Protective effect of Ocimum sanctum L after high-dose 131iodine exposure in mice: an in vivo study

Radioprotective effect of aqueous extract of Ocimum sanctum (40 mg/kg body weight, for 15 days) in mice exposed to high-doses (3.7 MBq) of oral 131iodine was investigated by studying the organ weights, lipid peroxidation and antioxidant defense enzymes in various target organs like liver, kidneys, salivary glands and stomach at 24 hr after exposure in adult Swiss mice. The mean weight of the salivary glands showed significant increase after 131iodine administration. 131iodine exposure significantly increased lipid peroxidation in kidneys and salivary glands in comparison to control animals. Pretreatment with O. sanctum in radioiodine exposed group showed significant reduction in lipid peroxidation in both kidneys and salivary glands. In liver, reduced glutathione (GSH) levels showed significant reduction after radioiodine exposure while pretreatment with O. sanctum exhibited less depletion in GSH level even after 131iodine exposure. However, no such changes were observed in stomach. The results indicate the possibility of using aqueous extract of O. sanctum for ameliorating 131Iodine induced damage to the salivary glands.     

“Male factors” in ticks: their role in feeding and egg development

Summary

Female ticks of the family Ixodidae utilize their salivary glands as the major organs for fluid balance, secreting back into the host a dilute saliva. Feeding is composed of three phases: a preparatory phase (1–2 days) during which the tick establishes the feeding lesion, a slow phase (~7 days) during which body weight increases 10-fold, and a rapid phase (~1 day) in which body weight increases a further 10-fold. Following engorgement, the salivary glands are resorbed by an autolytic process triggered by an ecdysteroid hormone. If a female is removed from the host prior to repletion, her subsequent behaviour depends mostly on two factors: the degree of engorgement achieved and whether or not she has mated. If removed during the preparatory or slow phase of engorgement, the salivary glands are not resorbed, the tick will lay virtually no eggs and she will reattach to a host if given the opportunity, all of this irrespective of whether she is virgin or mated. If removed during the rapid phase of engorgement, however, mated females will not reattach to a host even if given the opportunity. Instead, they will resorb the salivary glands within 4 days post-removal and lay a batch of eggs. Virgin females removed after exceeding 10-fold the unfed weight likewise refuse to resume feeding if given the opportunity, but salivary gland reabsorption is delayed (to 8 days post-removal); if any eggs are laid, they are infertile. A number of chemical “factors” entering the female during copulation influence her feeding behaviour and egg development. Here we discuss the complexities of these interactions and suggest how they might be adaptive to ticks in nature.     

Short and long term effects of root and shoot chilling of ransom soybean

The immediate short term effects on some physiological processes and the long term effects on morphology and reproductive development of root- and shoot-chilled soybeans (Glycine max L. cv Ransom) were studied. Roots or shoots of 16- or 17-day-old plants were chilled at 10°C for one week, and then rewarmed to 25°C. Leaf elongation rate, net CO₂ uptake rate, and stomatal conductance decreased during root or shoot chilling. Root chilling had only temporary effects on water relations, while shoot chilling caused large changes in potentials during chilling. Most processes measured returned to control levels after two days of rewarming. Root-chilled plants harvested 90 days after emergence were similar in morphology and seed weight to controls. Shoot-chilled plants showed a large increase over controls in axillary branch growth, but an early abortion of flowers and a delayed resumption of flowering caused a 78% reduction in seed weight. Root chilling in this study was found to have little or no long term effect on the plants, while shoot chilling caused significant changes in vegetative morphology, and a delay in flowering and subsequent pod filling.     

Salivary Gland Hypofunction in tyrosylprotein sulfotransferase-2 Knockout Mice Is Due to Primary Hypothyroidism

Background

Protein-tyrosine sulfation is a post-translational modification of an unknown number of secreted and membrane proteins mediated by two known Golgi tyrosylprotein sulfotransferases (TPST-1 and TPST-2). We reported that Tpst2-/- mice have mild-moderate primary hypothyroidism, whereas Tpst1-/- mice are euthyroid. While using magnetic resonance imaging (MRI) to look at the thyroid gland we noticed that the salivary glands in Tpst2-/- mice appeared smaller than in wild type mice. This prompted a detailed analysis to compare salivary gland structure and function in wild type, Tpst1-/-, and Tpst2 -/- mice.

Methodology/Principal Findings

Quantitative MRI imaging documented that salivary glands in Tpst2-/- females were ^≈ 30% smaller than wild type or Tpst1-/- mice and that the granular convoluted tubules in Tpst2-/- submandibular glands were less prominent and were almost completely devoid of exocrine secretory granules compared to glands from wild type or Tpst1-/- mice. In addition, pilocarpine–induced salivary flow and salivary α-amylase activity in Tpst2-/- mice of both sexes was substantially lower than in wild type and Tpst1-/- mice. Anti-sulfotyrosine Western blots of salivary gland extracts and saliva showed no differences between wild type, Tpst1-/-, and Tpst2-/- mice, suggesting that the salivary gland hypofunction is due to factor(s) extrinsic to the salivary glands. Finally, we found that all indicators of hypothyroidism (serum T4, body weight) and salivary gland hypofunction (salivary flow, salivary α-amylase activity, histological changes) were restored to normal or near normal by thyroid hormone supplementation.

Conclusions/Significance

Our findings conclusively demonstrate that low body weight and salivary gland hypofunction in Tpst2-/- mice is due solely to primary hypothyroidism.     

Endocannabinoids measurement in human saliva as potential biomarker of obesity

Background

The discovery of the endocannabinoid system and of its role in the regulation of energy balance has significantly advanced our understanding of the physiopathological mechanisms leading to obesity and type 2 diabetes. New knowledge on the role of this system in humans has been acquired by measuring blood endocannabinoids. Here we explored endocannabinoids and related N-acylethanolamines in saliva and verified their changes in relation to body weight status and in response to a meal or to body weight loss.

Methodology/Principal Findings

Fasting plasma and salivary endocannabinoids and N-acylethanolamines were measured through liquid mass spectrometry in 12 normal weight and 12 obese, insulin-resistant subjects. Salivary endocannabinoids and N-acylethanolamines were evaluated in the same cohort before and after the consumption of a meal. Changes in salivary endocannabinoids and N-acylethanolamines after body weight loss were investigated in a second group of 12 obese subjects following a 12-weeks lifestyle intervention program. The levels of mRNAs coding for enzymes regulating the metabolism of endocannabinoids, N-acylethanolamines and of cannabinoid type 1 (CB₁) receptor, alongside endocannabinoids and N-acylethanolamines content, were assessed in human salivary glands.The endocannabinoids 2-arachidonoylglycerol (2-AG), N-arachidonoylethanolamide (anandamide, AEA), and the N-acylethanolamines (oleoylethanolamide, OEA and palmitoylethanolamide, PEA) were quantifiable in saliva and their levels were significantly higher in obese than in normal weight subjects. Fasting salivary AEA and OEA directly correlated with BMI, waist circumference and fasting insulin. Salivary endocannabinoids and N-acylethanolamines did not change in response to a meal. CB₁ receptors, ligands and enzymes were expressed in the salivary glands. Finally, a body weight loss of 5.3% obtained after a 12-weeks lifestyle program significantly decreased salivary AEA levels.

Conclusions/Significance

Endocannabinoids and N-acylethanolamines are quantifiable in saliva and their levels correlate with obesity but not with feeding status. Body weight loss significantly decreases salivary AEA, which might represent a useful biomarker in obesity.     

The interaction between Trypanosoma rangeli and the nitrophorins in the salivary glands of the triatomine Rhodnius prolixus (Hemiptera; Reduviidae)

The parasite Trypanosoma rangeli develops in the intestinal tract of triatomines and, particularly in species of the genus Rhodnius, invades the hemolymph and salivary glands, where subsequent metacyclogenesis takes place. Many aspects of the interaction between T. rangeli and triatomines are still unclear, especially concerning the development of the parasite in the salivary glands and how the parasite interacts with the saliva. In this work, we describe new findings on the process of T. rangeli infection of the salivary glands and the impact of infection on the saliva composition. To ensure a complete infection (intestinal tract, hemolymph and salivary glands), 3rd instar Rhodnius prolixus nymphs were fed on blood containing T. rangeli epimastigotes using an artificial feeder. After molt to the 4th instar, the nymphs were inoculated with epimastigotes in the hemolymph. The results showed that the flagellates started to invade the salivary glands by the 7th day after the injection. The percentage of trypomastigotes inside the salivary glands continuously increased until the 25th day, at which time the trypomastigotes were more than 95% of the T. rangeli forms present. The salivary contents from T. rangeli-infected insects showed a pH that was significantly more acidic (<6.0) and had a lower total protein and hemeprotein contents compared with non-infected insects. However, the ratio of hemeprotein to total protein was similar in both control and infected insects. qPCR demonstrated that the expression levels of three housekeeping genes (18S rRNA, β-actin and α-tubulin) and nitrophorins 1–4 were not altered in the salivary glands after an infection with T. rangeli. In addition, the four major nitrophorins (NPs 1–4) were knocked down using RNAi and their suppression impacted T. rangeli survival in the salivary glands to the point that the parasite burden inside the R. prolixus salivary glands was reduced by more than 3-fold. These results indicated that these parasites most likely non-specifically incorporated the proteins that were present in R. prolixus saliva as nutrients, without impairing the biosynthesis of the antihemostatic molecules.     

Development and ageing of the salivary glands of adult male Aedes aegypti (L.) and Aedes togoi (theobald) mosquitoes (Dipteria : Culcidae)

The salivary glands of adult male Aedes aegypti and Aedes togoi (Diptera : Culicidae), varying in age from less than 1 day after emergence to 42 days or 33 days respectively, were examined by light microscopy. Following emergence, the trilobed glands rapidly accumulate secretory product and attain their full size within about 48 hr. The amount of secretion in fully developed glands shows marked individual variation, but it is predominantly located in the posterior parts of the glands. Ageing changes begin to appear after about 8 days (A. aegypti) or 10–11 days (A. togoi), and although there is wide individual variation in their extent, in general, they become progressively more severe until at the age of 4–5 weeks all mosquitoes are substantially affected. Since other tissues, including ganglia, also regress with age, it is unlikely that salivary gland changes are the prime cause of death.     

Reduction of EGF is associated with the delay of ulcer healing by cigarette smoking

Cigarette smoking is associated with peptic ulcer diseases. Smokers have lower levels of salivary epidermal growth factor (EGF) than nonsmokers. We investigated whether reduction of EGF is involved in the delay of gastric ulcer healing by cigarette smoking. Rats with acetic acid-induced ulcers were exposed to cigarette smoke (0, 2, or 4% vol/vol) 1 day after ulcer induction. EGF level was elevated 1 day after ulcer induction in salivary glands and serum, and 4 days after ulcer induction in the gastric mucosa. However, cigarette smoke depressed these beneficial effects and EGF mRNA expression in salivary glands and gastric mucosa. Cigarette smoke delayed gastric ulcer healing and reduced cell proliferation, angiogenesis, and mucus synthesis. Exogenous EGF (10 and 20 microg/kg i.v.) before smoke exposure reversed the adverse effects of cigarette smoke, whereas vascular endothelial growth factor level and nitric oxide synthase activity were unaffected. It is concluded that the detrimental effect of cigarette smoke on ulcer healing is a consequence of reduction of angiogenesis, cell proliferation, and mucus secretion through the depressive action on EGF biosynthesis and its mRNA expression in salivary glands and gastric mucosa.     

Influence of streptozotocin-induced diabetes on hexokinase activity of rat salivary glands

The influence of diabetes on the enzyme hexokinase (HK) was examined in the salivary glands of rats. Diabetes was induced by an intraperitoneal injection of streptozotocin (60 mg/Kg body weight) in overnight fasted rats (180-200 g). The animals were killed 48 hours and 30 days after the induction of diabetes and the submandibular and parotid salivary glands extracted for use. Hyperglycemia was evaluated by determining the blood sugar. The area occupied by each intralobular component, acini, ducts, total parenchyma and stroma was measured, and no differences were observed compared with control. In the soluble fraction of the submandibular gland, no difference in the specific activity of HK was observed, between the diabetic and control animals, however, the activity per gland and per g of tissue showed lower values than control. The specific activity of the bound form was reduced in the diabetic gland. The results obtained for the parotid gland were different from the submandibular. The specific activity of both the soluble and bound forms were increased in the diabetic animals. The DEAE-cellulose column chromatography of the soluble and bound forms of the enzyme from both glands showed a first peak appearing during the washing of the column and two other peaks were eluted by the gradient. Thus, three isoenzymes in the submandibular and parotid salivary glands for the control and diabetic rats have been found.     

Delayed metamorphosis in Galleria mellonella: Interaction of chilling and space deprivation

A 2 × 2 factorial experiment was performed with each of 18 age classes within the last instar of Galleria mellonella. The two experimental factors applied to each age class were chilling and space deprivation; combinations of each factor were tested at two levels (present or absent). The 3-parameter Weibull function was used to calculate the proportion of animals undergoing larval-pupal ecdysis. Significant differences among time-trend statistics were related to interaction between chilling and space deprivation, as well as to age class. In general, chilling without space deprivation produced a small delay relative to the unchilled, not space-deprived condition. With space deprivation, however, chilling accelerated pupation compared to space deprivation alone. The order in which the chilled, space-deprived and space-deprived groups pupated expresses the essence of the interaction. Contrary to an additive effect, delayed development resulting from space deprivation appeared to be mitigated by chilling. Salivary gland stiffening was observed in chilled, space-deprived animals. With space deprivation, stiffening was associated with faster development compared to that of unchilled animals. These observations are discussed in the context of extant hypotheses of endocrine mechanisms responsible for the separate effects of chilling and space deprivation.     

Quantitation of malaria sporozoites transmitted in vitro during salivation by wild Afrotropical Anopheles

Abstract. The malaria transmission potential of wild, infective Anopheles from western Kenya was evaluated by determining the number of sporozoites transmitted in vitro by salivation when their mouthparts were inserted into capillary tubes containing either sucrose or blood. With sucrose, 86.6% of 102 infective Anopheles transmitted a geometric mean (GM) of 3.84 sporozoites (range 1–34). With blood, 23.1% of 104 infective Anopheles , tested on the day of collection, transmitted a GM of 2.30 sporozoites (range 1–117). For Anopheles held 5 days postcapture before testing with blood, 53.6% of 56 transmitted a GM of 6.04 sporozoites (range 1–420). Transmitting Anopheles contained significantly more salivary gland sporozoites than non-transmitters. No significant differences were detected between Anopheles gambiae Giles sensu lato and Anopheles funestus Giles in sporozoite transmission by individuals with sporozoites in their salivary glands.
Sporozoites were detected microscopically in the salivary duct from heads in 80.3% of 117 infective Anopheles (GM=11.2, range 1–71). Sporozoite detection in mosquito heads by ELISA was 25% less efficient than microscopic detection.
Over 98% of the infective Anopheles transmitted less than twenty-five sporozoites. Transmitted sporozoites represented only about 3% of the total sporozoites in the salivary glands suggesting that sporozoite transmission may be restricted to sporozoites in the salivary duct at the time of feeding. Results are discussed in relation to anti-sporozoite vaccine development.     

Decreased saliva secretion and down-regulation of AQP5 in submandibular gland in irradiated rats

The molecular mechanisms of radiation-induced xerostomia remain unclear. The purpose of this study was to investigate the alterations of aquaporins (AQPs) and Na(+)/K(+)-ATPase in irradiated rat submandibular glands and to test the hypothesis that down-regulation of AQP5 expression in irradiated salivary glands is one of the mechanisms of radiation-induced xerostomia. Saliva from control and irradiated rat submandibular glands was analyzed. The mRNA level of AQP5 in the submandibular glands was assessed by semi-quantitative RT-PCR and in situ hybridization. The protein expression of AQP5, AQP1 and Na(+)/K(+)-ATPase was determined by Western blotting and immunohistochemistry. The body weight, submandibular gland weight, and saliva secretion of irradiated rats significantly decreased by 12, 24 and 32% on day 3 and 24, 16 and 38% on day 30 postirradiation, respectively. There was a significant increase in the protein concentration and osmolality of saliva in irradiated rats on days 3 and 30 postirradiation. However, there was no significant difference between irradiated and control rats in total saliva protein secretion. RT-PCR analysis showed that mRNA expression of AQP5 was significantly down-regulated by 37 and 51% in irradiated rats on days 3 and 30 postirradiation, respectively. Immunoblotting showed that the AQP5 protein level was decreased by 40 and 60% in irradiated glands, in contrast to the slight reductions of AQP1 and Na(+)/K(+)-ATPase proteins. Immunohistochemical analysis demonstrated that loss of AQP5 protein occurred throughout the irradiated glands, while no significant reduction was detected in AQP1 and Na(+)/ K(+)-ATPase labeling density. These results suggest that the preferential down-regulation of AQP5 with minor effects on AQP1 and Na(+)/K(+)-ATPase may contribute to radiation-induced salivary dysfunction.     

Adenylate cyclase activity in rat submandibular gland during postnatal development

Adenylate cyclase activity was measured in homogenates of submandibular glands of 1 to 42 day old rats. During this period of time the gland reached its final stage of differentiation. Adenylate cyclase activity was higher in the glands of one day old rats than in those of 7 and 14 day old animals. Between 14 and 28 days of age the enzyme activity more than doubled and approached the level that characterized the glands of adult animals. Fluoride (10mM) stimulated the enzyme activity in all age groups but the stimulation was less in the case of one day old rats as compared to older animals. Isoproterenol (10^?4 M) stimulated adenylate cyclase by 50–60% in the gland of adult rats but had no effect on the enzyme activity in 7 to 28 day old animals. Administration of isoproterenol for 5 days to 9 day old rats increased the weight of the submandibular gland by 70 per cent. Total adenylate cyclase activity increased parallel with the weight of the gland but the specific activity of the enzyme remained unchanged. It is concluded that during the postnatal development of the submandibular gland the rapid increase in adenylate cyclase activity occurs after weaning and it coincides with an accelerated rate of functional differentiation of the acinar cells.     

Alteration of Ca2+‐ATPase activity in the homogenate,plasma membrane and microsomes of the salivary glands of streptozotocin‐induced diabetic rats

Diabetes has been implicated in the dryness of the mouth, loss of taste sensation, sialosis, and other disorders of the oral cavity, by impairment of the salivary glands. The aim of the present study was to examine the plasma membrane, microsomal, and homogenate Ca²⁺‐ATPase activity in the rat submandibular and parotid salivary glands of streptozotocin‐induced diabetes. We have also examined the influence of the acidosis state on this parameter. Diabetes was induced by an intraperitoneal injection of streptozotocin and acidosis was induced by daily injection of NH₄Cl. At 15 and 30 days after diabetes induction, the animals were euthanized and the submandibular and parotid salivary glands were removed and analyzed. Ca²⁺‐ATPase (total, independent, and dependent) was determined in the homogenate, microsomal, and plasma membranes of the salivary glands of diabetic and control rats. Calcium concentration was also determined in the glands and showed to be higher in the diabetic animals. Ca²⁺‐ATPase activity was found to be reduced in all cell fractions studied in the diabetic animals compared with control. Similar results were obtained for the submandibular salivary glands of acidotic animals; however in the parotid salivary glands it was found an increase in the enzyme activity. Copyright © 2009 John Wiley & Sons, Ltd.     

Role of an aquaporin in the sheep tick Ixodes ricinus: Assessment as a potential control target

Ticks undergo tremendous osmoregulatory stress as they take on up to 100 times their body weight in blood, returning about 75% of the ingested water and ions via their saliva into the host. We postulated that water channels, or aquaporins, involved in this mass water transport might be good targets for acaricide development. An aquaporin (IrAQP1) identified in the sheep tick, Ixodes ricinus, was present only in tissues involved in mass water flux, namely the gut, rectal sac and especially abundant in the salivary glands. IrAQP1 was localised by in situ hybridisation in specific cell and acini types, possibly Type III acini, but absent from the type I acini that are responsible for rehydration of ticks in the non-feeding phase. Gene knockdown of IrAQP1 in isolated salivary glands completely inhibited dopamine-stimulated secretion. Further, IrAQP1 knockdown adult females had 50% reduced body weight gains over the first 5 days feeding on an artificial feeding apparatus and 21% at the point of engorgement on hosts. Haemolymph osmolarity was increased in the IrAQP1-knockdown ticks. Importantly, the blood volume ingested per body weight was reduced by 30%. Overall, it would appear that water passage from the gut to the saliva was disrupted and tick guts were simply too “full” to ingest more blood. However, double-stranded RNA interference of IrAQP1 did not affect mortality of the ticks which successfully fed to detachment at day 9. Overall, our data indicate that IrAQP1 plays a pivotal role in blood meal water handling through the gut and salivary gland, and although its disruption by double-stranded RNA interference dramatically affects feeding performance, ticks remained feeding on the host with subsequent potential pathogen transmission and, therefore, IrAQP1 is not a suitable candidate target for tick control.     

Tyrosine and phenylalanine concentrations in haemolymph and tissues of the American cockroach, Periplaneta americana, during metamorphosis

Phenylalanine and tyrosine concentrations were measured in the haemolymph, fat body, and abdominal integument of the American cockroach, Periplaneta americana, during the pre- and post-ecdysial periods of cuticle formation and sclerotization.Gas-liquid chromatography of trimethylsilyl derivatives of phenylalanine, tyrosine, and their metabolites provided a very sensitive and rapid method for determining those amino acids in small haemolymph and tissue samples.Haemolymph tyrosine increased in two stages: initially near apolysis and 16 to 25 hr pre-ecdysis, reaching its highest concentration at ecdysis (3·5 μg tyrosine/mg haemolymph). During that time, total haemolymph tyrosine increased by approximately 700 μg/insect. Fat body and abdominal integument began to accumulate tyrosine near apolysis. Fat body tyrosine peaked between ecdysis and 3·3 hr post-ecdysis whereas abdominal integument tyrosine peaked at ecdysis. Maximum concentrations were 6·0 μg and 4·1 μg tyrosine/mg wet wt. of tissue, respectively. Between ecdysis and 24 hr post-ecdysis, the period of maximum sclerotization, total tyrosine in haemolymph and fat body decreased by approximately 600 μg and 420 μg/insect, respectively. Phenylalanine concentrations did not change significantly in the haemolymph, fat body, or abdominal integument during the pre- and post-ecdysial periods.The cockroach apparently does not store free phenylalanine or tyrosine in the fat body during larval development as compared to tyrosine storage in some Diptera. The rapid increase of haemolymph, fat body, and integument tyrosine just prior to ecdysis suggests another form of storage for this important amino acid.     

Salivary amino acids in Lygus species (Heteroptera:Miridae)

Free and protein-bound amino acids were investigated in the phytophagous bug Lygus rugulipennis and its salivary gland. Over 38 substances were separated. The total content of amino compounds in the insects was about 1400 μmol/g fr. wt (16% by weight), of which 97% was amino acid residues in proteins.The salivary glands, which comprise about 1.5% of the live weight of the insects, contain 3.5% of the total free amino acids and 1% of the whote insect. Free and protein-bound amino acids comprise, respectively, about 1.4 and 11.6% of the fresh weight of the gland. The total concentration of free amino acids in the saliva was estimated to range from 0.5 to 2.2% by weight (ca. 0.1 M).The composition of free amino acids in the salivary gland of Lugus varies markedly. In four studied species (L. rugulipennis, L. gemellatus, L. pratensis, L. punctatus), the most abundant compounds were proline, arginine, lysine, leucine, glutamic acid, methionine sulphoxide and glycerophosphoethanolamine. In whole specimens of L. rugulipennis the predominant free amino acids were proline, alanine, taurine, glutamic acid, glutamine and methionine sulphoxide. The most abundant amino acids in proteins were glutamic and aspartic acid, glycine, alanine and leucine. The results indicate that the amino acid composition in the salivary glands of Lygus species does not differ markedly from that of the whole insect. The functions of salivary amino acids are discussed.     

A medium for the maintenance of Chironomus tentans salivary glands in vitro

A synthetic medium based upon the chemical composition of fourth instar Chironomus haemolymph was formulated for the in vitro culture of Chironomus tentans salivary glands.Salivary glands maintained in the medium for up to 4 days appeared morphologically normal. Secretion-free glands, obtained from pilocarpine-treated larvae, accumulated proteinaceous material in the gland lumen and exhibited a 46% increase in total gland protein after 24 hr in the medium. Cycloheximide almost totally inhibited the accumulation of secretion material and the increase in total gland protein by cultured glands.Glands cultured for up to 4 days continued to incorporate ¹⁴C-leucine into acid-insoluble total protein and ³H-uridine into total RNA, but at reduced levels. The incorporation of both isotopes was almost completely inhibited by cycloheximide.Autoradiographic squash preparations of glands pulse-labelled with ³H-thymidine after 3 days in culture revealed a normal pattern of asynchronous chromosomal DNA replication. Glands cultured for up to 4 days exhibited ³H-uridine incorporation into nucleoli and into distinct chromosomal regions which corresponded with sites of cytochemically demonstrable acidic protein.The chromosomes of cultured glands appeared morphologically and cytochemically normal, except for some regression of the Balbiani rings. Addition of ecdysterone to media containing glands previously cultured for 3 days resulted in puff induction at the IV-2-B chromosomal locus.     

Transgenic Mice Expressing Yeast CUP1 Exhibit Increased Copper Utilization from Feeds

Copper is required for structural and catalytic properties of a variety of enzymes participating in many vital biological processes for growth and development. Feeds provide most of the copper as an essential micronutrient consumed by animals, but inorganic copper could not be utilized effectively. In the present study, we aimed to develop transgenic mouse models to test if copper utilization will be increased by providing the animals with an exogenous gene for generation of copper chelatin in saliva. Considering that the S. cerevisiae CUP1 gene encodes a Cys-rich protein that can bind copper as specifically as copper chelatin in yeast, we therefore constructed a transgene plasmid containing the CUP1 gene regulated for specific expression in the salivary glands by a promoter of gene coding pig parotid secretory protein. Transgenic CUP1 was highly expressed in the parotid and submandibular salivary glands and secreted in saliva as a 9-kDa copper-chelating protein. Expression of salivary copper-chelating proteins reduced fecal copper contents by 21.61% and increased body-weight by 12.97%, suggesting that chelating proteins improve the utilization and absorbed efficacy of copper. No negative effects on the health of the transgenic mice were found by blood biochemistry and histology analysis. These results demonstrate that the introduction of the salivary CUP1 transgene into animals offers a possible approach to increase the utilization efficiency of copper and decrease the fecal copper contents.     

Characterization of Obesity Phenotypes in Psammomys Obesus (Israeli Sand Rats)

Psammomys obesus (the Israeli sand rat) has been well studied as an animal model of Type 2 diabetes. However, obesity phenotypes in these animals have not been fully characterized. We analyzed phenotypic data including body weight, percentage body fat, blood glucose and plasma insulin concentration for over 600 animals from the Psammomys obesus colony at Deakin University to investigate the relationships between body fat, body weight and Type 2 diabetes using regression analysis and general linear modelling. The body weight distribution in Psammomys obesus approximates a normal distribution and closely resembles that observed in human populations. Animals above the 75th percentile for body weight had increased body fat content and a greater risk of developing diabetes. Increased visceral fat content .was also associated with elevated blood glucose and plasma insulin concentrations in these animals. A familial effect was also demonstrated in Psammomys obesus, and accounted for 51% of the variation in body weight, and 23–26% of the variation in blood glucose and plasma insulin concentrations in these animals. Psammomys obesus represents an excellent animal model of.obesity and Type 2 diabetes that exhibits a phenotypic pattern closely resembling that observed in human population studies. The obesity described in these animals was familial in nature and was significantly associated with Type 2 diabetes.