Macropus Robustus Research Articles

Gene mapping in marsupials and monotremes

To study the location of autosomal genes in the wallaroo <i>(Macropus robustus</i>), a number of rodent-kangaroo cell hybrids that retained wallaroo autosomes were typed for 24 enzymes. Expression of the kangaroo form of peptidase A (PEPA), mitochondrial malate dehydrogenase (MDH2), and nucleoside phosphorylase (NP) was detected. Chromosome studies and enzyme analysis of hybrids, subclones, and revertants enabled confident assignment of PEPA to chromosome 4 and tentative assignment of MDH2 to chromosome 1 of this species.

Use of monoclonal antibodies as a taxonomic tool in Macropodoidea (Marsupialia).

Monoclonal antibody reagents (McAbs) to kangaroo red cells and the use of a simple agglutination test constitute an efficient way of answering certain taxonomic questions. Two types of antigens are recognised; a group of conservative antigens and a group of fast-evolving antigens. The former are frequently monomorphic, the latter frequently polymorphic, within a species. The conservative antigens distinguished the Macropodoidea from other marsupial families as well as the Macropodoidea from the Potoroidae. The fast-evolving were particularly useful in detecting a hybrid zone between two subspecies of Macropus robustus, M. r. robustus and M. r. erubescens in Queensland. They also showed that there is no detectable hybridisation between the two closely related species of grey kangaroo M. giganteus and M. fuliginosus in their zone of overlap. We suggest that McAbs are useful for recognising relationships between families and superfamilies, between very closely related species and subspecies, and individuals within a species. They are probably less useful for recognising intermediate relationships.

DYNAMICS OF PERENNIAL PLANTS IN THE MULGA (ACACIA ANEURA F. MUELL.) ZONE OF WESTERN AUSTRALIA 11. SURVIVAL OF PERENNIAL SHRUBS AND GRASSES

Survival rates of arid-land perennial plant species were significantly related to climate, site factors, and grazing by kangaroos (Macropus rufus, Desmarest and Macropus robustus, Gould). Rainfall patterns ranging from severe drought to well above average resulted in responses in all species. All but Frankenia (Frankeniapauciflora, DC) responded to spatial and temporal site factors. Survival of wire wanderrie grass (Eragrostis xerophila, Domin) was severely reduced by grazing kangaroos, while poverty bush (Eremophila spectabilis, C.A. Gardn.) and Frankenra responded positively to kangaroo activity. Cotton bush (Ptilotus obovatus, Gaud.), ball-leaf bluebush (Marreana glomerifolia), (F. MueH et Tate) Wils. and Wilcox bush (Eremophila leucophylla, Benth.) showed no survival response to kangaroo grazing. The application of maximum likelihood procedures permitted subtle effects to be detected and several significant causal factors to be separated.

Lack of Correlation between Gpd Expression and X Chromosome Late Replication in Cultured Fibroblasts of the Kangaroo Macropus robustus

Cultured fibroblasts and lymphocytes from M. robustus females heterozygous for the X-linked Gpd gene were examined electrophoretically and cytologically. Gpd expression in lymphocytes was restricted to the maternal allele while in fibroblasts there was also partial expression of the paternal allele. The Gpd gene is thought to be located on the long arm of the X chromosome. However, in fibroblasts the long arm of the paternal X chromosome showed no indication of an early replicating segment.

Dynamics of Perennial Plants in the Mulga (Acacia aneura F. Muell) Zone of Western Australia. I. Rates of Population Change.

The dynamics of populations of six plant species and their responses to environmental factors were examined at Yeelirrie station in the Mulga Zone rangelands of Western Australia. Populations of plants were sampled using sequential maps drawn from low level aerial photographs of areas from which livestock had been removed and which were fenced either to exclude or permit grazing by kangaroos (Macropus rufus Desmarest and Macropus robustus Gould). All six plant species were favoured by the combination of wet years (1973-76) and the removal of livestock from these arid rangelands. Increases ranged from about 20 plants/ha/yr (Eremophila leucophylla, Benth.) to more than 700 plants/ha/yr (Eremophila spectabilis, C.A. Gardn.) during this period. Drought (1977-1979) resulted in significant declines that ranged from about 10 plants/ha/yr (Eremophila leucophylla) to nearly 600 plants/ha/yr (Eremophila spectabilis) while three species (Eremophila leucophylla, Maireana glomerifolia, (F. Muell. et Tate) P.G. Wilson and Ptilotus obovatus, Gaud.) either did not change or increased by only 30 to 60 plants/ha/yr during this period. Responses to kangaroo grazing were strongest during 'normal', post-drought years (1980-82) when Eragrostis xerophila, Domin. decreased by 178 plants/ha/yr on grazed areas while on protected areas there was an increase of 299 plants/ha/yr. This response was due to effects on both recruitment and, as discussed by Gardiner (1986), survival. Maireana glomerifolia, another important plant for livestock was suppressed by kangaroo grazing via reduced recruitment during the 'normal' period. Other species (Frankenia paucifora, DC. and Eremophila spectabilis) responded positively to kangaroo grazing activity during the same period.

Glucose-6-phosphate dehydrogenase expression in heterozygous kangaroo embryos and extra-embryonic membranes.

SummaryThe electrophoretic expression of the X-linked enzyme glucose-6-phosphate dehydrogenase was examined in heterozygous Macropus robustus embryos and their extra-embryonic membranes. The amnion and allantois, like the somatic tissues of the embryo proper, showed paternal X inactivation while the avascular and vascular yolk sac cells showed evidence of activity of both maternal and paternal alleles.

Proteins of Marsupial Erythrocyte Membranes

The proteins of erythrocyte membranes from the red kangaroo, western grey kangaroo, eastern grey wallaroo (euro), red-necked wallaby, Tammar wallaby, and brush-tail possum have been fractionated on acrylamide gels in the presence of sodium dodecyl sulfate. The pattern of proteins was remarkably similar between the different marsupial species. The pattern of Coomassie blue-staining proteins in the membranes of these species was also very similar to that of the human erythrocyte membrane. However, the glycoproteins in the marsupial erythrocyte membranes were markedly less conspicuous than those of the human erythrocyte membrane. Furthermore, the mobilities of the glycoproteins from the marsupials were different from those of the human erythrocyte membrane. The erythrocytes of the western grey kangaroo, the eastern wallaroo and the red-necked wallaby showed pronounced resistance to hypotonic lysis compared with those of the Tammar wallaby and the human. This effect seems to be related to the size of the erythrocytes rather than to differences in their protein composition.

Dictyate Oocytes of a Kangaroo (Macropus robustus) Show Paternal Inactivation at the X-linked Gpd Locus

Purified samples of large numbers of dictyate oocytes from 13 M. robustus pouch young heterozygous for glucose-6-phosphate dehydrogenase type and six homozygous controls were examined electrophoretically to determine activity states at the Gpd locus. Like somatic cortical and medullary cells, oocytes expressed only the maternal phenotype irrespective of the direction of the cross. No evidence was found of reactivation of the inactive (paternal) allele or inactivation of both maternal and paternal alleles. It was therefore concluded that unlike eutherian dictyate oocytes, only a single (maternal) allele is active in each dictyate oocyte in M. robustus. The stage of reactivation of the paternal allele remains to be determined.

Habitat use by tbe eastern grey kangaroo and wallaroo in an area of sympatry

Etude menee dans des pâturages des hauts-plateaux de la Nouvelle-Angleterre, Nouvelle-Galles du Sud (Australie). Il existe chez Macropus giganteus et Macropus robustus robustus dont l'aire de repartition se chevauche largement des differences dans le choix de l'habitat, selon que l'animal se repose ou qu'il pâture. La repartition des deux especes a differe egalement en fonction de la qualite et de la composition du pâturage

Immunology of pouch young marsupials. I. Levels of immunoglobulin transferrin and albumin in the blood and milk of euros and wallaroos (hill kangaroos: [formula omitted][formula omitted], marsupialia).

The concentration of total protein, albumin, transferrin, and immunoglobulin G of adult serum, pouch young serum, milk whey and colostrum has been estimated in three species of kangaroos, Macropus robustus , Macropus rufus (= Megaleia rufa ) and Macropus giganteus . No study of this kind has previously been published for any marsupial species. The three individual proteins were antigenically identical in all four kinds of fluid. Colostrum and milk whey are relatively enriched in transferrin but have low levels of immunoglobulin G. Serum concentrations of total protein, albumin and transferrin rise steadily throughout pouch life and attain adult values when the young finally leaves the pouch. Serum concentrations of immunoglobulin G are very low for the first 90–100 days of pouch life, being approximately half of those in milk whey for this period. After this the level rises rapidly and also reaches adult values when the young leaves the pouch. We suggest that in the first 90–100 days the pouch young is largely protected humorally by passive immunity acquired from the mother, and after this it increasingly makes its own responses.

Seasonal Variation in Daily Activity Patterns, Water Relations and Diet of Emus

The pattern of activity of Emus Dromaius novaehollandae in western New South Wales has been examined and contrasted with that of the other large native animals in the area, Red Kangaroos Megaleia rufa and Euros Macropus robustus. A detailed behavioural analysis indicated that Emus were diurnal and speni a large part of theaay feeding in both summer and winter. During hot days in summer they occasionally sheltered among trees from the radiation heat load. The water requirements of adult Emus measured by tritiated water turnover do not appear high but intake may be limited by the size of the simple gut, resulting in a relatively high frequency of drinking, once per day and occasionally twice per day during hot summer conditions. The water use of chicks, especially young chicks, was much greater than that of the adults. Water losses from an incubating bird, however, were one fifth of those of adult birds in similar conditions. The Emus were omnivorous, relying on insects, seed heads, berries and succulent vegetation. The Emus successfully make their living in the arid zone very differently from the marsupials and the basis of this is discussed in relation to recent findings about their physiological adaptations.

Competitive interactions in the dietary preference of kangaroos and sheep, cattle and goats in inland Australia

The trophic ecology of the large macropods (kangaroos and euros) is summarized. Introduction of livestock has generally favoured the build up of numbers of kangaroos in the arid zone. The reasons are discussed. This paper also reviews work in the arid and semi-arid regions of Australia on diet selectivity of sheep, cattle and goats. Comparisons between the diets selected by domestic livestock and the large marsupials (red kangaroo, Megaleia rufa and euro Macropus robustus) are considered in detail. The degree of competitive interaction and the implications are discussed. Considerable overlap occurs in the diet of goats and cattle, and between sheep and cattle. Sheep, cattle and kangaroos eat similar foods, where there is a wide choice, but the degree of competition tends to be minimized by spatial and temporal separation. Under conditions of severe feed shortage kangaroos and livestock both concentrate on areas supporting the most nutritious forage and competition is intensified.

Records of the Mammal Survey Group of Victoria, 1966-80, on the Distribution of Terrestrial Mammals in Victoria

Records collected by the Mammal Survey Group of Victoria between 1966 and 1980 have been used to map the distributions of 48 species of mammals in Victoria. Data were collected by trapping, spotlighting and chance encounters. On the basis of these records, 11 species were widespread: these are Tachyglossus aculeatus, Omithorynchus anatinus, Antechinus stuartii, Trichosurus vulpecula, Pseudocheirus peregrinus, Macropus giganteus and M. fuliginosus, Wallabia bicolor, Hydromys chrysogaster, Rattus fuscipes, Mus musculus and Vulpes vulpes. Eleven species were very restricted: these are Antechinus minimus, Perameles gunnii, Cercartetus lepidus, Gymnobelideus leadbeuteri, Macropus robustus, Pseudomys apodemoides, P. shortridgei, P. fumeus, P. novaehollandiae, Mastacomys fuscus and Notomys mitchelli. The other 26 species have distributions between these two extremes.

Studies on the Nutrition of Macropodine Marsupials. 3. The Flow of Digesta Through the Stomach and Intestine of Macropodines and Sheep.

3. The two markers 51chromium EDTA and 103ruthenium were used to examine and compare digesta flow in the eastern grey kangaroo (Macropus giganteus), the red-necked pademelon (Thylogale thetis), the tammar wallaby (M. eugenii), the eastern wallaroo (M. robustus robustus) and in sheep fed on chopped lucerne hay, and in T. thetis and M. eugenii fed on fresh grass (Phalaris aquatica). The markers were also used to define the kinetics of digesta flow in the intestine, and to estimate the flow of fluid and DM through defined regions of the stomach and intestines of T. thetis and M. eugenii fed on the lucerne diet. The pattern of digesta flow and the degree of differential flow of the 2 markers observed in the macropodines differed markedly from those in sheep and were attributed solely to the mode of transport through the elongated stomach. In the macropodines it was apparent that total mixing of forestomach contents did not occur; rather, digesta flowed slowly along the tubiform forestomach. The relationship of this mode of transport, defined as tubular flow, to stomach structure, and the possible effects on digestion in the forestomach, are discussed.

Phylogeny of neurohypophyseal hormones. Vasopressin polymorphism in three kangaroo species.

The neurohypophyseal hormones of three species of Australian marsupials belonging to the family Macropodidae (Macropus rufus, Macropus giganteus, Macropus robustus) have been investigated. In these species three active peptides have been disclosed, one with oxytocic activity and two with pressor activity. The three hormones are present in all the individual glands which have been examined. Purification has been undertaken by ion-exchange chromatography and paper chromatoelectrophoresis. The more abundant of the pressor hormones (about 80% of the total pressor activity) has been identified as lysine-vasopressin by its biological properties, its chromatographic behaviour and its amino acid composition. The second pressor principle, more basic, has not yet been chemically characterized but its pharmacological properties and its chromatographic behaviour suggest that it is closely related or identical to arginine-vasopressin. Dimorphism of vasopressins seems peculiar to Metatheria since it has not been observed in Protheria and very rarely in Eutheria.

A Highly Repeated DNA From the Genome of the Wallaroo (Macro pus Robustus Robustus)

The major satellite of M. r. robustus DNA has been isolated in a Ag+-Cs2SO4 gradient. It has a density of 1.710 g/cm(3) compared with 1.697 g/cm(3) for the bulk of the DNA, and accounts for about 10% of the total DNA. Sequence heterogeneity within the satellite was shown by an increase in density to 1.715 g/cm(3) and by a reduction of 12 degrees C in the temperature of denaturation (Tm) after renaturation. The satellite was found to occur in the centromeric regions of all chromosomes. This pattern of distribution was essentially duplicated in the genomes of other members of the wallaroo group. A polymorphism for a major block of the sequences on chromosome 5 occurred in both M. r. erubescens and M. antilopinus. Species in the wallaroo group all contained about the same amount of this sequence, while M. rufus contained 30% and M. rufogriseus 16% of the wallaroo content; all other macropods and marsupials tested had 5% or less of the wallaroo level. The thermal denaturation profiles of the hybrids formed between cRNA (to the satellite) and DNA of species in the wallaroo group were identical; hybrids formed with DNA of other kangaroo species had a delta Tm of approximately 4 degrees C relative to the wallaroo. The chromosomal locations of the sequence in M. rufus and M. rufogriseus were in major blocks on the X chromosome, in association with the nucleolus organizer. The sequence also occurred at the centromere of the Y chromosome in M. rufogriseus, and in centromeric blocks on the four small acrocentric chromosomes of M. rufus which are believed to be related to metacentric chromosomes of 2n = 16 karyotypes by fusion or fission.

DNA content variability in several species of Australian and South American marsupials

Abstract The evaluation of DNA content in Australian marsupials (Martin & Hayman, 1967; Bick & Jackson, 1967) together with the morphological analysis of the karyotype (which shows a strong variability: 2n between 10 and 32 with modes at 14 and 22) has yielded useful information for the phylogenetic analysis of this order. In this paper the DNA content, evaluated microdensitometrically as Feulgen-DNA, is compared in 6 species of South American marsupials (Lutreolina crassicaudata Desmarest, Marmosa pusilla Desmarest, Marmosa agilis Burmeister, Didelphis marsupialis Linneus, Didelphis azarae. Temminck, Monodelphis dimidiata Wagner) and 5 species of Australian marsupials (Perameles gunnii Gray, Perameles nasuta Geoffroy, Macropus giganteus Zimmermann, Macropus robustus Gould and Potorous tridactylus Kerr). No data had so far been reported on the nuclear DNA content of the South American species. The mean values in the Australian and South American marsupials, are 124% and 120% respectively of those observed...

Hypodontus macropi Mönnig, 1929, a hookworm-like parasite of macropodid marsupials.

Hypodontus macropi Mönnig, 1929, is redescribed and its taxonomic affinities discussed. H. macropi is recorded for the first time from Wallabia bicolor, Macropus robustus, M. fuliginosus, M. dorsalis, M. agilis and Thylogale billardierii. The method of attachment of the parasite and gross and histopathological changes associated with it are described. Free living larval stages are described. Experimental infestations were attempted but were not successful. Hypodontus thetidis Johnston and Mawson, 1939, is made a synonym of H. macropi.

Observations on the chromosomes and reproductive systems of four macropodine interspecific hybrids (Marsupialia : Macropodidae)

Four interspecific hybrids (male parent first), Macropus robustus X M. rufus (a female), Wallabia bicolor X M. rufogriseus (a male), M. agilis X M. rufogriseus (a male) and M. eugenii X M. dorsalis (a male), have been verified by their chromosome number and morphology. In the hybrid W. bicolor X M. rufogriseus mosaicism occurred in the lymphocytes for the number of Y chromosomes present. The pelage and skull of each hybrid showed some characteristics of each of the parent species. All hybrids were sterile. The male hybrids had scrotal testes with abundant tubules but no spermatogenesis. The female hybrid lacked the left ovary and had an otherwise complete reproductive system. The potential use of the hybrids involving M. rufogriseus for cell biological studies is discussed.

Comparison of the Diets of Yellow-Footed Rock-Wallabies and Sympatric Herbivores in Western New South Wales.

Diet of the rare yellow-footed rock wallaby (Petrogale xanthopus) was found by study of faeces along the escarpment of the Coturaundee Range in western New South Wales, Australia. Normally 42 to 52% of the diet (estimated as the occurrence of recognizable particles within a microscope field) was of forbs, mostly small herbaceous ephemeral species. During drought the most important component was browse, 44% of diet. Grass was important. There was considerable overlap of species eaten by the rock wallabies and the introduced goats and rabbits, 75% in the case of goats during drought; rabbits were not seen in the higher parts of the escarpment. There was less competition from the euros (Macropus robustus). Control of introduced herbivores may be essential if the rock wallaby populations are to have a chance of recovery.