Two-dimensional longitudinal strains and torsion analysis to assess the protective effects of ischemic postconditioning on myocardial function: a speckle tracking echocardiography study in rabbits.

The reperfusion injury that occurs in the early reperfusion often results in myocardial dysfunction. This study evaluated global and regional left ventricular (LV) function using speckle tracking echocardiography (STE) in a rabbit ischemia-reperfusion (I/R) model with and without ischemic postconditioning (I-PostC). The aim is to investigate the potential benefit of I-PostC for myocardial function and validate whether regional longitudinal strain is an appropriate index to indicate myocardial dysfunction. Forty rabbits were divided into an ischemia-reperfusion group (group I) and an I-PostC group (group II). After the coronary arteries were ligated, LV systolic strain and twist parameters decreased, and absolute value of strain rate of isovolumetric relaxation period (SRivr) and post-systolic strain index (PSI) increased significantly in both groups (all p<0.05). After reperfusion, regional longitudinal systolic strain rate (SRsys), systolic strain (Ssys), LV twist and untwisting rate increased, and SRivr and PSI decreased in group II. These changes were not seen in group I. All STE parameters were correlated with area of necrosis (AN)/area at risk (AR) (all p<0.05). The correlations were morerelevant between SRsys and AN/AR (r=-0.673) and between Ssys and AN/AR (r=-0.777) (both p<0.001). The intra- and inter-observer repeatability of STE parameters were good with correlation coefficients (CCs) >0.8 or 0.6. The sensitivities of GSRsys, GSsys, SRsys, Ssys, and LV twist to detect the myocardial infarction were 81.3%, 62.5%, 87.5%, 93.8% and 81.3%, respectively. And the specificities of those parameters were 75.0%, 81.2%, 75.0%, 87.5% and 68.7%. These results indicate that STE is useful for quantitative detection on myocardial function improvement induced by I-PostC in a rabbit I/R model. The regional index-Ssys is an appropriate parameter to indicate myocardial dysfunction because of its sensitivity, specificity, and repeatability.

Cloning and expression of UDP-glucose: flavonoid 3-O-glucosyltransferase gene in peach flowers.

To elucidate the connection between flower coloration and the expression of genes associated with anthocyanin biosynthesis, a gene encoding UDP-glucose: flavonoid 3-O-glucosyltransferase (UFGT) was isolated, and the expression of the last four genes in the anthocyanin biosynthetic pathway during peach flower development was determined. The nucleotide sequence of the peach UFGT (GenBank accession No. JX149550) is highly similar to its homologs in other plants. Total anthocyanin content initially increased during peach flower development, and then decreased over time. Expression of the four anthocyanin biosynthesis genes increased until the full-bloom stage, and then decreased during late florescence. Expression of F3H, DFR, and UFGT increased dramatically at the full-bloom stage, coinciding with an increase in anthocyanin concentration. The UFGT gene may not be the only gene of the anthocyanin pathway to be differentially controlled in red peach flower tissues. Further studies are needed to genetically and physiologically characterize these genes and enzymes in peach flowers and to gain a better understanding of their functions and relationships with flower coloration.

Characterization of EST-derived and non-EST simple sequence repeats in an F1 hybrid population of Vitis vinifera L.

Among different classes of molecular markers, expressed sequence tags (ESTs) are a new resource for developing simple sequence repeat (SSR) functional markers for genotyping and genetic mapping in F1 hybrid populations of Vitis vinifera L. Recently, because of the availability of an enormous amount of data for ESTs in the public domain, the emphasis has shifted from genomic SSRs to EST-SSRs, which belong to transcribed regions of the genome and may have a role in gene expression or function. The objective of this study was to assess the polymorphisms among 94 F1 hybrids from "Early Rose" and "Red Globe" using 25 EST-derived and 25 non-EST SSR markers. A total collection of 362,375 grape ESTs that were retrieved from the National Center for Biotechnology Information (NCBI) and 2522 EST-SSR sequences were identified. From them, 205 primer pairs were randomly selected, including 176 pairs that were EST-derived and 29 non-EST SSR primer pairs, for polymerase chain reaction amplification. A total of 131 alleles were amplified using 50 pairs of primers; 78 alleles were amplified using EST-derived SSR primers and 53 were from non-EST SSR primers. At most, 6 and 5 alleles were amplified by EST-derived and non-EST SSR primers, respectively. The EST-derived SSR markers showed a maximum polymorphic information content (PIC) value of 1 and a minimum of 0.33 while non-EST SSR markers had maximum and minimum PIC values of 1 and 0.25, respectively. The average PIC value was 0.56 for EST-derived SSR markers and 0.45 for non-EST SSR markers.

Efficient identification of ornamental peach cultivars using RAPD markers with a manual cultivar identification diagram strategy.

One of the most important uses of DNA markers is cultivar identification. However, no DNA fingerprint analysis strategy is available for making DNA markers helpful in practical plant cultivar identification, especially for the identification of a large number of cultivars. We developed a manual cultivar identification diagram strategy for efficient identification of plant cultivars, from which a cultivar identification diagram (CID) of genotyped plant individuals can be constructed manually. This CID could be used as a reference for quick identification of plant cultivars of interest. We used 11-mer RAPD primers to amplify DNA samples of 32 ornamental peach genotypes; all the cultivars were well distinguished by fingerprints from 6 primers. The utility of this CID was verified by identification of three randomly chosen groups of cultivars among the 32 ones that we selected. This CID generated will be useful for the identification of commercially important ornamental peach cultivars.

Development of highly polymorphic EST-SSR markers and segregation in F1 hybrid population of Vitis vinifera L.

The objectives of this investigation were to develop and validate the expressed sequence tag (EST)-simple sequence repeat (SSR) markers from large EST sequences, and to study the segregation and distribution of SSRs within two grapevine parental lines. In total, 94 F1 lines crossed between "Early Rose" and "Red Globe" were studied. Approximately 2100 EST-SSR sequences of Vitis vinifera L. were searched for SSRs and analyzed for the design of polymerase chain reaction (PCR) primers amplifying the SSR-rich regions. Trinucleotide repeats were found to be the most abundant, followed by other nucleotide repeats. A total of 182 SSR primer pairs were first developed for the study on the parental polymorphism. Among the 182 SSR primers, 142 primer pairs (78%) could amplify the anticipated PCR products, among which only 52 primer pairs (36.62%) showed polymorphism between the two parents. These polymorphic bands were further surveyed among the 94 F1 lines, and the results showed that a total of 162 bands were amplified, and 98 of them were polymorphic in both parents (60.86% polymorphism), with an average of 1.88 polymorphic DNA bands for each primer pair. After testing with the chi-square test, 33 of the clearly amplified polymorphic bands followed a 3:1 ratio, and 37 followed a 1:1 ratio. The rest showed distorted segregation ratios.

A novel and efficient strategy for practical identification of tomato (Solanum lycopersicon) varieties using modified RAPD fingerprints.

Tomato breeding and variety development have led to the generation of a large number of varieties in many countries worldwide. This has created a growing and urgent need for an improved strategy for genotyping and identification since the traditional methods based on phenotype are growing unreliable. DNA markers could provide distinct benefits in tomato variety identification; however, DNA fingerprint analyses have not made DNA marker data readily usable for identification of varieties in tomato and other crops. A manual cultivar and/or variety identification diagram (MCID) strategy has been developed and has been found to make DNA markers more usable for the identification of genotyped plant individuals. We adopted this strategy, using modified RAPD markers to identify 42 tomato varieties from different geographical origins and seed merchants. All of the varieties were clearly separated and individually identified by reproducible fingerprints of only 6 RAPD primers. The tomato MCID that is generated is usable for the identification of any two or more tomato varieties. In addition, fewer primers can be used to make a distinction between varieties using this approach, since the selected fingerprints from each primer are used after they have been generated. The information in this first version of the tomato MCID can be enriched through identification and incorporation of more varieties and adaptation to other molecular markers in order to provide a more comprehensive tomato variety identification service for the horticultural industry.