4,404 research outputs found
Characterization of p-nitrophenylglycerol-resistant Proteus mirabilis super-swarming mutants
No full textRole of RsmA in the regulation of swarming motility and virulence factor expression in Proteus mirabilis
No full textG2 & G1 plants species of SW Colorado
No full textPresented at the 16th symposium held on September 27, 2019 in Grand Junction, Colorado.2019 G2 species of SW Colorado -- 2019 G1 species of SW Colorado
Inhibition of virulence factor expression and swarming differentiation in Proteus mirabilis by p-nitrophenylglycerol
No full textExpression and regulation of gill ion transporters in Japanese medaka (Oryzias latipes) during SW acclimation
No full text廣鹽性的硬骨魚類主要藉調節其離子和滲透壓的平衡來面對環境中鹽度的改變。在現今硬骨魚海水適應的鰓細胞模型中，富含粒線體細胞(Mitochondira-rich cells, MR cells)的離子通道和運輸蛋白負責最主要的離子調節，維持體液的恆定。其中最重要也被研究最透徹離子通道包括:鈉鉀幫浦(Na+/K+-ATPase, NKA)、鈉鉀二氯共通運輸蛋白(Na+/K+/2Cl- cotransporter, NKCC)和纖維性囊腫穿膜傳導調節蛋白(Cystic fibrosis transmembrane conductance regulator, CFTR)。本研究利用日本種稻田魚(Oryzias latipes)作為研究對象，分析這些離子運輸蛋白的生理功能和基因表現，發現日本種稻田魚的存活率測試在適應過海水之後有顯著的增加。顯示出適應過海水的日本種稻田魚應有特別的轉換調控機制維持其存活，因此研究日本種稻田魚可以提供線索以了解鹽度適應性和基因調控的關係。 將日本種稻田魚鰓細胞中離子通道之胺基酸序列個別進行演化樹分析，再利用即時定量聚合酉每連鎖反應(qRT-PCR)分析適應不同環境鹽度的日本種稻田魚鳃組織，發現atp1a1a.1, atp1b1a, atp1b1b, slc12a2a和abcc7可能與海水適應的離子調節相關，因其mRNA會受到海水刺激而表現增加；其中atp1b1a和atp1b1b由海水轉移回淡水表現量會維持增高的情形，可能共同參與維持日本種稻田魚適應過後的海水調節能力。同時以atp1a1a.1, atp1b1b, slc12a2a和abcc7核酸探針標定其基因表現位置，首次提供分子證據直接證實這些基因皆表現在相同的細胞。 另一方面，偵測細胞在的不同環境鹽度適應下增生和死亡的表現，發現轉移到海水時細胞增生和死亡率皆高於淡水；利用olfoxi3做標定發現細胞分化有增加的現象。基於上述的結果，我們認為當日本種稻田魚鰓上的離子通道受到鹽度的刺激，其細胞週期變短，且一些未分化的細胞會加速分化成海水型富含粒線體細胞表現以適應鹽度的改變。綜合上述之結果，本實驗首次提供分子生理證據，證明由淡水轉移到海水時，日本種稻田魚的海水型富含粒線體細胞相關基因參與滲透壓離子調節機制以對抗外在鹽度的改變。Euryhaline teleosts have to cope with the fluctuating salinities of the environments in which they inhabit during their life time. In current model of gill salt scecretion of seawater- (SW) adaptated teleosts, mitochondria-rich cells (MR cells) play the major roles in the active ion secretion mechanism. The ion secretion mechanism in SW gill MR cells is achieved by the balsolateral Na+/K+-ATPase (NKA) and Na+/K+/2Cl- cotransporter (NKCC), and an apical membrane located cystic fibrosis transmembrane conductance regulator (CFTR). However, this model still lacks sufficient molecular evidences and leaves some controversies in the previous studies. The present study used Japanese medaka (Oryzias latipes, OL) as the model species to provide molecular and physiological evidence to support the roles of the relevant transporters in the current NaCl secretion model of SW type MR cells. The mortality experiment showed that OL enhanced their salinity adaptability after a pre-acclimation to SW and even after back to FW for 1 wk. This study examined the mRNA expression patterns of 8 transporter isoforms, and found that 3 NKA isoforms (atp1a1a.1, atp1b1a and atp1b1b), 1 NKCC (slc12a1a) and 1 CFTR (abcc7) mRNA levels were up-regulated during SW exposure, suggesting that these genes may play critical roles in salt secretion. Interestingly, the elevated mRNA levels of atp1b1b and slc12a2a in SW medaka were prolonged even after transfer back to FW for 1 wk, indicating that occurrence of a latent salt secretion mechanism of these 2 genes may be necessary for the subsequent salinity challenge as we mentioned above. Furthermore, atp1a1a.1, atp1b1b, slc12a2a and abcc7 were found to be co-expressed in the same MR cell, providing the first molecular evidence for their isoform-specific identities. The cell number of proliferation (by PH3 stainning) and apoptosis (by TUNEL assay) in gill MR cells showed that the gill cell’s turnover rate is faster in SW than in FW. In addition, olfoxi3 expression indicated the differentiation of MR cells during SW acclimation. NKCC and CFTR mRNA expression levels highly related to the number of SW-type MR cells. According to these results, we proposed that the differentiation of immature cells into SW-type MR cells can be accelerated to enhance NaCl secretion pathway in SW. In summary, several isoforms were isolated from gill MR cells of OL, and in vivo molecular evidences demonstrated their roles in iono/osmo-regulation and cell differentiation mechanisms in fish gills. This supports the notion that the expressions of these ion transporters correlate with the NaCl secretion function in MR cells, and also offer new insights into the studies on salinity tolerance in euryhaline teleosts.Table of content文摘要…..........…………………………………………………………...1bstract………….………………………………………………………….3ntroducation…….…………………………………………………………...5alinity acclimation mechanism in euryhaline teleosts………………………….....5ransporters related to salinity acclimation………………………………………6ifferentiation of MR cells………………….…………………………………8edaka as a model to explore salinity acclimation mechanism………………….....9ims of study………………………………………………………………..10aterials and Methods……………………………………………………...12nimals…………………………………………………….........................12cclimation experiments……………………………………………………..12reparation of total RNA……………………………………………………..13everse transcription-PCR analysis……………………………………………13ene expressions in different tissues…………………………………………...15olecular cloning and sequencing analysis...…………………………………...15luorescence double in situ hybridization………………………………………16uantitative real-time PCR …………………………………………………...17hospho-Histone H3 staining………………………………………………….18ndirect TUNEL labeling assay………………………………………………..18tatistical analysis……………………………………………………............19esults……………………………………………………..........................20eawater acclimation and survival rate………………………............................20hylogenetic analysis of medaka genes………………………..........................20T-PCR analysis of gene expressions in different tissues………...........................21ffects of salinity on mRNA expressions of ion transporters in medaka gills….…...22hole-mount in situ hybridization expression of NKA, NKCC and CFTR genes…..23ell proliferation and apoptosis……….............................................................23ime course changes of foxi3, atp1a1a.1, atp1b1b and slc12a2a gene expressions rates in medaka gills after transfer to BW/SW.............................................................24iscussion………………………………………………….........................25eferences………………………………………………….........................33ables…………………………………………………................................41igures…………………………………………………..............................4
Rainfall interception by two deciduous Mediterranean forests of contrasting stature in Slovenia
Full text linkMeasurements of precipitation above the canopy, throughfall and stemflow were\ud
made on the south and north-facing slopes of a deciduous forest on the experimental\ud
watershed of the Dragonja river in SW Slovenia. The Dragonja watershed was\ud
chosen for the experimental watershed, being of interest because of intensive natural\ud
reforestation in the last decades that caused a decrease in minimum and maximum\ud
flows. At the same time no noticeable precipitation and temperature changes were\ud
observed. Two forest plots were selected. One is located on the north-facing slope\ud
(1419 m2) and the other on the south-facing slope (615 m2). Analyses and modelling\ud
were made for a one-year period from October 2000 to September 2001. The leaf\ud
area index (LAI) was estimated by three methods, one direct and two indirect ones.\ud
The obtained values of LAI with the direct method were 6.6 and 6.9 for the south and\ud
north slopes, respectively. Measurements and regression analyses gave the mean\ud
annual throughfall value (± standard error) on the south plot 67.1 (± 9.6) % of gross\ud
precipitation, and 71.5 (± 11.6) % on the north plot. The average stemflow values\ud
were 4.5 (± 0.8) % of gross precipitation in the south plot and 2.9 (± 0.6) % in the\ud
north plot. The average annual interception losses amount to 28.4 (± 4.1) and 25.4 (±\ud
4.0) % for the south and north slopes, respectively. In the study a significant influence\ud
of the south-east wind was proven. With regression analyses and the classification\ud
decision tree model it was established that at the events with more than 7 mm of\ud
precipitation and south-east wind with a speed higher than 4 m/s an unusually low\ud
amount of throughfall occurred and thus high interception losses. The analytical\ud
Gash model of rainfall interception (Gash, 1979; Gash et al., 1995) was successfully\ud
applied. The results of the modelling corresponded well to the observed values and\ud
were within the limits of the standard error of the observed values
Progression rates of colorectal cancer by Dukes’ stage in a high-risk group: analysis of selective colorectal cancer screening.
No full textRapid detection and biovar differentiation of Ureaplasma urealyticum in clinical specimens by PCR
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