Différenciation cytophysiologique régionale de l'épithélium uropygien chez l'embryon de canard Anas platyrhynchos

Development ◽  
1978 ◽  
Vol 46 (1) ◽  
pp. 21-35
Author(s):  
Par Jacqueline Bride
Keyword(s):  
Cellular Differentiation ◽  
Anas Platyrhynchos ◽  
Interaction Mechanism ◽  
Secretory Activity ◽  
Functional Differentiation ◽  
Branching Morphogenesis ◽  
Uropygial Gland ◽  
Preen Gland ◽  
Collecting Ducts ◽  
Set Up

The uropygial gland (preen gland), an epidermal derivative, is a bilobed, lipid-secreting gland located over the base of the tail of most birds. In the duck embryo Anas platyrhynchos, the internal branching morphogenesis of preen gland is set up at the 17th day of incubation. Each glandular lobe is made of numerous epidermal columns each of which is terminated by a bulb or end-bud. The functional differentiation of the end-buds and the development of the cellular columns into collecting ducts were investigated. The ductal epithelium, separated from the mesoderm by a continuous basal lamina, is keratinized just as in normal embryonic avian epidermis. The features which indicate glandular differentiation in the end-buds were described. Lipogenesis results from progressive cellular differentiation characterized by proliferation and development of smooth membranes. The direct ecto-mesodermal contacts, which were observed at the endbuds after the establishment of morphogenetic pattern and before the onset of glandular secretory activity, suggest that a new interaction mechanism would be required to initiate the functional differentiation.

Comparative Histomorphochemical Studies on Uropygial Gland of Kadaknath and White Leghorn Breeds of Poultry

2017 ◽  
Vol 13 (02) ◽  
Author(s):  
S. Kanasiya ◽  
S. K. Karmore ◽  
S. K. Deshmukh ◽  
R. K. Barhaiya ◽  
S. K. Gupta
Keyword(s):  
Characteristic Feature ◽  
Periodic Acid ◽  
Elastic Fibers ◽  
Moderate Activity ◽  
Uropygial Gland ◽  
White Leghorn ◽  
Preen Gland ◽  
Central Cavity ◽  
Tissue Samples ◽  
Melanin Pigmentation

The present study was conducted on ten each uropygial glands of 6 to 8 months old healthy Kadaknath and White Leghorn breeds of poultry. The tissue samples were stained by H and E for normal histological structures, Verhoeff’s stain for collagen and elastic fibers, PAS (Periodic Acid Schiff’s) for glycogen and Alcian Blue PAS method for acid mucopolysaccharides. The uropygial gland in Kadaknath and White Leghorn was composed of two lobes. Each lobe had a single duct and these ducts were joined together by isthmus. The thickness of capsule was more in White Leghorn than Kadaknath breed. The lumen of tubules showed higher concentration of secretary product in Kadaknath breed. Numbers of tubules were higher in Kadaknath. No aggregation of lymphocytes was found in the preen gland of White Leghorn, whereas in Kadaknath, there was large number of lymphocytes aggregation alongwith lymphatic nodules. Melanin pigmentation was the characteristic feature of Kadaknath which was found towards the central cavity and in between ductules. The capsule of White Leghorn showed intense PAS activity, while moderate activity was found in Kadaknath breed of poultry. Intense ACPase reaction was noticed in capsule of uropygial gland of Kadaknath and White Leghorn breeds of poultry.

scholarly journals Experimental Test of the Importance of Preen Oil in Rock Doves (Columba Livia)

The Auk ◽  
2003 ◽  
Vol 120 (2) ◽  
pp. 490-496 ◽  
Author(s):  
BrettR. Moyer ◽  
Alex N. Rock ◽  
Dale H. Clayton
Keyword(s):  
Experimental Test ◽  
Columba Livia ◽  
Uropygial Gland ◽  
Preen Gland ◽  
In Vivo Experiments ◽  
Preen Oil ◽  
Bacteria And Fungi

Abstract Most species of birds have a uropygial gland, also known as a preen gland, which produces oil that birds spread through their plumage when preening. The plumage of waterfowl deprived of uropygial oil becomes brittle and is subject to breakage. For other groups of birds, however, the importance of preen oil remains unclear. Previous workers have argued that preen oil may serve little or no function in Columbiforms (pigeons and doves). We tested that assertion by removing uropygial glands from Rock Doves (Columba livia) and assessing their plumage condition after several months. The results of that experiment showed significant degradation of plumage in the absence of oil. Our results are the first rigorous demonstration that preen oil is important for plumage condition in nonwaterfowl. We tested one possible function of preen oil—that it has insecticidal properties and that reduction in plumage condition on birds without glands is due to an increase in ectoparasites. We tested that hypothesis for feather-feeding lice (Phthiraptera:Ischnocera) using both in vitro and in vivo experiments. Lice raised in an incubator died more rapidly on feathers with preen oil than on feathers without oil, which suggests that preen oil may help combat lice. However, removal of the preen gland from captive birds had no significant effect on louse loads over the course of a four-month experiment. Although the results of our in vivo experiments suggest that preen oil may not be an important defense against lice, further experiments are needed. We also consider the possibility that preen oil may protect birds against other plumage-degrading organisms, such as bacteria and fungi.

Study on Anti-Skid Performance Degradation of Coating-Type Color Anti-Skid Pavement

2014 ◽  
Vol 716-717 ◽  
pp. 314-318 ◽  
Author(s):  
Feng Liu ◽  
Jie Sun
Keyword(s):  
Material Selection ◽  
Interaction Mechanism ◽  
Surface Characteristics ◽  
Performance Degradation ◽  
Raw Material ◽  
Degradation Model ◽  
Coating Type ◽  
Set Up ◽  
Raw Material Selection ◽  
Effect Of Surface

This study starts with analysis of interaction mechanism of tire and pavement to analyze the factors influencing anti-skid performance in pavement surface characteristics and confirm pavement characteristics related to anti-slide performance. Besides, this paper further analyzes the effect of surface coating on pavement anti-skid performance. The specific experimental study mainly concentrates on raw material selection and evaluation and the study on the performance of different particle anti-skid pavements. This paper also measures friction coefficient of anti-skid section of the extension line of Beiyuan Avenue within the use for one and a half years. The degradation model is set up to evaluate pavement performance degradation. Further, this paper estimates Jinan the service life of the experimental section of coating-type color anti-skid pavement and carries out benefit analysis and development prospect.

The Logic of the Soviet Organisational Society

2018 ◽  
Vol 23 (1-2) ◽  
pp. 91-111
Author(s):  
Evelyn Moser
Keyword(s):  
At Risk ◽  
Agricultural Production ◽  
Political Leadership ◽  
Functional Differentiation ◽  
Universal Function ◽  
The Political ◽  
Soviet Regime ◽  
The World ◽  
Set Up ◽  
The Stability

Abstract The paper describes and discusses the variant of societal differentiation that evolved under the Soviet regime. The argumentation starts with the conceptualisation of socialism as a program with a universal, function system-exceeding claim for validity. The implementation of the socialist program may be perceived as an effort to create structures which allow complete inclusion in the sense of an all-encompassing political addressability. In this regard, the political leadership tried to set up the society as a hierarchically structured organisation. The example of Soviet agriculture and the structures of Soviet villages, however, show that notwithstanding an all-encompassing degree of organisation, strictly ‘organised’ forms of economic communication coexisted with and were interrelated to ‘non-organisable’ and even ideologically deviant forms of agricultural production by personal smallholdings. Such niches of functional differentiation did not only provide compensation for the inability of the political leadership to cope with societal complexity, but also created connectivity in the world society and could hardly be oppressed without putting the stability of the regime at risk.

Differential development and emission ofTheileria parvasporozoites from the salivary gland ofRhipicephalus appendiculatus

Parasitology ◽  
1995 ◽  
Vol 111 (2) ◽  
pp. 153-160 ◽  
Author(s):  
M. K. Shaw ◽  
A. S. Young
Keyword(s):  
Salivary Gland ◽  
Salivary Glands ◽  
Rapid Development ◽  
Secretory Activity ◽  
Rhipicephalus Appendiculatus ◽  
Parasite Development ◽  
Mammalian Host ◽  
Free Access ◽  
Collecting Ducts ◽  
The Individual

SUMMARYThe initiation of feeding of infectedRhipicephalus appendiculatusadults induces the rapid development ofTheileria parvasporoblasts within the salivary gland acini leading to the production of numerous sporozoites which are inoculated into the mammalian host initiating infection. In this study the pattern of development, host cell specificity and emission ofT. parvasporozoites within the salivary glands of heavily infected, 4-day fed adultR. appendiculatusticks was examined. Infected acini were randomly distributed throughout the salivary gland. Sporozoite development within each gland was not synchronized and wide variation in the rate of parasite development, which correlated with the secretory activity of the individual acinus, was observed in all glands examined. Previous studies had shown thatT. parvadeveloped primarily in Type III ‘e’ cells. However, in heavily infected salivary glands sporogony and the emission of mature sporozoites also occurred in ‘c’ cells of Type II acini. Sporozoite emission from infected cells occurred by a process similar to apocrine secretion. The loss of the apical membrane of the infected cell allowed sporozoites free access to the lumen of the acinus and into the collecting ducts of the salivary gland. Sporozoite discharge was gradual since few parasites were found in the acinus valve or in the collecting ducts. Furthermore, the small size of the acinar valve aperature ensures that only small numbers of sporozoites can be released at any one time from an infected acinus.

Alpha 3 beta 1 integrin has a crucial role in kidney and lung organogenesis

Development ◽  
1996 ◽  
Vol 122 (11) ◽  
pp. 3537-3547 ◽  
Author(s):  
J.A. Kreidberg ◽  
M.J. Donovan ◽  
S.L. Goldstein ◽  
H. Rennke ◽  
K. Shepherd ◽  
...  
Keyword(s):  
Basement Membrane ◽  
Lung Development ◽  
Neonatal Period ◽  
Branching Morphogenesis ◽  
Mutant Mice ◽  
Integrin Receptors ◽  
Collecting Ducts ◽  
Beta 1 Integrin ◽  
Integrin Gene ◽  
Glomerular Development

A mutation was targeted to the murine alpha3 integrin gene. Homozygous mutant mice survived to birth, but died during the neonatal period. The mutation caused abnormal kidney and lung development. Mutant kidneys displayed decreased branching of the medullary collecting ducts, although the number of nephrons was not altered. Proximal tubules exhibited two distinct subsets of abnormalities, with the epithelial cells either containing excess lysosomes or becoming microcystic. In addition, glomerular development was markedly affected. In mutant kidneys, the extent of branching of glomerular capillary loops was decreased, with capillary lumina being wider than normal. The glomerular basement membrane was disorganized and glomerular podocytes were unable to form mature foot processes. Branching of the bronchi in lungs of mutant mice was also decreased and the large bronchi extended to the periphery. These results indicate a role for integrin receptors in basement membrane organization and branching morphogenesis.

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