bluuebunny/crossref_metadata_2025 huggingface dataset:
Perinatal Changes in Plasma Oestradiol-17b, Cortisol and Progesterone and the Initiation of Lactation in Sows
Authors: L Willcox David , G Arthur Peter , E Hartmann Peter , L Whitely Justin
Published: July 2016

The concentrations in peripheral plasma of oestradiol-17 p, cortisol and progesterone were determined in 10 sows from 5-6 days prepartum to 4 days post partum. At the same time, the presence and composition of mammary secretion was monitored. Plasma progesterone levels declined from 4�9�0�6flgl-1 (mean�s.e.m.) 12h prepartum to 2�6�0�5flgl-1 at farrowing, and to about 1 flg 1- I by day 1 post partum, although the timing of the fall in plasma progesterone level ranged from day 4 prepartum to the day of parturition in individual sows. Farrowing in all sows was associated with a fall in plasma oestradiol-17P levels, from 0'68�0'07 flgl-' to O'13flgl-' 12h after the start of labour, and with a rise in plasma cortisol level from 14'09�3'74flgl-1 24h prepartum to 43� 66 � 7� 06 flg 1- I when lactation was becoming established. Mammary secretion was obtained from individual sows up to 3 days prepartum: the onset of lactation was assessed visually by evaluation of the colour and viscosity of secretions against a six-point scale ranging from no secretion to precolostral secretion to mature milk. Lactogenesis was estimated also from the concentrations of lactose, immunoglobulins G, Na + and K + in mammary secretions obtained postnatally. The timing of the first expression from the teats was not correlated with the onset of lactation as measured by changes in milk composition. Further more, there was no relationship between circulating progesterone, oestradiol-17 p or cortisol levels and the day on which secretion was first expressed. We conclude that, in the sow, lactogenesis, as indicated by changes in milk composition, coincides postnatally with decreased plasma concentrations of oestradiol-17 p, cortisol and progesterone. Furthermore, observation of the colour and viscosity of mammary secretion, rather than analysis of its constituents, may determine lactogenesis inaccurately in sows owing to the rapid but variable onset of lactation in this species.
Antifungal Activity of Western Australian Soil Actinomycetes against Phytophthora and Pythium Species and a Mycorrhizal Fungus, Laccaria laccata
Authors: Keast D , Tonkin C
Published: July 2016

Soil pH, soil moisture content and soil organic matter content did not appear to influence significantly the total numbers of actinomycetes isolated from sample sites in Western Australia. However, seasonal influences exist with summer conditions leading to higher spore isolation. Substantial but non-specific antifungal activity against Phytophthora cinnamomi, P. cryptogea, P. nicotiana, Pythium proli/erum and L. laccata was detected in vitro from many of the 2367 actinomycetes isolated. Antifungal activity mayor may not occur in members of the same actinomycete group, suggesting segregation of antifungal capacity within all groups. A limited number of actinomycete groups was isolated from the rhizosphere of plants and these exhibited similar properties to their counterparts in soil or litter. Actinomycetes isolated from the rhizosphere of Pinus radiata produced a high degree of in vitro antifungal activity against the Phytophthora species but, in general, actinomycetes isolated from root surfaces exhibited antibiosis against all the fungi tested. More actinomycetes showed antifungal activity from soils where P. cinnamomi was causing dieback of jarrah and other understorey species.
Amino Acid Sequence Studies on Sheep Liver Fructose-bisphosphatase. II The Complete Sequence
Authors: Fisher WK , Thompson EOP
Published: July 2016

The cyanogen bromide fragments of S-carboxymethylated fructose-bisphosphatase were purified. The amino acid sequences of the small fragments were determined by the dansyl-Edman method. The large fragments were subjected to proteolytic digestion to give smaller peptides more amenable for purification and sequencing by similar methods. Enzyme digests of the S-carboxymethylated enzyme gave overlap peptides containing the methionine residues.
Integumental Chitin Synthase Activity in Cell-free Extracts of Larvae of the Australian Sheep Blowfly, Lucilia cuprina, and Two Other Species of Diptera
Authors: Turnbull IF , Howells AJ
Published: July 2016

Chitin synthase activity has been demonstrated in crude homogenates of larval integuments from L. cuprina and in similar preparations from Musca domestica and Calliphora erythrocephala. This is the first report of an insect integumental chitin synthase. This activity brings about the incorporation of radioactivity from UDP-N-acetyl-[14C]glucosamine into an ethanol- and alkali-insoluble form. A major part of this labelled product has been characterized as chitin by its insolubility in alkali, resistance to degradation by proteases and its susceptibility to digestion by chitinase and RCI. Most of the radioactivity solubilized during digestion by chitinase co-migrates with N-acetylglucosamine, glucosamine and chitobiose during paper chromatography. Some radioactivity also becomes incorporated into non-chitin products in this system. There is substantial evidence that incorporation is not brought about by whole epidermal cells or by microbial contamination in the homogenates. The extent of incorporation obtained with the homogenates is limited by the presence of degradative enzymes which rapidly break down the substrate (UDP-N-acetylglucosamine). The incorporation was partially inhibited (50-70%) by both polyoxin-D (apparent Ki 0'04I1M) and diftubenzuron (apparent Ki 5-8 11M). This is the first report of a cell-free chitin-synthesizing system derived from insect tissue which is sensitive to inhibition by diftubenzuron.
Glucose Turnover and Hepatocyte Glucose Production of Starved and Toxaemic Pregnant Sheep
Authors: E Wastney M , Wolff JE , Bickerstaffe R
Published: July 2016

Ewes bearing twins were starved for 10 days during the last month of gestation to induce ovine pregnancy toxaemia (OPT). Glucose turnover was measl,lred by a primed continuous infusion of [U_ '4C]_ and [6-3HJglucose at the end of 10 days of starvation (non-susceptible), or earlier when ewes became recumbent with OPT (susceptible). All ewes were slaughtered at the end of the infusion and hepatocytes were prepared in order to measure glucose production from different substrates. Many of the ewes had dead foetuses when slaughtered. Glucose production rates by hepatocytes with the substrates propionate, lactate or alanine were significantly less from the susceptible ewes than were those from non-susceptible ewes. These low rates were not stimulated by incubation with glucagon (10-8 M), glutamine or glycerol. Rates of glucose turnover and of hepatic glucose production from all substrates were higher for ewes with dead than with live foetuses. The data support the hypothesis that pathogenesis of OPT is related to an impairment of hepatic gluconeogenesis, and further suggest that, in starved pregnant ewes, maternal glucose production may be restrained in the presence of a live foetus.
Limitations Imposed by Testicular Blood Flow on the Function of Leydig Cells in Rats in vivo
Authors: Setchell BP , Galil KAA
Published: July 2016

Testis blood flow per testis closely follows testis weight in rats made aspermatogenic by a single exposure of the testis to 43�C for 30 min or 500 rad (5 Gy) of irradiation from a caesium source, or following ligation of the efferent ducts. Aspermatogenesis following these treatments was associated with only minor changes in the concentrations of testosterone in peripheral blood before stimulation with human chorionic gonadotrophin (hCG), and a reduced responsiveness to hCG when testis weight had fallen after heating. The concentrations of testosterone in testicular venous blood was normal or above normal during aspermatogenesis resulting from heat or irradiation, and only slightly reduced following efferent duct ligation.
Effects of Oestradiol on Plasma Concentrations of Luteinizing Hormone in Ovariectomized Ewes with Clover Disease
Authors: Adams NR , Martin GB
Published: July 2016

The effects of oestradiol on plasma luteinizing hormone (LH) concentrations were examined in 15 ovariectomized control ewes and 15 similar ewes with permanent infertility after prolonged grazing on oestrogenic clover pasture ('clover disease'). Before treatment, the plasma concentrations of LH were similar in the control and affected ewes. After intravenous injection with 40 pg oestradiol-I 7 p during the anoestrous season, the decline in LH concentration was greater in the clover-affected ewes and the subsequent elevation above original baseline levels was smaller. After intramuscular injection with 15 or 30 pg oestradiol benzoate during the normal breeding season, fewer clover-affected ewes showed a surge of LH, and the response was both reduced and retarded. This difference between the two groups has not been observed in studies on intact ewes, and it is suggested that in intact ewes the difference is masked by a greater tonic LH activity in affected ewes. The results of the present study are consistent with the hypothesis that prolonged exposure to oestrogenic pasture has a differentiating, or 'androgenizing' effect on the adult ewe.
Heritability of Worker Characters in the Honeybee (Apis mellifera)
Authors: Oldroyd B , Moran C
Published: July 2016

Heritability of characters (e.g. hamuli number) of honeybee workers can be estimated from data obtained from a random sample of colonies from a single population without the need for controlled matings. Formulae are developed for the estimation of relatedness among workers within colonies as a function of number of drone matings with the queen and the relatedness among these drones. Heritability is then estimated by dividing the intraclass correlation of the character by the relatedness among the workers within colonies. Estimates obtained by this method are shown to be considerably less biased than those obtained by analysing data from single-drone inseminations because of the contribution of dominance variance to the covariance of sib workers.
Qualitative and Quantitative Changes in Milk Fat during Lactation in the Tammar Wallaby (Macro pus eugenii)
Authors: Green Brian , Griffiths Mervyn , MC Leckie R
Published: July 2016

There are major quantitative and qualitative changes in the milk lipids during lactation in the tammar wallaby, Macropus eugenii. The crude lipid content of the milk is relatively low during the first 10 weeks of lactation; between 10 and 26 weeks post partum the lipid content increases gradually but after that it increases rapidly. The triglyceride fraction of the lipid at early stages oflactation contains a large amount of palmitic acid and relatively little oleic acid whereas mature milk exhibits little palmitic and much oleic acid. In the early stages of lactation fat represents 15% of the total solids and carbohydrate 55%; around 26-30 weeks post partum the carbohydrate moiety falls sharply to a level less than 2% of the solids while lipids increase to c. 60% of the solids. These changes coincide with increases in milk solids, emergence of the young from the pouch, ingestion of herbage, and fermentation of cellulose in the stomach.
Studies on metatherian sex chromosomes. XII. Sex-linked inheritance and probable paternal X-inactivation of a-galactosidase A in Australian marsupials.
Authors: Cooper DW , Woolley PA , Maynes GM , Sherman FS , Poole WE
Published: July 2016

An investigation of genetic variation in the electrophoretic mobility of the enzyme a-galactosidase A (EC 3.2.1.22) has been carried out for 33 species of Australian metatherian (marsupial) mammals. The results are compatible with the enzyme being sex-linked in macropodids (kangaroos and wallabies) and probably in dasyurids (marsupial 'mice', etc.), as it is in eutherian (placental) mammals. The results also suggest that the mode of dosage compensation for this locus is the same as for other sexlinked loci in kangaroos, i.e. paternal X inactivation, rather than the random X inactivation system of eutherian mammals. The bearing of the enzyme mobility data on phylogenetic relationships among macropodid species is discussed.
Plasma Luteinizing Hormone and Testosterone Concentrations in Different Breeds of Young Beef Bulls in the Tropics
Authors: Post TB , Bindon BM
Published: July 2016

Plasma concentrations of luteinizing hormone (LH) and testosterone were measured at 3, 8 and 11 months of age in 48 Africander cross (AX), 24 Brahman cross (BX), 21 Hereford-Shorthorn, selected (HSS) and 14 Hereford-Shorthorn, random-bred (HSR) bulls. In all breeds plasma LH was lower (P<O� 01) at 8 months (1�7 ng/ml) than at 3 months (2�6 ng/ml) or at 11 months (2�6 ng/ml). Over all ages there were no differences among breeds in mean plasma LH (AX 2�4, BX 2�4, HSS 1�8, HSR 2�2 ng/ml) and no breed X age interactions. In contrast, plasma testosterone increased significantly (P<O� 01) with age and at a faster rate in the AX breed, resulting in a significant (P<O� 05) breed X age interaction. Testosterone concentrations, though similar among breeds at 3 months of age (0�45 ng/ml), were much higher (P<O� 01) by 11 months in AX (2�56 ng/ml) than in BX (1�30 ng/ml), HSS (0�78 ng/ml) or HSR (0�66 ng/ml) bulls.
Cortical Cell Types and their Distribution in Wool Fibres
Authors: FG Orwin Donald , L Woods Joy , L Ranford Stephen
Published: July 2016

A method of determining cell types in wool fibres by methylene-blue staining has been extended to allow relationships between cortical cell type and cortical diameter to be studied in wools from individual sheep. Application of the method to wools from 12 sheep from six breeds showed that orthocortical cells were the predominant cell type produced. The percentage area occupied by orthocortical cells in a fibre cross-section increased with increasing cortical diameter in either a curvilinear (log-linear) or a linear manner. Nutritional stress or season may have affected the relationship in some sheep.
A Sensitive Procedure for Screening Microorganisms for the Presence of Penicillin Amidase
Authors: Baker WL
Published: July 2016

A procedure is described for screening bacteria for the presence of penicillin amidase. Cells, grown in the presence of phenylacetic acid, are incubated with phenoxymethylpenicillin (type I), benzylpenicillin (type II) or ampicillin and the 6-aminopenicillanic acid formed is detected and quantitatively estimated by its strong reaction with fluorescamine at pH 4. There is no requirement for separation of the penicillin substrate from the product but when a-aminobenzylpenicillin derivatives are used as enzyme substrates the amount of 6-aminopenicillanic acid formed must be determined by calculation. The procedure allowed positive and reliable identification of penicillin amidases in six organisms known to produce the enzyme and indicated that some of these enzymes had different properties in reactivity towards a-aminobenzylpenicillin derivatives.
Serological and Biochemical Factors in Bovine Ephemeral Fever
Authors: D St George T , Cybinski DH , Murphy GM , K Dimmock Corrine
Published: July 2016

Clinical signs of ephemeral fever, which were observed in individual cattle during two successive epidemics in 1973 and 1976, were related to biochemical, cellular and serological changes in the blood. The rise in peripheral blood neutrophil counts in sampies collected from 12 sentinel cattle on a daily basis before, during and after natural disease in the two epidemics to mean peaks of 9 . 6-12 . 5 X 109 per litre, and fall in counts of lymphocytes to a trough of 5-7 X 109 per litre was found to occur on the same day as the fever peak. A fall in serum calcium levels from a normal mean of 2�55 mmol/l to 2�0 mmol/I occurred on the day clinical signs were most pronounced. Serum magnesium levels were affected to only a minor degree. Plasma fibrinogen rose from a normal mean of 5�0 g/I to a peak of 18 g/I on the second day of disease and fell towards normal in the week after recovery. Neutralizing antibodies to bovine ephemeral fever virus were detected up to 63 days prior to clinical disease, and the rise of antibody after recovery was secondary in pattern. Serological evidence of a prior infection with an antigenically related virus, Kimberley virus, was found in these animals. In more severe clinical cases of ephemeral fever serum calcium levels were as low as 1�95 mmol/l. Treatment of cattle showing clinical signs of the disease with phenylbutazone and calcium borogluconate was favourable.
Characterization of Melanocytes in Wool-bearing Skin of Merino Sheep
Authors: Forrest JW , Fleet MR , Rogers GE
Published: July 2016

The distribution and character of melanocytes in the wool-bearing skin of Merino sheep of known genotypes were examined by light and electron microscopy. In black Merino sheep (ww, homozygous recessive), melanocytes were localized within three regions of the skin: epidermal-dermal border, outer root sheath and follicle bulb. Melanocytes within these regions were found to be actively producing melanin, had numerous dendritic extensions and were able to transfer melanin to adjacent keratinocytes. In a black Merino sheep whose fibres were white due to an experimentally induced copper deficiency the melanocytes were amelanotic. In contrast, for both WW (homozygous dominant) and Ww (heterozygous) white Merino sheep melanocytes were observed only at the epidermal-dermal border of the epidermis. The melanocytes appeared also to differ in character containing less melanin, appearing less dendritic in shape and having a reduced ability to transfer melanin to adjacent keratinocytes. The gene for white fleece (W), therefore, appears able to regulate pigmentation in Merino sheep, at least in part, by controlling the location and activity of melanocytes within the wool-bearing skin.
Flow Cytometry and Flow Sorting of Metaphase Chromosomes from the Dasyurid Marsupial Dasyurus viverrinus
Authors: Wainwright Brandon , Hope Rory
Published: July 2016

Metaphase chromosomes (2n = 14) from D. viverrinus were analysed by flow cytometry and flow sorted into six homogeneous groups. Relative chromosomal DNA contents and distribution frequencies of the groups corresponded closely with values for the karyotype obtained by conventional methods.
Genetic Variation of the Dimeric Haemoglobin of the Bivalve Mollusc Anadara trapezia
Authors: Mann RG , Fisher WK , Gilbert AT , Thompson EOP
Published: July 2016

The bivalve mollusc A. trapezia has two haemoglobins, a tetrameric major haemoglobin, and a dimeric minor haemoglobin, the latter having two identical chains that are different from the chains in the tetramer. Genetic variation in the dimer results in two different haemoglobins, HbIIa and HbIIb, and it is known that the relative proportions of these two polymorphic forms vary with latitude along the eastern coastline of Australia. The HbIIb variant is more common at higher latitudes where water temperature may act as selecting agent. Comparative peptide mapping and amino acid analysis of peptides have shown that in HbIIa an aspartyl residue replaces the seryl residue found in HbIIb at residue 64, position E2 in the E helix. The E and F helices have recently been shown to be highly conserved in arcid globins and to be involved in subunit contacts in the cooperative dimers.
Solubilization of Native Actin Monomers from Human Erythrocyte Membranes
Authors: Tilley Leann , Dwyer Margaret , Ralston GB
Published: July 2016

Up to 50% of the actin in erythrocyte membranes can be solubilized at low ionic strength in a form capable of inhibiting DNAse I, in the presence of 0�4 mM ATP and 0�05 mM calcium. In the absence of calcium and A TP, actin is released but is apparently rapidly denatured. Solubilization of G-actin increases with temperature up to 37�C. At higher temperatures, actin is released rapidly but quickly loses its ability to inhibit DNAse 1.
Pigmented Spots in the WoolBearing Skin of White Merino Sheep Induced by Ultraviolet Light
Authors: Forrest JW , Fleet MR
Published: July 2016

Black-grey pigmented skin spots, some of which contained pigmented wool fibres, were observed in a flock of 8� 5-year-old white Merino ewes. The spots were concentrated along the backline and increased in number following shearing, suggesting exposure to sunlight to be of importance in the development of these non-congenital pigmented skin spots in genetically white Merino sheep. To test the effect of ultraviolet light, white Merino sheep, ranging in age from 3 to 8 years, had a closely clipped mid side area of wool-bearing skin irradiated on each of 28 consecutive days. Pigmented skin spots developed in 6 of the 16 white Merino sheep irradiated. Spots first appeared after 10 days of irradiation, the number subsequently increasing with time, and two skin spots were found to contain sparse numbers of blackgrey pigmented wool fibres. Histological examination showed both the naturally occurring and irradiationinduced pigmented skin spots resulted from an increase in both number and activity of melanocytes localized along the epidermal-dermal border of the epidermis. With time, the melanocytes were observed to have entered, to varying depths, the outer-root sheath of follicles still producing white wool fibres. These ultraviolet-light-induced changes to epidermal melanocytes in white Merino sheep presumably occur due to alterations within the local tissue environment in which the melanocytes lie.
Effects of the Sheep-Chewing Louse (Damalinia ovis) on the Epidermis of the Australian Merino
Authors: Britt AG , Cotton CL , Pitman IH , Sinclair AN
Published: July 2016

Frozen longitudinal skin sections taken from the dorsal thoraco-lumbar region of adult Merino sheep that were infested with the sheep-chewing louse were examined by light microscopy. The epidermis of infested sheep exhibited acanthosis due to hyperplasia of the stratum spinosum, and orthokeratosis. The thicknesses of the uncornified epidermis, the stratum corneum, and the sudanophilic region were significantly greater (P < O� 005) than equivalent regions in louse-free Merinos and the results suggest that a positive correlation exists between the thickness of each region and the level of louse infestation. The results indicate that the variance in region thickness was greater in lousy than in louse-free sheep (P < 0'005).
Changes in Prolactin in Peripheral Plasma during Lactation in the Brushtail Possum Trichosurus vulpecula
Authors: Hinds LA , Janssens PA
Published: July 2016

A heterologous double-antibody radioimmunoassay has been validated for prolactin in plasma and pituitary preparations of T. vulpecula. Serial dilutions of crude pituitary homogenates and plasmas from several marsupials and purified prolactin from the tammar, Macropus eugenii, showed parallel dose response curves. In both male and female possums plasma prolactin concentrations increased in response to a single intravenous injection of thyrotrophin releasing hormone.
Plasma Prolactin Concentrations throughout Lactation in the Eastern Quoll, Dasyurus viverrinus (Marsupialia: Dasyuridae)
Authors: Hinds LA , Merchant JC
Published: July 2016

Blood samples were collected throughout lactation from eight D. viverrinus, and the concentrations of prolactin in the plasma determined by an heterologous, double-antibody radioimmunoassay
The Movement of Fluids and Substances in the Testis
Authors: Setchell BP
Published: July 2016

Department of Animal Sciences, Waite Agricultural Research Institute, University of Adelaide, Glen Osmond, S.A. 5064
Isolation of a New Rhabdovirus in Australia Related to Tibrogargan Virus
Authors: Cybinski DH , PGard G
Published: July 2016

A virus isolated from the blood of a healthy steer and designated DPP53 was shown to have rhabdovirus morphology. Although DPP53 virus was antigenically related to Tibrogargan virus by reciprocal immunofluorescence and neutralization tests, the viruses were distinguishable by neutralization tests. DPP53 virus contained RNA and was sensitive to both ether and chloroform. The geographical distribution of neutralizing antibody to DPP53 virus in Australian cattle corresponded to the distribution of Culicoides brevitarsis indicating that this virus may be arthropod-borne with this midge as a possible vector. Antibody to DPP53 virus was detected in serum from cattle, buffalo, dogs and one horse, but not in serum from deer, pigs, humans or wallabies. Highest virus titres were obtained by growth in Vero and BHK2l cell cultures, but the virus could also be grown in Aedes albopictus cell cultures. Higher virus tit res were obtained when the multiplicity of infection was low. The name advanced for DPP53 virus is 'Coastal Plains' virus.
Oxygen and Morphological Changes in Allomyces macrogynus
Authors: Youatt Jean
Published: July 2016

The supply of oxygen to cultures of A. macrogynus influenced the time of hyphal emergence, the angle of the hyphal tube to the rhizoid and the hyphal diameter. Reduced aeration favoured the release of both zoosporangia and resistant sporangia in cultures. Spores exhibited chemotaxis and hyphae exhibited chemotropism to oxygen.
Osmotic Pressure Measurements on Insulin: Anomalous Results Indicate that the Monomer is Preferentially Adsorbed
Authors: D Jeffrey Peter
Published: July 2016

The concentration dependence of the number average molecular weight of insulin at pH 2, ionic strength 0'05, and 20�C as determined by osmotic pressure measurements indicates that the .hormone is a homogeneous protein of molecular weight close to that of the dimer. Since sedimentation equilibrium experiments confirm what is well known, namely that insulin is a self-associating protein dissociating to monomer under these conditions, an explanation for the anomaly was sought in the possible loss of protein from solution by adsorption. Analysis of the results strongly supports this conclusion and consideration of the adsorption properties of insulin in terms of hydrophobic interactions shows them to be consistent with the behaviour of insulin as a self-associating protein. The monomer appears to be the primary molecular species responsible for insulin adsorption.
Mitotic Activity in Cells of the Wool Follicle Bulb
Authors: Hynd PI , Schlink AC , Phillips PM , Scobie DR
Published: July 2016

Mitotic activity in the cells of the germinative region of wool follicle bulbs was quantified by using small (0 '1-0; 5 ml) intradermal doses of colchicine and selective staining of the metaphase-blocked nuclei using either crystal violet, iodine and eosin or haematoxylin and eosin. The number of metaphase nuclei present 3 h after colchicine administration increased with colchicine dose from 0 to 1 p,g and thereafter remained relatively constant up to 200 p,g colchicine. The accumulation of metaphase nuclei was linear for up to 6 h after intradermal colchicine. The metaphase-blocking effect of intradermal colchicine was confined to a radius of less than 5 cm from the injection site, allowing a number of estimates of mitotic rates to be made over a small area of skin. Such estimates revealed little variation in mitotic activity over the midside region of the sheep, although there were substantial differences in follicle activity at different sites over the body. The technique is simple, allows serial or concurrent estimates of mitotic activity to be made in the same animal, and eliminates problems associated with intravenous colchicine administration. It was used to derive the relationship between follicle activity and fibre production after nutritional changes, and to define the time course of mitotic events after administration of the antimitotic defleecing agent cyclophosphamide.
Response of Pre-pubertally Castrated Rams and Ewes to Artificial PhotoperiodChanges in Plasma LH and Prolactin
Authors: Poulton AL
Published: July 2016

Castrate rams and ovariectomized ewes were maintained in the presence of entire rams and ewes and subjected to successive periods of alternating 6 h light: 18 h darkness ('short' days) and 18 h light: 6 h darkness ('long' days) preceeded by a period of 12 h light: 12 h darkness ('constant' light days). Plasma concentrations of LH and prolactin were measured in the castrate animals in order to determine how LH and prolactin secretion responded to (i) the artificial light regime and (ii) corresponding periods of elevated or depressed testicular and ovarian activity in the entire rams and ewes.
Electrophoretic Resolution of Species Boundaries in Australian Microchiroptera. II. The Pipistrellus Group (Chiroptera: Vespertilionidae)
Authors: Adams M , Baverstock PR , Watts CHS , Reardon T
Published: July 2016

Forty-four specimens of the Pipistrellus complex from Australia were analysed for 36 allozyme loci. The data show that four species were represented in the material, two of which are sympatric in the north, and two of which are allopatric in the south. The data are consistent with separate generic status for the two southern species.
Variation in Plasma Concentration of Insulin-like Growth Factor-l and its Covariation with Liveweight in Mice
Authors: T Blair H , McCutcheon SN , Mackenzie DDS , Gluckman PD , Ormsby JE
Published: July 2016

Three experiments were undertaken to examine the degree and causes of variation in plasma concentrations of insulin-like growth factor-l (IOF-I) in mice. The relationship between IOF-l concentrations and liveweight was also examined. In all three experiments, a number of non-genetic factors were found to contribute significantly to the variation in IOF-l concentrations, the most important of these being sex and litter size. In one experiment, where pups from 16 litters were cross-fostered to avoid the confounding of maternal and direct genetic effects, a heritability of 0'40 � 0�27 was estimated for plasma IOF-l concentration at 35 days of age. To examine further the existence of genetic variation in plasma concentrations of IOF-l and the genetic covariation between plasma IOF-l levels and other body traits, a selection experiment with mice has been initiated. Moderate to strong phenotypic correlations between IOF-l concentrations and weight at an early age have been found in all three experiments.
Effect of Immunization against Progesterone on Oestrus, Cycle Length, Ovulation Rate, Luteal Regression and LH Secretion in the Ewe
Authors: Thomas GB , Oldham CM , Hoskinson RM , Scaramuzzi RJ , Martin GB
Published: July 2016

The effects of active immunization against progesterone on reproductive activity were studied in Merino ewes. Immunization against progesterone caused a shortening (P < 0'01) of the interval between ovulations from 17-18 days (controls) to between 6 and 10 days (immunized group); this was associated with a corresponding reduction in the interval between LH surges. The immunized ewes also had higher (P < O� 05) ovulation rates (1' 72) than controls (I. 25) and exhibited a reduced (P < 0'01) incidence of oestrus (26% v. 95%). Many immunized ewes continued to ovulate despite the persistence of corpora lutea from earlier ovulations which led to an accumulation on the ovaries of many corpora lutea of different ages. The frequency of LH pulses in ewes immunized against progesterone (1'8 � 0�2 pulses/4 h) was significantly (P < 0'001) higher than that of control ewes (0'3 � 0�1 pulses/4 h). This study highlights the importance of progesterone in the control of oestrus, ovulation, ovulation rate, luteal regression and the secretion of LH in the ewe.
Control of Steroidogenesis in Small and Large Bovine Luteal. Cells
Authors: Hansel William , W Alila Hector , P Dowd Joseph , Yang Xiangzhong
Published: July 2016

Evidence was cited to show that: (1) prostacyclin (PGI2) plays a luteotrophic role in the bovine corpus luteum and that products of the lipoxygenase pathway of arachidonic acid metabolism, especially 5-hydroxyeicosatetraenoic acid play luteolytic roles; (2) oxytocin of luteal cell origin plays a role in development, and possibly in regression, of the bovine corpus luteum; and (3) luteal cells arise from two sources; the characteristic small luteal cells at all stages of the o~strous cycle and pregnancy are of theca cell origin; the large cells are of granulosa cell origin early in the cycle, but a population of theca-derived large cells appears later in the cycle. Results of in vitro studies with total dispersed cells and essentially pure preparations of large and small luteal cells indicate that : (1) the recently described Ca2+ -polyphosphoinositol-protein kinase C second messenger system is involved in progesterone synthesis in the bovine corpus luteum; (2) activation of protein kinase C is stimulatory to progesterone synthesis in the small luteal cells; (3) activation of protein kinase C has no effect on progesterone synthesis in the large luteal cells; and (4) protein kinase C exerts its luteotrophic effect in total cell preparations, in part at least, by stimulating the production of prostacyclin. The protein kinase C system may cause down regulation of LH receptors in the large cells.
Mutagenic Action of Phaseolinone, a Mycotoxin Isolated from Macrophomina phaseolina
Authors: Bhattacharya Gautam , K Dhar Tarun , Kathleen Bhattacharya F , A I Siddiqui Kazi
Published: July 2016

Phaseolinone was mutagenic to excision-repair-deficient strains of Escherichia coli WP2 and also to Salmonella typhimurium TA100. The repair test was indicative of covalent binding of the toxin to DNA. The side-chain epoxide and the hydroxy groups of the molecule were found to be essential for mutagenic activity.
Effects of Maternal Nutritional Status on Fetal and Placental Growth and on Fetal Urea Synthesis in Sheep
Authors: Faichney GJ , White GA
Published: July 2016

Fetal and placental growth, and fetal and maternal urea synthesis in late gestation, were studied in 2-yearold Corriedale ewes on a maintenance ration (M) except when subjected to moderate dietary restriction from day 50 to day 100 (RM), day 100 to day 135 (MR) or day 50 to day 135 (RR). In comparison with fetuses of ewes maintained throughout the experiment (MM), RR fetuses were smaller and RM fetuses were larger whereas MR fetuses were unaffected; all restrictions were associated with increased placental size. Fetal urea synthesis at day 133 in the well-nourished ewes (MM) was 21.5 mg N h- i kg- i increasing to, respectively, 25.7, 27.3 and 38.8 mg N h- i kg- i in groups MR, RM and RR; these values were 1.6, 3.9,2.2 and 3.8 times the maternal rates of synthesis. On the basis of the observed urea synthesis rates, amino acid oxidation could have accounted for up to, respectively, 32, 38, 40 and 571110 of fetal oxygen consumption in groups MM, MR, RM and RR. Amino acids, in addition to their role in tissue accretion, may be key energy substrates for the fetus.
Milk Composition in the Eastern Quoll, Dasyurus viverrinus (Marsupialia : Dasyuridae)
Authors: Green Brian , Merchant Jim , Newgrain Keith
Published: July 2016

The milk constituents of Dasyurus viverrinus, a carnivorous marsupial, exhibited major quantitative and qualitative changes during the course of lactation. The milk produced in the early stages of lactation was dilute, about 13-16070 (w/w) solids before 3 weeks with carbohydrate representing the major fraction. In the latter stages of lactation the milk was concentrated, around 30% solids, and lipid was the predominant fraction. Palmitic acid was the major fatty acid present in early-stage milk but oleic acid became predominant in milk after 10 weeks post-partum. The changes in milk composition in D. viverrinus were similar to those described for the milks of herbivorous marsupials which therefore suggests that this pattern may be uniform throughout the Marsupialia.
Effects of Coculture with Uterine Epithelial Cells on the Metabolism of Glucose by Mouse Morulae and Early Blastocysts
Authors: Khurana NK , Wales RG
Published: July 2016

Coculture of mouse morulae/early blastocysts with isolated endometrial epithelial cells reduced incorporation of glucose carbon into embryonic glycogen but had no significant effect on incorporation into other internal carbon pools during a 5-h culture in serum-supplemented Dulbecco's modification of Eagle's minimum essential medium. Turnover of glycogen pools during 24-h chase culture of pulse-labelled embryos was unaffected by the presence of uterine epithelial cells recovered from day-4 pregnant or non-pregnant mice. However, significantly more label was retained in non-glycogen macromolecules during chase in the presence of endometrium recovered from non-pregnant than from pregnant uteri.
Electrophoretic Resolution of Species Boundaries in Australian Microchiroptera. III. The Nycticeiini?Scotorepens and Scoteanax (Chiroptera : Vespertilionidae)
Authors: Baverstock PR , Adams M , Reardon T , Watts CHS
Published: July 2016

Two hundred and sixty two specimens of bats of the tribe Nycticeiini were sampled from throughout Australia, and their tissues subjected to aliozyme electrophoresis with a view towards delineating species boundaries. A total of 30 loci were resolved, detailed analysis of which revealed five species - greyii, sanborni, balstoni, orion and rueppellii. The specific boundaries recognized differ from ali previous treatments of Australian members, but are supported by the taxonomic arrangement proposed by Kitchener and Caputi (1985). The data also support separate generic recognition of rueppe/lii. Finally, the genetic data reveal a high level of population sub structuring in these bats.
Cellularity of Organs in Mature Rams of Different Breeds
Authors: Colebrook WF , Black JL , Brown GH , Donnelly JB
Published: July 2016

The relative importance of cell number and cell size in determining the mass of 16 organs and tissues in mature rams of six different breeds was studied through estimation of organ deoxyribonucleic acid (DNA) content. The mean fleece-free empty body weight (FFEBW) ranged from 54�6 � O� 3 kg for Camden Park Merinos to 76�7 � 1�6 kg for Strong Wool Merinos. For all organs, mass increased with FFEBW, but the relationship was significant across all sheep for only eight organs (blood, kidney, liver, abomasum, vastus lateralis muscle, skin, perirenal fat and triceps muscle). There were significant differences between breeds in the mass of 11 organs. With four (heart, rumen reticulum, small intestine and testicular fat) this difference was independent of breed differences in FFEBW, whereas with another four (kidney, abomasum, vastus lateralis muscle and skin), it was closely related to FFEBW. Breed differences in the mass of the remaining three organs (blood, liver and perirenal fat) were partly related to FFEBW and partly breed specific. Blood mass increased with FFEBW across all animals, but, within a breed, it declined as FFEBW increased. The increase in the mass of perirenal fat with FFEBW was significantly greater within a breed than between breeds.
Experimental Diabetes in Lactating Sheep: Effects of Alloxan on Plasma Insulin, Glucose, Glucose Kinetics and Milk Characteristics
Authors: Leenanuruksa D , McDowell GH
Published: July 2016

After intravenous administration of alloxan (50 mg kg-1 liveweight) to lactating ewes, there were triphasic changes in plasma glucose and insulin. Almost immediately, plasma insulin decreased and hyperglycaemia occurred, then, between c. 5-12 h, insulin increased and ewes became hypoglycaemic. Thereafter, insulin decreased and glucose increased from c. 20 h after alloxan and the diabetic state was established. Changes in glucose production and utilization correlated with changes in plasma glucose.
Effects of Intradermally Injected and Topically Applied Mouse Epidermal Growth Factor on Wool Growth, Skin and Wool Follicles of Merino Sheep
Authors: Chapman RE , Hardy MH
Published: July 2016

Twice daily intradermal (ID) injections of mouse epidermal growth factor (mEGF) in sterile saline for 1-4 days into delineated areas of skin of Merino sheep produced dose-dependent changes in wool follicles and fibres, ranging from slight reduction in follicle bulb size and transient disturbance of cuticle formation on some fibres to the induction of catagen of follicles and shedding of fibres with distorted, tapered ends. Regeneration of follicles commenced by day 7. By contrast, ID injections of saline did not affect follicle activity. The epidermis became thicker and more parakeratotic after multiple injections of mEGF than after injection of saline, but was almost normal again by day 14. Persistent small increases in sebaceous gland size, additional to those induced by ID injections of saline, and delayed small increases in sweat gland size also occurred after multiple injections of mEGF.
Secretion of LH, FSH and Oestradiol-17ß During the Follicular Phase of the Oestrous Cycle in the Ewe
Authors: Thomas GB , Martin GB , Ford JR , Moore PM , Campbell BK , Lindsay DR
Published: July 2016

Plasma concentrations of LH, FSH and oestradiol-17iJ were measured in blood samples taken at 15 min intervals for 48 h during the follicular phase of four Merino ewes. The amplitude of pulses of LH and the mean concentration of LH were higher at the beginning of the follicular phase, 36-24 h before the preovulatory surge of LH (amplitude 2�4 ng ml- 1, mean concentration 3�9 ng ml- 1), than at the end, 24-0 h before the preovulatory surge (amplitude 1� 2 � 0�1 ng ml- 1; mean concentration 1�4 � 0�1 ng ml- 1). There was no change in the inter-pulse interval during this time (mean 74 � 5 min). Over the same period, oestradiol levels increased from 7-8 pg ml- 1 to a peak of 10- 15 pg ml- 1. Mean FSH concentrations declined (36-24 h: 3� 6 ng ml - 1 vs 24-0 h: 1� 8 � O� 3 ng ml- 1) before rising at the time of the preovulatory surge of LH and again 24 h later. It was concluded that the biphasic response of LH to oestrogen that is seen in ovariectomized ewes may also operate during the follicular phase of the oestrous cycle in entire ewes.
Development of Sheep Embryos in vitro in a Medium Supplemented with Different Batches of Serum Albumin
Authors: Batt PA , Miller BG
Published: July 2016

Variability in different lots of commercial serum albumin affects mammalian embryo development in culture. The composition of commercial preparations of ovine, bovine and defatted bovine serum albumin and a fraction of ovine serum containing proteins with a mean molecular weight of 65 kDa (fraction 3) was examined by polyacrylamide gel electrophoresis. All preparations were heavily contaminated with serum proteins other than albumin. Day-6 sheep morulae were cultured for 48 h in a basal bicarbonate-buffered salt solution supplemented with the commercial preparations of ovine, bovine or defatted bovine serum albumin. These three albumin preparations differed in their abilities to support the development of morulae into expanded blastocysts, but these differences disappeared when the basal medium was also supplemented with a component of ovine serum containing substances with molecular weights of less than 10 kDa. In the latter case, the three commercial albumin preparations and fraction 3 of ovine serum all supported full development in about 40-60% of morulae.
Structure-Activity Studies of Melatonin Analogues in Prepubertal Male Rats
Authors: Kennaway DJ , Hugel HM , Clarke S , Tjandra A , WJohnson D , Royles P , Webb HA , Carbone F
Published: July 2016

Comparison has been made between the activity of the pineal hormone melatonin, and several analogues and metabolites in inhibiting sexual development in a protein-restricted prepubertal rat model. Eleven melatonin analogues or metabolites were tested with the aim of evaluating the model as a test of the hypothesis that melatonin acts as a prohormone and that the ring schism metabolites (kynurenamines) mediate many of the effects attributable to melatonin. Although the hypothesis could not be confirmed, modification of the melatonin structure by lengthening the acylamide side chain or by replacing the 5 methoxy function with fluorine resulted in loss of biological potency. Modification of the melatonin structure to block the two known points of metabolism resulted in no significant alteration in biological activity. Thus 6-chloromelatonin (blocking 6-hydroxylation) and 2,3-dihydromelatonin (blocking oxidative cleavage of the C2-C3 bond) and 6-chloro-2,3-dihydromelatonin remained biologically active. The metabolic products of brain indolearnine-2,3-dioxygenase, N-acetyl-N2-formyl-5-methoxy kynurenamine (aFoMK) and N-acetyl-5-methoxy kynurenamine (aMK), paradoxically were also biologically active.
Oestrogen Sulfotransferase: Molecular Cloning and Sequencing of cDNA for the Bovine Placental Enzyme
Authors: R Nash Allan , K Glenn Wendy , S Moore Stephen , Kerr Judith , R Thompson Adrienne , Thompson EOP
Published: July 2016

The female sex hormone, oestrogen, plays a central role in breast cell proliferation in both the normal and malignant state. It controls transcription from several genes, including that for the progesterone receptor, and in endometrial tissue, via this receptor, it controls the gene for the enzyme oestrogen sulfotransferase. This enzyme may control the level of the oestrogen receptor by sulfurylating free oestradiol. To study the mode of transcriptional control exercised by oestrogen, bovine oestrogen sulfotransferase cDNA has been cloned and the nucleotide sequence determined. The message, of which 1812 bases have been sequenced, contains an open reading frame of 885 bases which encode a protein of 295 amino acids and a maximum apparent molecular weight of 34 600. The deduced protein sequence is supported by existing peptide sequence data and appears to contain a steroid-binding region. Some physico-chemical characteristics of the enzyme appear to differ markedly from those previously reported.
The Occurrence of Antibody to Bluetongue Virus in New South Wales. ' I. Statewide Surveys of Cattle and Sheep
Authors: Burton RW , R Littiejohns I
Published: July 2016

Two State-wide surveys were carried out in 1978 to detect bluetongue (BLU) virus antibody in cattle and sheep sera in New South Wales (NSW). The first survey showed that BLU group antibody in cattle 18-24 months old was confined to the coastal regions (east of the Great Dividing Range) and the Hunter Valley. However, in the second survey, of cattle more than 5 years old, reactors were much more widely distributed over the north-eastern third of the State and into the western division with prevalences up to 85% in some areas. In contrast, very few reactors were detected in sheep in either survey (less than 1 % of the sheep sera tested).
Oxidation products of α- and β-amyrins: potential tracers of abiotic degradation of vascular-plant organic matter in aquatic environments
Authors: Galeron M.-A. , Vaultier F. , Rontani J.-F.
Published: July 2016

Environmental contextHow can we know what happens to organic matter in aquatic environments? Although several compounds exist that can be used to trace the origin and state of organic matter, not many are sufficiently stable and specific to trace degradation processes, but α- and β-amyrins can fulfil that role. Such knowledge will help us better understand and better quantify carbon fluxes in riverine and marine environments. AbstractIn order to fulfil the current need for stable and specific tracers to monitor vascular-plant organic matter degradation in aquatic environments, α-amyrin (urs-12-en-3β-ol) and β-amyrin (olean-12-en-3β-ol) were oxidised in vitro and their abiotic degradation products quantified in environmental samples from the Rhône River in France. Although they appear inert to photooxidation, they are clearly affected by autoxidation and the tracer potential of the resulting products was confirmed. Autoxidation of α- and β-amyrins produces urs or olean-12-en-3-one, 3β-hydroxy-urs or olean-12-en-11-one, urs or olean-12-en-3β,11α-diol and urs or olean-12-en-3,11-dione. 3β-Hydroxy-urs-12-en-11-one and 3β-hydroxy-olean-12-en-11-one, the main oxidation products detected, were selected as autoxidation tracers. These compounds, specific to autoxidation, were detected in dry leaves of Smilax aspera and in suspended particulate matter samples collected in the Rhône River and evidenced the importance of autoxidation in the degradation of organic matter of terrestrial origin.