Chemical characterization of milk oligosaccharides of the tiger quoll (Dasyurus maculatus), a marsupial.

Milk oligosaccharides were separated from the carbohydrate fraction of milk of the tiger quoll a species of marsupial that is closely related to the eastern quoll, Dasyurus viverrinus. They were characterized by (1)H - nuclear magnetic resonance spectroscopy and matrix - assisted laser desorption/ionization time-of-flight mass spectrometry. The following oligosaccharides were identified; Gal(ß1-3)Gal(ß1-4)Glc, Gal(ß1-3)Gal(ß1-3)Gal(ß1-4)Glc, Gal(ß1-3)[Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-4)Glc, Gal(ß1-3)Gal(ß1-3)[Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-4)Glc, Gal(ß1-3)[Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-3)Gal(ß1-4)Glc, Gal(ß1-3)[Gal(ß1-3)Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-4)Glc, Gal(ß1-3)[Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-3)[Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-4)Glc, Neu5Ac(α2-3) Gal(ß1-3)[Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-3)[Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-4)Glc, Gal(ß1-3)[Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-3)[Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-4)Glc with an α(2-3)Neu5Ac linked to ß(1-4)Gal residue of either branch of Gal(ß1-4)GlcNAc(ß1-6) units, and Gal(ß1-3)[Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-3)[Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-4)Glc with a ß(1-3) linked Gal and an α(2-3) linked Neu5Ac. In addition, larger oligosaccharides were characterized as follows; Gal(ß1-3){Gal(ß1-3)[Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-4)GlcNAc(ß1-6)}Gal(ß1-3)[Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-4)Glc and Gal(ß1-3)[Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-3){Gal(ß1-3)[Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-4)GlcNAc(ß1-6)}Gal(ß1-4)Glc and their α(2-3) linked Neu5Ac derivatives.

Chemical characterization of milk oligosaccharides of the common wombat (Vombatus ursinus).

Previous structural characterizations of marsupial milk oligosaccharides have been performed in the tammar wallaby, red kangaroo, koala, common brushtail possum and the eastern quoll. To clarify the homology and heterogeneity of milk oligosaccharides among marsupial species, which could provide information on their evolution, the oligosaccharides of wombat milk carbohydrate were characterized in this study. Neutral and acidic oligosaccharides were isolated from the carbohydrate fractions of two samples of milk of the common wombat and characterized by (1) H-nuclear magnetic resonance spectroscopy. The structures of six neutral saccharides were found to be Gal(ß1-4)Glc (lactose), Gal(ß1-3)Gal(ß1-4)Glc (3'-galactosyllactose), Gal(ß1-3)Gal(ß1-3)Gal(ß1-4)Glc (3',3"-digalactosyllactose), Gal(ß1-3)Gal(ß1-3)Gal(ß1-3)Gal(ß1-4)Glc, Gal(ß1-3)Gal(ß1-3)[Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-4)Glc (galactosyl lacto-N-novopentaose I) and Gal(ß1-3)[Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-3)[Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-4)Glc (lacto-N-novooctaose), while those of six acidic saccharides were Neu5Ac(α2-3)Gal(ß1-3)Gal(ß1-4)Glc. (sialyl 3'-galactosyllactose), Neu5Ac(α2-3)Gal(ß1-3)Gal(ß1-3)Gal(ß1-4)Glc (sialyl 3',3"-digalactosyllactose), Neu5Ac(α2-3)Gal(ß1-3)[Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-4)Glc (sialyl lacto-N-novopentaose a), Gal(ß1-3)[Neu5Ac(α2-3)Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-4)Glc (sialyl lacto-N-novopentaose c), Neu5Ac(α2-3)Gal(ß1-3)Gal(ß1-3)Gal(ß1-3)Gal(ß1-4)Glc,, Neu5Ac(α2-3)Gal(ß1-3)Gal(ß1-3)[Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-4)Glc and Gal(ß1-3)Gal(ß1-3)[Neu5Ac(α2-3)Gal(ß1-4)GlcNAc(ß1-6)]Gal(ß1-4)Glc. In addition, small amounts of sulfated oligosaccharides but no oligosaccharides containing Neu5Gc or α(2-6) linked Neu5Ac were detected.

The field energetics and water fluxes of free-living wombats (Marsupialia: Vombatidae).

Wombats are large, fossorial, herbivorous marsupials exhibiting physical and behavioural characteristics indicative of extreme energy conservation. Previous energetics studies have been limited to their basal metabolism under laboratory conditions; little is known of the energetics of free-living wombats. We measured seasonal field metabolic rates (FMR) and water fluxes in the three species of free-living wombat using the doubly labelled water technique, to further investigate the extent of energy conservation in the Vombatidae. Measurements were taken during the wet and dry annual extremes of their characteristically harsh environments, which corresponded to seasonal extremes of food and water availability. Seasonal FMRs for all wombat species were lower than that recorded for other marsupials and well below that predicted for herbivorous mammals. Dry-season FMR of Lasiorhinus kreftii was 40% of that predicted for a mammal. Wombats maintained energy balance during the poor season by reducing FMR to about half that of the good season. Water flux rates during the dry season for the arid-adapted Lasiorhinus are amongst the lowest recorded for mammals, being only 25% of that predicted for a similarly sized herbivorous mammal. These low water flux rates enable wombats in semi-arid areas to maintain water balance without drinking. Estimated food and nitrogen intake rates were also low. We conclude that the energetically frugal lifestyle of the Vombatidae is amongst the most extreme for mammals.

Energetics and water flux of the marbled velvet gecko (Oedura marmorata) in tropical and temperate habitats.

The gecko Oedura marmorata was studied in two different climatic zones: the arid zone of central Australia and in the wet-dry tropics of northern Australia. Doubly labelled water was used to measure field metabolic rate (FMR) and water flux rates of animals in the field during the temperate seasons of spring, summer and winter, and during the tropical wet and dry seasons. FMRs were highest in the tropical wet season and lowest in the temperate winter. The geckos in central Australia expended less energy than predicted for a similarly sized iguanid lizard, but geckos from the tropics expended about the same amount of energy as predicted for an iguanid. Water flux rates of geckos from the arid zone were extremely low in all seasons compared to other reptiles, and although water flux was higher in tropical geckos, the rates were low compared to other tropical reptiles. The standard metabolic rates (SMRs) of geckos were similar between the two regions and among the seasons. Geckos selected higher body temperatures (T bs) in a laboratory thermal gradient in the summer (33.5°C) and wet (33.8°C) seasons compared to the winter (31.7°C) and dry (31.4°C) seasons. The mean T bs selected in the laboratory thermal gradient by geckos from the two regions were not different at a given time of year. The energy expended during each season was partitioned into components of resting metabolism, T b and activity. Most of the energy expended by geckos from central Australia could be attributed to the effects of temperature on resting lizards in all three seasons, but the energy expended by tropical geckos includes a substantial component due to activity during both seasons. This study revealed variability in patterns of ecological energetics between populations of closely related geckos, differences which cannot be entirely attributed to seasonal or temperature effects.