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At least 721 records · Page 40Linked to original sources
PubMed1994

The use of museum specimens to reconstruct the genetic variability and relationships of extinct populations.

In this review, we discuss the use of DNA from museum specimens to address conservation genetic questions. We provide four examples from our previous studies of the northern hairy-nosed wombat, African wild dog, Ethiopian wolf and red wolf. These species were genetically surveyed using two molecular approaches: first, analysis of short sequences in the mitochondrial genome using species-specific primers, and second, analysis of hypervariable microsatellite loci. The studies demonstrate that museum-derived DNA adds an important dimension to the genetic study of extant populations. Inaccessible populations can be studied, and both the loss of genetic variation and its distribution over space and time can be better understood. Finally, analysis of additional museum material provides definitive evidence for a hybrid origin of the red wolf.

Animals↗
PubMed1977

Red cell metabolism in red and grey kangaroos.

Glucose utilization, lactate production and glutathione regeneration were measured in the red blood cells of 2 species of Australian Marsupials, Eastern grey Kangaroo (Macropus gigantus) and red kangaroo (Macropus rufus), and were found to be significantly lower in the red blood cells from grey than that of red kangaroos.

Animals↗
PubMed1979

A histochemical study of denervated marsupial hemidiaphragm.

The marsupial (quokka) hemidiaphragm showed postdenervation hypertrophy and subsequent atrophy. The type II muscle fibres hypertrophied up to 20 days postoperation and then regressed. However, the type I fibres hypertrophied throughout the experimental period (100 days) studied. Unlike denervated eutherian hemidiaphragm, fibre-splitting was absent in the denervated marsupial muscle. An enhancement of the ATPase reaction in the denervated type I fibres may be due to dedifferentiation. Presumably innervation exerts a 'negative control' and prevents increase of type I fibre size in the normal hemidiaphragm.

Adenosine Triphosphatases↗
PubMed1976

Locomotory energetics in a marsupial (Antechinomys spenceri) and a rodent (Notomys alexis).

Steady state oxygen consumption was compared in a rodent Notomys alexis and a marsupial Antechinomys spenceri. The marsupial was found to diverge from predicted eutherian energic patterns. N. alexis appears to use energy storage as a significant part of the step cycle before becoming bipedal. Aerobic scope and heat storage during running are similar in both species.

Animals↗
PubMed1996

Review of Australian species of Theileria, with special reference to Theileria buffeli of cattle.

This review describes 4 species of parasites in Australia generally regarded as Theileria. The physiological and epidemiological characteristics of the species that occurs in cattle are discussed. Confusion still surrounds the relationship of this species with benign species of Theileria in other countries. Arguments are presented to support the proposal that the bovine species in Australia is correctly designated Theileria buffeli and that this name should apply to all the benign species of Theileria of cattle in Eurasia. The other 3 species considered in the review are proposed species from marsupials. Of these, only Theileria tachyglossi can confidently be included in the genus Theileria, because schizonts have yet to be detected in the other 2 species.

Animals↗
PubMed1991

Lens protein expression in mammals: taxon-specificity and the recruitment of crystallins.

Vertebrate lenses show remarkably taxon-specific patterns of protein composition, most obviously in the recruitment of enzymes as major crystallins. Phylogenetic relationships are particularly apparent in mammals. Here we describe eta-crystallin, which is probably identical to cytosolic aldehyde dehydrogenase, lens-specifically expressed at high abundance in the elephant shrews, primitive eutherians of the family Macroscelidae, and mu-crystallin, a novel lens protein expressed in some marsupials. We have also observed that enzymes that have been recruited as crystallins in some species are also moderately abundant in the lenses of other species. This hints that the origins of enzyme-crystallins may lie in a pool of enzymes widely expressed in lenses at fairly high levels, perhaps because they have important developmental or functional roles in the tissue.

Alcohol Dehydrogenase↗
PubMed1993

DNA fingerprint analysis of a free-range koala population.

Thirty-six koalas in a free-range Queensland population were fingerprinted using an M13 probe in combination with MspI digestion. The technique was found to be highly repeatable, with estimates of 0.1-1.6% within-gel error and 0.1-2.5% between-gel error. Of the 43 different-size fingerprint bands produced in the population, only 2 bands were common to all 36 koalas. Ten bands were quite rare, occurring at a frequency of 0.2 or less. All 36 koalas had unique DNA fingerprints (probability of 1.88 x 10(-7)), which enabled them each to be uniquely identified. Despite this, there was still a high level of band sharing in the population (mean number of shared bands = 0.749). This level is much higher than that reported for humans, birds, cats, dogs, and cattle but not as high as that reported previously for Victorian koalas. This lack of genetic variation may influence the ability of the population to respond to stress situations, such as lack of food, habitat destruction, and disease.

Animals↗
PubMed1982

Positional distribution of fatty acids in triglycerides from milk of several species of mammals.

Milk triglycerides from the echidna, koala, Tammar wallaby, guinea pig, dog, cat, Weddell seal, horse, pig and cow were subjected to fatty acid and stereospecific analysis to determine the positional distribution of the fatty acids in the triglycerides. The samples presented a wide range of fatty acids, most of which varied in content among species. The compositions of the acids at the 3 positions also varied among species, reflecting the content of these acids in the triglycerides. However, there was a general similarity in fatty acid positional distribution patterns for all the species with the exception of the echidna. The echidna exhibited a completely different fatty acid positional distribution pattern. The saturated acids were preferentialy esterified at the sn-1-position whereas the unsaturated acids were selectively esterified at the sn-2-position. The triglyceride carbon number distribution of milk from the above species (with the exception of the Weddell seal) was determined by gas liquid chromatography and compared to that predicted by the 1-random-2-random-3-random fatty acid distribution hypothesis. Agreement was excellent between observed and predicted composition for echidna, koala, Tammar wallaby, guinea pig and pig milk, and agreement was reasonable for dog, cat, horse and cow milk. Results are discussed in relation to biochemical mechanisms.

Animals↗
PubMed1977

Marsupial cells in long-term culture.

Cell lines have been developed from several species of Australian marsupials and studied during long-term growth. Cell lines developed from macropodid skin or heart tissues all had reproducible finite life-spans. However, cell lines developed from dasyurids showed bariable behavior in culture: lines developed from Antechinus stuartii and Dasyurus viverrinus had finite life-spans, while lines developed from Sminthopsis crassicaudata had indefinite life-spans. S. crassicaudata lines usually became heteroplloid, but one was still diploid after 150 population doublings, while another contained a proportion (10%) of haploid cells. Other lines were developed from the peramelid, Perameles nasuta, and the phanlngerid, Trichosurus vulpecula.

Animals↗
PubMedDate not supplied

Early chromosome condensation without cell fusion. I. Preliminary results with allogeneic and xenogeneic cells.

Early chromatin condensation in interphase cells (G1) of human peripheral blood lymphocytes has been induced without virus or cell fusion by exposure to allogeneic or xenogeneic mitotic cells. The event, although similar in some ways to the phenomenon described as "premature chromosome condensation," "chromosome pulverization," and "prophasing," differs in that it does not require the presence of viruses and cell fusion before mitosis proceeds in the G1 cell. Early chromatin condensation in interphase cells induced by mitotic cells only, consists of chromatids in the early or late G1 phase of the cell cycle that are not pulverized or fragmented at mitosis. Some of the chromosomes are twice as long as the metaphase chromosomes and exhibit natural bands. Almost twice as many of these bands are produced as by trypsin treatment of metaphase chromosomes. The nuclear membrane is intact and nucleoli are present, to which some chromosomes are attached. The DNA content of the precocious chromosomes in G1 is half the amount of the metaphase complement.

Animals↗
PubMed1997

Molecular phylogeny and evolution of the neurotrophins from monotremes and marsupials.

We have investigated the phylogenetic relationships of monotremes and marsupials using nucleotide sequence data from the neurotrophins; nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and neurotrophin-3 (NT-3). The study included species representing monotremes, Australasian marsupials and placentals, as well as species representing birds, reptiles, and fish. PCR was used to amplify fragments encoding parts of the neurotrophin genes from echidna, platypus, and eight marsupials from four different orders. Phylogenetic trees were generated using parsimony analysis, and support for the different tree structures was evaluated by bootstrapping. The analysis was performed with NGF, BDNF, or NT-3 sequence data used individually as well as with the three neurotrophins in a combined matrix, thereby simultaneously considering phylogenetic information from three separate genes. The results showed that the monotreme neurotrophin sequences associate to either therian or bird neurotrophin sequences and suggests that the monotremes are not necessarily related closer to therians than to birds. Furthermore, the results confirmed the present classification of four Australasian marsupial orders based on morphological characters, and suggested a phylogenetic relationship where Dasyuromorphia is related closest to Peramelemorphia followed by Notoryctemorphia and Diprotodontia. These studies show that sequence data from neurotrophins are well suited for phylogenetic analysis of mammals and that neurotrophins can resolve basal relationships in the evolutionary tree.

Amino Acid Sequence↗