Anatomy and physiology of the gastrointestinal tract of the Julia Creek dunnart, Sminthopsis douglasi (Marsupialia : Dasyuridae)

2000 ◽  
Vol 48 (5) ◽  
pp. 475 ◽  
Author(s):  
I. D. Hume ◽  
C. Smith ◽  
P. A. Woolley
Keyword(s):  
Gastrointestinal Tract ◽  
Cell Walls ◽  
Plant Cell Walls ◽  
Mean Retention Time ◽  
Main Site ◽  
Anatomy And Physiology ◽  
Well Differentiated ◽  
Minced Meat ◽  
Mealworm Larvae ◽  
Passage Times

The gastrointestinal tract of the endangered Julia Creek dunnart (Sminthopsis douglasi), the largest member of the genus Sminthopsis, consists of a simple, unilocular stomach and an intestine of relatively uniform calibre throughout. There is no hindgut caecum, in common with other Australian carnivorous marsupials. Brunner’s glands form a collar at the proximal end of the duodenum; they consist of simple uncoiled tubes at Day 45 of pouch life but are well differentiated at Day 60, before the young take their first solid food at Day 65–70. Rate of passage of digesta was measured in nine adult Julia Creek dunnarts on diets of minced meat with either mealworm larvae or adult crickets added, using pulse doses of the solute marker Co–EDTA and large (0.5–1.0 mm) particles of plant cell walls mordanted with Cr. Transit time (time of first appearance in the faeces) of both markers (P < 0.001) and mean retention time (the average time markers are retained in the tract) of the solute marker (P < 0.05) were shorter on the diet containing mealworms than the cricket diet. These results suggest that emptying of the stomach (the main site of digesta retention in carnivores) was delayed on the cricket diet, possibly because of longer digestion times as a result of a tougher exoskeleton. Comparison with other data suggests that total tract passage times increase among dasyurids as body size increases.

scholarly journals Uniformly 14C-labelled plant cell walls: Production, analysis and behaviour in rat gastrointestinal tract

1993 ◽  
Vol 69 (1) ◽  
pp. 177-188 ◽  
Author(s):  
D. F. Gray ◽  
S. C. Fry ◽  
M. A. Eastwood
Keyword(s):  
Gastrointestinal Tract ◽  
Cell Walls ◽  
Cultured Cells ◽  
Spinacia Oleracea ◽  
Primary Cell ◽  
Polymer Composition ◽  
Gut Contents ◽  
Gut Microflora ◽  
Plant Cell Walls ◽  
Pectic Polysaccharides

Uniformly 14C-labelled primary cell walls (14C-PCW) were purified from suspension-cultured cells of spinach (Spinacia oleracea L.) grown in a medium containing D-[U-14C]glucose. The approximate polymer composition of the 14C-PCW preparation (% total 14C) was homogalacturonan 30,rhamnogalacturonan 23, xyloglucan 10, other hemicelluloses 3, cellulose 21, lignin 0,14C-labelled protein < 3 and [14C]starch < 2. The degree of methyl esterification of the pectic polysaccharides was about 25%. The 14C-PCW contained about 4% O-acetyl and 3% non-volatile ester-linked residues. When tracer levels of these 14C-PCW were fed to rats, only about 18% of the 14C appeared in the faeces;negligible levels of 14C (0.07%) remained in the gut contents 4 d after feeding. Some 14C was present in the carcass. The results show that U-14C-labelled primary cell walls can be purified and radiochemically analysed by the methods developed here, and that primary cell walls are extensively fermented by the gut microflora of the rat.

Exploration of cell wall architecture with the rapid-freeze deep-etch technique

1993 ◽  
Vol 51 ◽  
pp. 128-129
Author(s):  
Béatrice Satiat-Jeunemaitre ◽  
Chris Hawes
Keyword(s):  
Plant Cell ◽  
Cell Walls ◽  
Cell Biology ◽  
Molecular Model ◽  
Three Dimensional ◽  
Secretory Activity ◽  
Wall Structure ◽  
Specimen Preparation ◽  
Molecular Architecture ◽  
Plant Cell Walls

The comprehension of the molecular architecture of plant cell walls is one of the best examples in cell biology which illustrates how developments in microscopy have extended the frontiers of a topic. Indeed from the first electron microscope observation of cell walls it has become apparent that our understanding of wall structure has advanced hand in hand with improvements in the technology of specimen preparation for electron microscopy. Cell walls are sub-cellular compartments outside the peripheral plasma membrane, the construction of which depends on a complex cellular biosynthetic and secretory activity (1). They are composed of interwoven polymers, synthesised independently, which together perform a number of varied functions. Biochemical studies have provided us with much data on the varied molecular composition of plant cell walls. However, the detailed intermolecular relationships and the three dimensional arrangement of the polymers in situ remains a mystery. The difficulty in establishing a general molecular model for plant cell walls is also complicated by the vast diversity in wall composition among plant species.

Wheat cell walls and constituent polysaccharides induce similar microbiota profiles upon in vitro fermentation despite different short chain fatty acid end-product levels.

2021 ◽  
Author(s):  
Shiyi Lu ◽  
Deirdre Mikkelsen ◽  
Hong Yao ◽  
Barbara Williams ◽  
Bernadine Flanagan ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Gut Microbiota ◽  
Plant Cell ◽  
Cell Walls ◽  
Short Chain Fatty Acid ◽  
Chain Fatty Acid ◽  
Plant Cell Walls ◽  
Human Gut ◽  
In Vitro Fermentation

Plant cell walls as well as their component polysaccharides in foods can be utilized to alter and maintain a beneficial human gut microbiota, but it is not known whether the...

scholarly journals Plant Cell Wall Hydration and Plant Physiology: An Exploration of the Consequences of Direct Effects of Water Deficit on the Plant Cell Wall

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1263
Author(s):  
David Stuart Thompson ◽  
Azharul Islam
Keyword(s):  
Cell Wall ◽  
Water Content ◽  
Bacterial Cellulose ◽  
Plant Cell ◽  
Cell Walls ◽  
Plant Cell Wall ◽  
Plant Cell Walls ◽  
Cell Wall Polysaccharides ◽  
Degree Of Hydration ◽  
Cellulose Composites

The extensibility of synthetic polymers is routinely modulated by the addition of lower molecular weight spacing molecules known as plasticizers, and there is some evidence that water may have similar effects on plant cell walls. Furthermore, it appears that changes in wall hydration could affect wall behavior to a degree that seems likely to have physiological consequences at water potentials that many plants would experience under field conditions. Osmotica large enough to be excluded from plant cell walls and bacterial cellulose composites with other cell wall polysaccharides were used to alter their water content and to demonstrate that the relationship between water potential and degree of hydration of these materials is affected by their composition. Additionally, it was found that expansins facilitate rehydration of bacterial cellulose and cellulose composites and cause swelling of plant cell wall fragments in suspension and that these responses are also affected by polysaccharide composition. Given these observations, it seems probable that plant environmental responses include measures to regulate cell wall water content or mitigate the consequences of changes in wall hydration and that it may be possible to exploit such mechanisms to improve crop resilience.

Glycoprotein conformation in plant cell walls

Planta ◽  
1979 ◽  
Vol 146 (2) ◽  
pp. 217-222 ◽  
Author(s):  
Roger B. Homer ◽  
Keith Roberts
Keyword(s):  
Plant Cell ◽  
Cell Walls ◽  
Plant Cell Walls

The Fine Structure of Fossil Plant Cell Walls

Science ◽  
1984 ◽  
Vol 225 (4662) ◽  
pp. 621-623 ◽  
Author(s):  
E. L. SMOOT ◽  
T. N. TAYLOR
Keyword(s):  
Fine Structure ◽  
Plant Cell ◽  
Cell Walls ◽  
Plant Cell Walls ◽  
Fossil Plant
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