In the wild, Coni/urus penicillatus has two tail colour morphs, one entirely black and the other with a white distal brush of variable length. These colour morphs have been used in the past for taxonomic purposes. A small proportion (4'6%) of laboratory-reared animals have a white interstitial section. Pedigree data were collected from a laboratory colony (n = 173) established using seven wild-caught animals from the north Kimberley region, Western Australia. The hypothesis tested was that black tail is inherited as a Mendelian character recessive to white tip. Matings between black-tailed individuals always gave black offspring. Crosses between other colour morphs also supported this hypothesis.
Sheep reproduction from ovulation to weaning was modelled as a Markov series of multiple binomial distributions, which required a minimum of assumptions and a small number of parameters for the entire reproductive process. Methods of constructing the model and of estimating the parameters are described, and results from simulated example flocks with different ovulatory potentials are presented. A variety of potential applications, for example as an adjunct to economic modelling and methods of validation and use in the analysis of reproductive experiments, are discussed.
When 5-day-old laboratory-raised Queensland fruit flies (Dacus tryoni) were fed a dinitrogen-fixing bacterial strain of Klebsiella oxytoca isolated from the crop of a wild fly, acetylene reduction (nitrogenase) activity associated with the flies was detected after 2 to 3 days and persisted for at least 22 days. Flies not fed the dinitrogen-fixing strain were negative for acetylene reduction until 21 days after emergence. Presumably such dinitrogen-fixing bacteria are able to supply some Queensland fruit flies with a small part of their nitrogen requirements, but its importance is unknown.
Allozyme electrophoresis of 35 loci in 156 specimens of Australian bats belonging to the Molossidae was used to help elucidate the species-level taxonomy of the group in Australia. The electrophoretic data support the current species-level taxonomy of Tadarida australis and Chaerephon jobensis. However, for specimens currently allocated to the genus Mormopterus, the electrophoretic data fail to support any previous species-level account. On the electrophoretic data, a minimum of five species of the genus Mormopterus occur in Australia. A single specimen of a sixth species, whose generic affinities are undetermined, was also found.
Soybean nodules have been examined for localization of glutamate dehydrogenase, using a monospecific antiserum to the plant enzyme prepared from lupin nodules. By immunofluorescence techniques, glutamate dehydrogenase was located in the cytoplasm at the periphery of infected cells adjacent to air spaces. A more precise localization within soybean-nodule mitochondria was shown by immuno-electron microscopy using protein A-gold labelling of thin sections.
Scanning and transmission electron microscopy were used to study the progressive disruption of Merino wool during the vigorous agitation of the fibres in aqueous 10J0 (w Iv) solutions of sodium dodecylsulfate (SDS). In contrast to the general disruption observed when wool was vigorously agitated in formic acid, the cuticle was slowly stripped from the fibre with virtually no release of cortical material unless prolonged periods of agitation were used. A similar type of disruption took place in aqueous 10J0 (w Iv) solutions of cetyltrimethylammonium bromide (CETAB) and Triton X-lOO. After the agitation in 10J0 (w/v) SDS solution, the released cuticle fragments and the remaining fibres were examined. Only a minority of the cell portions constituting the cuticle fragments had been cleaved within the endocuticle. Often, the fragments included portions from more than one cuticle cell, with the cell junctions still intact. An understanding of the disruptive process was facilitated by the frequent observation, on residual fibres, of low ridges on exposed underlying cuticle cells. These low ridges corresponded with the distal edges of the originally overlying cuticle cells. Amino-acid analysis and scanning electron microscopy performed on preparations of cuticle obtained in solutions of the above detergents and in formic acid indicated close similarities between all of the cuticle preparations.
The temperature and humidity of expired air from three adult Merino sheep were measured at air temperatures of 20, 30 and 40 degrees C before and after the animals were shorn. Expired air was apparently always saturated with water vapour. At the higher air temperatures the temperature of expired air was close to deep body temperature; at lower air temperatures, expired air had been significantly cooled, e.g. to 32.3 degrees C in shorn sheep at 20 degrees C air temperature. Expired air was cooler from shorn than from unshorn animals at 20 and 30 degrees C air temperature, possibly due to thermally induced vasomotor changes in the upper respiratory tract. Cooling of expired air would be expected to lead to recovery of some of the water evaporated during inspiration; at 20 degrees C air temperature, this fraction was estimated to be 25% in unshorn sheep and 36% in shorn sheep.
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 +/- 0.3 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. Cell number increased significantly with the mass of all organs except blood and brain. There were between-breed differences in the number of cells in seven organs (liver, heart, rumen reticulum, abomasum, small intestine, vastus lateralis muscle and skin), which, except for heart, were attributable to between-breed differences in organ mass. With heart, the increase in cell number with organ mass within a breed was greater than across all breeds. Cell size was significantly related to organ mass only with vastus lateralis muscle, spleen, perirenal fat and liver. The relationship for vastus lateralis muscle and spleen was negative, indicating that cells were smaller in larger organs. There were differences between breeds in cell size for heart, vastus lateralis and triceps muscles. These differences for heart and triceps muscle were breed specific, whereas for vastus lateralis muscle it was attributed to breed differences in organ weight. There was a 30-fold range in mean cell size across organs, with adipose tissue having the largest cells, muscle tissue intermediate and visceral tissues the smallest. In general, organ mass is positively related to FFEBW. Cell number, not cell size, is largely responsible for differences in organ mass between mature sheep of different breeds.
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 acrylamide 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 indoleamine-2,3-dioxygenase, N-acetyl-N2-formyl-5-methoxy kynurenamine (aFoMK) and N-acetyl-5-methoxy kynurenamine (aMK), paradoxically were also biologically active.
Seasonality of the reproductive cycle in sheep is a general phenomenon for mid-latitude breeds. The proximal part (breeding season) and also partially distal part (end of gestation and beginning of lactation) of this cycle is controlled by photoperiod, whatever the form of light regimens. Data are presented which indicate that male and female do not necessarily have the same photoperiodic sensitivity. Gonadal stimulation in the ram starts 1.5-2 months earlier than in the ewe under annual variations. Photoperiod controls the reproductive cycle by the intermediary of the hypothalamo-pituitary axis. There are both a steroid-independent and a steroid-dependent effect of light, depending on both decreasing and increasing daylength in mid-latitudes. Data are also presented which support Bunning's hypothesis on photoperiodic time measurement in mammals. Sheep measure photoperiodic time by using a circadian rhythm of photosensitivity. Daylength is not measured by the total duration of exposure to light but by the illumination of two special set points during the day, one of them entraining the circadian rhythm of photosensitivity and the other inducing or not inducing a physiological response if it is coincident, or not coincident, with photoinducible phase of that rhythm. A photoinducible phase has been found for prolactin secretion, and perhaps also for LH secretion. Melatonin secretion is used by sheep for measuring daylength. However, that secretion disappears during two set points during the day, thus raising the possibility of using alternatively melatonin and light pulse for controlling the reproductive cycle in sheep.
The results of four experiments are presented in summary form. The data are considered in relationship to the improvement of the fecundity and fertility of the Australian ewe breeding flock. In the first, three commonly used methods of oestrous synchronization were examined and showed differences that are attributed to the different patterns of hormonal changes associated with the methods demonstrated. The second experiment looked at the use of active immunization against testosterone and concluded that this method can improve fecundity but not fertility. The third experiment, a group of five trials, studied the use of progestagen sponges and PMSG in anoestrous ewes as a means of inducing normal fertility. The extensive data produced in this experiment allowed the relationships between ovulation rate and fertility and between fertility and prolificacy (fecundity) to be examined. Fertility appeared greatest when the mean flock ovulation rate was about 25. At this ovulation rate prolificacy was also improved and a high proportion of twins were produced. We concluded that high fertility and low prolificacy (i.e. of 100) are an unlikely combination. In the final experiment the effect of post-mating hormonal supplementation on fertility was examined and a number of earlier reports were confirmed by showing that fertility can be improved with supplementary progesterone between days 10 and 25 post-mating. The effect appears to be modified by hormonal and nutritional factors.
The stoichiometry of the two heavy chains of myosin in smooth muscle was determined by electrophoresing extracts of native myosin and of dissociated myosin on sodium dodecyl sulfate (SDS) 4%-polyacrylamide gels. The slower migrating heavy chain was 3.6 times more abundant in toad stomach, 2.3 in rabbit myometrium, 2.0 in rat femoral artery, 1.3 in guinea pig ileum, 0.93 in pig trachea and 0.69 in human bronchus, than the more rapidly migrating chain. Both heavy chains were identified as smooth muscle myosin by immunoblotting using antibodies to smooth muscle and non-muscle myosin. The unequal proportion of heavy chains suggested the possibility of native isoforms of myosin comprised of heavy-chain homodimers. To test this, native myosin extracts wer electrophoresed on non-dissociating (pyrophosphate) gels. When each band was individually analysed on SDS-polyacrylamide gel the slowest was found to be filamin and the other bands were myosin in which the relative proportion of the heavy chains was unchanged from that found in the original tissue extracts. Since this is incompatible with either a heterodimeric or a homodimeric arrangement it suggests that pyrophosphate gel electrophoresis is incapable of separating putative isoforms of native myosin.
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). In a retrospective study of stored cattle sera, BLU group reactors were detected in the north-east of the State in each year examined since 1968, the earliest year in which samples were available from that region. Areas to the south and west were free of antibody from 1966 until the summer of 1973, but subsequently reactors were common. Examination of selected area for type-specific antibody indicated that infection of cattle with two of the three Australian BLU serotypes which were known at the time, BLU-1 and BLU-21, had occurred in NSW. No antibody to BLU-20, the original Australian isolate, was detected. A close association was observed between strong group antibody reactions and type-specific neutralizing activity against BLU-1 and BLU-21. Both were largely confined to that area of the State in which a high (75% or more) prevalence of group antibody was recognised in the older animals.(ABSTRACT TRUNCATED AT 250 WORDS)
Fetal and placental growth, and fetal and maternal urea synthesis in late gestation, were studied in 2-year-old 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-1 kg-1 increasing to, respectively, 25.7, 27.3 and 38.8 mg N h-1 kg-1 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 57% 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.
Ascorbic acid (vitamin C) was given to 144-days-old layer chickens mixed with their ration at three concentrations: 30, 60 and 90 p.p.m. for 6 months. Cholesterol levels in blood serum (CS) and egg yolk (CE) were measured every 6 weeks (four periods); there was a marked decrease in CS in most treated birds, especially those receiving the highest concentration of vitamin C. There was also a slight decrease in CE in most treated birds. Thyroidal weight showed a significant increase in most treated groups, especially those receiving the highest concentration of vitamin C.
A field experiment was conducted to examine the effect of anti-oestradiol-17B antibody titre on the oestrous and ovulatory responses of ewes to low (600 i.u.) or high (1200 i.u.) doses of pregnant mare's serum gonadotrophin (PMSG). Merino ewes were treated with intravaginal sponges and were subsequently used as vehicle-treated controls or were immunized to produce reciprocal anti-oestradiol-17B antibody titres less than 1000 or greater than 1000. Ewes were then treated with PMSG and the incidence of oestrus and ovulation, ovulation rate, and yield of embryos recorded. Treatment of immune ewes with 1200 i.u. PMSG resulted in both a higher proportion of ewes ovulating and a higher ovulation rate than in immune ewes treated with 600 i.u. (86% v. 67% and 13.4 v. 6.0 respectively). As anti-oestradiol-17B titres increased there was a reduction in the proportion of ewes exhibiting oestrus. The proportion of ewes ovulating decreased as antibody increased in ewes treated with 600 i.u. PMSG but not in those treated with 1200 i.u., suggesting an increased positive feedback of oestradiol with high PMSG doses. Fertilization rates were highest at the lower PMSG dose (68% v. 42%) and increased with increasing titre. Overall, there was no increase in ovulation rate or in yield of embryos over control values from either low (less than 1000) or high (greater than 1000) antibody titres.
In the rat, changes in dietary protein intake give rise to changes in the levels of ornithine transcarbamylase (OTC) in liver and small intestine-an increase in liver and decrease in small intestine. The changes in enzyme level are accompanied by similar changes in levels of specific mRNA. Thus in liver, there is an increase in the level of specific mRNA when protein intake is increased, whereas in small intestine there is a small decrease. Comparison of changes in specific mRNA with total poly-Acontaining RNA showed that the change in OTC mRNA in liver paralleled the change in total RNA levels. In contrast, in small intestine the small decrease in OTC mRNA levels when protein intake was increased was in the face of an increase in the level of total mRNA. Whereas the level of OTC is 20-fold higher in liver than in small intestine, the mRNA level for the enzyme differs by only 2 5-fold.
The beta-casein gene is a member of a small gene family encoding the calcium-sensitive caseins, which are specifically synthesized and secreted by the mammary gland during lactation in response to both peptide and steroid hormones. The caseins are involved in the transport of calcium phosphate in milk, which is important for bone development in the infant mammal. We report here the organization and complete DNA sequence of the 8.5 kb long bovine beta-casein gene. Comparison with the rat beta-casein gene reveals that the exons of both genes correspond exactly. The 5' flanking sequences of all Ca-sensitive casein genes are conserved within the proximal 200 bp and contain several elements that probably function as cis-acting regulatory elements, including an octamer-like motif, and SV40-type core enhancer and a sequence that appears to be common to all lactoprotein genes. The latter sequence is flanked on either side by 12 bp direct repeats. These direct repeats are themselves each part of sequences that display two-fold symmetry. The first 30 nucleotides of the 3' flanking regions in the bovine and rat beta-caseins are well conserved, indicating that they are likely to be involved in the mechanism of 3' end processing of the primary transcript.
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.
