Observation and Quantification of Mating Behavior in the Pinewood Nematode, <em>Bursaphelenchus xylophilus</em>

A method for observing and quantifying the mating behavior of the pinewood nematode, Bursaphelenchus xylophilus, was established under a stereomicroscope. ...

Zhejiang agricultural & forestry University

The current studies were designed to characterize type IIb sodium-inorganic phosphate (P(i)) cotransporter (NaP(i)-IIb) expression and to assess the effect of 1,25-(OH)(2) vitamin D(3) on NaP(i)-IIb gene expression during rat ontogeny. Sodium-dependent P(i) absorption by intestinal brush-border membrane vesicles (BBMVs) decreased with age, and NaP(i)-IIb gene expression also decreased proportionally with age. 1,25-(OH)(2) vitamin D(3) treatment increased intestinal BBMV P(i) absorption by approximately 2.5-fold in suckling rats and by approximately 2.1-fold in adult rats. 1,25-(OH)(2) vitamin D(3) treatment also increased NaP(i)-IIb mRNA abundance by approximately 2-fold in 14-day-old rats but had no effect on mRNA expression in adults. Furthermore, in rat intestinal epithelial (RIE) cells, 1,25-(OH)(2) vitamin D(3) increased NaP(i)-IIb mRNA abundance, an effect that was abolished by actinomycin D. Additionally, human NaP(i)-IIb gene promoter activity in transiently transfected RIE cells showed approximately 1.6-fold increase after 1,25-(OH)(2) vitamin D(3) treatment. In conclusion, we demonstrate that the age-related decrease in intestinal sodium-dependent P(i) absorption correlates with decreased NaP(i)-IIb mRNA expression. Our data also suggest that the effect of 1,25-(OH)(2) vitamin D(3) on NaP(i)-IIb expression is at least partially mediated by gene transcription in suckling rats.

Age-dependent regulation of rat intestinal type IIb sodium-phosphate cotransporter by 1,25-(OH)(2) vitamin D(3).

Glutamate has been suggested to play an important role in the release of insulin and glucagon from pancreatic cells via exocytosis. Vesicular glutamate transporter is a rate-limiting step for glutamate release and is involved in the glutamate-evoked exocytosis. Two vesicular glutamate transporters (VGLUT1 and -2) have recently been cloned from the brain. In this report, we first functionally characterized vesicular glutamate transporter in cultured pancreatic alpha- and beta-cells, and then detected mRNA expression of VGLUT1 and -2 in these cells. We also investigated the effect of high or low level of glucose on vesicular glutamate transport in cultured pancreas cells. Our results suggest that both alpha- and beta-cells contain functional vesicular glutamate transporter. The transport characteristics are similar to the cloned neuronal VGLUT1 and -2 in regard to ATP dependence, substrate specificity, kinetics, and chloride dependence. VGLUT2 mRNA is expressed in both alpha- and beta-cells, whereas VGLUT1 is only expressed in beta-cells. High (12.8 mM) and low (2.8 mM) concentrations of glucose increased vesicular glutamate transport in beta- and alpha-cells, respectively. VGLUT2 mRNA was significantly increased in beta- and alpha-cells by high and low glucose concentration, respectively. This increase in VGLUT2 mRNA was suppressed by actinomycin D. We conclude that both alpha- and beta-cells possess functional vesicular glutamate transporters regulated by alteration in glucose concentration, partly via the transcriptional mechanism.

Characterization of vesicular glutamate transporter in pancreatic alpha - and beta -cells and its regulation by glucose.

The SLC20 family transport proteins were originally identified as retroviral receptors (called Glvr-1 and Ram-1). Since then, they have been shown to function as sodium-phosphate (Na/P(i)) cotransporters, and have subsequently been classified as type III Na/P(i) cotransporters (now called Pit-1 and Pit-2). The Pit cotransporters share approximately 60% sequence homology, they have a high affinity for P(i), they are electrogenic with a coupling stoichiometry of >1 Na(+) per P(i) ion cotransported, and are inhibited by alkaline pH and phosphonoformic acid (PFA). Pit-1 and Pit-2 expression and/or activity has also been shown to be regulated by P(i) deprivation in some, but not all cells and tissues examined. The Pit-1 and Pit-2 cotransporters are widely expressed, but cell-type specific expression has only been investigated in bone, kidney and intestine. Both proteins are likely expressed on the basolateral membranes of polarized epithelial cells, where they are likely involved in cellular P(i) homeostasis. The Pit-1 and Pit-2 gene promoters have been cloned and characterized. While the exact roles of the Pit cotransporters in different cell types has not been definitively determined, they may be involved in important physiological pathways in bone, aortic smooth muscle cells, parathyroid glands, kidney and intestine.

The SLC20 family of proteins: dual functions as sodium-phosphate cotransporters and viral receptors.

The purpose of the present study was to determine the effect of angiotensin II (A-II) on membrane expression of Na+/H+ exchange isoforms NHE3 and NHE2 in the rat renal cortex. A-II (500 ng/kg per min) was chronically infused into the Sprague-Dawley rats by miniosmotic pump for 7 days. Arterial pressure and circulating plasma A-II level were significantly increased in A-II rats as compared to control rats. pH-dependent uptake of 22Na+ study in the presence of 50 microM HOE-694 revealed that Na+ uptake mediated by NHE3 was increased approximately 88% in the brush border membrane from renal cortex of A-II-treated rats. Western blotting showed that A-II increased NHE3 immunoreactive protein levels in the brush border membrane of the proximal tubules by 31%. Northern blotting revealed that A-II increased NHE3 mRNA abundance in the renal cortex by 42%. A-II treatment did not alter brush border NHE2 protein abundance in the renal proximal tubules. In conclusion, chronic A-II treatment increases NHE3-mediated Na+ uptake by stimulating NHE3 mRNA and protein content.

Effect of angiotensin-II on renal Na+/H+ exchanger-NHE3 and NHE2.

We report the novel cloning and preliminary characterization of a human urate transporter (hURAT1) gene promoter. The transcription initiation site was mapped to a base 337 bp upstream of the ATG start codon by primer extension and 5'-RACE. The minimal functional promoter region is within 253 bp when the promoter/luciferase constructs were transfected into OK cells. The sex hormone testosterone significantly increases promoter activity, suggesting that hormonal regulation of hURAT1 is the root cause of observed differences in urate levels between males and females.

Molecular cloning and characterization of a human urate transporter (hURAT1) gene promoter.

Glutamate is the major excitatory neurotransmitter in the mammalian central nervous system (CNS). Packaging and storage of glutamate into glutamatergic neuronal vesicles require ATP-dependent vesicular glutamate uptake systems, which utilize the electrochemical proton gradient as a driving force. Three vesicular glutamate transporters (VGLUT1-3) have been recently identified from neuronal tissue where they play a key role to maintain the vesicular glutamate level. Recently, it has been demonstrated that glutamate signaling is also functional in peripheral neuronal and non-neuronal tissues, and occurs in sites of pituitary, adrenal, pineal glands, bone, GI tract, pancreas, skin, and testis. The glutamate receptors and VGLUTs in digestive system have been found in both neuronal and endocrinal cells. The glutamate signaling in the digestive system may have significant relevance to diabetes and GI tract motility disorders. This review will focus on the most recent update of molecular physiology of digestive VGLUTs.

Molecular physiology of vesicular glutamate transporters in the digestive system.

Vesicular glutamate transporter (VGLUT) has been reported to be involved in glucose-induced insulin secretion. It has been shown that glucose stimulates the expression of VGLUT isoform 2 (VGLUT2) in beta cells via transcriptional mechanism. In this study, we identified the mouse VGLUT2 (mVGLUT2) promoter and characterized the transcriptional mechanism of glucose-stimulated mVGLUT2 expression in beta-cells.

Sp1 is required for glucose-induced transcriptional regulation of mouse vesicular glutamate transporter 2 gene.

Celery was found to provoke human allergenic response in some countries. Labeling of celery ingredients was required by the European Union, and the threshold set at 10 mg/kg (0.001%). In our study, a celery mannitol transporter (Mat3) gene-based detection method was established by means of SYBR Green real-time PCR technique. No cross-reactivity was found between celery and the other food materials. Absolute detection limit (LODa), relative detection limit (LODr), and practical detection limit (LODp) of the method were determined through experiments on pure celery DNA, DNA mix, and spiked food samples. The method was able to detect 0.001% raw food sample and 0.01% heated food sample. The utility of the method was confirmed by the investigation of 13 commercial foods.

SYBR green real-time PCR used to detect celery in food.

Some of the neuroprotective effects of hydrogen sulfide (H(2)S) have been attributed to systemic hypometabolism and hypothermia. However, systemic metabolism may vary more dramatically than brain metabolism after cardiac arrest (CA). The authors investigated the effects of inhaled exogenous hydrogen sulfide on brain metabolism and neurological function in rabbits after CA and resuscitation.

Effects of exogenous hydrogen sulfide on brain metabolism and early neurological function in rabbits after cardiac arrest.

To understand the efficacy of emamectin benzoate, avermectin, milbemectin, and thiacloprid on the reproduction and development of Bursaphelenchus xylophilus, seven parameters, namely population growth, fecundity, egg hatchability, larval lethality, percent larval development, body size, and sexual ratio, were investigated using sublethal (LC20) doses of these compounds in the laboratory. Emamectin benzoate treatment led to a significant suppression in population size, brood size, and percent larval development with 411, 3.50, and 49.63%, respectively, compared to 20850, 24.33, and 61.43% for the negative control. The embryonic and larval lethality increased obviously from 12.47% and 13.70% to 51.37% and 75.30%, respectively. In addition, the body length was also significantly reduced for both males and females in the emamectin benzoate treatment. Avermectin and milbemectin were also effective in suppressing population growth by increasing larval lethality and reducing larval development, although they did not affect either brood size or embryonic lethality. Body length for both male and female worms was increased by avermectin. Thiacloprid caused no adverse reproductive effects, although it suppressed larval development. Sexual ratio was not affected by any of these four nematicides. Our results indicate that emamectin benzoate, milbemectin, and avermectin are effective against the reproduction of B. xylophilus. We think these three nematicides can be useful for the control of pine wilt disease.

Liqun Bai

Department of Forest Protection

Zhejiang agricultural & forestry University

Observation and Quantification of Mating Behavior in the Pinewood Nematode, Bursaphelenchus xylophilus

Liqun Bai

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}Department of Forest Protection

Zhejiang agricultural & forestry University

Observation and Quantification of Mating Behavior in the Pinewood Nematode, Bursaphelenchus xylophilus

Department of Forest Protection