Lasiorhinus Latifrons Research Articles

Informative enzyme/probe combinations for the multilocus DNA fingerprinting of marsupials.

DNA fingerprinting has become an invaluable tool in the study of population genetics, paternity success, and individual identification; however, the species specificity of some methods has made the wide-range screening of many different species very time-consuming. In this study we describe the development and application of reliable and informative DNA fingerprinting techniques in a range of marsupial species using three different restriction enzyme and two oligonucleotide probe combinations. Six species from four marsupial families, the koala (Phascolarctidae), tammar wallaby (Macropodidae), southern hairy-nosed wombat (Vombatidae), kowari, and dusky and brown marsupial mice (Dasyuridae) were examined. Restriction enzymes HinfI AluI and HaeIII were used in combination with the digoxygenin (DIG)-labelled oligonucleotide probes (CAC)5 and (GGAT)4. The combinations of HinfI/(GGAT)4, AluI/ (CAC)5 and AluI/(GGAT)4 were the most informative, providing highly resolved bands, low background, and the lowest band sharing between individuals. The genetic diversity evident within the different species showed a clear relationship between the level of band sharing and population size. The greatest levels of band sharing were found in the kowaris (80%), which were part of a long-term captive colony originating from a few founders, and the lowest levels of band sharing were found in the marsupial mice (30-35%) and tammar wallaby (45%), which were caught from large outbred wild populations.

Glucose-6-phosphate dehydrogenase and oxidant sensitivity of erythrocytes of three species of wombats

The investigations presented in this paper were undertaken to examine the antioxidant defence systems in the erythrocytes of three extant species of wombats: the common wombat (CW) (Vombatus ursinus), the southern hairy-nosed wombat (SHW) (Lasiorhinus latifrons) and the northern hairy-nosed wombat (NHW) (Lasiorhinus krefftii). Some of the important observations were: (1) the activity of glucose-6-phosphate dehydrogenase was 5.14 ± 0.96 enzyme units/g haemoglobin (EU/gHb) in CW, 35.69 ± 1.02 EU in SHW and 30.71 ± 1.49 EU in NHW and the levels of glucose phosphate isomerase were 40.1 ± 3.39, 93.2 ±1.96 and 74.9 ± 4.9 EU/gHb, respectively and (2) the erythrocytes of CW were found to be more sensitive to oxidant stress as measured by the degree of lipid peroxidation, haemolysis, number of Heinz bodies, and the methaemoglobin formation in the intact cells and/or haemolysates treated with three different oxidising agents — acetylphenylhydrazine, sodium nitrite and hydrogen peroxide. The CW lives in a temperate environment and the SHW, and NHW live in arid to semi-arid environments. The consequences in terms of antioxidant defence requirements are discussed.

Comparative study of the antioxidant defence systems in the erythrocytes of australian marsupials and monotremes

A comparison of the erythrocyte (RBC) antioxidant metabolites and enzymes in nine marsupial and two monotreme species was carried out. Reduced glutathione (GSH) concentrations were comparable with those reported for other marsupial and eutherian species. An important finding was that the erythrocytes of the southern hairy nosed wombat regenerated GSH faster than the erythrocytes from its close relative, the common wombat. The activities of glutathione- S-transferase, NADH-methaemoglobin reductase, Superoxide dismutase, and glutathione peroxidase (GSH-Px), showed similar levels and extents of variation as those observed in other marsupial and eutherian species. Catalase activities in the marsupials were lower than those measured in the two monotreme species and much lower than those reported in eutherian species. A negative correlation, significant at P < 0.05, was observed between GSH-Px and catalase activities in the RBC of the marsupials. Since both these enzymes “detoxify” H 2O 2, there appears to be a reciprocal relationship between the activities of these enzymes in marsupial RBC

Comparative erythrocyte metabolism in marsupials and monotremes

Concentrations of ATP and DPG, activities of 10 enzymes and the glycolytic rates were measured in the erythrocytes of 11 species of marsupials and two species of monotremes. Mean DPG concentrations were greater in the erythrocytes of marsupials than those of eutherian mammals. The opposite is true of ATP. Significant findings from the results of enzyme activities were: high activity of hexokinase (7.39 ± 0.82 EU/g Hb) in the short-beaked echidna, pyruvate kinase (37.49 ± 1.0 EU/g) Hb in bridled nailtail wallaby and glucose-6-phosphate dehydrogenase (G6PD; 41.66 ± 1.24 EU/g Hb) in black-striped wallaby. About 6- to 7-fold difference in the activity of G6PD levels between the two species of wombats was confirmed. Glucose phosphate isomerase activity was also shown to be twice as high in the red cells of the common wombat compared with those of the southern hairy nosed wombat. There were wide variations in the glycolytic rate among the species examined.

The Kidney Structure of the Common Wombat (Vombatus-Ursinus) and the Hairy-Nosed Wombat (Lasiorhinus-Latifrons)

The common wombat (Vombatus ursinus) lives in a mesic habitat whereas the hairy-nosed wombat (Lasiorhinus latifrons) inhabits a xeric habitat. The kidney structure of these two wombats was studied and it was found that kidney size, kidney weight, and kidney weight as a percentage of body weight, were larger in V. ursinus. However, relative medullary thickness, percentage medullary volume, and medullary thickness as a percentage of total thickness, were significantly greater in L. latifrons, suggesting that L. latifrons has a greater capacity to conserve water than does V. ursinus. The number of glomeruli and mean glomerular area were the same in both species whereas the mean diameter of the proximal and distal tubules was larger in V. ursinus. There were more proximal tubules per square millimetre in L. latifrons. The larger number of collecting ducts per square millimetre in the medullary region in L. latifrons indicates that the nephrons join the collecting ducts deep in the medulla, a feature that has been associated with increased urinary concentrating ability. Urinary pH was significantly lower, and urinary ammonia, creatinine and sodium levels were higher, in L. latifrons, as were plasma sodium and chloride levels. These data suggest that L. latifrons has a greater capacity to conserve water.

A morphometric study of the skulls of two species of wombats (Vombatus ursinus and Lasiorhinus latifrons).

The skulls of the wombats, Lasiorhinus latifrons and Vombatus ursinus, were measured in order to compare the craniofacial morphology, including sexual dimorphism, in these two species. The skulls of V. ursinus tend to be bigger than that of L. latifrons. In both species measurements of males are greater than those of females. The difference between maxillary and mandibular inter-molar breadth was greater, and the skull length/zygomatic arch breadth ratio was smaller, in V. ursinus than in L. latifrons. It is proposed that the masseter muscles of V. ursinus are better developed than those of L. latifrons, and that the interspecific difference in skull form is influenced by environmental factors and diet.

Digestive Strategies of the Wombats: Feed Intake, Fiber Digestion, and Digesta Passage in Two Grazing Marsupials with Hindgut Fermentation

The wombats are grazing marsupials from mesic (Vombatus ursinus) and xeric (Lasiorhinus latifrons) regions of Australia. Feed intake and digestive responses of four wombats of each species were compared on two dietary fiber levels with pelleted straw-based diets of 59% and 44% neutral detergent fiber (NDF), and on two feed particle sizes with unpelleted and pelleted alfalfa hay. Dry matter (DM) intakes were similar between fiber levels but digestibilities of DM and NDF were greater on the low-fiber diet, with a trend to longer retention of digesta markers than on the high-fiber diet. Particulate (103Ruphenanthroline) and fluid (51CrEDTA) digesta markers were excreted in similar patterns, but mean retention times were longer for particles than for fluids (52-62 h vs. 30-36 h on the high-fiber diet). Marker excretion patterns and digestive tract anatomy were integrated into a model of digesta flow where axial flow of digesta was combined with irregular mixing along the haustrated proximal colon. Patterns of fecal particle size distribution and DM in-take of the alfalfa hays indicated a more thorough comminution of feed in the dental mill of Lasiorhinus than of Vombatus. The digestive strategies of the wombats feature enhanced digestive tract capacity (Vombatus) or length (Lasiorhinus) combined with low feed intakes, which result in long retention of digesta and yield fiber digestibilities similar to those of equids and macropod marsupials. These strategies enable wombats to utilize small home ranges with pastures of poor quality and/or low abundance.

Nitrogen Metabolism and Requirements of Nitrogen and Energy in the Wombats (Marsupialia: Vombatidae)

The Wombats Vombatus ursinus and Lasiorhinus latifrons are grazing marsupials from mesic and xeric habitats, respectively. Four wombats of each species were fed pelleted isocaloric diets containing 1.0% and 0.6% N. Urea kinetics (14C-urea and 15N-urea) and whole-body protein turnover (15N-glycine) were integrated into a model of N flow through pools of amino acids, protein, and urea in the body. Maintenance dietary N requirements were the lowest reported for herbivorous marsupials: 201 and 158 mg · kg−0.75 · d−1 for Lasiorhinus and Vombatus, respectively. The mean maintenance energy requirement (140 kJ · kg−0.75 · d−1) was only 32% of the estimate for macropod marsupials. Urea was recycled extensively, with 64%–78% of synthesized urea degraded and 34%-42% reutilized in the body. Rates of creatinine excretion and whole-body protein turnover were similar to those for macropods (4.06–6.66 g crude protein· kg−0.75 d−1), even though wombats excreted 15N-glycine slowly, indicating that wombats have large protein pools, consistent with their muscular conformation. The low requirements for N and energy enable the wombats to utilize poor-quality pastures and to exploit habitats where food abundance may be limited seasonally.

Effects of Restricted Water-Intake on Digestion, Urea Recycling and Renal-Function in Wombats (Marsupialia, Vombatidae) From Contrasting Habitats

Responses to limited water availability were studied in two species of wombats from mesic (Vombatus ursinus) or xeric (Lasiorhinus latifrons) habitats. Four Vombatus and three Lasiorhinus were fed a low-quality straw-based diet containing 0.6% nitrogen and 68% neutral detergent fibre (dry-matter basis). Restriction to 50% of ad libitum intakes of drinking water reduced dry-matter intakes by 30% but did not alter digestibilities of fibre or nitrogen. Nitrogen balances were negative and similar between species and water intakes. Urea pool size (C-14 urea) increased during water restriction but urea-entry rates and the proportion of urea recycled to the gut were similar between water intakes (78-89%). Tritiated water was given to wombats in single intramuscular or intraperitoneal doses. Times to equilibration of tritium in urinary water were large and variable (45 +/- 36 h). Urinary tritium concentrations often declined erratically after equilibration, and were 14 +/- 14% lower than the tritium concentration in the blood. These irregular kinetics for tritiated water suggest that the water-dilution method requires validation for the wombats. Urinary and faecal water losses were reduced by 60% during water restriction. Water was mainly lost in the faeces, which were drier in Lasiorhinus (41 % dry matter) than in Vombatus (31 %). As blood haematocrit and plasma osmolality were similar between water intakes, extracellular spaces were apparently maintained during water restriction. Glomerular filtration rates (creatinine clearance) were low (12 mL min-1) and similar between water intakes. Therefore, a more concentrated urine was produced by tubular resorption in water-restricted wombats. Lasiorhinus had greater urinary osmolalities and urine: plasma ratios of creatinine, which reflected a greater urine-concentrating ability than Vombatus. Apparent water intakes and the ability to reduce urinary and faecal water losses in the wombats are similar to those of kangaroos. The contrasting abilities of Vombatus and Lasiorhinus to minimise both these water losses are directly related to their separate distributions.

Hindgut fermentation in the wombats: two marsupial grazers.

The wombats Vombatus ursinus and Lasiorhinus latifrons have a capacious proximal colon with only a vestigial caecum. The pattern of microbial fermentation in the hindgut of both species was studied in captive animals fed a pelleted straw diet and in wild wombats feeding on their natural winter diets. Digesta pH was low in the stomach but near neutrality along the hindgut, indicating effective absorption and/or buffering of the colonic contents. Initial proportions and production rates of short chain fatty acids in vitro reflected the fermentation of plant cell walls. Proportions of isobutyrate, isovalerate and n-valerate increased towards the distal colon indicating proteolysis and subsequent fermentation of amino acids. The low ammonia content of digesta fluid suggested that ammonia released from these amino acids was absorbed and utilized by the wombats and their gut microbes. Wild wombats had higher concentrations and production rates of short chain fatty acids than captive animals, which was consistent with the higher apparent digestibility of their natural diet. The energy from short chain fatty acids in captive animals was 30-33% of digestible intake. Energy intakes were low and similar to resting metabolic rates estimated for marsupials. Actual resting metabolic rates of the wombats are probably lower than these estimates, and the proportion of energy derived from fermentation substantially higher than the 53-61% estimated in wild wombats. The energy from fermentation clearly enables wombats to utilize diets high in fibre.

Osteological Differences of the Skulls of Lasiorhinus-Latifrons Owen, 1845 and Vombatus-Ursinus Shaw, 1800 (Marsupialia, Vombatidae)

The two extant genera of wombats, the hairy-nosed wombat Lasiorhinus latifrons and common wombat Vombatus ursinus, are distinguishable by their skull morphology. Significant size differences were found for skull length, nasal length binasal breadth, bitemporal breadth, bizygomatic breadth, parietal bone thickness and mandible length. The important different gross morphological features are summarised to allow rapid identification of these two species. A number of new diagnostic differences are described which distinguish the species from dorsal, lateral and ventral views and on the basis of mandibles and dentition. Some of these differences, and those listed in the results, also distinguish the Pleistocene fossil wombats V. mitchelli (Owen, 1838) and L. krefftii (Owen, 1871) from each other, and strongly suggest their generic status.

Effect of Drought on the Health of Wild Hairy-Nosed Wombats, Lasiorhinus latifrons

The health and nutritional status of a population of the hairy-nosed wombat Lasiorhinus latifrons inhabiting the Blanche Town region of South Australia was assessed over a period of 18 months, 12 of which were during a drought. Measurements were made of body morphology, haematological and biochemical constituents and vitamin and trace element status of animals in the field: these were examined in relation to the chemical composition of stomach contents and of faeces. During the study period, changes in body weight, body condition and selected haematological and chemical constituents were closely associated with changes in the quantity and quality of food, as measured by faecal nitrogen and organic matter and by a plant growth index. It appears that wombats in the Blanche Town region survived a drought of 12 months duration with minimal loss of body tissues and maintained physiological functions.

ADIASPIROMYCOSIS IN SOUTH AUSTRALIAN HAIRY-NOSED WOMBATS (Lasiorhinus latifrons)

Spherical organisms, with an average diameter of about 22 microns, were detected in the lungs of adult and pouched young hairy-nosed wombats (Lasiorhinus latifrons). Although infections of up to 640 X 10(3) organisms per cubic centimeter were detected, their presence produced only limited pathological change. In-vitro growth was obtained at 30 C but not at 37 C or 40 C. However, at the higher temperatures, typical chlamydospore spherules were produced by colonies initially grown at 30 c. This report presents the first record of adiaspiromycosis in Australia and in wombats.

The distribution and sizes of ganglion cells in the retinas of five Australian marsupials.

Maps of ganglion-cell distribution have been constructed from whole-mounted retinas of five Australian marsupial species. The pademelon wallaby (Thylogale billiardieri), the scrub wallaby or tammar (Macropus eugenii), and the carnivorous Tasmanian devil (Sarcophilus harissi) have both a visual streak and an area centralis. The retina of the brown bandicoot (Isoodon obesulus) also shows both these features but they are less prominent than in the former three species, whereas the burrow-dwelling, hairy-nosed wombat (Lasiorhinus latifrons) possesses a well-developed visual streak but seems to lack an area centralis. A study of ganglion-cell sizes comparing nasal and temporal retina, the visual streak, and/or the area centralis was undertaken in each species. Results show that as in the cat, small ganglion cells tend to concentrate in the visual streak. However, the temporal-nasal differences in cell sizes described in the cat (Stone et al., '80) could be detected only in those marsupials in which an area centralis was clearly recognizable.

Histology and histochemistry of the accessory reproductive glands in the male hairy-nosed wombat (Lasiorhinus latifrons).

The accessory male reproductive glands of the hairy-nosed wombat, Lasiorhinus latifrons, are a prostate and three pairs of Cowper's glands. Component units of all are branched tubular structures of varying epithelial makeup and secretory content. The prostate has the carrotlike shape and three consecutive regions commonly found in marsupials. The regions differ in their tubular histology and histochemistry: all contain secretory globules in glandular lumina. Cowper's glands A and B are histologically identical except for the absence of interstitial mast cells from gland G: gland C is characterized by narrower tubules and larger epithelial cells. Histochemical tests for protein, carbohydrate and iron indicate that glycogen is a major secretory product of the prostate (largely posterior region), iron is also secreted (mainly posterior region) and a small quantity of acid mucin is produced (mainly central region). Glycogen is a feature also of anterior prostatic glandular epithelium and of the capping cells of the urethral transitional epithelium. Cowper's gland A has considerable protein in its secretion, gland B a neutral glycoprotein and gland C a sialomucin: the latter two also exhibit cytoplasmic glycogen in their secretory cells.

Wombats detected from space

The hairy-nosed wombat ( Lasiorhinus latifrons) is a large marsupial that occurs in great numbers on the Nullarbor Plain, South Australia. Because of the animal's burrowing and mound building, which creates areas of bare ground and freshly dug soil, its approximate distribution can be mapped from digitally enhanced color LANDSAT imagery and even to some degree from good quality band-7 black and white imagery. The wombats also seem to destroy large areas of shrubland and they appear to have increased greatly in recent years. Monitoring of their spread by satellite imagery could provide a valuable and effective management tool.

The occurrence of flehmen in a marsupial — The hairy-nosed wombat ( Lasiorhinus latifrons)

The first reported occurrence of flehmen in the marsupialia is described. In addition to its previously suggested role of aiding olfactory analysis of urine, the evolution and occurrence of flehmen is discussed in terms of social structure at mating, and sexuality of adult males.

Coccidia of Wombats: Correction of Host-Parasite Relationships. Eimeria wombati (Gilruth and Bull, 1912) comb. nov. and Eimeria ursini Supperer, 1957 from the Hairy-Nosed Wombat and Eimeria arundeli sp. n. from the Common Wombat

Coccidial oocysts morphologically consistent with Eimeria ursini Supperer 1957, and E. tasmaniae Supperer 1957 were recovered from the feces of wild and captive hairy-nosed wombats (Lasiorhinus latifrons) in Australia. Eimeria arundeli so. n. was recovered from the feces of wild and captive common wombats (Vombatus ursinus). Eimeria arundeli oocysts are ellipsoidal to slightly ovoid 60.2--67.2 (63.7) X 40.6--47.6 (43.4); micropyle 3 in diameter usually visible; with oocyst wall granular, dark brown and occasionally opaque, 4--7 thick; inner oocyst wall clear, about 1.5 thick; small oocyst residuum present, four sporocysts ovoid 22.4--29.4 (25.8) X 12.6--15.4 (14.1) with protuberant Stieda body; opposite end of sporocyst also often slighly pointed; large granular sporocyst residuum obscuring sporozoites. Gametocytes of E. arundeli sp. n. and of an organism which is consistent with E. tasmaniae, are described developing in the lamina propria of villi in the small intestine. The stages in the hairy-nosed wombat are those described as Ileocystis wombati Gilruth and Bull 1912. It is suggested that the identification of the host of Supperer's E. ursini and E. tasmaniae as V. ursinus was in error and that the allopatric L. latifrons is the natural host. Eimeria tasmaniae Supperer 1957 is suppressed and E. wombati (Gilruth and Bull, 1912) comb. nov. is proposed and redescribed. No schizonts were identified among the endogenous stages, consistent with observations in the literature on other coccidia with similar gametocyte and oocyst structure.

Cholangitis associated with species of Progamotaenia (Cestoda: Anoplocephalidae) in the bile ducts of marsupials.

Gross and histopathologic changes due to infection with Progamotaenia festiva and P. effigia in the bile ducts of the marsupials, Macropus rufus, M. giganteus, M. fuliginosus, Lagorchestes conspicillatus, Vombatus ursinus and Lasiorhinus latifrons are described. The integrity of the bile duct mucosa was not impaired but varying degrees of hyperplasia and hypertrophy of mucosa and mucosal glands, inflammatory infiltration and fibrosis were found. Portal fibrosis was the prominent reaction in Lasiorhinus latifrons. Reduced prevalence of cestode infection was recorded in two populations of M. giganteus in which Fasciola hepatica also was recovered.

Structural and biochemical characteristics of the male accessory organs of reproduction in the hairy-nosed wombat (Lasiorhinus latifrons),.

A description is given of the male reproductive tract in the South Australian marsupial, the hairy-nosed wombat,Lasiorhinus latifrons; the study was based mainly on material obtained from animals shot in the field during the period October-December, but a few observations on captive wombats are also reported. The testes, located in a pre-penile scrotum, contained in the region of the ductuli efferentes a characteristic pigment, which occasionally extended as far as the caput epididymidis. The cauda epididymidis was enclosed within a separate pocket formed by the tunica vaginalis. The ductus deferens had no ampulla. The penis, bifid at the tip, was held in an S-bend position by the retractor penis muscles. The male accessory apparatus was of a highly complex type. In addition to the carrot-shaped prostate gland with three clearly discernible portions (anterior, central and posterior), three other pairs of glands were identified, which for the purpose of the present study have been designated as ‘Cowper’s glands’ (A,B, andC) without implying, however, that they are strictly analogous to the Cowper’s gland of eutherian mammals. Chemical examination of the male accessory glands led to the identification of a number of chemical substances, including fructose, sorbitol, glycogen, glucose, inositol, glycerol, citric acid, sialic acid,N-acetylglucosamine andN-acetylgalactosamine. The three most characteristic constituents of the anterior, central and posterior segments of the prostate gland were sorbitol, fructose and glycogen, respectively; the central and posterior segment of the prostate contained also some glucose andN-acetylhexosamine. Citric acid was shown to occur at high concentration in the Cowper’s glandAwhile theCgland was characteristically rich in sialic acid. A description is given of spermatozoa which had been recovered from the urine.