Blog Archive

Αλέξανδρος Γ. Σφακιανάκης

Wednesday, June 12, 2019

Biochemical Genetics

Expression of Concern: Genetic Diversity Among Historical Olive (Olea europaea L.) Genotypes from Southern Anatolia Based on SSR Markers


Identification and Characterization of a Novel Strigolactone-Insensitive Mutant, Dwarfism with High Tillering Ability 34 ( dhta-34 ) in Rice ( Oryza sativa L.)

Abstract

Rice tillering ability and plant height are two of the important traits determining the grain yield. A novel rice (Oryza sativa L.) mutant dhta-34 from an Indica cultivar Zhenong 34 treated by ethyl methy1 sulfonate (EMS) was investigated in this study. The dhta-34 mutant significantly revealed thrifty tillers with reduced plant height, smaller panicles and lighter grains. It also exhibited late-maturing (19.80 days later than the wild type) and withered leaf tip during the mature stage. The length of each internode was reduced compared to the wild type, belonging to the dn type (each internode of the plant stem decreased in the same ratio). The longitudinal section of dhta-34 internodes showed that the length of cells was reduced leading to the dwarfism of the mutant. The F2 population derived from a cross between dhta-34 and an Japonica cultivar Zhenongda 104 were used for gene mapping by using the map-based cloning strategy. The gene DHTA-34 was fine mapped in 183.8kb region flanked by markers 3R-7 and 3R-10. The cloning and sequencing of the target region from the mutant revealed that there was a substitution of G to A in the second exon of LOC_Os03g10620, which resulted in an amino acid substitution arginine to histidine. DHTA-34 encoded a protein of the α/β-fold hydrolase superfamily, which could suppress the tillering ability of rice. DHTA-34 was a strong loss-of-function allele of the Arabidopsis thaliana D14 gene, which was involved in part of strigolactones (SLs) perception and signaling. Moreover, the relative expression of DHTA-34 gene in leaf was higher than that in bud, internode, root or sheath. This study revealed that DHTA-34 played an important role in inhabiting tiller development in rice and further identifying the function of D14.



Association of SHMT1, MAZ, ERG, and L3MBTL3 Gene Polymorphisms with Susceptibility to Multiple Sclerosis

Abstract

Multiple sclerosis (MS) is the most common inflammatory and chronic disease of the central nervous system (CNS). A complex interaction between genetic, environmental, and epigenetic factors is involved in the pathogenesis of MS. With the advancement of GWAS, various variants associated with MS have been identified. This study aimed to evaluate the association of single-nucleotide polymorphisms (SNPs) rs4925166 and rs1979277 in the SHMT1MAZ rs34286592, ERG rs2836425, and L3MBTL3 rs4364506 with MS. In this case–control study, the association of five SNPs in SHMT1MAZERG, and L3MBTL3 genes with relapsing–remitting MS (RR-MS) was investigated in 190 patients and 200 healthy individuals. Four SNPs including SHMT1 rs4925166, SHMT1 rs1979277, MAZ rs34286592, and L3MBTL3 rs4364506 were genotyped using PCR–RFLP and genotyping of ERG rs2836425 was performed by tetra-primer ARMS PCR. Our findings showed a significant difference in the allelic frequencies for the four SNPs of SHMT1 rs4925166, SHMT1 rs1979277, MAZrs34286592, and ERG rs2836425, while there were no differences in the allele and genotype frequencies for L3MBTL3 rs4364506. These significant associations were observed for the following genotypes: TT and GG genotypes of SHMT1 rs4925166 (OR 0.47 and 1.90, respectively) genotype GG of SHMT1 rs1979277 (OR 0.63), genotype GG of MAZ rs34286592 (OR 0.61), TC and CC genotypes of ERG rs2836425 (OR 1.89 and 0.50, respectively). Our study highlighted that people who are carrying genotypes including GG (SHMT1 rs4925166) and TC (ERG rs2836425) have the highest susceptibility chance for MS, respectively. However, genotypes TT (SHMT1 rs4925166), CC (ERG rs2836425), GG (MAZ rs34286592), and GG (SHMT1 rs1979277) had the highest negative association (protective effect) with MS, respectively. L3MBTL3 rs4364506 was found neither as a predisposing nor a protective variant.



Genetic Diversity and Population Structure in Upland Rice ( Oryza sativa L.) of Mizoram, North East India as Revealed by Morphological, Biochemical and Molecular Markers

Abstract

Upland rice landraces from different villages of Mizoram, Northeast India were analyzed for seed morphology, amylose content, aromatic characteristic, seed storage protein profiling and genetic diversity. Results revealed variation in grain length, width, weight and shape. Protein profiling showed polypeptide bands ranging from 7 to 10 with similarity coefficient from 0.556 to 1.000 in the studied populations. Population genetic analysis using simple sequence repeats markers revealed a total of 63 alleles with a high level of gene diversity at 0.6468. High values of Fst and PIC estimates were found at 0.7239 and 0.5984 respectively. The Biruchuk population was found to be the most genetically diverse cultivar and least gene diversity was found in Tuikuk buh. The UPGMA trees based on seed morphology, seed storage protein profiling and simple sequence repeats diversity showed the grouping of rice cultivars into three clusters which were further supported by model-based STRUCTURE analysis. This finding is the first-hand report in upland rice of the state and can be useful for selecting suitable rice lines for prebreeding and germplasm conservation of indigenous hill rice cultivars of Mizoram.



Evolution and Expression of S100A7 Gene in Vertebrates

Abstract

The skin is the primary barrier between the internal organs of an organism and the environment, and it provides protection from ultraviolet (UV) radiation. According to the nocturnal bottleneck hypothesis, ungulates might have traversed to the grasslands and were exposed to UV radiation subsequent to the reduction in predation pressure. UV light exposure might have increased the S100A7 expression. In order to test whether the UV radiation is associated with the selection pressure on S100A7, we acquired the complete S100A7 DNA sequences from each of 42 vertebrate species. The results suggested that the evidence of diversifying selection in S100A7 occurred at the end of Mesozoic era, and the site of positive selection was observed in the branch of Artiodactyla (even-toed ungulates). In addition, we found that the transcription level of S100A7 in cashmere goat skin correlates with UV radiation. Our results indicated that S100A7 plays a role in the signaling between the skin genes and UV radiation during evolution.



Comparative Analysis of Expression Profiles of Reg Signaling Pathways-Related Genes Between AHF and HCC

Abstract

Regenerating islet-derived protein (Reg) could participate in the occurrence of diabetes mellitus, inflammation, tumors, and other diseased or damaged tissues. However, the correlation of Reg with acute hepatic failure (AHF) and hepatocellular carcinoma (HCC) is poorly defined. To reveal the expression profiles of Reg family and their possible regulatory roles in AHF and HCC, rat models of HCC and AHF were separately established, and Rat Genome 230 2.0 was used to detect expression profiles of Reg-mediated signaling pathways-associated genes from liver tissues in AHF and HCC. The results showed that a total of 79 genes were significantly changed. Among these genes, 67 genes were the AHF-specific genes, 45 genes were the HCC-specific genes, and 33 genes were the common genes. Then, K-means clustering classified these genes into 4 clusters based on the gene expression similarity, and DAVID analysis showed that the above altered genes were mainly associated with stress response, inflammatory response, and cell cycle regulation. Thereafter, IPA software was used to analyze potential effects of these genes, and the predicted results suggested that the Reg-mediated JAK/STAT, NF-κB, MAPK (ERK1/2, P38 and JNK), PLC, and PI3K/AKT signaling pathways may account for the activated inflammation and cell proliferation, and the attenuated apoptosis and cell death during the occurrence of AHF and HCC.



PTPN22  +788 G>A (R263Q) Polymorphism is Associated with mRNA Expression but it is not a Susceptibility Marker for Rheumatoid Arthritis Patients from Western Mexico

Abstract

PTPN22 represents an important non-HLA gene that has been strongly associated with rheumatoid arthritis (RA) pathogenesis. Several studies have reported a specific genetic variant for PTPN22 (+788 G>A; rs33996649) that might be associated with decreased RA risk in Caucasian population; nevertheless, its specific role in western Mexican population has not been yet described. A case–control study with 443 RA patients and 317 control subjects (CS) was conducted. The genotyping was performed by Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) technique and the PTPN22 mRNA expression was determined by SYBR Green-based real-time quantitative-PCR assay. No association between the PTPN22 +788 G>A polymorphism and RA susceptibility in western Mexican population was found when comparing genotype and allelic frequencies between RA patients and CS (G/G vs. G/A: OR 0.55, = 0.14, 95% CI 0.22–1.32; G vs. A: OR 0.56, = 0.14, 95% CI 0.23–1.36). The PTPN22 mRNA expression increased 4.6-fold more in RA patients than in CS, and RA patients, carriers of PTPN22 +788 G/A genotype, expressed 15.6-fold more than RA patients carrying the homozygous G/G genotype. Overall, these results showed that the PTPN22 +788 G>A polymorphism is not associated with RA susceptibility in western Mexican population, whereas the presence of G/A genotype is associated with increased PTPN22 mRNA expression in RA patients.



Screening of Genetic Factor in the Interaction Between Periodontitis and Metabolic Traits Using Candidate Gene Association Study (CGAS)

Abstract

Periodontitis has been reported to relate to metabolic syndrome traits such as obesity, blood pressure, and so on. However, the relation between periodontitis and metabolic syndrome remains unclear. The present study aimed to confirm common genetic factors between periodontitis and metabolic traits using Candidate gene association study (CGAS) in the Korean population. Based on the analysis of CGAS, this study performed linear regression analyses to examine the single-nucleotide polymorphisms (SNPs) between periodontitis and metabolic syndrome traits. Among the analyzed SNPs, 2649 SNPs in five genes (TENM2LDLRAD4SLC9C2MFSD1, and A2BP1) showed a statistical significance at p < 0.05. Interestingly, A2BP1 and TENM2 were related to obesity. Also, elevated levels of LDLRAD4SLC9C2, and MFSD1 were observed in the patients with high blood pressure. Taken together, the present study suggests that some of the SNPs are related to periodontitis. Therefore, if any of TENM2A2BP1LDLRAD4SLC9C2, and MFSD1 is detected in the patients with periodontitis, obesity and blood pressure have to be treated simultaneously.



Engineering Corynebacterium glutamicum Mutants for 3-Methyl-1-butanol Production

Abstract

3-Methyl-1-butanol (3MB) is a promising biofuel that can be produced from 2-ketoisocaproate via the common l-leucine biosynthesis pathway. Corynebacterium glutamicum was chosen as a host bacterium because of its strong resistance to isobutanol. In the current study, several strategies were designed to overproduce 3MB in C. glutamicum through a non-fermentation pathway. The engineered C. glutamicum mutant was obtained by silencing the pyruvate dehydrogenase gene complex (aceE) and deleting the lactic dehydrogenase gene (ldh), followed by mutagenesis with diethyl sulfate (DES) and selection with Fmoc-3-4-thiazolyl-l-alanine (FTA). The mutant could produce 659 mg/L of 3MB after 12 h of incubation. To facilitate carbon flux to 3MB biosynthesis, the engineered recombinant was also constructed without branched-chain acid aminotransferase (ilvE) activity by deleting the ilvE gene. This recombinant could produce 697 mg/L of 3MB after 12 h of incubation.



Identification, Expression, and Interaction Network Analyses of the CDPK Gene Family Reveal Their Involvement in the Development, Ripening, and Abiotic Stress Response in Banana

Abstract

Calcium-dependent protein kinases (CDPKs) play vital roles in the regulation of plant growth, development, and tolerance to various abiotic stresses. However, little information is available for this gene family in banana. In this study, 44 CDPKs were identified in banana and were classified into four groups based on phylogenetic, gene structure, and conserved motif analyses. The majority of MaCDPKs generally exhibited similar expression patterns in the different tissues. Transcriptome analyses revealed that many CDPKs showed strong transcript accumulation at the early stages of fruit development and postharvest ripening in both varieties. Interaction network and co-expression analysis further identified some CDPKs-mediated network that was potentially active at the early stages of fruit development. Comparative expression analysis suggested that the high levels of CDPK expression in FJ might be related to its fast ripening characteristic. CDPK expression following the abiotic stress treatments indicated a significant transcriptional response to osmotic, cold, and salt treatment, as well as differential expression profiles, between BX and FJ. The findings of this study elucidate the transcriptional control of CDPKs in development, ripening, and the abiotic stress response in banana. Some tissue-specific, development/ripening-dependent, and abiotic stress-responsive candidate MaCDPK genes were identified for further genetic improvement of banana.



Alexandros Sfakianakis
Anapafseos 5 . Agios Nikolaos
Crete.Greece.72100
2841026182
6948891480

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