The role of Islet-1 in cell specification,differentiation,and maintenance of phenotypes in the vertebrate neural retina

Many blinding diseases,such as retinitis pigmentosa,age-related macular degeneration,and glaucoma involve the permanent loss of retinal neurons,especially photoreceptors or the centrally projecting retinal ganglion cells.Stem cells have been proposed as a potential source of cells for neuronal transplantation.

Biomechanical forces in atherosclerosis-susceptible and -resistant regions of human vasculature differentially regulate endothelial vaso-protective phenotypes

Introduction Atherosclerosis is a potentially life-threatening disease of large arteries that is strongly associated with systemic risk factors such as hypercholesterolemia,hypertension,smoking,and diabetes. However,atherosclerosis develops as a

Analysis of Population Genetic Change to Single Oospore Strains of Phytophthora infestans

The occurrence of sexual reproduction accelerates the population genetic variation of Phytophthora infestans and makes it more difficult to control.The systematic analysis of the differentiation of phenotype(mating type and metalaxyl sensitivity)and genotype(mtDNA haplotype and SSR genotype)of 65 single oospore strains of P.infestans was carried out in this article.Five test strains were isolated from Heilongjiang Province and Mongolia Autonomous Region.The experiment results showed that the isolation ratio of metalaxyl resistance(MR:HR)of single oospore strains produced through the cross of medium resistance and high resistant parents was 18:13;the isolation ratio of the metalaxyl resistance(S:MR:HR)of single oospore strains produced through the cross of sensitive and high resistant parents was 4:12:7.The progenies of single oospore strains produced through self-fertility parents with medium resistance were all of the medium resistance.The mating types A1:A2 was greater than 1:1 in single oospore strains of the progenies,which did not conform to the Mendel's law of inheritance.All single oospore strains of the progenies inherited mitochondrial DNA fragments from only one parent.Sexual recombination of single oospore strains was verified by using two pairs of SSR primers(Pi4B and Pi4G).At the locus of Pi4B and Pi4G in the cross of KS-37 and KS-25,the separation frequencies of allele were 19:12 and 14:17,respectively.They produced two new genotype strains.This study could provide a basis for formulating disease control strategies.

Identification of Phenotypic and Genotypic Variability among the Isolates of Ramularia areola of Brazilian Cotton

Genotypic and phenotypic variation among 16 isolates of Ramularia areola of Gossypium hirsutum collected from five different geographical regions of Brazil was studied through virulence spectrum on three cultivars in the glasshouse and through ERIC- and REP-PCR and ITS1-5.8S-ITS2 rDNA analysis. Difference in virulence spectrum and molecular analysis of some isolates was observed. ERIC- and REP-PCR showed similar results and revealed a high level of diversity among the isolates. A unique profile for both ERIC and REP was obtained for most isolates. On the other hand, the ITS rDNA analysis did not show different PCR-RFLP patterns. While some isolates differed among each other considering genotypic and phenotypic reactions, no clear cut evidence was found about the existence of genetic lineages of R. areola in Brazil. Identification of genetic variability among the R. areola isolates originated from different geographic regions would permit screening of Brazilian germplasm and achieve sources with a wide spectrum of resistance. This is the first report of the genotypic and phenotypic variability among the R. areola isolates originated from five cotton growing regions of Brazil.

Transforming growth factor-β1 involved in urotensin Ⅱ-induced phenotypic differentiation of adventitial fibroblasts from rat aorta

Background Urotensin Ⅱ （UⅡ） is a new vasoconstrictive peptide that may activate the adventitial fibroblasts.Transforming growth factor-β1 （TGF-β1） is an important factor that could induce the phenotypical transdifferentiation of adventitial fibroblasts. This study aimed to explore whether TGF-β1 is involved in UⅡ-induced phenotypic differentiation of adventitial fibroblasts from rat aorta.Methods Adventitial fibroblasts were prepared by the explant culture method. TGF-β1 protein secretion from the cells was determined by enzyme-linked immunosorbent assay （ELISA）. The mRNA and protein expression of α-smooth nuscle actin （α-SM-actin）, the marker of phenotypic differentiation from fibroblasts to myofibroblasts, were determined using real-time quantitative RT-PCR （real-time RT-PCR） and Western blotting, respectively.Results UⅡ stimulated the secretion of TGF-β1 in cultured adventitial fibroblasts in a time-dependent manner. The secretion reached a peak at 24 hours, was higher by 69.8% （P ＜0.01）, than the control group. This effect was also concentration dependent. Maximal stimulation was reached at 10-8 mol/L of UⅡ （P ＜0.01）, which was increased by 59.9%,compared with in the control group （P ＜0.01）. The secretion of TGF-β1 induced by UⅡ was significantly blocked by SB-710411 （10-7 mol/L）, a specific antagonist of UⅡ receptor. In addition, both UⅡ （10-8 mol/L） and TGF-β1 significantly stimulated α-SM-actin mRNA and protein expression. Moreover, the α-SM-actin induced by UⅡ was inhibited by the specific neutralizing antibody （20 μg/ml） of TGF-β1, while the α-SM-actin expression stimulated by TGF-β1 （20 ng/ml）was inhibited by SB-710411 （10-7 mol/L）, the UⅡ receptor antagonist.Conclusion This study suggests that UⅡ could induce TGF-β1 secretion in adventitial fibroblasts via UT activation, and TGF-β1 might be involved in phenotypic differentiation from adventitial fibroblasts into myofibroblasts induced by UⅡ, and TGF-β1 signaling might be one of the important pathways by which UⅡ is involved in vascular fibrosis.