◽  
Vol 353 (1372) ◽  
pp. 1171-1186 ◽  
Author(s):  
Paul R. Manger ◽  
Rita Collins ◽  
John D. Pettigrew
Keyword(s):  
Histological Examination ◽  
Developmental Stages ◽  
Developmental Profile ◽  
Ornithorhynchus Anatinus ◽  
Adult Pattern ◽  
Poorly Differentiated ◽  
Sensory Structures

A series of developmental stages of the platypus were examined to obtain an anatomical description of the development of the periphery of the electroreceptive system. Putative electroreceptors, composed of modified mucous glands, were observed to appear at 10 days post hatching (p.h.). The typical striped arrangement of peripheral electroreceptors in the platypus was seen at 12 days p.h. The arrangement of the stripes was modified during development with a range of additions and divisions of stripes occurring until the adult pattern is obtained, approximately 6 months p.h. After appearing at 10 days p.h., the number of electroreceptors increases rapidly until sometime between 24 and 28 days p.h. when there is massive death of electroreceptors, the number present at 28 days p.h. being 60% of the number present at 24 days p.h. This massive death of receptors is coincident with the appearance of other sensory structures in the epidermis of the bill skin, the push–rod mechanoreceptors and the sensory serous glands. Histological examination of a range of developmental stages demonstrated poorly differentiated innervation at 28 days p.h., which became differentiated and reached the adult configuration between 11 weeks p.h. and 6 months p.h., the time at which nestling platypus leave the burrow. Lamination of the cells lining the duct of the electroreceptors showed a similar developmental profile. This study indicates that the electroreceptive system of the developing platypus is not functional, in a similar manner to the adult, until it is time for the platypus to leave the nesting burrow. However, the system may be functional in the developing platypus, and may be used speculatively in the location of the mammary region for suckling.

The Fetal Dermal but Not Loose Fascial Mesenchymal Cells Possess Regenerative Activity of Dermal Structure

2005 ◽  
Vol 14 (9) ◽  
pp. 709-714 ◽  
Author(s):  
Kazuo Kishi ◽  
Kenichi Katsube ◽  
Hiroko Satoh ◽  
Nobuaki Imanishi ◽  
Hideo Nakajima ◽  
...  
Keyword(s):  
Histological Examination ◽  
Developmental Stages ◽  
Mesenchymal Cells ◽  
Epidermal Cells ◽  
Scid Mice ◽  
Skin Defect ◽  
Fetal Skin ◽  
Regenerative Activity

Fetal skin possesses a regenerative activity until certain developmental stages. However, the origin of cells that regenerate dermis after wounding has not been clarified yet. In the present study we located the origin of cells that reconstruct fetal dermal structure by histological examination and by marking cells in the loose fascia. Next we evaluated the regenerative activity of fetal dermal mesenchymal cells by cotransplanting with fetal epidermal cells onto the skin defect of scid mice. We conclude that fetal dermal mesenchymal cells but not loose fascial cells possess regenerative activity even on the environment in scid mice.

The surface topography of Eudiplozoon nipponicum (Monogenea) developmental stages parasitizing carp (Cyprinus carpio L.)

2010 ◽  
Vol 5 (5) ◽  
pp. 702-709 ◽  
Author(s):  
Iveta Hodová ◽  
Iveta Matejusova ◽  
Milan Gelnar
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Food Intake ◽  
Developmental Stages ◽  
Gill Tissue ◽  
Free Swimming ◽  
Carp Cyprinus Carpio ◽  
Sensory Structures ◽  
Eudiplozoon Nipponicum ◽  
Scanning Electron

AbstractUsing scanning electron microscopy (SEM), the external morphology of all developmental stages (egg, oncomiracidium, diporpa, just fused juvenile and adult) of the parasite, Eudiplozoon nipponicum (Monogenea, Diplozoidae), from the gills of carp was studied. During the ontogeny, the tegument, tegumentary and sensory structures are subsequently developed. The tegument of free swimming oncomiracidium occurs in two types — the ciliated and non-ciliated with numerous uniciliated sensory structures. An attachment apparatus starts to form during the oncomiracidium stage. Further developmental stages are adapted to the environment of the gills. Tegumentary folds become more apparent later in development and assist to the parasite’s attachment. In connection with its reproductive strategy, the two morphological structures of diporpa (ventral sucker and dorsal papilla) appear to play important role. On the gills, two individuals need to meet and these structures mediate the fusion between two diporpae. The hindbody of adult parasite is highly modified for attachment. The haptor, folds and lobular extensions are most developed. The forebody is flexible and able to interact with host gill tissue via the mouth and associated mouth structures. The process of food intake of the parasite was discussed.

Developmental expression of the creatine kinase isozyme system of Xenopus: maternally derived CK-IV isoform persists far beyond the degradation of its maternal mRNA and into the zygotic expression period

Development ◽  
1990 ◽  
Vol 108 (3) ◽  
pp. 507-514
Author(s):  
J. Robert ◽  
J. Wolff ◽  
H. Jijakli ◽  
J.D. Graf ◽  
F. Karch ◽  
...  
Keyword(s):  
Creatine Kinase ◽  
Differential Expression ◽  
Early Development ◽  
Developmental Expression ◽  
Developmental Profile ◽  
Maternal Mrna ◽  
Skeletal Musculature ◽  
Adult Pattern ◽  
Specific Manner ◽  
Isozyme System

The differential expression of the multilocus CK isozyme system throughout development of the two Xenopus species X. laevis and X. borealis was investigated. A cDNA containing the nearly complete coding sequence of the CK-IV subunit of X. laevis was isolated and sequenced. Early development of X. laevis proceeds with a stock of maternally derived CK-IV/IV isozyme. While the mRNA declines rapidly after fertilization and disappears before neurulation, maternal CK-IV/IV isozyme is active far beyond the onset of zygotic expression and is still detectable when tadpoles start feeding. Zygotic expression of CK-IV begins after neurulation, at stage 22/24, and seems to start simultaneously with that of another gene, CK-III. Modulation in the expression of these two genes and the appearance of two other isoforms, the CK-I and CK-II/III isozymes, take place during development in a tissue-specific manner. During metamorphosis, the CK phenotypes of eyes and skeletal musculature undergo additional changes. The final adult pattern only appears several weeks after metamorphosis. The presumed orthologous CK isozymes of X. borealis show a developmental profile similar to that of X. laevis, except that CK-II/II is equally present in oocytes and during early development, in addition to CK-IV/IV isozyme. These results show that the expression of each of the four CK genes of Xenopus is under differential developmental control.

Correlation between Chondroitin Sulfate Iron Colloid-Enhanced MR Imaging and the Histological Grade of Hepatocellular Carcinoma

1995 ◽  
Vol 36 (1) ◽  
pp. 102-105 ◽  
Author(s):  
Y. Suto ◽  
F. Kodama ◽  
M. Kamba ◽  
Y. Ohta
Keyword(s):  
Hepatocellular Carcinoma ◽  
Mr Imaging ◽  
Chondroitin Sulfate ◽  
Contrast Enhancement ◽  
Histological Examination ◽  
Histological Grade ◽  
Poorly Differentiated ◽  
Noise Ratio ◽  
Well Differentiated ◽  
T2 Weighted Images

The association between contrast enhancement by chondroitin sulfate iron colloid (CSIC) and the histological grade of hepatocellular carcinoma (HCC) was evaluated in 24 patients diagnosed by histological examination of surgical specimens (26 nodules: 11 well-differentiated and 15 poorly—moderately-differentiated nodules). In the well-differentiated HCC nodules, the tumor—liver contrast to noise ratio (CNR) was not significantly increased after i.v. CSIC injection on both T1-weighted and T2-weighted images. In the moderately-poorly-differentiated HCC, CNR was significantly increased after CSIC administration on both T1-weighted and T2-weighted images (p<0.01). MR imaging using CSIC may be useful for diagnosing the degree of HCC differentiation.

On the diet and reproduction of the oilfishRuvettus pretiosus(Perciformes: Gempylidae) in the eastern Mediterranean

2010 ◽  
Vol 91 (4) ◽  
pp. 873-881 ◽  
Author(s):  
P. Vasilakopoulos ◽  
M. Pavlidis ◽  
G. Tserpes
Keyword(s):  
Sex Ratio ◽  
Histological Examination ◽  
Developmental Stages ◽  
Eastern Mediterranean ◽  
Late Summer ◽  
Oocyte Diameter ◽  
Dietary Preferences ◽  
Fishing Gears ◽  
By Catch ◽  
Prey Items

The oilfish,Ruvettus pretiosus, is an incidental by-catch of the drifting surface longlines targeting swordfish and Thunnidae in the Mediterranean and elsewhere. Despite its global distribution and frequent occurrence in the catch of many fishing gears, little is known about its biology. In this study we examined the dietary preferences and reproductive biology of this species from specimens caught in the eastern Mediterranean. The most numerous and frequently occurring prey items were benthopelagic fish, followed by cephalopods. The sex-ratio was highly skewed in favour of females (1:8.4), while histological examination of the collected ovaries displayed six developmental stages (perinucleolar, early and late lipid stage; early, middle and late vitellogenesis). Oocyte diameter ranged from 23–69 μm at the perinucleolar stage to 224–366 μm at the late vitellogenesis stage. Spawning is expected to occur during mid and late summer; however there were no individuals available from this period. The findings are discussed in relation to the ecology of the species.

scholarly journals STUDY IN THE EPIDEMIOLOGY OF SARCOCYSTOSIS SARCOCYSTIS CAMELI IN CAMELS IN AI-QADISIYAH PROVINCE

2021 ◽  
Vol 26 (1) ◽  
pp. 56-64
Author(s):  
N. N. A. Al-Hamad ◽  
A. Y. Yacoub ◽  
A. Raishan
Keyword(s):  
Histological Examination ◽  
Post Infection ◽  
Skeletal Muscles ◽  
Developmental Stages ◽  
Thin Wall ◽  
Digestion Method ◽  
Naked Eye ◽  
Intestine Mucosa ◽  
Peptic Digestion ◽  
Eye Examination

The aim of study was to investigate the prevalence of macroscopic and microscopic sarcocystosis of 312 camels slaughtered in Al-Qadisiyah province abattoirs. The developmental stages were studied in experimentally infected dogs with Sarcocystis cameli. For macroscopic sarcocystis naked eye examination was done while for microscopic type, the methods were employed (peptic muscular digestion, trichinoscopy, squeezing and histological examination) for the detection of infection in esophagus, heart, diaphragm and skeletal muscles. The percentage prevalence of macroscopic cysts were first recorded (0.64%) among the different organs examined. The rate of microscopic infection was (83.3%) in peptic digestion method followed by squeezing and trichinoscopy were 78.47 % and 58% respectively The highest rate of infection was recorded in the esophagus and the lowest in the heart. Histological examination revealed two different morphological cysts, the first one with thin wall and the other thick striated wall. The pre patent periods were 8-9 and 10-12day respectively, each infected dog-shed total about 32 * 10* sporocysts per gram of faeces. The peak of shedding reached 326*10* sarocystis per gram of faeces day12 post infection histological development stages of the parasite were detected in the small intestine mucosa of dog in days 6 and 12 post infection.

scholarly journals Histopathological changes in the stomach wall of the European grayling Thymallus thymallus associated with severe infection by the nematode Cystidicoloides ephemeridarum

2017 ◽  
Vol 73 (11) ◽  
pp. 687-689
Author(s):  
Marek Kulikowski ◽  
Zenon Sołtysiak ◽  
Jerzy Rokicki
Keyword(s):  
Histological Examination ◽  
Developmental Stages ◽  
Severe Infection ◽  
Stomach Wall ◽  
Histopathological Changes ◽  
Thymallus Thymallus ◽  
Stomach Mucosa ◽  
European Grayling ◽  
Common Parasite

This study is a report of lesions associated with the nematode Cystidicoloides ephemeridarum (Linstow, 1972). It is a common parasite of the stomach mucosa of fish, mainly salmonids. In stomachs of 30 graylings were observed strong infection with C. ephemeridarum caught in July 2013 and February 2014 in the Dobrzyca River were examined. Adult nematodes, including females with mature eggs, and L3 and L4 larvae were recorded. Stomachs of graylings with intensive infection (146–261examples) were examined. The histological examination of a sample taken from the tissue surrounding nematodes revealed the presence of more or less confluent focal areas of destruction of gastric laminae. The numerous invasions of C. ephemeridarum are associated with intensive feeding of fish, but the different developmental stages of the parasite do not induce sufficiently strong histopathological changes in the stomach of graylings to be a cause of their death.

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