Graft-transformation,the mechanism for graft-induced genetic changes in higher plants   总被引：9，自引：0，他引：9  

Yasuo Ohta 《Euphytica》1991,55(1):91-99

Summary In our previous report of a series of experiments involving ordinary grafting, virus-inoculated grafting and DNA treatment in Capsicum annuum L., we described the variants as well as gene analyses of individual variants, together with the characteristics of the graft-induced genetic changes obtained.Microhistological analysis of the stock stems revealed that chromatin masses, stained to greenish blue and in various sizes and shapes, were moving through cell wall and intercellular space from the lignifying and dying cells, stained to lighter purplish brown, towards the vascular bundles (Fig. 1). I discussed the mechanisms of chromatin transfer from the stock dying cells through the vascular system across the graft-union to the growing point(s) of the scion (Fig. 3), and how that process causes transformation in the fast dividing scion flower primordia (Fig. 4).The significance of chromatin translocation can be understood in the following way: Genetic information is never transmitted from the stock to the scion, unless a DNA molecule larger than a functional unit such as a gene translocates from the stock, and unless the DNA molecules per se are integrated into new cell nuclei of the scion. In other words, no transmission of genetic information will take place, if DNA molecules of the stock disintegrated to nucleotides, as when a protein molecule is digested into amino acids, and are utilized by the scion simply as raw material in the formation of new cell nuclei with its own DNA strand as template.Also discussed were the significance of mentor methods, and the importance of distinguishing between horticultural graft and genetical graft (Fig. 2).  相似文献   

Evaluation of left ventricular diastolic dysfunction at the early stage of pressure overload-induced myocardial remodeling in rats     

GAI Ying-li  XU Ming  BAI Yan  XIAO Han  MA Xiao-wei  LV Zhi-zhen  FENG Jie-li  ZHANG You-yi  LI Zhao-ping 《园艺学报》2011,27(9):1665-1670

AIM: To investigate the evaluation method of left ventricular diastolic function and myocardial hypertrophy induced by pressure overload in rats.METHODS: Male Sprague-Dawley rats were subject to left ventricular pressure overload by transverse aortic constriction (TAC).Cardiac structure and diastolic function were evaluated by echocardiography, hemodynamic analysis and examination of hydroxyproline concentration in the myocardial tissues.RESULTS: Compared with the sham-operated controls, left ventricular wall dimension in diastole significantly increased in the rats 3 weeks after TAC .Left ventricular early diastolic posterior wall motion velocity (E') significantly decreased in the rats 3 weeks after TAC , and was much lower than that in the rats 6 weeks after TAC.Left ventricular mass to tibia length in TAC rats was much higher than that in sham-operated controls .The ratio of maximum rate of degression of left ventricular pressure (dp/dt_min) to left ventricular systolic pressure (dp/dt_min/LVSP) started to decrease in TAC rats in the 3rd week (48.9±5.9 vs 63.5±9.9) and significantly decreased in TAC rats in the 6th week as compared with sham-operated controls (35.4±4.0 vs 54.4±2.9, P<0.01).Sirius red-stained collagen in cardiac interstitium, especially around the blood vessels, was increased in TAC rats.Six weeks after TAC, a significant increase in the content of myocardial hydroxyproline was observed.CONCLUSION: The early diastolic posterior wall motion velocity (E') detected by tissue Doppler imaging is a sensitive indicator of diastolic dysfunction at the early stage of myocardial remodeling induced by pressure overload in rats.  相似文献   

MyoD介导肌肉特异性基因染色质重塑激活与成肌分化控制     

熊琪  李晓锋  索效军  张年  刘洋  陈明新 《湖北农业科学》2014,53(20):4780-4782,4804

骨骼肌纤维的数目由出生前肌源细胞的成肌分化进程所决定,直接影响家畜的生长潜能和肉质.MyoD依赖的肌肉特异性基因的染色质重塑激活是控制成肌分化的重要方式,其作用模式已有一些报道.PI3K/Akt和p38信号也参与了这一过程的调控.对这一研究进展进行了综述.  相似文献   

Use of a Single-Layer Density Centrifugation Method Enhances Sperm Quality in Cryopreserved–Thawed Equine Spermatozoa     

Anja Stoll  Charles C. Love  Barry A. Ball 《Journal of Equine Veterinary Science》2013

The objective of this study was to improve the quality of cryopreserved–thawed equine sperm using single-layer density centrifugation (SLC). Sperm quality was assessed by DNA integrity, motility, morphology, mitochondrial membrane potential, viability, and plasma membrane alteration. The percentage of DNA-damaged sperm (expressed in % COMP) was lower (P = .001) after SLC (1.6 ± 0.5% vs. 6.8 ± 0.5%). Total sperm motility (80 ± 2.4% vs. 41.7 ± 2.4%) and progressive sperm motility (69.5 ± 2.9% vs. 31.5 ± 2.9%) (P < .001), as well as the percentage of morphologically normal sperm (45 ± 3.9% vs. 27.7 ± 3.9%), increased after SLC compared with control sample. In addition, the proportion of sperm with high mitochondrial membrane potential increased (81.6 ± 1.8% vs. 42.1 ± 1.8%), as did the viability of sperm (71.1 ± 2.4% vs. 39.5 ± 2.4%), after SLC compared with the control sperm. The proportion of sperm with alteration in plasma membrane structure was lower after SLC compared with control sample (6.4 ± 1.1% vs. 18.9 ± 1.1%). Overall, sperm recovery was 72.7 ± 3.6% in the control sample compared with 14.8 ± 3.6% after SLC (P < .001). We conclude that based on the sperm parameters evaluated, SLC improves the quality of cryopreserved–thawed equine spermatozoa.  相似文献   

Microcystin-LR and Cylindrospermopsin Induced Alterations in Chromatin Organization of Plant Cells     

Csaba Máthé  Márta M-Hamvas  Gábor Vasas 《Marine drugs》2013,11(10):3689-3717

Cyanobacteria produce metabolites with diverse bioactivities, structures and pharmacological properties. The effects of microcystins (MCYs), a family of peptide type protein-phosphatase inhibitors and cylindrospermopsin (CYN), an alkaloid type of protein synthesis blocker will be discussed in this review. We are focusing mainly on cyanotoxin-induced changes of chromatin organization and their possible cellular mechanisms. The particularities of plant cells explain the importance of such studies. Preprophase bands (PPBs) are premitotic cytoskeletal structures important in the determination of plant cell division plane. Phragmoplasts are cytoskeletal structures involved in plant cytokinesis. Both cyanotoxins induce the formation of multipolar spindles and disrupted phragmoplasts, leading to abnormal sister chromatid segregation during mitosis. Thus, MCY and CYN are probably inducing alterations of chromosome number. MCY induces programmed cell death: chromatin condensation, nucleus fragmentation, necrosis, alterations of nuclease and protease enzyme activities and patterns. The above effects may be related to elevated reactive oxygen species (ROS) and/or disfunctioning of microtubule associated proteins. Specific effects: MCY-LR induces histone H3 hyperphosphorylation leading to incomplete chromatid segregation and the formation of micronuclei. CYN induces the formation of split or double PPB directly related to protein synthesis inhibition. Cyanotoxins are powerful tools in the study of plant cell organization.  相似文献   

Effect of TRPC6 on PDGF-induced proliferation of rat airway smooth muscle cells     

CHENG Ying  ZENG Xin  XU Ji-de  YUE Xi-lei  HAN Zhi-yuan  YANG Chun-tao 《园艺学报》2013,29(12):2229-2234

AIM:To investigate the role of canonical transient receptor potential channel 6 (TRPC6) in the proliferation of airway smooth muscle cells (ASMCs) induced by platelet-derived growth factor (PDGF). METHODS:Rat ASMCs were cultured by enzyme digestion and tissue adhesion. The method of indirect immunofluorescence was applied to identify the ASMCs and to detect the expression of TRPC6 in ASMCs. The proliferation of ASMCs was determined by CCK-8 assay. The mRNA expression of TRPC6 was tested by real-time PCR. The protein expression of TRPC6 was analyzed by Western blotting. The influence of TRPC6 blocker at different concentrations on the proliferation of ASMCs was measured by CCK-8 assay. RESULTS:The results of immunofluorescence indicated that TRPC6 expression in ASMCs was positive. PDGF at concentration of 20 μg/L induced the proliferation of ASMCs compared with control group (P<0.05). When ASMCs were treated with both PDGF and different concentrations of TRPC6 blocker SKF96365, the proliferation of ASMCs was attenuated in dose-dependent and time-dependent manners as compared with the cells treated with PDGF alone (P<0.05). The mRNA expression of TRPC6 in PDGF group was significantly increased (P<0.05) after ASMCs were treated with PDGF for 12 h, 24 h and 48 h. The protein level of TRPC6 in PDGF group was significantly increased after ASMCs were treated with PDGF for 24 h and 48 h compared with control group (P<0.05). CONCLUSION: Up-regulation of TRPC6 at mRNA and protein levels is most possibly related to the proliferation of ASMCs induced by PDGF. Therefore, TRPC6 is involved in the proliferation of ASMCs.  相似文献   

Effects of cardiac remodeling on atrial arrhythmogenesis in aged rabbit left atrium     

WANG Teng  CHEN Yu-ting  CAO Hong  HUANG Yan  LIU Tao  ZOU Qiang 《园艺学报》2017,33(2):244-250

AIM: To investigate the effects of myocardial remodeling of aged left atrium (LA) on atrial arrhythmogenesis in rabbits.METHODS: The male New Zealand rabbits were divided into young LA and aged LA groups. By observing the changes of monophasic action potential (MAP) and burst-pacing in LA of the rabbits in vivo, the main cardioelectrophysiological parameters such as resting membrane potential (RMP), action potential amplitude (APA), ma-ximum rise veloctiy of action potential (dv/dt_max), plateau potential and action potential duration at 30%, 50% and 90% (APD₃₀, APD₅₀ and APD₉₀), as well as the inducibility and duration of atrial arrhythmias were recorded. L-type calcium current (I_Ca,L) was analyzed via whole-cell patch-clamp technique in enzymatically dissociated single rabbit LA myocytes. The myocardial collagen content was quantified after Masson staining, and the ultrastructure of the LA cells was observed under scanning electron microscope. The expression of Cav1.2 in LA tissue of the 2 groups was detected by Western blot.RESULTS: Compared with young LA group, dv/dt_max and plateau potential were significantly decreased, APD₃₀ and APD₅₀ were shortened, and APD₉₀ was notably prolongated in aged LA group (P<0.01). The inducibility or duration of atrial arrhythmias was severely increased or prolongated in aged LA group (P<0.01). With voltage clamp model, the density of I_Ca,L in aged LA group was significantly decreased, and current-voltage curve was notably moved upward compared with young LA group. When the clamp potential was +20 mV, the density of I_Ca,L was notably modified from (11.72±1.39) pA/pF in young LA group to (6.08±0.98) pA/pF in aged LA group (P<0.01). Compared with young LA group, the protein level of collagen was significantly increased (P<0.01), and the arrange of atrial myocytes was irregular in LA of rabbits in aged LA group. The atrial myocytes of the LA wall in aged LA group exhibited abnormal ultrastructural alterations, such as karyopyknosis, irregular and swelling mitochondria with the presence of vacuoles, and mild and severe sarcomere degeneration. Compared with those in LA tissues of young rabbits, the expression levels of Cav1.2 in the LA tissues of aged rabbits were severely reduced (P<0.01), and had a significant positive correlation with the reduction of I_Ca,L (r=0.83, P<0.01).CONCLUSION: The pathophysiological characteristics of aged LA are significantly altered, and might contribute to vulnerability and susceptibility of occurrence of atrial fibillation in aged rabbits. The mechanisms might completely attribute to the notable reduction of I_Ca,L, abnormal alterations of ultrastructures and obvious decrease in the expression of Cav1.2 in the aged LA of aged rabbits.  相似文献   

Expression of PDGF-β receptor in broilers with pulmonary hypertension induced by cold temperature and its association with pulmonary vascular remodeling   总被引：1，自引：0，他引：1  

Jin-Chun Li  Jia-Qiang Pan  Guo-qing Huang  Wei-Dong Sun  Xiao-Long Wang 《Research in veterinary science》2010,88(1):116-121

Objective

The purpose of the present study was to characterize the relationship between platelet-derived growth factor β receptor (PDGF-β receptor) expression and pulmonary vascular remodeling found in broilers subjected to cold temperature beginning at 14 days of age.

Method

One hundred and sixty-one-day-old mixed-sex Avian-2000 commercial broilers were randomly divided into a normal temperature group (control) and a cold temperature group (cold). All the birds were brooded in normal temperature up to day 14, with the lighting schedule at 24 h per day. Starting at day 14, birds in the cold group were moved to a pen in the cold house and subjected to low temperature, while birds in the control group were still brooded at normal temperature. On days 14, 23, 30, 37 and 44, the right/total ventricle weight ratio (RV/TV), packed cell volume (PCV), the vessel wall area to vessel total area ratio (WA/TA), mean media thickness in pulmonary arterioles (mMTPA) and the expression of PDGF-β receptor in pulmonary arterioles were measured, respectively. Cumulative pulmonary hypertension syndrome (PHS) morbidity was recorded in each group.

Results

Cool ambient temperature increased PHS morbidity of broilers. The values of WA/TA and mMTPA were also increased significantly compared with control group. PCV values in the cold temperature group were elevated from days 30 to 44, and RV/TV ratios were increased on days 37 and 44. Cold exposure enhanced PDGF-β receptor expression in pulmonary arterioles, and the PDGF-β receptor expression was significantly correlated with pulmonary vascular remodeling that was dedicated by increased WA/TA and mMTPA.

Conclusion

The results indicated that PDGF-β and its receptor were involved in the underlying mechanisms of pulmonary vascular remodeling in pulmonary hypertensive broilers.  相似文献   

Effect of PPARδ activation on expression of MMP-9 and fibronectin in infarcted myocardium     

YANG Da-chun  MA Shuang-tao  YANG Yong-jian  LI Xiu-chuan  ZHANG Ji-hong  TANG Bing  LI De 《园艺学报》2010,26(11):2130-2135

AIM:To investigate the effect of peroxisome proliferator-activated receptor δ (PPARδ) activation with dietary GW610742X on the expression of matrix metalloproteinase-9 (MMP-9) and fibronectin (FN) in infarcted and remodeling myocardium. METHODS: Wistar rats were divided into 4 groups: control group, sham group, myocardial infarction (MI) group and MI+GW610742X (GW) group. The left coronary artery was ligated to establish the MI model. PPARδ activator GW610742X (100 mg·kg^-1·d^-1) was given to the rats in GW group. At the 3rd month of the procedure, the expression of PPARδ, MMP-9 and FN at mRNA and protein levels in the left ventricular free wall(LVFW) of the heart from each group was identified and the distribution of FN was detected by immunofluorescence. RESULTS: After 3 months following the procedure, obvious necrosis and fibrosis in LVFW were observed in MI group. The expression of PPARδ in MI group was higher than that in control, sham and GW groups (P<0.01), and PPARδ expression in GW group was lower than that in control and sham group (P<0.05). In MI and GW groups, the expression of MMP-9 was higher while the expression of FN was lower than those in control and sham group (P<0.05 or P<0.01). In GW group, the expression of MMP-9 was lower (P<0.05) while the expression of FN was higher (P<0.01) than those in MI group. Meanwhile, the expression of MMP-9 and FN in sham group was similar to those in control group (P>0.05). CONCLUSION: MMP-9 is upregulated and FN is downregulated in infarcted myocardium during the remodeling process. Activation of PPARδ inhibits the upregulation of MMP-9 and degradation of FN, thus ameliorating the myocardial remodeling.  相似文献   

绵羊不同直径卵泡卵母细胞特征及染色体形态分析   总被引：1，自引：0，他引：1  

郭延华  周平  石国庆  王立民  唐红  万鹏程  代蓉 《新疆农业科学》2012,49(7):1307-1314

[目的]剥离不同直径卵泡卵母细胞,比较卵母细胞成熟前后的特征.[方法]测量绵羊卵巢表面卵泡直径后进行剥离,研究卵泡表面直径与卵泡实际直径之间的关系.按表面直径分组(1.0 mm以下、1.0～2.0mm、2.1～4.0 mm、4.1 mm以上),比较各分组间卵母细胞透明带厚度、卵丘复合体质量、卵母细胞成熟前后的染色体形态变化的差异.[结果]随着卵泡直径的增大,卵泡实际直径差异极显著(P＜0.01);各组间透明带厚度差异不显著(P＞0 05),但有降低的趋势;卵丘复合体质量分为A级、B级和C级,A级有增加的趋势,B级C级有降低的趋势;卵母细胞成熟后GV/GVBD比率有下降的趋势,MAT -I、NII有增加的趋势.[结论]随着卵泡直径增大,未成熟卵母细胞的质量提高,卵母细胞核成熟比例增加.  相似文献