The Structure and Radiographic Analysis of the Alimentary Tract of the Tammar Wallaby, Macropus Eugenii (Marsupialia) Ii. The Intestines.

1980 ◽  
Vol 28 (4) ◽  
pp. 499 ◽  
Author(s):  
KC Richardson ◽  
RS Wyburn
Keyword(s):  
Alimentary Tract ◽  
Tammar Wallaby ◽  
Radiographic Analysis ◽  
Macropus Eugenii

The Structure and Radiographic Anatomy of the Alimentary Tract of the Tammar Wallaby, Macropus Eugenii (Marsupialia) 1. The Stomach.

1980 ◽  
Vol 28 (3) ◽  
pp. 367 ◽  
Author(s):  
KC Richardson
Keyword(s):  
Gastric Emptying ◽  
Contrast Agent ◽  
Distal Part ◽  
Alimentary Tract ◽  
Tammar Wallaby ◽  
Barium Sulphate ◽  
Macropus Eugenii ◽  
Middle Compartment ◽  
The Right

A description is given of the gross and radiographic anatomy of the stomach of Macropus eugenii. The stomach is in the form of a sigmoid tube beginning at a blind sac on the left side and ending at the caudally directed pylorus on the right side. It is haustrated over the whole length of the proximal compartment and most of the middle compartment. The distal part of the middle compartment, and the distal compartment, are not haustrated. The time, but not the pattern, of distribution and mixing with digesta of orally administered barium sulphate is shown to be different in wallabies which had been recently fed and those which had not been fed for 24 h. The contrast agent was carried from the cardia towards the caudal gastric flexure along the ventricular groove. The barium sulphate first dispersed both cranially and caudally from the ends of the groove and was subsequently mixed with digesta. Gastric emptying was difficult to determine radiographically. No radiopaque material was seen in the duodenum, and digesta were therefore assumed to have passed rapidly through into the jejunum.

scholarly journals Digestive plasticity of the small intestine and the fermentative hindgut in a marsupial herbivore, the tammar wallaby (Macropus eugenii)

2006 ◽  
Vol 54 (4) ◽  
pp. 287 ◽  
Author(s):  
Adam J. Munn ◽  
Peter Banks ◽  
Ian D. Hume
Keyword(s):  
Small Intestine ◽  
Body Mass ◽  
Alimentary Tract ◽  
Nutritional Ecology ◽  
Tammar Wallaby ◽  
Proximal Colon ◽  
The Body ◽  
Macropus Eugenii ◽  
Diet Versus ◽  
Pelleted Diet

We investigated the effects of a ground, pelleted diet versus natural forage on the gross morphology of the gastrointestinal tract of a medium-sized (5–7 kg body mass) macropodid marsupial, the tammar wallaby (Macropus eugenii). The empty wet mass (g) of the small intestine of tammar wallabies maintained on a pelleted diet for 6 weeks was 22% greater than that of animals maintained on natural forage, once body mass was taken into account by ANCOVA. Similarly, the body-mass-adjusted length of the tammar wallaby caecum and proximal colon combined was 25% longer in animals maintained on the pelleted diet compared with those maintained on forage. Our data suggest that food particle size may be directly involved in controlling the size of the post-gastric alimentary tract in tammar wallabies, and thus in their diet choice and nutritional ecology. Notably, this is the first study that links phenotypic plasticity of the gut directly to diet in a marsupial and we conclude that the tammar wallaby is an excellent model for exploring the causes and consequences of digestive plasticity in macropodid marsupials.

scholarly journals Growth of the corpus luteum and its progesterone content during pregnancy in the tammar wallaby, Macropus eugenii

Reproduction ◽  
1979 ◽  
Vol 57 (1) ◽  
pp. 131-136 ◽  
Author(s):  
M. B. Renfree ◽  
S. W. Green ◽  
I. R. Young
Keyword(s):  
Corpus Luteum ◽  
Tammar Wallaby ◽  
Macropus Eugenii

Mullerian inhibiting substance production and testicular migration and descent in the pouch young of a marsupial

Development ◽  
1988 ◽  
Vol 104 (4) ◽  
pp. 549-556 ◽  
Author(s):  
J.M. Hutson ◽  
G. Shaw ◽  
W.S. O ◽  
R.V. Short ◽  
M.B. Renfree
Keyword(s):  
Tammar Wallaby ◽  
Testicular Descent ◽  
Future Studies ◽  
Macropus Eugenii ◽  
Müllerian Inhibiting Substance ◽  
Sequence Of Events ◽  
Testicular Differentiation ◽  
Testicular Migration ◽  
Australian Marsupial ◽  
Mullerian Inhibiting Substance

The ontogeny of Mullerian inhibiting substance (MIS) production by the developing testis of an Australian marsupial, the tammar wallaby (Macropus eugenii), was determined during pouch life using an organ-culture bioassay of mouse fetal urogenital ridge. This information was related to the morphological events during testicular migration and descent. MIS biological activity was found in testes (but not ovaries or liver) of pouch young from 2 to 85 days of age. MIS production had commenced by day 2, which is within a day of the first gross morphological signs of testicular differentiation. Mullerian duct regression occurred between 10 and 30 days, which partly coincided with testicular migration to the inguinal region and enlargement of the gubernacular bulb (15 to 30 days). These observations are consistent with the hypothesis that MIS may be involved in testicular transabdominal migration. The epididymis commenced development and growth only after the testis had descended through the inguinal ring. This provides no support for the suggestion that the epididymis is involved in testicular descent into the scrotum. The basic sequence of events in post-testicular sexual differentiation in the wallaby is sufficiently similar to that seen in eutherian mammals to make it an excellent experimental model for future studies of testicular differentiation, migration and descent.

Biochemical studies of intrauterine components of the tammar wallaby Macropus eugenii during pregnancy

Development ◽  
1981 ◽  
Vol 62 (1) ◽  
pp. 325-338
Author(s):  
Elizabeth J. Thornber ◽  
Marilyn B. Renfree ◽  
Gregory I. Wallace
Keyword(s):  
Protein Concentration ◽  
Specific Binding ◽  
Polyacrylamide Gel Electrophoresis ◽  
Fold Increase ◽  
Tammar Wallaby ◽  
Macropus Eugenii ◽  
Tenfold Increase ◽  
Specific Proteins ◽  
Wet Weight

The in vitro uptake and incorporation of [3H]ui idine by blastocysts of the tammar wallaby showed a 16- and 30-fold increase from day 0 to day 10 after removal of pouch young, respectively. Two of the six non-expanded blastocysts recovered on day 5 showed a tenfold increase in incorporation. During the first ten days after removal of pouch young the diameter of the blastocyst increased threefold. Endometrial exudate from gravid uteri had a higher protein concentration than exudate from nongravid uteri (39·5 ± 0·9 and 32·0 ± 2·0 mg/ml (mean ± s.e.m.), respectively). Endometrial exudates from uteri where the blastocyst was actively growing were found to contain six uterine-specific proteins. These were separated by gradient polyacrylamide gel electrophoresis. Two of the proteins were pre-albumins and the others were larger molecules (M.W. 153000–670000). Two proteins were only present at particular stages of pregnancy: the other four were present at all stages from diapause to birth, in exudate from gravid and nongravid uteri. The specific binding of progesterone and androstenedione to proteins in endometrial exudates or uterine flushings from pregnant wallabies was less than one per cent of the value obtained from day-5 pregnant rabbits. The ability of mouse blastocysts to take up and incorporate [3H]uridine into acidinsoluble material increased threefold in the presence of day-10 endometrial exudates from wallabies. However, this was less than ten percent of the values obtained in the presence of bovine serum albumin. The concentration of calcium in endometrial exudates increased from 23·6 to 45·2 μg/ml during pregnancy; in endometrium it remained at 88·7 μg/g (wet weight) throughout pregnancy, and in plasma it was 53·3 μg/ml. The concentration of zinc in endometrial exudates was 4·5 μg/ml; in endometrium it decreased from 21·8 to 13·3 μg/g (wet weight) during pregnancy and in plasma it was 0·6 μg/ml.

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