scholarly journals Characteristics of defensin1 gene and designing structure to create resistant transgenic corn lines to weevils

2016 ◽  
Vol 14 (2) ◽  
pp. 279-286
Author(s):  
Vì Thị Xuân Thủy ◽  
Lò Thị Mai Thu ◽  
Hồ Mạnh Tường ◽  
Lê Văn Sơn ◽  
Nguyễn Vũ Thanh Thanh ◽  
...  

Plant defensins are multifunctional proteins, inhibiting the growth of fungal, anti-bacterial, altering membrane channels, inhibiting activity of trypsin and α-amylase. Plant defensin consists of 18 groups in which the group 1 includes  defensins to inhibit either α-amylase enzyme or trypsin. Defensins bind to the active site of α-amylase in the weevil gut, thus inhibit starch digestion in weevils. In this report, we present the results of cloning and determining the ZmDEF1 gene sequence isolated from mRNA and DNA of Sonla province local maize and LVN99 hybrid maize cultivar. The coding region of ZmDEF1 gene isolated from some maize samples had the size of 243 nucleotides, encoding 80 amino acids. Gen ZmDEF1 isolated from DNA had the size 345bp consists of two exons and one in tron (102 bp). The nucleotide sequences of ZmDEF1 gene (DNA) of the samples have 6 positions nucleotide difference, on exon 1 has two points difference (position 43, 53), on intron has a difference (position 150), on exon 2 has 3 nucleotide site difference (203, 263 and 297 position). Deduced amino acid sequences of defensin of the Sonla local maize sample has 8 cysteines to make 4 disulfide bridges, while LVN99 hybrid maize has 7 cysteines, which can formed only 3 disulfide bridges. Transformation vector pBetaPhaso-ZmDEF1 has been designed successfully, in which ZmDEF1 is controlled by seed specific Phasoline promoter. The correct insertion and expression of ZmDEF1 was examinated in transgenic tobacco plants throught PCR and RT-PCR, respectively. These results provide an firm evident for using the designed transformation vector to produce transgenic maỉze lines with an improved resistant ability  to weevils.

2016 ◽  
Vol 14 (1) ◽  
pp. 105-113
Author(s):  
Hoàng Thị Thao ◽  
Hồ Mạnh Tường ◽  
Nguyễn Thị Ngọc Lan ◽  
Nguyễn Vũ Thanh Thanh ◽  
Nguyễn Văn Sơn ◽  
...  

Plant defensins play a role against the seed-feeding insects. Defensin associates with the center of α-amylase activity in the gut of weevils, thus inhibiting the digestion of starch by weevils. In this study, the resistance of eight mungbean cultivars to weevils was evaluated by the method of artificial weevils infection. The Tam TH cultivar had lowest index of susceptibility to weevils (634.63) and DX22 cultivar had highest index (1058.72), and the highest resistance to weevils was found in Tam TH and DX22 was found to have the lowest resistance. VrPDF1 genes isolated from mungbean cultivars are 356 bp in length with two exons interrupted by an intron. The coding region of the VrPDF1 gene is 228 bp in length, encoding 75 amino acids. The comparative results of the nucleotide sequence of cDNA between Tam TH  and DX22 showed that there was a difference in 13 nucleotides and comparison of amino acid sequences of the deduced protein indicated that there was a difference in 9 amino acids. Within the intron region of the VrPDF1 genes there was difference in 5 nucleotides. The genetic distance based on nucleotide sequences of the coding region of VrPDF1 gene of DX22 and seven other mungbean cultivars is 6.2% and based on the amino acid sequence deduced is 7.7%. The coding region of the VrPDF1 gene of DX22 was used to create a transformation vector aimed at creating weevil-resistant transgenic mungbean.


1998 ◽  
Vol 83 (10) ◽  
pp. 3604-3608
Author(s):  
Gisah A. Carvalho ◽  
Roy E. Weiss ◽  
Samuel Refetoff

Fourteen T4-binding globulin (TBG) variants have been identified at the gene level. They are all located in the coding region of the gene and 6 produce complete deficiency of TBG (TBG-CD). We now describe the first mutation in a noncoding region producing TBG-CD. The proband was treated for over 20 yr with L-T4 because of fatigue associated with a low concentration of serum total T4. Fifteen family members were studied showing low total T4 inherited as an X chromosome-linked trait, and affected males had undetectable TBG in serum. Sequencing of the entire coding region and promoter of the TBG gene revealed no abnormality. However, an A to G transition was found in the acceptor splice junction of intron II that produced a new HaeIII restriction site cosegregating with the TBG-CD phenotype. Sequencing exon 1 to exon 3 of TBG complementary DNA reverse transcribed from messenger RNA of skin fibroblasts from an affected male, confirmed a shift in the ag acceptor splice site. This results in the insertion of a G in exon 2 and causes a frameshift and a premature stop at codon 195. This early termination of translation predicts a truncated TBG lacking 201 amino acids.


1993 ◽  
Vol 11 (2) ◽  
pp. 141-149 ◽  
Author(s):  
S M Duthie ◽  
P L Taylor ◽  
K A Eidne

ABSTRACT The cloning and characterization of the mouse TRH receptor (TRH-R) gene revealed an untranslated exon (exon 1), a single intron and an upstream dinucleotide repeat sequence (d(TG)16.d(AG)21) in the 5′ untranslated region (UTR). The coding region was contained almost entirely on a second exon (exon 2), with the final amino acid and stop codon at the COOH terminus of the gene encoded by a third exon (exon 3) flanked by two introns. The 3′ UTR was contained on the remainder of exon 3 and on the final exon (exon 4). Exon 3 (228 bp) corresponds exactly to a 228 bp deletion that exists in the rat TRH-R cDNA, but not in the mouse cDNA. The mouse TRH-R cDNA encodes a protein of 393 amino acids which is 96% homologous to the rat TRH-R protein of 412 amino acids, but is 19 amino acids shorter at its COOH terminus. The coding sequence for these 19 amino acids (plus 1 extra amino acid) does exist in the mouse TRH-R gene, but the sequence is encoded by exon 4, separated from the rest of the coding region by the stop codon and 223 bp of 3′ UTR on exon 3. Splicing of exon 3 in the mouse TRH-R gene would remove the last amino acid, the stop codon and the 223 bp of 3′ UTR, allowing transcription to continue into the 3′ UTR on exon 4, which encodes the 19 extra amino acids found in the rat cDNA. This would then result in an alternative 412 amino acid version of the mouse TRH-R protein, with 95% homology to the rat TRH-R. This study focused on the structural differences in the intracellular COOH-terminal tail of the receptor, which is known to be a functionally important domain in other members of the G protein-coupled receptor family. We have also recently characterized the human TRH-R cDNA, which revealed a third variant at the COOH terminus. Comparisons between mouse, rat and human TRH-Rs show that the amino acid sequences are virtually identical. However, significant differences between these species exist at the COOH terminus, with each TRH-R having a unique form of the COOH-terminal tail, beginning at exactly the same site and encoding 1, 20 and 6 amino acids in the mouse, rat and human respectively.


F1000Research ◽  
2017 ◽  
Vol 6 ◽  
pp. 1016 ◽  
Author(s):  
Armando Totomoch-Serra ◽  
Manlio F. Marquez ◽  
David E. Cervantes-Barragán

In 1977, Frederick Sanger developed a new method for DNA sequencing based on the chain termination method, now known as the Sanger sequencing method (SSM).  Recently, massive parallel sequencing, better known as next-generation sequencing (NGS),  is replacing the SSM for detecting mutations in cardiovascular diseases with a genetic background. The present opinion article wants to remark that “targeted” SSM is still effective as a first-line approach for the molecular diagnosis of some specific conditions, as is the case for Andersen-Tawil syndrome (ATS). ATS is described as a rare multisystemic autosomal dominant channelopathy syndrome caused mainly by a heterozygous mutation in the KCNJ2 gene. KCJN2 has particular characteristics that make it attractive for “directed” SSM. KCNJ2 has a sequence of 17,510 base pairs (bp), and a short coding region with two exons (exon 1=166 bp and exon 2=5220 bp), half of the mutations are located in the C-terminal cytosolic domain, a mutational hotspot has been described in residue Arg218, and this gene explains the phenotype in 60% of ATS cases that fulfill all the clinical criteria of the disease. In order to increase the diagnosis of ATS we urge cardiologists to search for facial and muscular abnormalities in subjects with frequent ventricular arrhythmias (especially bigeminy) and prominent U waves on the electrocardiogram.


1994 ◽  
Vol 5 (5) ◽  
pp. 597-609 ◽  
Author(s):  
E M Blackwood ◽  
T G Lugo ◽  
L Kretzner ◽  
M W King ◽  
A J Street ◽  
...  

Activation of the c-myc proto-oncogene by chromosomal translocation or proviral insertion frequently results in the separation of the c-myc coding region from its normal regulatory elements. Such rearrangements are often accompanied by loss or mutation of c-myc exon 1 sequences. These genetic alterations do not affect synthesis of the major c-myc protein, p64, which is initiated from the first AUG codon in exon 2. However they can result in mutation or loss of the CUG codon located in exon 1 that normally serves as an alternative translational initiation codon for synthesis of an N-terminally extended form of c-Myc (p67). It has been hypothesized that p67 is a functionally distinct form of c-Myc whose specific loss during c-myc rearrangements confers a selective growth advantage. Here we describe experiments designed to test the functional properties of the two c-Myc protein forms. We introduced mutations within the translational initiation codons of a normal human c-myc cDNA that alter the pattern of Myc protein synthesis (p64 vs. p67). The functions of each of these proteins were experimentally addressed using co-transformation and transcriptional activation assays. Both the p64 and p67 c-Myc proteins were independently able to collaborate with bcr-abl in the transformation of Rat-1 fibroblasts. In addition, both the exon 1- and exon 2-initiated forms of the c-Myc protein stimulated transcription of a Myc/Max-responsive reporter construct to a similar level. Given the apparent absence of functional differences between p64 and p67, we conclude that the basis for c-Myc oncogenic activation lies primarily in the overall deregulation of its expression and not in alterations in the protein. The existence of the CUG translational initiator may reflect a mechanism for the continued synthesis of c-Myc protein under conditions where AUG initiation is inhibited.


1998 ◽  
Vol 332 (2) ◽  
pp. 303-307 ◽  
Author(s):  
Donald E. HUMPHRIES ◽  
Julia LANCIOTTI ◽  
Joel B. KARLINSKY

The cDNA and gene encoding human heparan glucosaminyl N-deacetylase/N-sulphotransferase-2 have been cloned. The cDNA encoded a protein of 883 amino acids that was 94% similar to heparan N-sulphotransferase-2 from mouse mast cells. Comparison of the deduced amino acid sequences of human heparan N-sulphotransferase-1 and -2 showed that the enzymes were 70% similar; greater than 90% of the amino acids between residues 418 and 543 were identical. The least conserved amino acids were found in the N-terminus/putative transmembrane regions of the two enzymes. The human heparan N-sulphotransferase-2 gene was localized to chromosome arm 10q (band 10q22) by in situ fluorescent hybridization. The gene contains 13 exons spanning 6.5 kb, ranging in size from 88 bp (exon 2) to > 1 kb (exon 1), and 12 introns, which were found to occur at similar sites within the coding sequence of the human heparan N-sulphotransferase-1 gene. The structure of the two genes differed in that the heparan N-sulphotransferase-1 gene contained one additional intron. The similarity of the heparan N-sulphotransferase-1 and -2 proteins and their similar exon-intron organization suggest that they derive from a common ancestral gene.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Rajiv Sharma ◽  
Daniel P. Dever ◽  
Ciaran M. Lee ◽  
Armon Azizi ◽  
Yidan Pan ◽  
...  

AbstractTargeted DNA correction of disease-causing mutations in hematopoietic stem and progenitor cells (HSPCs) may enable the treatment of genetic diseases of the blood and immune system. It is now possible to correct mutations at high frequencies in HSPCs by combining CRISPR/Cas9 with homologous DNA donors. Because of the precision of gene correction, these approaches preclude clonal tracking of gene-targeted HSPCs. Here, we describe Tracking Recombination Alleles in Clonal Engraftment using sequencing (TRACE-Seq), a methodology that utilizes barcoded AAV6 donor template libraries, carrying in-frame silent mutations or semi-randomized nucleotides outside the coding region, to track the in vivo lineage contribution of gene-targeted HSPC clones. By targeting the HBB gene with an AAV6 donor template library consisting of ~20,000 possible unique exon 1 in-frame silent mutations, we track the hematopoietic reconstitution of HBB targeted myeloid-skewed, lymphoid-skewed, and balanced multi-lineage repopulating human HSPC clones in mice. We anticipate this methodology could potentially be used for HSPC clonal tracking of Cas9 RNP and AAV6-mediated gene targeting outcomes in translational and basic research settings.


Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 888
Author(s):  
Mohammed A. Ibrahim Al-Obaide ◽  
Kalkunte S. Srivenugopal

Background: The therapeutically important DNA repair gene O6-methylguanine DNA methyltransferase (MGMT) is silenced by promoter methylation in human brain cancers. The co-players/regulators associated with this process and the subsequent progression of MGMT gene transcription beyond the non-coding exon 1 are unknown. As a follow-up to our recent finding of a predicted second promoter mapped proximal to the exon 2 [Int. J. Mol. Sci.2021, 22(5), 2492], we addressed its significance in MGMT transcription. Methods: RT-PCR, RT q-PCR, and nuclear run-on transcription assays were performed to compare and contrast the transcription rates of exon 1 and exon 2 of the MGMT gene in glioblastoma cells. Results: Bioinformatic characterization of the predicted MGMT exon 2 promoter showed several consensus TATA box and INR motifs and the absence of CpG islands in contrast to the established TATA-less, CpG-rich, and GAF-bindable exon 1 promoter. RT-PCR showed very weak MGMT-E1 expression in MGMT-proficient SF188 and T98G GBM cells, compared to active transcription of MGMT-E2. In the MGMT-deficient SNB-19 cells, the expression of both exons remained weak. The RT q-PCR revealed that MGMT-E2 and MGMT-E5 expression was about 80- to 175-fold higher than that of E1 in SF188 and T98G cells. Nuclear run-on transcription assays using bromo-uridine immunocapture followed by RT q-PCR confirmed the exceptionally lower and higher transcription rates for MGMT-E1 and MGMT-E2, respectively. Conclusions: The results provide the first evidence for transcriptional pausing at the promoter 1- and non-coding exon 1 junction of the human MGMT gene and its activation/elongation through the protein-coding exons 2 through 5, possibly mediated by a second promoter. The findings offer novel insight into the regulation of MGMT transcription in glioma and other cancer types.


Genes ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 29
Author(s):  
Lilia González-Cerón ◽  
José Cebrián-Carmona ◽  
Concepción M. Mesa-Valle ◽  
Federico García-Maroto ◽  
Frida Santillán-Valenzuela ◽  
...  

Plasmodium vivax Cysteine-Rich Protective Antigen (CyRPA) is a merozoite protein participating in the parasite invasion of human reticulocytes. During natural P. vivax infection, antibody responses against PvCyRPA have been detected. In children, low anti-CyRPA antibody titers correlated with clinical protection, which suggests this protein as a potential vaccine candidate. This work analyzed the genetic and amino acid diversity of pvcyrpa in Mexican and global parasites. Consensus coding sequences of pvcyrpa were obtained from seven isolates. Other sequences were extracted from a repository. Maximum likelihood phylogenetic trees, genetic diversity parameters, linkage disequilibrium (LD), and neutrality tests were analyzed, and the potential amino acid polymorphism participation in B-cell epitopes was investigated. In 22 sequences from Southern Mexico, two synonymous and 21 nonsynonymous mutations defined nine private haplotypes. These parasites had the highest LD-R2 index and the lowest nucleotide diversity compared to isolates from South America or Asia. The nucleotide diversity and Tajima’s D values varied across the coding gene. The exon-1 sequence had greater diversity and Rm values than those of exon-2. Exon-1 had significant positive values for Tajima’s D, β-α values, and for the Z (HA: dN > dS) and MK tests. These patterns were similar for parasites of different origin. The polymorphic amino acid residues at PvCyRPA resembled the conformational B-cell peptides reported in PfCyRPA. Diversity at pvcyrpa exon-1 is caused by mutation and recombination. This seems to be maintained by balancing selection, likely due to selective immune pressure, all of which merit further study.


Animals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 668
Author(s):  
Zhi-gang Niu ◽  
Jin Qin ◽  
Yao Jiang ◽  
Xiang-Dong Ding ◽  
Yu-gong Ding ◽  
...  

The Bone Morphogenetic Protein 15 (BMP15) gene is known to have multiple single-nucleotide polymorphism sites associated with sheep fecundity. This study used gene sequence analysis and mutation detection assays for BMP15 by using 205 blood samples of ewes with known lambing records. Sequence analysis showed that mutation B1 missed the CTT base in exon 1 at positions 28–30, leading to a leucine deletion in the BMP15 protein. Litter size of ewes differed significantly between BB and B+ genotypes of B1 (p < 0.05); however, the differences between wild genotype (++) and homozygous (BB) or wild genotype (++) and heterozygous (B+) were not significant (p > 0.05). Another mutation, T755C, is a T-to-C base change at position 755 of exon 2, resulting in leucine replacement by proline at this position of the BMP15 protein (p.L252P). Two genotypes were identified in the flock: heterozygous (E+) and wild-type genotype (++). Ewes with heterozygous (E+) p.L252P had significantly larger litter sizes than those with the wild-type genotype (p < 0.05). Comprehensive analysis suggests that p.L252P is a mutation that affects fecundity in Cele black sheep.


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