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91.
Harvinder Singh Rupesh K. Deshmukh Abhinay Singh Ashok K. Singh Kishor Gaikwad Tilak R. Sharma Trilochan Mohapatra Nagendra K. Singh 《Molecular breeding : new strategies in plant improvement》2010,25(2):359-364
Simple sequence repeats (SSR) are the DNA markers of choice for genetic analysis in rice (Oryza sativa L.) due to their abundance, high polymorphism and simple assays using agarose gel electrophoresis. In an attempt to find
most variable SSR loci for the agarose gel system, the relationship between SSR length and level of polymorphism was evaluated
in a set of eight diverse rice genotypes using 201 random SSR loci of different repeat motifs and lengths, representing both
genic and intergenic sequences from the 12 rice chromosomes. There was a positive correlation between SSR length and average
number of alleles per locus but linearity of this relationship was limited to the SSR length range of 10–70 bp. The highest
level of polymorphism was in the SSR length range of 51–70 bp, beyond which there was stabilization and then decline of polymorphism
in SSRs longer than 70 bp. Proportion of polymorphic loci in the different SSR length groups also followed similar pattern
with even sharper decline of polymorphism in the highest size range. Here we describe a genome wide set of 436 validated highly
variable SSR (HvSSR) markers with repeat lengths of 51–70 bp for their consistent amplification and high polymorphism. In
the parental lines of three different mapping populations, the HvSSR loci showed more than twice the level of polymorphism
than random SSR markers with average repeat length of 34 bp, and therefore are suitable for QTL mapping and fingerprinting
studies in rice employing agarose gels. 相似文献
92.
Anuradha Singh Pradeep K. Singh Rakesh Singh Awadhesh Pandit Ajay K. Mahato Deepak K. Gupta Kuldeep Tyagi Ashok K. Singh Nagendra K. Singh Tilak R. Sharma 《Molecular breeding : new strategies in plant improvement》2010,26(2):325-338
Betaine aldehyde dehydrogenase (BADH) is a key enzyme involved in the synthesis of glycinebetaine—a powerful osmoprotectant
against salt and drought stress in a large number of species. Rice is not known to accumulate glycinebetaine but it has two
functional genes coding for the BADH enzyme. A non-functional allele of the BADH2 gene located on chromosome 8 is a major factor associated with rice aroma. However, similar information is not available
regarding the BADH1 gene located on chromosome 4 despite the similar biochemical function of the two genes. Here we report on the discovery and
validation of SNPs in the BADH1 gene by re-sequencing of diverse rice varieties differing in aroma and salt tolerance. There were 17 SNPs in introns with
an average density of one per 171 bp, but only three SNPs in exons at a density of one per 505 bp. Each of the three exonic
SNPs led to changes in amino acids with functional significance. Multiplex SNP assays were used for genotyping of 127 diverse
rice varieties and landraces. In total 15 SNP haplotypes were identified but only four of these, corresponding to two protein
haplotypes, were common, representing more than 85% of the cultivars. Determination of population structure using 54 random
SNPs classified the varieties into two groups broadly corresponding to indica and japonica cultivar groups, aromatic varieties clustering with the japonica group. There was no association between salt tolerance and the common BADH1 haplotypes, but aromatic varieties showed specific
association with a BADH1 protein haplotype (PH2) having lysine144 to asparagine144 and lysine345 to glutamine345 substitutions. Protein modeling and ligand docking studies show that these two substitutions lead to reduction in the substrate
binding capacity of the BADH1 enzyme towards gamma-aminobutyraldehyde (GABald), which is a precursor of the major aroma compound
2-acetyl-1-pyrroline (2-AP). This association requires further validation in segregating populations for potential utilization
in the rice breeding programs. 相似文献
93.
Ervin D. Nagy Ye Chu Yufang Guo Sameer Khanal Shunxue Tang Yan Li Weibo B. Dong Patricia Timper Christopher Taylor Peggy Ozias-Akins C. Corley Holbrook Vadim Beilinson Niels C. Nielsen H. Thomas Stalker Steven J. Knapp 《Molecular breeding : new strategies in plant improvement》2010,26(2):357-370
Rma, a dominant root-knot nematode resistance gene introduced into tetraploid peanut (Arachis hypogaea) from a synthetic allotetraploid donor (TxAG-6), has been widely deployed in modern cultivars. The genomic location and borders of the alien chromosome segment introgressed from TxAG-6 into NemaTAM (a BC7-derived introgression line) and other modern cultivars carrying Rma have not been genetically mapped, and resistance gene candidates (RGCs) have not been identified for Rma. Our study focused on densely populating the alien introgression with codominant DNA markers, identifying and mapping the borders of the alien introgression carried by NemaTAM, and identifying RGCs for Rma. Altogether, 2,847 simple sequence repeat (SSR) and 380 single strand conformational polymorphism (SSCP) markers were screened for linkage to Rma-247 of the SSCP markers targeted 202 nucleotide binding site (NBS) leucine-rich repeat (LRR) and other resistance (R) gene homologs (75 were identified by mining a peanut EST database). SSR, NBS-LRR, and Ser/Thr receptor-like protein loci within the alien introgression co-segregated with Rma in an F4 population (Gregory × Tifguard) and were tightly linked and spanned 3.4 cM in an F5 population (NemaTAM × GP-NC-WS-14). By comparative mapping in the A-genome progenitor of peanut (A. duranensis), Rma was discovered to have been introduced on an interstitial alien chromosome segment spanning one-third to one-half of chromosome 9A. Numerous codominant DNA markers were identified for finer mapping of Rma, shortening the alien introgression harboring Rma by marker-assisted selection, and introducing novel root-knot nematode R-genes into peanut by targeting syntenic segments on chromosomes 9A and 9B in wild diploid donors. 相似文献
94.
95.
Morita H Khanal S Rastogi S Suzuki G Imai M Todor A Sharov VG Goldstein S O'Neill TP Sabbah HN 《American journal of physiology. Heart and circulatory physiology》2006,290(6):H2522-H2527
Matrix metalloproteinases (MMPs) contribute to the progression of left ventricular (LV) dysfunction and remodeling associated with heart failure (HF). The present study examined the long-term effects of a selective MMP inhibitor PG-530742 (PG) on the progression of LV dysfunction and remodeling in dogs with HF. Chronic HF [LV ejection fraction (LVEF), =36%] was produced by multiple sequential intracoronary microembolizations in 24 dogs. Two weeks after the last embolization, dogs were randomized to 3 mo of therapy with either high-dose (HD) PG (3.5 mg/kg, n = 8), low-dose (LD) PG (0.2 mg/kg, n = 8), or to a matched placebo (PL, n = 8). PG has been shown to produce complete inhibition of MMP-2, -3, -9, and -13, while sparing MMPs-1 and -7. Hemodynamic and echocardiographic measurements were made before and 3 mo after initiating therapy. In PL and LD dogs, LVEF decreased significantly, and LV end-systolic volume (ESV) and LV end-diastolic volume (EDV) increased significantly during the 3-mo follow-up period. Whereas in HD dogs ejection fraction increased from 36 +/- 1 to 40 +/- 1% (P = 0.003), EDV and ESV decreased (59 +/- 4 vs. 57 +/- 4 ml, P = 0.02; and 38 +/- 2 vs. 34 +/- 2 ml, P = 0.00001, respectively). When compared with controls, HD-treated dogs showed 30% reduction in replacement fibrosis, 29% reduction in interstitial fibrosis, and 28% reduction in myocyte cross-sectional area. mRNA expression of selective MMPs was also reduced in LV tissue in HD- but not LD-treated dogs. In conclusion, in dogs with moderate HF, long-term monotherapy with HD selective MMP inhibitor PG prevents LV remodeling and the progression of global LV dysfunction. 相似文献
96.
97.
Ilka Nemere Natalio Garbi Gunter J. H?mmerling Ramesh C. Khanal 《The Journal of biological chemistry》2010,285(41):31859-31866
We have crossed ERp57flx/flx mice with commercially available mice expressing villin-driven cre-recombinase. Lysates of intestinal epithelial cells were prepared from knock-out (KO) mice and littermates (LM) and used in Western blot analyses with Ab099 against the N terminus of the 1,25D3-MARRS (membrane-associated, rapid response steroid-binding) receptor: LM mice exhibited one positive band, which was absent in preparations from KO mice. Saturation analyses of cell lysates with [3H]1,25D3 revealed negligible binding in preparations from either female or male KOs. Lysates from female and male LM mice had similar affinities but different numbers of binding sites. Isolated enterocytes were tested for steroid-stimulated calcium uptake. Treatment of cells from female or male LM mice with 1,25D3 elicited enhanced calcium uptake in females and males within 5 min. Intestinal cells from KO mice exhibited a severely blunted or completely absent response to hormone. Confocal microscopy of intestinal cells revealed the presence of cell surface vitamin D receptors. However, antibodies to the vitamin D receptor failed to block 1,25D3-stimulated calcium uptake. In chick enterocytes we have found that the PKA pathway mediates calcium uptake. The time course for activation of PKA in mouse enterocytes paralleled that for enhanced calcium uptake and for LM females reached 250% of controls within 5 min, and 150% of controls in cells prepared from LM males. Enterocytes from female or male KO mice failed to exhibit steroid hormone-stimulated PKA activity, but did respond to forskolin with enhanced calcium uptake. We conclude that the 1,25D3-MARRS receptor is of central importance to steroid hormone-stimulated calcium uptake in mammalian intestinal cells. 相似文献
98.
Sheelavanta M. Shivaraj Sanskriti Vats Javaid A. Bhat Priyanka Dhakte Vinod Goyal Praveen Khatri Surbhi Kumawat Akshay Singh Manoj Prasad Humira Sonah Tilak R. Sharma Rupesh Deshmukh 《Physiologia plantarum》2020,168(2):437-455
Gases such as ethylene, hydrogen peroxide (H2O2), nitric oxide (NO), carbon monoxide (CO) and hydrogen sulfide (H2S) have been recognized as vital signaling molecules in plants and animals. Of these gasotransmitters, NO and H2S have recently gained momentum mainly because of their involvement in numerous cellular processes. It is therefore important to study their various attributes including their biosynthetic and signaling pathways. The present review provides an insight into various routes for the biosynthesis of NO and H2S as well as their signaling role in plant cells under different conditions, more particularly under heavy metal stress. Their beneficial roles in the plant's protection against abiotic and biotic stresses as well as their adverse effects have been addressed. This review describes how H2S and NO, being very small-sized molecules, can quickly pass through the cell membranes and trigger a multitude of responses to various factors, notably to various stress conditions such as drought, heat, osmotic, heavy metal and multiple biotic stresses. The versatile interactions between H2S and NO involved in the different molecular pathways have been discussed. In addition to the signaling role of H2S and NO, their direct role in posttranslational modifications is also considered. The information provided here will be helpful to better understand the multifaceted roles of H2S and NO in plants, particularly under stress conditions. 相似文献
99.
An efficient and consistent method of monoclonal antibody (mAb) purification can improve process productivity and product consistency. Although protein A chromatography removes most host‐cell proteins (HCPs), mAb aggregates and the remaining HCPs are challenging to remove in a typical bind‐and‐elute cation‐exchange chromatography (CEX) polishing step. A variant of the bind‐and‐elute mode is the displacement mode, which allows strongly binding impurities to be preferentially retained and significantly improves resin utilization. Improved resin utilization renders displacement chromatography particularly suitable in continuous chromatography operations. In this study we demonstrate and exploit sample displacement between a mAb and impurities present at low prevalence (0.002%–1.4%) using different multicolumn designs and recycling. Aggregate displacement depends on the residence time, sample concentration, and solution environment, the latter by enhancing the differences between the binding affinities of the product and the impurities. Displacement among the mAb and low‐prevalence HCPs resulted in an effectively bimodal‐like distribution of HCPs along the length of a multi‐column system, with the mAb separating the relatively more basic group of HCPs from those that are more acidic. Our findings demonstrate that displacement of low‐prevalence impurities along multiple CEX columns allows for selective separation of mAb aggregates and HCPs that persist through protein A chromatography. 相似文献
100.
Perroud Pierre-François Demko Viktor Ako Ako Eugene Khanal Rajendra Bokor Boris Pavlovič Andrej Jásik Ján Johansen Wenche 《Plant molecular biology》2021,107(4-5):307-325
Plant Molecular Biology - In Physcomitrium patens, PpRH1/PpRH2 are GUCT-domain-containing DEAD-BOX RNA helicases localize to the nucleus. They are implicated in cell and tissue development in all... 相似文献