Characterization of the acetohydroxyacid synthase multigene family in the tetraploide plant Chenopodium quinoa

Background Currently, the technology called Clearfield® is used in the development of crops resistant to herbicides that inhibit the enzyme acetohydroxy acid synthase (AHAS, EC 2.2.1.6). AHAS is the first enzyme of the biosynthetic pathway that produces the branched-chain of the essential amino acids valine, leucine, and isoleucine. Therefore, multiple copies of the AHAS gene might be of interest for breeding programs targeting herbicide resistance. In this work, the characterization of the AHAS gene was accomplished for the Chenopodium quinoa Regalona-Baer cultivar. Cloning, sequencing, and Southern blotting were conducted to determine the number of gene copies. Results The presence of multiple copies of the AHAS gene as has been shown previously in several other species is described. Six copies of the AHAS gene were confirmed with Southern blot analyses. CqHAS1 and CqAHAS2 variants showed the highest homology with AHAS mRNA sequences found in the NR Database. A third copy, CqAHAS3, shared similar fragments with both CqAHAS1 and CqAHAS2, suggesting duplication through homeologous chromosomes pairing. Conclusions The presence of multiple copies of the gene AHAS shows that gene duplication is a common feature in polyploid species during evolution. In addition, to our knowledge, this is the first report of the interaction of sub-genomes in quinoa.

General Anesthetics and Single-Channel Recording / 한양의대학술지

Introduction of patch-clamp techniques allowed an increase in resolution of membrane current recordings. However, the technique was limited by apparent need for direct contact of pipette with cell membrane. Thus, this technique was restricted to isolated or cultured cell preparation. Although much has been achieved with such preparations, the studies of synapsis between cultured cells are undefined. Many of these problems were overcome by application of patch-clamp techniques to brain-slices. The use of high-resolution optics allowed visualization of cells to be recorded. It was possible to remove tissue covering cells and record currents in synaptically connected neurons. The brain-slice technique has greatly facilitated the investigation of electrical properties of neurons and the analysis of synaptic transmission between neurons. "Blow and seal"technique, when combined with infrared differential interference contrast video microscopy, permits recording of membrane potential and currents, not only from large cell body of neurons, but also from small processes. The technique offers many advantages, such as the case with which patch-pipette recordings can be made, the possibility of identifying cell type prior to recording and finally, the ability to visualize and record electrical activity from different compartments or from more than one site in the same neuron.

Effects of EGb761 on hippocamal synaptic plasticity of vascular dementia rats / 中国应用生理学杂志

<p><b>AIM</b>To investigate the effects of ginkgo biloba extract 761 (EGb761) on synaptic plasticity in hippocampus of vascular dementia (VD) rats.</p><p><b>METHODS</b>The escape latency (EL) of Morris water maze (MWM) task was measured at different time points (4 W, 8 W and 16 W), and the population spikes (PS) of granule cell layer in the dentate gyrus were induced by single pulse stimulation to perfo rate path fibers before and after high frequency stimulation (HFS) in vivo.</p><p><b>RESULTS</b>MWM test showed that the escape latency (EL) of VD model group were highly longer than that of the sham-operated group, while the EL of EGb761-treated group was significantly shorter than that of model group, but still longer than that of the sham-operated group. The incidence rates of LTP induction in 1 m, 2 m and 4 m subgroups of model group were significantly lower than that of sham-operated group and EGb761-treated group at different time point. The relative amplitudes of PS after HFS in 1 m, 2 m and 4 m subgroups of model group were obviously reduced compared with that of the corresponding subgroups of sham-operated group and EGb761-treated group. There was no obvious significance in the peak latency of PS between different subgroups and different LTP-tested time point.</p><p><b>CONCLUSION</b>VD model rats had apparent and long-lasting dysfunction of learning and memory, EGb761 could accelerate the recovery of the pathological synaptic plasticity. This suggested that EGb761 played an important and improving role on learning and memory dysfunction of VD.</p>

Eph in the mechanism of mossy fiber axon sprouting in dentate gyrus in rats with chronic temporal lobe epilepsy / 中南大学学报(医学版)

OBJECTIVE@#To investigate the relationship among mossy fiber axon sprouting(MFS), synaptic reorganization, and the alteration of expression of Eph A5 and ephrin A3 in the dentate gyrus in rats with pilocarpine-induced chronic temporal lobe epilepsy.@*METHODS@#Mossy fiber sprouting and synaptic formation in rats were observed by Neo-Timm staining, after the acute status epilepticus and chronic spontaneous temporal lobe epilepsy induced by lithium-chloride and pilocarpine. In situ hybridization was used to detect ephrin A3 mRNA and an immunohistochemical staining was applied to determine Eph A5 protein.@*RESULTS@#In entorhinal cortex, only Eph A5 mRNA and protein expressed, which significantly decreased on Day 7 after pilocarpine induced status epilepticus(P0.05). In the dentate granule cells, ephrin A3 mRNA reduced obviously on Day 7 after pilocarpine-induced status epilepticus (P0.05).@*CONCLUSION@#The down-regulation of Eph A5 mRNA and protein in entorhinal cortex and dentate gyrus, and ephrin A3 mRNA in dentate gyrus after status epilepticus may be part of the endogenous molecular mechanism of mossy fiber sprouting to the inner molecular layer of dentate gyrus.

Effects of yi-zhi II on synaptic structure of hippocampal CA3 and maintenance of memory / 中国应用生理学杂志

<p><b>AIM</b>To study the effects of yi-zhi II (a compond of Chinese Traditional Medicine) on the alteration of synaptic structure in hippocampal CA3 and maintenance of memoy.</p><p><b>METHODS</b>By using the method of oral administration of yi-zhi II, the step-through test and electron microscopy, the latency of step-through and synaptic structure in hippocamal CA3 were tested.</p><p><b>RESULTS</b>(1) The mice which had been given yi-zhi II prolong significantly the latency of step through (P < 0.05 or P < 0.01) on the 1st, 6th and 12th day after learning. (2) On the 6th and 12th day after learning, the length of synaptic active zone were markly improved in yi-zhi II and control, but that of yi-zhi II was better than that of control. (On the 6th day after learning, the number of perforated synapses and axo-dendrite synapses were significantly improved by the yi-zhi II (P < 0.05).</p><p><b>CONCLUSION</b>The yi-zhi II could improve the learning and memory in mice. It migth improve the memory by increasing the length of synaptic active zone and the number of perforated synapses and axo-dendrite synapses in hippocampal CA3.</p>

Morphological, yield, cytological and molecular characterization of a bread wheat x tritordeum F1 hybrid.

The morphological, yield, cytological and molecular characteristics of bread wheat x tritordeum F(1) hybrids (2n = 6x = 42; AABBDH(ch)) and their parents were analysed. Morphologically, these hybrids resembled the wheat parent. They were slightly bigger than both parents, had more spikelets per spike, and tillered more profusely. The hybrids are self-fertile but a reduction of average values of yield parameters was observed. For the cytological approach we used a double-target fluorescence in situ hybridization performed with total genomic DNA from Hordeum chilense L. and the ribosomal sequence pTa71. This technique allowed us to confirm the hybrid nature and to analyse chromosome pairing in this material. Our results showed that the expected complete homologous pairing (14 bivalents plus 14 univalents) was only observed in 9.59% of the pollen mother cells (PMCs) analysed. Some PMCs presented autosyndetic pairing of H(ch) and A, B or D chromosomes. The average number of univalents was higher in the wheat genome (6.8) than in the H(ch) genome (5.4). The maximum number of univalents per PMC was 20. We only observed wheat multivalents (one per PMC) but the frequency of trivalents (0.08) was higher than that of quadrivalents (0.058). We amplified 50 RAPD bands polymorphic between the F(1) hybrid and one of its parents, and 31 ISSR polymorphic bands. Both sets of markers proved to be reliable for DNA fingerprinting. The complementary use of morphological and yield analysis, molecular cytogenetic techniques and molecular markers allowed a more accurate evaluation and characterization of the hybrids analysed here.

Reproductive relationships and degree of synapsis in the polytene chromosomes of the Drosophila buzzatii species cluster

O processo de especiação ocorre pela evolução de qualquer uma das diversas formas de isolamento reprodutivo entre táxons, incluindo inviabilidade de híbridos. Neste trabalho, linhagens provenientes de populações alopátricas de espécies de Drosophila do cluster buzzatii foram cruzadas experimentalmente com o objetivo de avaliar suas relações reprodutivas e citogenéticas, e contribuir para o entendimento do isolamento reprodutivo neste grupo de espécies intimamente relacionadas. Os cruzamentos dentro de uma mesma linhagem foram altamente férteis, contudo as diferenças na fertilidade e fecundidade encontradas intra e interespecificamente são discutidas neste artigo. Dos 30 cruzamentos interespecíficos, 63% foram parcialmente ou completamente estéreis. Cinqüenta e três por cento dos cruzamentos de F1 interespecíficos (fêmeas e machos F1 cruzados entre si) também foram parcialmente ou completamente estéreis, em contraste com apenas um, em 24 cruzamentos de F1 intra-específicos, que foi parcialmente estéril. A análise dos cromossomos politênicos nos híbridos revelou sinapse completa, exceto nos microcromossomos (VI) e na região proximal do cromossomo X. A divergência intra-específica e o grau variável de pareamento cromossômico, observados neste estudo, revelam parte da complexidade do processo de especiação pertinente ao cluster buzzatii, o que é consistente com diferentes caracteres estudados neste cluster.

Effect of ketogenic diet on hippocampus synaptic reorganization and GluR5 expression in kainic acid induced rat model of epilepsy / 中华儿科杂志

<p><b>OBJECTIVE</b>Ketogenic diet (KD) is a high fat, low protein, low carbohydrate diet. Its antiepileptic effect is certain but the underlying mechanism is unknown. The aim of the study was to reveal the possible mechanism from the view points of synaptic reorganization and GluR(5) expression in hippocampus.</p><p><b>METHODS</b>Epilepsy was induced in Sprague-Dawley rats by kainic acid at postnatal day 28, all control animals were fed with normal rodent chow, whereas experimental rats were fed with ketogenic feed for 8 weeks. Spontaneous recurrent seizures were recorded. Mossy fiber sprouting and neuron damage in hippocampus were investigated by Timm staining and Nissl staining. Western blot and RT-PCR methods were applied to detect the expression of GluR(5) and GluR(5) mRNA in hippocampus.</p><p><b>RESULTS</b>KD-fed rats (1.40 +/- 1.03) had significantly fewer spontaneous recurrent seizures than control diet-fed rats (7.36 +/- 3.75). The mean A of mossy fiber sprouting in the inner molecular layer of dentate gyrus was markedly higher in KA induced animals than that in saline control animals but it was similar in different diet fed groups. No significant differences were found in the mean A of Timm staining in CA(3) area and Nissl staining of neuron in hilus, CA(3) and CA(1) area. After KA kindling, KD-fed animals [(189.38 +/- 40.03)/mg pro] had significantly higher GluR(5) expression in hippocampus than control diet-fed animals [(128.79 +/- 46.51)/mg pro] although their GluR(5) mRNA was the same.</p><p><b>CONCLUSION</b>Mossy fiber sprouting may be responsible for epileptogenesis in KA induced model and KD can suppress seizures in these animals. KD may upregulate young rat GluR(5) in inhibitory interneurons of CA(1) thus lead to an increased inhibition to prevent the propagation of seizure.</p>

Lutzomyia longipalpis (Diptera: Psychodidae: Phlebotominae): a review

Lutzomyia longipalpis is the most important vector of AmericanVisceral Leishmaniasis (AVL) due to Leishmania chagasi in the New World. Despite its importance, AVL, a disease primarily of rural areas, has increased its prevalence and became urbanized in some large cities in Brazil and other countries in Latin America. Although the disease is treatable, other control measures include elimination of infected dogs and the use of insecticides to kill the sand flies. A better understanding of vector biology could also account as one more tool for AVL control. A wide variety of papers about L. longipalpis have been published in the recent past years. This review summarizes our current information of this particular sand fly regarding its importance, biology, morphology, pheromones genetics, saliva, gut physiology and parasite interactions

Immuno-electronmicroscopic study on the serotoninergic taste cells and calcitonin gene-related peptide nerve fibers in mouse taste buds / 대한해부학회지

To investigate the distribution, ultrastructure and synapsis of serotoninergic cells and CGRP nerve fibers in mammalian taste buds, immunohistochemistry and electronmicroscopy were applied to mice vallate papillae. In normal mice, 1~2 serotonin immunoreactive cells were present in each taste bud section. After preloading 5-HTP, 3~6 cells showed strong immunoreactivity for serotonin. These cells were elongated, and their cytoplasm extended from the taste pore to the base of the taste bud. CGRP nerve fibers formed thick subgemmal nerve plexus under the basal lamina, and branched varicose perigemmal and intragemmal nerve fibers. Under the electron-microscope, three types of taste cells; dark cell, light cell and basal cells, were identified by their shape, location and electrical densities. Immuno-electronmicroscopy revealed that serotoninergic cells were dark cells. CGRP nerve fibers were located in and around taste buds, but the synaptic contacts with taste cells was not found. These findings indicate that mice taste cells are consisted of dark cell, light cell and basal cells, and dark cells contain serotonin. And, CGRP nerve fibers in taste buds may function as general sensory fibers.

Central Neurocytoma: A Case Report

A rare case of intraventricular central neurocytoma in 17-year-old male is reported. The patient had diffuse headache and diplopia. Radiologic findings displayed obstructive hydrocephalus and a large, well-demarcated intraventricular mass lesion obstructing the foramen of Monroe. The tumor arouse from the splenium of corpus callosum. It was removed successfully using two different approaches after extraventricular drainage of the cerebrospinal fluid(CSF). Histologically, the tumor showed pathological features as that of oligodengroglioma on the light microscope. In immunohistochemical examination, glial fibrillary acidic protein(GFAP) was negative and synaptophysin, positive. Numerous neurosecretory granules were found and no typical synapsis was noticed on the electron microscope. No shunt operation was needed. Postoperative radiotherapy or chemotherapy was not performed and no tumor recurrence was detected during the one year follow-up period. We present the case together with a review of the literatures.