Systematic analysis of MYB transcription factors related to the geniposide biosynthesis in Gardenia jasminoides Ellis based on whole genome / 药学学报

MYB transcription factors are involved in the regulation of various secondary metabolites biosynthesis. Gardenia jasminoides Ellis is the commonly used Chinese herbal medicine, and its main active ingredient is geniposide. Here, leaves and flower buds at different developmental stages of G. jasminoides were used to explore MYB transcription factors related to geniposide biosynthesis based on genome and transcriptome analysis. Transcriptome data analysis showed that, different from the expression of the common pathway genes for terpenoid biosynthesis, the expression level of genes in the specific pathway of geniposide biosynthesis was significantly higher in flower buds than in leaves, which was the same as the organ accumulation pattern of this component. And the promoter regions of geraniol synthase, iridoid synthase and geniposidic acid methyltransferase involved in the specific pathway all contained multiple MYB-binding sites. A total of 105 MYB transcription factors were obtained by annotating the coding genes of G. jasminoides, which were divided into 68 1R-MYB, 33 R2R3-MYB, 3 3R-MYB and 1 atypical MYB transcription factor according to the number of conserved domain. Based on the analysis of phylogenetic tree and quantitative real-time PCR, three candidate MYB transcription factors related to geniposide biosynthesis were selected, including potential positive regulation factor GjMYB23 and negative regulation factors GjMYB31 and GjMYB73. The results of this study will lay a foundation for searching the regulation of geniposide biosynthesis and further analysis of the quality formation mechanism of G. jasminoides, so as to promote the breeding of excellent varieties of G. jasminoides.

Mining and identification of members of MYB transcription factor family in Lonicera macranthoides / 中国中药杂志

As a large family of transcription factors, the MYB family plays a vital role in regulating flower development. We studied the MYB family members in Lonicera macranthoides for the first time and identified three sequences of 1R-MYB, 47 sequences of R2R3-MYB, two sequences of 3R-MYB, and one sequence of 4R-MYB from the transcriptome data. Further, their physicochemical properties, conserved domains, phylogenetic relationship, protein structure, functional information, and expression were analyzed. The results show that the 53 MYB transcription factors had different conserved motifs, physicochemical properties, structures, and functions in wild type and 'Xianglei' cultivar of L. macranthoides, indicating their conservation and diversity in evolution. The transcript level of LmMYB was significantly different between the wild type and 'Xianglei' cultivar as well as between flowers and leaves, and some genes were specifically expressed. Forty-three out of 53 LmMYB sequences were expressed in both flowers and leaves, and 9 of the LmMYB members showed significantly different transcript levels between the wild type and 'Xianglei' cultivar, which were up-regulated in the wild type. The results provide a theoretical basis for further studying the specific functional mechanism of the MYB family.

Identification and analysis of R1-MYB gene family in Rheum palmatum L. based on full-length transcriptome sequencing / 药学学报

As one kind of v-myb avian myeloblastosis viral oncogene homolog (MYB) transcription factors, R1-MYB (MYB-related) family plays an important role in plant growth and development, as well as environmental stress and hormone signal transduction. In this study, R1-MYB family genes in Rheum palmatum L. were systematically screened based on full-length transcriptome sequencing analysis. Firstly, the physicochemical, protein domain and molecular evolution characteristics of the coding proteins were analyzed. Furthermore, the tissue expression levels of R1-MYB genes were analyzed by RNA-seq. We also investigated the expression pattern of RpMYB24 in response to various hormones and abiotic stresses. The results showed that a total of 49 R1-MYB genes were identified, which mainly encoded thermally stable hydrophilic proteins. Most of the deduced proteins were predicted to locate in nucleus. Each protein had a large proportion of random curl and α helix, and also had the W-type conserved amino acids which were the signature of MYB. R1-MYB family members were distributed in five subgroups, including circadian clock associated 1 (CCA1)-like, I-box (GATAAG)-like, CAPRICE (CPC)-like, telomere repeat binding factor (TRF)-like and TATA binding protein (TBP)-like, and the number of CCA1-like was the majority. RNA-seq revealed that 49 R1-MYB genes were differentially expressed in roots, rhizomes and leaves of R. palmatum, and the expression levels of 15 and 23 genes in roots and rhizomes were higher than those in leaves, respectively. RpMYB24 transcript was induced by abscisic acid (ABA), salicylic acid (SA), and methyl jasmonate (MeJA) treatment, and could also significantly respond to injury, low temperature and high temperature stresses except drought stress. This study systematically identified the R1-MYB family genes and their molecular characteristics, better for further gene functional validation, and then provide a scientific basis for the transcriptional regulation mechanism research into rhubarb quality formation.

Wheat TaMYB1A Negatively Regulates the Phenylpropanoid Pathway and Plant Height / 中国生物化学与分子生物学报

The phenylpropanoid pathway is one of the important pathways for synthesizing plant secondary metabolites, which can produce lignin, flavonoid, and sinapoylmalate. These compounds can not only affect the plant growth, development, and stress response, but also be used to produce perfume, pesticide, dye, medicine, feed, and biomass energy. R2R3-MYBs play important roles in regulating plant secondary metabolism, organ development, and in responding to environmental stresses. Wheat (Triticum aestivum L.) is an important food crop, but lots of straw will be produced accompanied by grain yields. Therefore, elucidating the function and regulatory mechanism of R2R3 MYBs of wheat is crucial for the effective utilization of the wheat straw. RT-PCR results showed that TaMYB1A was highly expressed in the wheat stems, and the GFP-TaMYB1A fusion protein was mainly localized in the nucleus of the N. benthamiana epidermal cells. TaMYB1A has transcriptional repressive activity in yeast cells. In this study, TaMYB1A-overexpressed transgenic Arabidopsis lines were generated to elucidate the effect of overexpression of TaMYB1A on the biosynthesis of lignin and flavonoid. Our results suggested that overexpression of TaMYB1A inhibited the plant height (P < 0. 05) and decreased the lignin (P < 0. 05) and flavonoid (P < 0. 05) biosynthesis of the transgenic Arabidopsis plants significantly. TaMYB1A could bind to the promoters of the Arabidopsis At4CL1, AtC4H, AtC3H, and AtCHS as well as the wheat Ta4CL1 and TaC4H1 revealed by yeast one-hybrid (Y1H) assasy, the transcriptional repressive effect of TaMYB1A on At4CL1, AtC4H, AtC3H, and AtCHS was confirmed by dual-luciferase reporter systems and also on Ta4CL1 and TaC4H1 by a genetic approach. Gene chip and quantitative RT-PCR (qRT-PCR) results showed that overexpression of TaMYB1A down-regulated the expression of most of the key genes involved in the phenylpropanoid metabolism and decreased the 4CL activity (P < 0. 05) of the transgenic Arabidopsis plants significantly. As suggested above, the wheat TaMYB1A belongs to the subgroup 4 R2R3 MYB transcription factors. TaMYB1A could bind to the promoters of the key genes involved in phenylpropanoid metabolism, repress their expression and negatively regulate the phenylpropanoid metabolism pathway and plant height.

Molecular dynamics simulation reveals DNA-specific recognition mechanism via c-Myb in pseudo-palindromic consensus of mim-1 promoter / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

This study aims to gain insight into the DNA-specific recognition mechanism of c-Myb transcription factor during the regulation of cell early differentiation and proliferation. Therefore, we chose the chicken myeloid gene, mitochondrial import protein 1 (mim-1), as a target to study the binding specificity between potential dual-Myb-binding sites. The c-Myb-binding site in mim-1 is a pseudo-palindromic sequence AACGGTT, which contains two AACNG consensuses. Simulation studies in different biological scenarios revealed that c-Myb binding with mim-1 in the forward strand (complex F) ismore stable than that inthereverse strand (complex R). The principal component analysis (PCA) dynamics trajectory analyses suggested an opening motion of the recognition helices of R2 and R3 (R2R3), resulting in the dissociation of DNA from c-Myb in complex R at 330 K, triggered by the reduced electrostatic potential on the surface of R2R3. Furthermore, the DNA confirmation and hydrogen-bond interaction analyses indicated that the major groove width of DNA increased in complex R, which affected on the hydrogen-bond formation ability between R2R3 and DNA, and directly resulted in the dissociation of DNA from R2R3. The steered molecular dynamics (SMD) simulation studies also suggested that the electrostatic potential, major groove width, and hydrogen bonds made major contribution to the DNA‍-specific recognition. In vitro trials confirmed the simulation results that c-Myb specifically bound to mim-1 in the forward strand. This study indicates that the three-dimensional (3D) structure features play an important role in the DNA-specific recognition mechanism by c-Myb besides the AACNG consensuses, which is beneficial to understanding the cell early differentiation and proliferation regulated by c-Myb, as well as the prediction of novel c-Myb-binding motifs in tumorigenesis.

Bioinformatics and expression analysis on MYB-related family in Angelica dahurica var. formosana / 中国中药杂志

In recent years, the MYB-related gene family has been found pivotal in plant growth and development. MYB-related gene family in Angelica dahurica var. formosana was systematically investigated based on "Chuanzhi No. 2" through transcriptome database search and bioinformatics and the temporal and spatial expression patterns were analyzed through real-time fluorescence-based quantitative polymerase chain reaction(PCR). The results showed that 122 MYB-related proteins family were identified, mainly including the unstable hydrophilic proteins with good thermal stability. Most of the proteins were located in nuclei. The majority of the proteins had the structures of random coil and α-helix. Five MYB-related proteins family of A. dahurica var. formosana had membrane-binding domains. The conserved domain analysis of MYB-related proteins family of A. dahurica var. formosana showed that the MYB domains of genes in five subgroups, similar to 2 R-, 3 R-, and 4 R-MYB proteins, contained three evenly distributed Trp(W) residues in the MYB repeat sequence. The phylogenetic analysis of MYB-related proteins family in A. dahurica var. formosana and Arabidopsis thaliana showed that the MYB-related members were unevenly distributed in five subgroups, and A. thaliana and A. dahurica var. formosana had almost the same number of genes in the CCA1-like subgroup. There were differences in the number, type, and distribution of motifs contained in 122 encoded proteins. Transcription factors with similar branches had similar domains and motifs. The expression pattern analysis showed that the transcription factors AdMYB53, AdMYB83, and AdMYB89 responded to hormones to varying degrees, and they were highly expressed in leaves and responded quickly in roots. This study lays a foundation for further investigating the function of MYB-related transcription factors of A. dahurica var. formosana and solving the corresponding biological problems such as bolting early.

Identification and expression analysis of R2R3-MYB gene family in Andrographis paniculata / 中国中药杂志

The plant growth, development, and secondary metabolism are regulated by R2 R3-MYB transcription factors. This study identified the R2 R3-MYB genes in the genome of Andrographis paniculata and analyzed the chromosomal localization, gene structure, and conserved domains, phylogenetic relationship, and promoter cis-acting elements of these R2 R3-MYB genes. Moreover, the gene expression profiles of R2 R3-MYB genes under abiotic stress and hormone treatments were generated by RNA-seq and validated by qRT-PCR. The results showed that A. paniculata contained 73 R2 R3-MYB genes on 21 chromosomes. These members belonged to 34 subfamilies, 19 of which could be classified into the known subfamilies in Arabidopsis thaliana. The 73 R2 R3-MYB members included 36 acidic proteins and 37 basic proteins, with the lengths of 148-887 aa. The domains, motifs, and gene structures of R2 R3-MYBs in A. paniculata were conserved. The promoter regions of these genes contains a variety of cis-acting elements related to the responses to environmental factors and plant hormones including light, ABA, MeJA, and drought. Based on the similarity of functions of R2 R3-MYBs in the same subfamily and the transcription profiles, ApMYB13/21/35/67/73(S22) may regulate drought stress through ABA pathway; ApMYB20(S11) and ApMYB55(S2) may play a role in the response of A. paniculata to high temperature and UV-C stress; ApMYB5(S7) and ApMYB33(S20) may affect the accumulation of andrographolide by regulating the expression of key enzymes in the MEP pathway. This study provides theoretical reference for further research on the functions of R2 R3-MYB genes in A. paniculata and breeding of A. paniculata varieties with high andrographolide content.

Cloning, structure analysis and functional verification of MYB10 in Ribes L / 生物工程学报

This study aims to investigate the molecular mechanism of the transcription factor MYB10, which is involved in anthocyanin biosynthesis, in different colors of Ribes L. fruitification. Rapid amplification of cDNA ends (RACE) was used to clone the MYB10 genes from Ribes nigrum L. (RnMYB10), Ribes rubrum L. (RrMYB10), and Ribes album L. (RaMYB10), respectively. Phylogenetic analysis showed that RnMYB10 and RrMYB10 were evolutionarily homologous. Real-time quantitative PCR (RT-qPCR) showed that the expression of MYB10 in the fruits of Ribes nigrum L. was higher than that of Ribes rubrum L. and much higher than that of Ribes album L. The expression of RnMYB10 and RrMYB10 increased at first and then decreased as the fruit diameter increased and the fruit color deepened (the maximum expression level was reached at 75% of the fruit color change), while the expression level of RaMYB10 was very low. Overexpression of RnMYB10 and RrMYB10 in Arabidopsis thaliana resulted in purple petioles and leaves, whereas overexpression of RaMYB10 resulted in no significant color changes. This indicates that MYB10 gene plays an important role in the coloration of Ribes L. fruit.

Association of HMIP1 C-893A polymorphism and disease severity in patients with sickle cell anemia

Abstract Introduction: Sickle cell anemia (SCA) is a Mendelian disorder with a heterogeneous clinical course. The reasons for this phenotypic diversity are not entirely established, but it is known that high fetal hemoglobin levels lead to a milder course of the disease. Additionally, genetic variants in the intergenic region HBS1L-MYB promote high levels of fetal hemoglobin into adulthood. Objective: In the present study, we investigated the HMIP1 C-839A (rs9376092) polymorphism, located at the HBS1L-MYB intergenic region block 1, in SCA patients. Method: We analyzed 299 SCA patients followed in two reference centers in Brazil. The HMIP1 C-839A (rs9376092) genotypes were determined by allele specific polymerase chain reactions. Clinical and laboratory data were obtained from patient interviews and medical records. Results: The median fetal hemoglobin levels were higher in patients with the HMIP1 C-839A (rs9376092) AA genotype (CC = 6.4%, CA = 5.6% and AA = 8.6%), but this difference did not reach significance (p = 0.194). No association between HMIP1 C-839A (rs9376092) genotypes and other clinical and laboratorial features was detected (p > 0.05). Conclusion: In summary, our data could not support the previously related association between the HMIP1 C-893A (rs9376092) polymorphism and differential fetal hemoglobin levels.

Identification and expression profiling of R2R3-MYB transcription factors in Erigeron breviscapus / 中国中药杂志

R2 R3-MYB transcription factors are ubiquitous in plants, playing a role in the regulation of plant growth, development, and secondary metabolism. In this paper, the R2 R3-MYB transcription factors were identified by bioinformatics analysis of the genomic data of Erigeron breviscapus, and their gene sequences, structures, physical and chemical properties were analyzed. The functions of R2 R3-MYB transcription factors were predicted by cluster analysis. Meanwhile, the expression patterns of R2 R3-MYB transcription factors in response to hormone treatments were analyzed. A total of 108 R2 R3-MYB transcription factors, named EbMYB1-EbMYB108, were identified from the genome of E. breviscapus. Most of the R2 R3-MYB genes carried 2-4 exons. The phylogenetic tree of MYBs in E. breviscapus and Arabidopsis thaliala was constructed, which classified 234 MYBs into 30 subfamilies. The MYBs in the five MYB subfamilies of A.thaliala were clustered into independent clades, and those in E. breviscapus were clustered into four clades. The transcriptome data showed that MYB genes were differentially expressed in different tissues of E. breviscapus and in response to the treatments with exogenous hormones such as ABA, SA, and GA for different time. The transcription of 13 R2 R3-MYB genes did not change significantly, and the expression patterns of some genes were up-regulated or down-regulated with the extension of hormone treatment time. This study provides a theoretical basis for revealing the mechanisms of R2 R3-MYB transcription factors in regulating the growth and development, stress(hormone) response, and active ingredient accumulation in E. breviscapus.

Cloning and expression of AeMYB4 gene related to stolon development of Amana edulis / 中国中药杂志

Stolon is an important organ for reproduction and regeneration of Amana edulis. Previous analysis of transcriptome showed that MYB was one of the most active transcription factor families during the development of A. edulis stolon. In order to study the possible role of MYB transcription factors in stolon development, the authors screened out an up-regulated MYB gene named AeMYB4 was by analyzing the expression profile of MYB transcription factors. In the present study, sequence analysis demonstrated that AeMYB4 contained an open reading frame of 756 bp encoding 251 amino acids, and domain analysis revealed that the predicted amino acids sequence contained two highly conserved SANT domains and binding sites for cold stress factor CBF. By multiple sequence alignment and phylogenetic analysis, it is indicated that AeMYB4 clustered with AtMYB15 from Arabidopsis thaliana, belonging to subgroup S2 of R2 R3-MYB. And most of the transcription factors in this subfamily are related to low temperature stress. The GFP-AeMYB4 fusion protein expression vector for subcellular localization was constructed and transferred into Agrobacterium tumefaciens to infect the leaves of Nicotiana benthamiana, and the results showed the protein was located in the nucleus. To investigate the transcriptional activation, the constructed pGBKT7-AeMYB4 fusion expression vector was transferred into Y2 H Gold yeast cells, which proved that AeMYB4 was a transcription activator with strong transcriptional activity. Real-time quantitative PCR was used to detect the expression of AeMYB4 gene in three different development stages of stolon and in leaves, flowers, and bulbs of A. edulis, which indicated that AeMYB4 transcription factor was tissue-specific in expression, mainly in the stolon development stage, and that the expression was the most active in the middle stage of stolon development, suggesting that AeMYB4 gene may play an important role in stolon development. This study contributes to the further research on the function of AeMYB4 transcription factor in stolon development of A. edulis.

Cloning and expression characteristics of a transcription factor gene RpMYB4 in Rheum palmatum L / 药学学报

MYB transcription factors play many important regulatory roles in plant growth and development, secondary metabolism, and stress adaptation processes. In this work, an MYB gene containing a complete open reading frame (ORF) was selected from the transcriptome database of R. palmatum L. RpMYB4 ORF and cloned, encoding a polypeptide of 245 amino acids with a molecular weight of 26.99 kDa. RpMYB4 lacks a signal peptide or transmembrane domain but contains two conserved DNA binding domains (HTH-MYB) of the R2R3-MYB subfamily at the N-terminus. Multiple-sequence alignment demonstrated that RpMYB4 shared as high as 61% identity with many MYB proteins from other species. Phylogenetic analysis showed that RpMYB4 had the closest relationship with FtMYB8 and was clustered in the S4 subfamily. Subcellular localization by confocal microscopy showed that an RpMYB4-GFP-fusion protein localized to the nucleus in tobacco. Real-time fluorescence quantitative PCR analyses revealed that RpMYB4 was differentially expressed in various tissues, with the highest expression in leaves, followed by petioles, rhizome, and roots, and with the lowest level in mature seeds. After treatment of R. palmatum L. seedlings with 200 μmol·L-1 MeJA, the expression of RpMYB4 in leaves was down-regulated within 24 h, and significantly up-regulated after 200 μmol·L-1 SA treatment at 12 h and 24 h. However, gene expression did not change with 200 μmol·L-1 ABA treatment. The transcripts of RpMYB4 under drought, high temperature, and mechanical injury stresses reached a peak at 24 h, 24 h, and at 3 h, respectively, while RpMYB4 expression was inhibited by low temperature stress, reaching its lowest value at 6 h. The gene showed no significant response to salt stress. Overall, RpMYB4 was cloned from R. palmatum L. for the first time, showed high expression in leaves, and was responsive to SA and various abiotic stress treatments including drought, high temperature, and mechanical injury. The results will be useful for further analysis of secondary metabolism and stress adaptations in R. palmatum L.

Regulation of plant MYB transcription factors in anther development / 生物工程学报

MYB transcription factor is one of the largest transcription families and involved in plant growth and development, stress response, product metabolism and other processes. It regulates the development of plant flowers, especially anther development, a key role in the reproduction of plant progeny. Here, we discuss the regulatory effects of MYB transcription factors on the development of anther, including tapetum development, anther dehiscence, pollen development, carbohydrates and hormone pathways. We provide a reference for the further study of the regulation mechanism and network of plant anther development.

Identification and analysis of the R2R3-MYB transcription factor based on a transcriptome database in Morinda officinalis / 药学学报

In order to explore MYB transcription factors related to developmental processes and secondary metabolism in Morinda officinalis, we analyzed MoMYB expression based on transcriptome data from three tissues (root, stem and leaf). We used this analysis to provide a theoretical foundation for regulating the metabolism of M. officinalis. RNA-seq data along with the five databases including PFAM and plantTFDB and others were used to screen and classify MoMYB, including GO functional annotation and classification, subcellular localization, signal peptide prediction, conserved motif discovery, and comparative phylogenetic analysis. RT-qPCR was carried out to detect tissue-specific expression differences of MoMYB genes. According to transcriptome data, 109 MoMYB sequences were identified and divided into four classes, containing 51 sequences related to R2R3-MYB. Subcellular localization analysis indicated that a majority of sequences were located in nucleus. Blast2GO analysis showed that 109 MoMYB sequences were classified into three major functional ontologies including molecular function (112), biological processes (76) and cellular components (239). The R2-MYB conserved motif of 51 R2R3-MYB sequences possessed three significantly conserved tryptophan residues, whereas a phenylalanine replaced the first tryptophan in R3-MYB. The results of multiple sequence alignment and phylogenetic analysis revealed that the R2R3-MYB was distributed in all subgroups, apart from the S10, S19 and S21 subgroups. RT-qPCR indicated that several R2R3-MYB genes were differentially expressed among the three tissues, and this finding was consistent with transcriptome data. The 109 MoMYB sequences were annotated and divided into different classes, which lays the foundation for further study on MYB transcriptional factors in M. officinalis.

Molecular characterization of PgUFGT gene and R2R3-PgMYB transcription factor involved in flavonoid biosynthesis in four tissues of wild pomegranate (Punica granatum L.)

The diversity on fruit colouration in plants directly depends on the flavonoids that explain the development of different pigmentation patterns. Anthocyanins are the major class of flavonoid pigments that are synthesized through flavonoid biosynthetic pathway. In the present study, two genes: PgUFGT gene and R2R3-PgMYB gene, involved in anthocyanin biosynthesis were analysed in four tissues of wild pomegranate. The structural genes, UDP-glucose: flavonoid-3-O-glucosyl transferase (PgUFGT; GenBank accession number: MK058491) and its myeloblastosis transcription factor (R2R3-PgMYB; GenBank accession number: MK092063) were isolated and their expression pattern were studied. Molecular modelling indicated that the main secondary structures of PgUFGT and R2R3-PgMYB genes are α-helix and random coil. In addition, expression profiling of PgUFGTand R2R3-PgMYB by quantitative-real time PCR indicated a positive correlation between anthocyanin content and their expression in leaves, flowers, green and red fruits of wild pomegranate. Among all the tissues, the red fruit exhibited high transcripts levels of PgUFGT as well as R2R3-PgMYB transcription factor. An extensive homology with UFGTs from other plants was revealed on comparative and bioinformatic analyses. Present study reveals that PgUFGT plays a predominant role in anthocyanin content in wild pomegranate fruits. Further, it is strongly suggested that R2R3-PgMYB transcription factor regulates the anthocyanin biosynthesis in wild pomegranate via expression of PgUFGT gene. This is the first study which provides an insight on expression profile of PgUFGT and R2R3-PgMYB that are involved in colour development and fruit ripening in wild pomegranate.

Analysis of MYB transcription factors related to triterpenoids and phenolic acids biosynthesis of Prunella vulgaris / 中草药

Objective To identify the MYB transcription factors that may regulate the biosynthesis of triterpenoids and phenolic acids in Prunella vulgaris. Methods MYB transcription factor were identified from the P. vulgaris transcriptome database, their motif, physical and chemical properties, functional annotation, family evolution and expression patterns were examined. Results A total of 27 MYB transcription factors were identified. c32045.graph_c0 might inhibit the biosynthesis of rosmarinic acid by inhibiting the expression of cinnamic acid 4-hydroxylase gene, thus acting as a transcription suppressor to negatively regulate the biosynthesis of phenolic acids. c26895.graph_c0 might inhibit the biosynthesis of triterpenoids and phenolic acids by regulating the flow of metabolic intermediates in the biosynthesis of triterpenoids and rosmarinic acids. Conclusion The candidate MYB transcription factors related to the biosynthesis of triterpenoids and phenolic acids were obtained. It also laid a foundation for the further study of MYB in regulating of secondary metabolites in P. vulgaris.

Expression of MYB protein in adenoid cystic carcinoma of the salivary gland / 临床与实验病理学杂志

Purpose To investigate the role of MYB in adenoid cystic carcinoma (ACC) of different origins and grades.Methods A total of 103 specimens of salivary gland tumors with complete pathologic data were collected from the Department of Pathology, Affiliated Hospital of Inner Mongolia Medical University. 64 cases of ACC of the salivary gland, which included 19 cases of grade I, 27 cases of grade Ⅱ, and 18 cases of grade Ⅲ were selected as experimental group. 7 cases of exrras-alivary ACC and 32 cases of non-ACC benign and malignant tumor of salivary gland were served as control group. The MYB protein expression was detected by MYB immunohistochemical En Vision two-step staining for both experimental and control group. Results The positive expression rates of MYB in 64 cases of salivary ACC and 7 cases of extrasalivary ACC were 54.69％ (35/64) and 57.14％ (4/7), respectively, with no statistically significant difference (P> 0.05). The positive expression rates of MYB in 64 cases of salivary ACC and 32 cases of non-ACC salivary benign and malignant tumors were 54.69％ (35/64) and 6.25％ (2/32), respectively, which showed statistically significant difference (P < 0.05). The positive expression rates of MYB were 68.42％ (13/19), 66.67％ (18/27) and 14.29％ (4/18) in 64 cases of salivary ACC Ⅰ, Ⅱ and Ⅲ, respectively, and the difference was significant (P <0.05). The difference between grade Ⅰ and Ⅱ was not statistically significant (P> 0.016 7), while compared with grade Ⅲ, there was a statistical increase of positive expression rate of MYB in both grade Ⅰ and Ⅱ (P < 0.016 7). Conclusion MYB is highly expressed in grade I and Ⅱ of the salivary ACC and low expressed in grade Ⅲ. It is speculated that there may be other fusion gene mutation in salivary ACC grade Ⅲ. MYB is lowly expressed in non-ACC benign and malignant tumors of salivary gland, suggesting that MYB protein expression has a certain diagnostic value for the diagnosis of salivary ACC.

PLAG1, SOX10, and Myb Expression in Benign and Malignant Salivary Gland Neoplasms

BACKGROUND: Recent findings in molecular pathology suggest that genetic translocation and/or overexpression of oncoproteins is important in salivary gland tumorigenesis and diagnosis. We investigated PLAG1, SOX10, and Myb protein expression in various salivary gland neoplasm tissues. METHODS: A total of 113 cases of surgically resected salivary gland neoplasms at the National Cancer Center from January 2007 to March 2017 were identified. Immunohistochemical staining of PLAG1, SOX10, and Myb in tissue samples was performed using tissue microarrays. RESULTS: Among the 113 cases, 82 (72.6%) were benign and 31 (27.4%) were malignant. PLAG1 showed nuclear staining and normal parotid gland was not stained. Among 48 cases of pleomorphic adenoma, 29 (60.4%) were positive for PLAG1. All other benign and malignant salivary gland neoplasms were PLAG1-negative. SOX10 showed nuclear staining. In normal salivary gland tissues SOX10 was expressed in cells of acinus and intercalated ducts. In benign tumors, SOX10 expression was observed in all pleomorphic adenoma (48/48), and basal cell adenoma (3/3), but not in other benign tumors. SOX10 positivity was observed in nine of 31 (29.0%) malignant tumors. Myb showed nuclear staining but was not detected in normal parotid glands. Four of 31 (12.9%) malignant tumors showed Myb positivity: three adenoid cystic carcinomas (AdCC) and one myoepithelial carcinoma with focal AdCC-like histology. CONCLUSIONS: PLAG1 expression is specific to pleomorphic adenoma. SOX10 expression is helpful to rule out excretory duct origin tumor, but its diagnostic value is relatively low. Myb is useful for diagnosing AdCC when histology is unclear in the surgical specimen.

MYB Transcription Factors in Fagopyrum tataricum / 中国实验方剂学杂志

Known as "the king of the five grains",tartary buckwheat (Fagopyrum tataricum) is a medicinal and edible plant with both nutritional and healthcare functions. It contains rich flavonoids, such as rutin,with balanced amino acid composition and multiple effects, like blood fat-lowering,blood giucose-lowering,blood pressure-lowering,anti-oxidation,anti-aging,anti-cancer,anti-cancer,and microcirculation-improving. Transcription factors play important roles in plant growth and development by regulating gene expressions. MYB family is one of the largest transcription factor families in plant,contains the MYB domain,and can be divided into four subfamilies:1R-MYB,R2R3-MYB,3R-MYB,4R-MYB. This family plays various roles in plant growth,plant development and flavonoid biosynthesis of secondary metabolism. In this study,the reported MYB transcription factors in F. tataricum were summarized and systemically clustered,and their interrelationships were defined to provide references for further exploring and cloning MYB transcription factors in F. tataricum. In addition,this study reviewed their regulatory functions of MYB transcription factors in flavonoid biosynthesis pathway,plant hormones pathways and other abiotic stress pathways,and made a conclusion and advances about the future research in F. tataricum. Therefore,this study will provide valuable scientific references for the functional studies of MYB family transcription factors in F. tataricum and its molecular breeding for high-quality varieties.

Cloning and expression analysis of R1-MYB transcription factor in Lycium ruthenicum / 中草药

Objective To clone the R1-MYB transcription factor participated in the anthocyanidin metabolism, and to analyze by bioinformatics analysis. Different expression of different varieties, different organs of the same species and salt stress conditions in Lycium were analyzed. To clone the full-length cDNA encoding R1-MYB, to perform bioinformatic analysis, and to study its expression in different cultivators and different developmental stage and in response to NaCl stress in Lycium ruthenicum and L. barbarum. Methods The full-length cDNA encoding R1-MYB was cloned using homology-based cloning and rapid amplification of cDNA ends (RACE) technique in L. ruthenicum, and the homologous gene was obtained by transcriptome in L. barbarum. The bioinformatics analysis was carried out by using Prot, Param, Smart, PSORT, and SOPMA methods. And the phylogenetic tree was constructed based on software MEGA5.0. Gene expression analysis was done by method of Real-time PCR. Results We the MYB transcription factor in L. ruthenicum was cloned and named as LrMYB1R1 (GenBank accession number KY568981), and LbMYB1R1 (GenBank accession number KY568982) in L. barbarum. Bioinformatics analysis showed that the length of LrMYB1R1 was 1 496 bp and the CDS was 927 bp. The coding products contained 308 amino acids, the molecular weight of the protein was 33 400 and 33 490, the theoretical isoelectric point was 7.80 and 7.78, belonging to the R1-MYB transcription factor, and the encoded protein is predicted to be located in the nucleus. The results of phylogenetic tree analysis showed that LrMYB1R1 and LbMYB1R1 were highly similar to MYB1R1-like protein in Solanum lycopersicum, Solanum tuberosum, and Nicotiana tabacum. Real-time PCR analysis showed that LrMYB1R1 had higher expression level in leaves and young fruits in L. ruthenicum, followed by stems, young leaves, flowers, purple fruits and black fruits, only slightly expressed in roots. In addition, the relative expression levels of LrMYB1R1 decreased in response to salt stress. Conclusion The study of R1 MYB transcription factor has been enriched, which has laid the foundation for the subsequent research on gene function and for the high-yielding anthocyanin by genetic engineering method in L. ruthenicum.