Identification of QTLs for seed germination capability after various storage periods using two RIL populations in rice

Seed germination capability of rice is one of the important traits in the production and storage of seeds. Quantitative trait loci (QTL) associated with seed germination capability in various storage periods was identified using two sets of recombinant inbred lines (RILs) which derived from crosses between Milyang 23 and Tong 88-7 (MT-RILs) and between Dasanbyeo and TR22183 (DT-RILs). A total of five and three main additive effects (QTLs) associated with seed germination capability were identified in MT-RILs and DT-RILs, respectively. Among them, six QTLs were identified repeatedly in various seed storage periods designated as qMT-SGC5.1, qMT-SGC7.2, and qMT-SGC9.1 on chromosomes 5, 7, and 9 in MT-RILs, and qDT-SGC2.1, qDT-SGC3.1, and qDT-SGC9.1 on chromosomes 2, 3, and 9 in DT-RILs, respectively. The QTL on chromosome 9 was identified in both RIL populations under all three storage periods, explaining up to 40% of the phenotypic variation. Eight and eighteen pairs additive × additive epistatic effect (epistatic QTL) were identified in MT-RILs and DT-RILs, respectively. In addition, several near isogenic lines (NILs) were developed to confirm six repeatable QTL effects using controlled deterioration test (CDT). The identified QTLs will be further studied to elucidate the mechanisms controlling seed germination capability, which have important implications for long-term seed storage.     

Multiple copies of 16s rRNA gene affect the restriction patterns and DGGE profile as revealed by analysis of genome database

The use of 16S rRNA gene has been a golden method to determine the diversity of microbial communities in environmental samples, phylogenetic relationships of prokaryotes and taxonomic position of newly isolated organisms. However due to the presence of multiple heterogeneous 16S rRNA gene copies in many strains, the interpretation of microbial ecology via 16S rRNA sequences is complicated. Purpose of present paper is to demonstrate the extent to which the multiple heterogeneous 16S rRNA gene copies affect RFLP patterns and DGG E profiles by using the genome database. In present genome database, there are 782 bacterial strains in total whose genomes have been completely sequenced and annotated. Among the total strains, 639 strains (82%) possess multiple 16S rRNA gene copies, 415 strains (53%) whose multiple copies are heterogeneous in sequences as revealed by alignment, 236 strains (30%) whose multiple copies show different restrict patterns by CSP61 + Hinfl, MspI + Rsal or HhaI as analyzed in silico. Polymorphisms of the multiple copies in certain strains were further characterized by G + C% and phylogentic distances based on the sequences of V3 region, which are linked to DGGE patters. Polymorphisms of a few strains were shown as examples. Using artificial communities, it is demonstrated that the presence of multiple heterogeneous 16S rRNA gene copies potentially leads to over-estimation of the diversity of a community. It is suggested that care must be taken when interpreting 16S rRNA-based RFLP and DGGE data and profiling an environmental community.     

Multiple copies of 16S rRNA gene affect the restriction patterns and DGGE profile revealed by analysis of genome database

The use of 16S rRNA gene has been a “golden” method to determine the diversity of microbial communities in environmental samples, phylogenetic relationships of prokaryotes and taxonomic position of newly isolated organisms. However due to the presence of multiple heterogeneous 16S rRNA gene copies in many strains, the interpretation of microbial ecology via 16S rRNA sequences is complicated. Purpose of present paper is to demonstrate the extent to which the multiple heterogeneous 16S rRNA gene copies affect RFLP patterns and DGGE profiles by using the genome database. In present genome database, there are 782 bacterial strains in total whose genomes have been completely sequenced and annotated. Among the total strains, 639 strains (82%) possess multiple 16S rRNA gene copies, 415 strains (53%) whose multiple copies are heterogeneous in sequences as revealed by alignment, 236 strains (30%) whose multiple copies show different restrict patterns by CSP6I+HinfI, MspI+RsaI or HhaI as analyzed in silico. Polymorphisms of the multiple copies in certain strains were further characterized by G+C% and phy-logentic distances based on the sequences of V3 region, which are linked to DGGE patters. Polymorphisms of a few strains were shown as examples. Using artificial communities, it is demonstrated that the presence of multiple heterogeneous 16S rRNA gene copies potentially leads to over-estimation of the diversity of a community. It is suggested that care must be taken when interpreting 16S rRNA-based RFLP and DGGE data and profiling an environmental community.     

Dendroaspis natriuretic peptide protects the post-ischemic myocardial injury

The present study used isolated rat hearts to investigate whether (1) Dendroaspis natriuretic peptide (DNP) is protective against post-ischemic myocardial dysfunction, and (2) whether the cardioprotective effects of DNP is related to alteration of Bcl-2 family protein levels. The excised hearts of Sprague-Dawley rats were perfused on a Langendorff apparatus with Krebs-Henseleit solution with a gas mixture of 95% O2 and 5% CO2. Left ventricular end-diastolic pressure (LVEDP, mmHg), left ventricular developed pressure (LVDP, mmHg) and coronary flow (CF, ml/min) were continuously monitored. In the presence of 50 nM DNP, all hearts were perfused for a total of 100 min consisting of a 20 min pre-ischemic period followed by a 30 min global ischemia and 50 min reperfusion. Lactate dehydrogenase (LDH) activity in the effluent was measured during reperfusion. Treatment with DNP alone improved the pre-ischemic LVEDP and post-ischemic LVEDP significantly comparing with the untreated control hearts during reperfusion. However, DNP did not affect the LVDP, heart rate (HR, beats/min), and CF. Bcl-2, an anti-apoptotic protein expressed in ischemic myocardium of DNP+ischemia/reperfusion (I/R) group, was higher than that in I/R alone group. Bax, a pro-apoptotic protein expressed in ischemic myocardium of DNP+I/R group, has no significant difference compared with I/R alone group. These results suggest that the protective effects of DNP against I/R injury would be mediated, at least in part, through the increased ratio of Bcl-2 to Bax protein after ischemia-reperfusion.     

Quantitative chromatics analysis for computer imaging of cytologic subtypes of lung cancer stained by Papanicolaou stain

OBJECTIVE: To determine the role of quantitative chromatics analysis in the classification of subtypes of lung cancer stained by Papanicolaou stain. STUDY DESIGN: By means of computer image analysis, 60 keratinized squamous carcinoma cells (KSCC), 88 nonkeratinized squamous carcinoma cells (NKSCC) and 150 adenocarcinoma cells (ACC) from lung cancer in sputum smears stained by Papanicolaou stain were analyzed and distinguished based on quantitative colorimetry. The features measured were the content of three primary colors, red (R), green (G) and blue (B) and the coefficients of R, G and B (r, g and b, respectively). Hue, saturation, brightness and gray level were also measured. A stepwise discriminant analysis was carried out. RESULTS: The values of R, G and B and r, g and b, hue and saturation in NKSCC and ACC were significantly different from those of KSCC, and the changes in the three primary colors were more sensitive than those in the gray level. Computer assessment based on three primary color coefficients, hue and saturation yielded accuracy of distinguishing KSCC from NKSCC and KSCC from ACC of 95.2% and 95%, respectively. CONCLUSION: Quantitative analyses of R, G and B and r, g, b and hue and saturation are valuable in distinguishing KSCC from NKSCC and ACC.     

Joint structural and physiological control on the interannual variation in productivity in a temperate grassland: A data‐model comparison

Given the important contributions of semiarid region to global land carbon cycle, accurate modeling of the interannual variability (IAV) of terrestrial gross primary productivity (GPP) is important but remains challenging. By decomposing GPP into leaf area index (LAI) and photosynthesis per leaf area (i.e., GPP_leaf), we investigated the IAV of GPP and the mechanisms responsible in a temperate grassland of northwestern China. We further assessed six ecosystem models for their capabilities in reproducing the observed IAV of GPP in a temperate grassland from 2004 to 2011 in China. We observed that the responses to LAI and GPP_leaf to soil water significantly contributed to IAV of GPP at the grassland ecosystem. Two of six models with prescribed LAI simulated of the observed IAV of GPP quite well, but still underestimated the variance of GPP_leaf, therefore the variance of GPP. In comparison, simulated pattern by the other four models with prognostic LAI differed significantly from the observed IAV of GPP. Only some models with prognostic LAI can capture the observed sharp decline of GPP in drought years. Further analysis indicated that accurately representing the responses of GPP_leaf and leaf stomatal conductance to soil moisture are critical for the models to reproduce the observed IAV of GPP_leaf. Our framework also identified that the contributions of LAI and GPP_leaf to the observed IAV of GPP were relatively independent. We conclude that our framework of decomposing GPP into LAI and GPP_leaf has a significant potential for facilitating future model intercomparison, benchmarking and optimization should be adopted for future data‐model comparisons.     

利用假型反转录病毒对大部分胰腺切除后再生细胞的世系追踪

胰腺是一个重要的内外分泌混合腺, 胰腺发生损伤后能够再生。为了探讨胰腺活体细胞世系追踪的方法和胰腺损伤后再生细胞的来源,分别通过胰腺伤口涂抹并胰内注射、尾静脉注射及腹腔注射三种方法, 利用假型反转录病毒对成体小鼠大部分切除后胰腺的细胞进行世系追踪。结果发现在活体条件下, 与尾静脉注射及腹腔注射法相比, 胰腺伤口涂抹并胰腺内注射反转录病毒的方法能够更有效的标记胰腺细胞; 而且, 通过对标记细胞的世系追踪研究证明, 在胰腺损伤后, 胰腺腺泡细胞能够接受损伤信号刺激发生再生。为今后进一步利用反转录假病毒对活体胰腺进行细胞命运追踪研究奠定基础, 为利用反转录病毒载体进行胰腺疾病的基因治疗提供线索。