scholarly journals Orchestration of the distinct morphogenetic movements in different tissues drives tail regression during ascidian metamorphosis

2020 ◽  
Vol 465 (1) ◽  
pp. 66-78
Author(s):  
Sota Yamaji ◽  
Akiko Hozumi ◽  
Shohei Matsunobu ◽  
Yasunori Sasakura
1981 ◽  
Vol 45 (02) ◽  
pp. 110-115 ◽  
Author(s):  
György Csákó ◽  
Eva A Suba

SummaryPlatelet aggregations were studied by a turbidimetric method in citrated human platelet-rich plasmas (PRP) in vitro. Human Clq inhibited the aggregations caused by collagens derived from different tissues and species. Clq was needed by weight in comparable quantities to collagen for neutralizing the aggregating effect. The dependence of the inhibitory reaction on the preincubation of platelets with Clq and the differences in the occurrence of aggregating substances in supernatants of PRP triggered with collagen in the presence or absence of Clq, confirmed that Clq exerts its effect by preventing fixation of collagen to platelets. In addition, the high specificity of the inhibitory action of Clq for collagen-induced platelet aggregation was demonstrated by results obtained for testing a variety of aggregating agents in combination with Clq and/or collagen.Since normal concentrations of Clq in the blood are in the range of inhibitory doses of Clq for collagen-induced platelet aggregations in vitro and upon activation of complement Clq is known to dissociate from Cl, it is proposed that Clq may participate in a highly specific manner in regulating platelet reactivity to collagen in vivo.


2017 ◽  
Vol 43 (9) ◽  
pp. 1410 ◽  
Author(s):  
Xiao-Chun WANG ◽  
Hao-Ran ZHANG ◽  
Yi-Hao WEI ◽  
Xi-Ting JIA ◽  
Ming-Xin GU ◽  
...  

2017 ◽  
Vol 10 (1) ◽  
pp. 35-45
Author(s):  
N.F. Lunkova ◽  
N.A. Burmistrova ◽  
M.S. Krasavina

Background:A growing part of the root is one of the most active sinks for sucrose coming from source leaves through the phloem. In the root, sucrose is unloaded from conducting bundles and is distributed among the surrounding cells. To be involved in the metabolism, sucrose should disintegrate into hexoses by means of degrading enzymes.Aims:The aim of this research was to explore the possibility of the involvement of one such enzymes, invertase, in phloem unloading as well as distribution of its activity in the functionally different tissues of the plant root tips.Method:To estimate the enzyme activities in root tissues, we applied two techniques: the histochemical method using nitro blue tetrazolium. The localization of phloem unloading was studied with carboxyfluorescein, a fluorescent marker for symplastic transport.Results:Invertase activity was not detected in the apical part of the meristem. It appeared only between the basal part of this zone and the beginning of the elongation zone. There is the root phloem unloading in that area. Invertase activity increased with increasing the distance from the root tip and reached the highest values in the region of cell transition to elongation and in the elongation zone. The activities of the enzyme varied in different tissues of the same zone and sometimes in the neighboring cells of the same tissue. Biochemical determination of invertase activity was made in the maize root segments coincident to the zones of meristem, cell elongation and differentiation. The results of both methods of determination of invertase activity were in agreement.Conclusion:It was concluded that phloem unloading correlated with invertase activity, possibly because of the activation of invertase by unloaded sucrose. Invertase is one of the factors involved in the processes preparing the cells for their transition to elongation because the concentration of osmotically active hexoses increases after cleavage of sucrose, that stimulates water entry into the cells, which is necessary for elongation growth.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yuping Li ◽  
Xiaoju Liang ◽  
Xuguo Zhou ◽  
Yu An ◽  
Ming Li ◽  
...  

AbstractGlycyrrhiza, a genus of perennial medicinal herbs, has been traditionally used to treat human diseases, including respiratory disorders. Functional analysis of genes involved in the synthesis, accumulation, and degradation of bioactive compounds in these medicinal plants requires accurate measurement of their expression profiles. Reverse transcription quantitative real-time PCR (RT-qPCR) is a primary tool, which requires stably expressed reference genes to serve as the internal references to normalize the target gene expression. In this study, the stability of 14 candidate reference genes from the two congeneric species G. uralensis and G. inflata, including ACT, CAC, CYP, DNAJ, DREB, EF1, RAN, TIF1, TUB, UBC2, ABCC2, COPS3, CS, R3HDM2, were evaluated across different tissues and throughout various developmental stages. More importantly, we investigated the impact of interactions between tissue and developmental stage on the performance of candidate reference genes. Four algorithms, including geNorm, NormFinder, BestKeeper, and Delta Ct, were used to analyze the expression stability and RefFinder, a comprehensive software, provided the final recommendation. Based on previous research and our preliminary data, we hypothesized that internal references for spatio-temporal gene expression are different from the reference genes suited for individual factors. In G. uralensis, the top three most stable reference genes across different tissues were R3HDM2, CAC and TUB, while CAC, CYP and ABCC2 were most suited for different developmental stages. CAC is the only candidate recommended for both biotic factors, which is reflected in the stability ranking for the spatio (tissue)-temporal (developmental stage) interactions (CAC, R3HDM2 and DNAJ). Similarly, in G. inflata, COPS3, R3HDM2 and DREB were selected for tissues, while RAN, COPS3 and CS were recommended for developmental stages. For the tissue-developmental stage interactions, COPS3, DREB and ABCC2 were the most suited reference genes. In both species, only one of the top three candidates was shared between the individual factors and their interactions, specifically, CAC in G. uralensis and COPS3 in G. inflata, which supports our overarching hypothesis. In summary, spatio-temporal selection of reference genes not only lays the foundation for functional genomics research in Glycyrrhiza, but also facilitates these traditional medicinal herbs to reach/maximize their pharmaceutical potential.


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