Targeted Next Generation Sequencing Reveals a Third Breakpoint Cluster Region and New Partner Genes in the KMT2A Recombinome

Abstract Chromosomal rearrangements of the KMT2A gene are associated with acute leukemias and myelodysplastic syndromes. The large number of known KMT2A fusions (>100) renders a precise diagnosis a demanding task. More than 50% of all KMT2A partner genes have been analyzed at the DCAL, including the novel partner genes BCAS4, FAM13A, RANBP3, and STK4. Even though all KMT2A rearrangements are associated with high-risk acute leukemia, the outcome (poor or very poor) is influenced by the partner gene. So far, we have analyzed more than 3,200 patients positive for a KMT2A rearrangement. The breakpoints of these cases are located mainly in the major breakpoint cluster region (bcr1) and to a small extent in the recently described minor bcr (bcr2). A small number of breakpoints were also found outside of these two bcrs. Most of these patients were analyzed by long distance inverse (LDI)- or multiplex-PCR which only cover bcr1. More recently, we used targeted KMT2A-NGS with whole gene coverage in over 450 patients, which was initially applied selectively in patients negative by LDI- and multiplex-PCR and then used more widely. Within the KMT2A-NGS group, 410 patients had bcr1 breakpoints mainly between the KMT2A exons 7 and 13, while 46 patients bcr2 breakpoints mainly between exons 20 and 24. Of note, five patients had their breakpoint outside of these two bcrs: three of them within intron 2 and no functional KMT2A rearrangement; the other two within intron 35 and intron 36, fusing almost the whole KMT2A gene in frame to the respective partner genes ARHGEF12 and MLLT4. These two breakpoints may define a third and rare bcr (bcr3), although further cases are needed to support this hypothesis. Interestingly, 70 patients displayed a 3'-KMT2A deletion, indicating that the number of terminal deletions is higher than described previously. Two patients had a 5'-KMT2A deletion. All deletions started or ended in bcr1 and bcr2. We also observed a striking difference in the distribution of partner genes between bcr1 and bcr2. The most frequent translocation partners fused to bcr1 sites are transcription factors, while the partner genes linked to bcr2 sites generally code for cytosolic proteins. In bcr1, the 4 most frequent partner genes AFF1, MLLT3, MLLT1, and MLLT10, found in 80% of cases, all code for transcription factors that are part of the super elongation complex (SEC). These fusions therefore all lead to disruption of the hematopoietic lineage commitment. In contrast in bcr2, 3 partner genes USP2, MLLT4, and USP8 account for 85% of the cases. USP2 and USP8 are ubiquitin specific peptidases involved in cell signaling and exclusively fused to bcr2 in KMT2A. While MLLT4 is found as a partner in bcr1, bcr2 and bcr3 fusions; unlike other recurrent KMT2A partners linked to bcr1, it is not a transcription factor and it exerts oncogenic potential via dimerization like other cytosolic partners. We hypothesize that the oncogenic properties of USP2 and USP8 are dependent on dimerization like MLLT4 and that the most frequent fusions involving at different bcrs favor different oncogenic mechanisms: bcr1 transactivation and bcr2 dimerization. Further studies are needed to explain why USP2 and USP8 are exclusively associated with bcr2, and why the most frequent partner genes AFF1 and MLLT3 of the bcr1 are less frequent in bcr2. In conclusion, targeted NGS combined with bioinformatic analysis has expanded our knowledge of the KMT2A recombinome to include more fusion partners and has generated new hypotheses for future research on oncogenic mechanisms. Disclosures No relevant conflicts of interest to declare.

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MLL-USP2: An Underestimated New Entity of MLL-Rearranged Leukemia Identified By NGS Analysis

Blood ◽

10.1182/blood-2018-99-112594 ◽

2018 ◽

Vol 132 (Supplement 1) ◽

pp. 3920-3920 ◽

Cited By ~ 1

Author(s):

Claus Meyer ◽

Bruno Lopes ◽

Aurélie Caye-Eude ◽

Hélène Cavé ◽

Chloé Arfeuille ◽

...

Keyword(s):

High Risk ◽

Acute Leukemia ◽

Diagnostic Methods ◽

Patient Specific ◽

Fish Analysis ◽

Acute Leukemias ◽

Breakpoint Cluster Region ◽

Cluster Region ◽

Mll Gene ◽

Partner Gene

Abstract Chromosomal rearrangements of the MLL gene are responsible for 5-10% of all acute leukemias, biphenotypic leukemias and myelodysplastic syndromes. The large number of known MLL fusions (>80) renders a precise diagnosis a demanding task. Even though all MLL rearrangements are associated with high-risk acute leukemia, the outcome (poor or very poor) is influenced by the partner gene. The applied diagnostic methods (LDI-PCR and multiplex PCR) allows the identification of MLL fusion genes at the nucleotide level, providing important information on the genetics of leukemia patients, and patient-specific biomarkers. These biomarkers are used for monitoring of minimal residual disease in acute leukemia patients during and after therapy. Thus, the identification of MLL gene fusions is necessary for rapid clinical decisions to determine the best therapy regimen. We have developed a customized NGS panel for MLL diagnostics to utilize state of the art technology at DCAL. With this new tool, the whole MLL gene is analyzed in contrast to the LDI-PCR where only the main MLL breakpoint cluster region (BCR-1) is covered. The first results of the NGS analysis of 84 patients identified MLL breakpoints located outside the main BCR-1 of MLL. Furthermore, a novel MLL partner gene USP2 was identified in 16 patients. All MLL-USP2 positive patients had a breakpoint located outside BCR-1 and within a newly defined breakpoint cluster region BCR-2. The BCR-2 site was also used in 2 other patients with MLL-AFF1 and one patient with MLL-MLLT3. These findings reveal USP2 as a new entity for MLL rearrangements affecting indifferently children aged 3 months to 10 years old (mean 30 months) with no gender bias (M/F=1.3). Interestingly, only 5/16 affected children were below 1 year of age at diagnosis and thus treated according to the Interfant trial. Clinical presentation as well as outcome associated with this new entity deserves further investigation to define whether those patients should be allocated, as other MLL-rearranged ones, in high-risk treatment groups. More MLL patients should also be analyzed to get a better idea of the frequency of breakpoints within BCR-2, especially the frequency of MLL-USP2 fusions. Indeed, standard FISH analysis and CGH array do not permit reliable detection of this fusion, explaining why they remained undetected so far. The biology of this novel MLL rearrangement also deserves further investigation, considering that USP2 is the only MLL partner fused exclusively to BCR-2. Disclosures No relevant conflicts of interest to declare.

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Identification of Multiple, Patient-Specific MLL Fusion Transcript Isoforms in Childhood Leukemia Using Anchored Multiplex PCR-Based Enrichment (AMP-E)

Blood ◽

10.1182/blood.v128.22.2908.2908 ◽

2016 ◽

Vol 128 (22) ◽

pp. 2908-2908

Author(s):

Sadia Afrin ◽

Claus Meyer ◽

Caedyn L. Stinson ◽

Thy Pham ◽

Timothy J.C. Bruxner ◽

...

Keyword(s):

Multiplex Pcr ◽

Childhood Leukemia ◽

Conflicts Of Interest ◽

False Negative ◽

Illumina Miseq ◽

Patient Specific ◽

Gene Fusions ◽

Long Distance ◽

Transcript Isoforms ◽

Fusion Transcripts

Abstract Chromosomal translocations involving 11q23, resulting in rearrangements of the mixed lineage leukemia gene (MLL, re-named KMT2A) are frequent events in childhood leukemia. MLL is highly promiscuous, with approximately 80 fusions now characterized. Although fluorescence in situ hybridization (FISH) has high specificity for detecting MLL-rearrangements (MLL-r), sensitivity is limited and the translocation partner gene (TPG) cannot always be identified. In contrast, long-distance inverse-PCR (LDI-PCR) permits sequence-specific characterization of MLL breakpoints and the resultant fusion gene, which can then be used for monitoring minimal residual disease (MRD). A limitation of LDI-PCR is the relatively large input of DNA (≈ 1μg) required, with a blast cell percentage of > 20-30% to achieve sufficient sensitivity. Next-generation sequencing (NGS) approaches such as RNAseq and whole-genome sequencing (WGS) have the potential to identify multiple gene fusions, however their ability to detect the full spectrum of MLL fusions is limited by coverage, read depth and thereby cost. Such limitations can potentially be overcome with targeted sequencing panels, although their performance against "gold standard" assays, such as LDI-PCR, is unknown. We therefore aimed to assess the ability of a novel, targeted NGS approach for characterizing patient-specific MLLgene rearrangements from low inputs of RNA. The Archer™ FusionPlex™ Heme and Myeloid panels utilize anchored multiplex PCR-based enrichment (AMP-E) to rapidly enrich a number of targets, including MLL, creating libraries for NGS. The NGS libraries are generated using rapid workflows and are compatible with nucleic acid inputs of ≈ 20-200ng. Briefly, double stranded cDNA is generated from patient RNA and subjected to end repair, adenylation and ligation with unique, half-functional adaptors. Following two rounds of nested PCR with primers attached to common sequencing adaptors, the resulting target amplicons become functional and ready for clonal amplification and sequencing. Using AMP-E, we tested 23 paediatric MLL-r samples (15 ALL, 8 AML) that had previously been analyzed by LDI-PCR and were known to harbor 8 different MLL fusions, including MLL-AFF1 (n = 8), -MLLT3 (5), -MLLT10 (3), -ELL (2), -DCP1A (1), -MLLT1 (1), - AFF3 (1), and -TNRC18 (1). A patient sample known to express BCR-ABL1 was used as a positive control and a cytogenetically normal AML sample in remission was used as a negative control in each panel. The median blast count for samples analyzed was 86.1% (range 25%-97%). On average, 100ng of RNA was used per sample, with RIN values ranging from 2.7 to 9.1. Libraries generated using either the Archer™ FusionPlex™ Heme or Myeloid kit were sequenced to sufficient read depths by Illumina MiSeq® and NextSeq®, respectively. Bioinformatic analyses were performed with the Archer™ Analysis 4.1 software. Results were then compared with fusions identified by LDI-PCR. There was high concordance between AMP-E and LDI-PCR, with all MLL fusion genes identified by LDI-PCR also detected by AMP-E. Of note, an ALL sample with t(11;19), unable to be characterized by LDI-PCR, was identified by AMP-E to express MLL-MLLT1. The control BCR-ABL1 fusion was identified in every run and there were no false-negative results. Furthermore, AMP-E identified multiple MLL-fusion transcripts in 56.5% of patients. Analysis of paired diagnosis-relapse samples from an AML patient with MLL-MLLT3demonstrated that the two discrete transcripts present at diagnosis persisted at relapse, with emergence of a third transcript. In summary, detection of MLL gene fusions in acute leukemia using AMP-E is both sensitive and specific. The low RNA requirement, rapid workflow, compatibility with Illumina MiSeq® and cloud-based proprietary analysis software, together with the array of additional fusions and mutations detected by the Archer™ panels, show promise for translation into clinical diagnostic settings. The persistence of discrete transcript isoforms at relapse also highlights the potential for AMP-E to identify multiple, patient-specific MLL fusion transcripts which may have utility in refining prognostication, MRD monitoring and informing future functional studies of MLL-driven leukemogenesis. Disclosures No relevant conflicts of interest to declare.

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Consistent involvement of the bcr gene by 9;22 breakpoints in pediatric acute leukemias

Blood ◽

10.1182/blood.v77.2.324.324 ◽

1991 ◽

Vol 77 (2) ◽

pp. 324-330 ◽

Cited By ~ 77

Author(s):

K Suryanarayan ◽

SP Hunger ◽

S Kohler ◽

AJ Carroll ◽

W Crist ◽

...

Keyword(s):

Clinical Features ◽

Blast Crisis ◽

Philadelphia Chromosome ◽

Acute Leukemias ◽

Breakpoint Cluster Region ◽

Cluster Region ◽

Pcr Product ◽

Pcr Products ◽

Precursor Rna ◽

Relationship Of

Abstract To investigate the relationship of bcr-abl fusion mRNAs with childhood acute lymphoblastic leukemias (ALL), we examined 27 pediatric Philadelphia chromosome (Ph1)-positive acute leukemias using a reverse polymerase chain reaction (PCR) procedure. In cells from 24 leukemias, single bcr-abl PCR products were detected that corresponded to breakpoints in the minor breakpoint cluster region (mbcr in intron 1 of the bcr gene) associated with production of the P190 fusion protein. Cells from the three remaining leukemias contained breakpoints in the major breakpoint cluster region (Mbcr) as shown by PCR and Southern blot analyses. These three leukemias also contained low levels of the mbcr PCR product that may have resulted from alternative splicing of the bcr-abl precursor RNA. A screen of 35 additional leukemias from patients who failed therapy before day 180 (induction failures or early relapses) found one case with unsuccessful cytogenetics to express Mbcr- abl RNA. All four children with Mbcr breakpoints had white blood cell levels in excess of 250,000 at presentation (compared with 2 of 24 with mbcr breakpoints) and two had hematologic and clinical features suggestive of chronic myelogenous leukemias (CML) in lymphoid blast crisis. Our results indicate that in Ph1-positive pediatric leukemias, all 9;22 breakpoints occur in one of the two known breakpoint cluster regions in the bcr gene on chromosome 22. The reverse PCR reliably detected all patients with cytogenetic t(9;22) and is capable of detecting additional Ph1-positive leukemias that are missed by standard cytogenetics. Furthermore, the Mbcr-type breakpoint, associated with production of p210, can be seen in childhood leukemias presenting either as clinical ALL or as apparent lymphoid blast crisis of CML, suggesting that t(9;22) breakpoint locations do not exclusively determine the biologic and clinical features of pediatric Ph1-positive ALL.

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Novel KMT2A Partner Gene NUTM2A Revealed By Anchored Multiplex PCR in ALL

Blood ◽

10.1182/blood-2019-126602 ◽

2019 ◽

Vol 134 (Supplement_1) ◽

pp. 5203-5203 ◽

Cited By ~ 1

Author(s):

Svetlana Lebedeva ◽

Elena Zerkalenkova ◽

Olga Soldatkina ◽

Michael Maschan ◽

Alexey A. Maschan ◽

...

Keyword(s):

Acute Lymphoblastic Leukemia ◽

T Cell ◽

Multiplex Pcr ◽

Pleural Fluid ◽

Lymphoblastic Leukemia ◽

Patient Specific ◽

Long Distance ◽

Acute Leukemias ◽

Cell Acute Lymphoblastic Leukemia ◽

Frame Fusion

Objectives Chromosomal rearrangements of the human MLL/KMT2A gene are associated with infant, pediatric and adult acute leukemias. Such rearrangements are more frequent in infants, in whom they are found in 60% - 80% of acute lymphoblastic leukemias (ALL). KMT2A-r group itself is genetically heterogeneous. KMT2A-r can occur with at least 94 partner genes previously described in «THE MLL RECOMBINOME <…> IN 2017». Detection of KMT2A-r is an essential part of AL initial diagnostics. Also, the accurate detection of all KMT2A-r types is crucial in order to perform minimal residual disease (MRD) monitoring, as it is clear now that MRD-based therapy adjustment has a very strong impact on outcome. Here we report a case of novel KMT2A partner in pediatric ALL - NUT family member 2A (NUTM2A). Methods The patient is 8 y.o. girl with T-cell acute lymphoblastic leukemia with pleural effusion. Bone marrow and pleural fluid aspirates were analyzed by G-banded karyotyping and FISH with KMT2A breakapart probe. Pleural fluid aspirates were also analyzed by real-time RT-PCR for 8 most common KMT2A rearrangements screening, long-distance inversed PCR and targeted RNA-seq with FusionPlex Myeloid kit (ArcherDX, CO, USA). Sanger sequencing was used for validation. Results Conventional cytogenetics and FISH showed 47,XX,t(10;11)(q22;q23),+mar[5] karyotype with 100% KMT2A-rearranged nuclei. Gene fusion analysis identified novel fusion KMT2A-NUTM2A with exon 11 - exon 1 breakpoint junction. NUTM2A is a gene at 10q23.2. This gene is not fully described in the literature. Rearrangements of this gene were identified in endometrial stromal sarcomas (ESS) (Cheng-Han Lee et al. 2012) and small round cell sarcoma (SRCS) (Sugita et al. 2017). In case of ESS, this rearrangement results in an in-frame fusion between YWHAE and NUTM2A (or highly homologous gene NUTM2B), and in case of SRCS it results in an in-frame fusion between NUTM2A and CIC. To our knowledge, KMT2A-NUTM2A fusion in our study is the first case demonstrating NUTM2A rearrangement in hematological malignancies. Conclusions Here we for the first time show the novel KMT2A-NUTM2A fusion transcript, which was found in pediatric T-cell acute lymphoblastic leukemia. Anchored multiplex PCR is one of the most sensitive way to detect rare variants of KMT2A rearrangements. It also allows selecting patient-specific primers for further PCR detection of MRD. Disclosures No relevant conflicts of interest to declare.

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Consistent involvement of the bcr gene by 9;22 breakpoints in pediatric acute leukemias

Blood ◽

10.1182/blood.v77.2.324.bloodjournal772324 ◽

1991 ◽

Vol 77 (2) ◽

pp. 324-330 ◽

Cited By ~ 2

Author(s):

K Suryanarayan ◽

SP Hunger ◽

S Kohler ◽

AJ Carroll ◽

W Crist ◽

...

Keyword(s):

Clinical Features ◽

Blast Crisis ◽

Philadelphia Chromosome ◽

Acute Leukemias ◽

Breakpoint Cluster Region ◽

Cluster Region ◽

Pcr Product ◽

Pcr Products ◽

Precursor Rna ◽

Relationship Of

To investigate the relationship of bcr-abl fusion mRNAs with childhood acute lymphoblastic leukemias (ALL), we examined 27 pediatric Philadelphia chromosome (Ph1)-positive acute leukemias using a reverse polymerase chain reaction (PCR) procedure. In cells from 24 leukemias, single bcr-abl PCR products were detected that corresponded to breakpoints in the minor breakpoint cluster region (mbcr in intron 1 of the bcr gene) associated with production of the P190 fusion protein. Cells from the three remaining leukemias contained breakpoints in the major breakpoint cluster region (Mbcr) as shown by PCR and Southern blot analyses. These three leukemias also contained low levels of the mbcr PCR product that may have resulted from alternative splicing of the bcr-abl precursor RNA. A screen of 35 additional leukemias from patients who failed therapy before day 180 (induction failures or early relapses) found one case with unsuccessful cytogenetics to express Mbcr- abl RNA. All four children with Mbcr breakpoints had white blood cell levels in excess of 250,000 at presentation (compared with 2 of 24 with mbcr breakpoints) and two had hematologic and clinical features suggestive of chronic myelogenous leukemias (CML) in lymphoid blast crisis. Our results indicate that in Ph1-positive pediatric leukemias, all 9;22 breakpoints occur in one of the two known breakpoint cluster regions in the bcr gene on chromosome 22. The reverse PCR reliably detected all patients with cytogenetic t(9;22) and is capable of detecting additional Ph1-positive leukemias that are missed by standard cytogenetics. Furthermore, the Mbcr-type breakpoint, associated with production of p210, can be seen in childhood leukemias presenting either as clinical ALL or as apparent lymphoid blast crisis of CML, suggesting that t(9;22) breakpoint locations do not exclusively determine the biologic and clinical features of pediatric Ph1-positive ALL.

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BCR-ABL Splice Variants In Three Phases Of CML: Association With Disease Biology and Response To Imatinib

Blood ◽

10.1182/blood.v122.21.5191.5191 ◽

2013 ◽

Vol 122 (21) ◽

pp. 5191-5191

Author(s):

Iqbal Zafar ◽

Saba Shahzadi ◽

Tanveer Akhtar ◽

Aleem Aamer ◽

Ahmad Mukhtar Khalid ◽

...

Keyword(s):

Splice Variant ◽

Conflicts Of Interest ◽

Splice Variants ◽

Philadelphia Chromosome ◽

Chronic Phase ◽

Cancer Drug ◽

Imatinib Treatment ◽

Breakpoint Cluster Region ◽

Cluster Region ◽

Disease Biology

Abstract Background Philadelphia chromosome, a characteristic chromosomal translocation (breakpoint cluster region-Abelson [BCR–ABL]; t [9; 22] [q34; q11]) in chronic myeloid leukemia (CML) encodes a product, which is the target of tyrosine kinase inhibitors (TKIs). In most CML patients, during translocation, the break takes place within a 5.8-kb region on both sides of BCR exons12-16 (originally referred to as exons b1-b5), described as themajor breakpoint cluster region (M-bcr)1. It can be either between exons b2 and b3, or between exons b3 and b4. The ABL exon which is mostly inserted in break points of BCR is a2. As a result of alternativesplicing, fusion transcripts with either b2a2 or b3a2 splicing variantcan be produced. Occasionally, breakpoints occur in unusual places, resulting in generation of rare BCR-ABL transcripts (b2a3, b3a3, e1a2, e8a2, e19a2). Association of BCR-ABL splice variants with clinical outcome in different phases of CML has rarely been studied2. We studied BCR/ABL splice variants and their association with disease biology and response to imatinib in 3 phases of CML in 70 patients. Methods Total RNA was extracted and reverse transcribed. PCR primers and nested PCR protocol for the detection of BCR-ABL splice variants in CML patients were adopted from van Dongen et al., 1999 3. Data was analyzed using SPSS Software version 17. Results Median age of the patients was 34 years; 10 patients were 18 or younger and there were 40 females. 26 patients were in chronic phase (CP), 26 in accelerated phase (AP) and 18 in blast phase (BP). Overall, the frequencies of BCR/ABL splice variants b3a2, b2a2 and b3a2+b2a2 were found in 49 (70%), 15 (21.4%) and 6 (8.6%) patients, respectively. No rare BCR-ABL transcripts were identified. Percentage of BCR-ABL splice variant b2a2 was similar in patients with CP (31) and BP (28) of CML and low in AP (7.75). While the percentage of BCR-ABL splice variant b3a2 was more common in AP (84.5) and BP (72) as compared to CP (54). The combined expression of both transcripts (b3a2 and b2a2) was found in 4 patients with CP and 2 in AP of CML but none in BP of CML (Table 1). The co-existence of b2a2 and b3a2 transcripts was observed only in male patients. The BCR-ABL transcripts had no correlation with the age. Patients with the splice variant b2a2 had a better response to imatinib treatment and better survival as compared to patients with b3a2. The patients expressing both transcripts (b3a2 and b2a2) also showed better survival as compared to patients with only b3a2 transcript (figure 1). Discussion and Conclusions We found a higher percentage of BCR-ABL splice variant b3a2 in AP & BP as compared to CP. Patients with the BCR-ABL splice variant b2a2 had a better response to imatinib and better survival, which is in contrast to previous reports 4. Co-existence of two transcripts b3a2 and b2a2 was observed mostly in CP, and in some patients in AP; it was also associated with a better response to imatinib. Larger studies are needed to further define the role of BCR-ABL splice variants in different phases of CML and their association with response to TKIs and prognosis. Studies of BCR-ABL splice variants can provide further insights into CML biology and new targets for BCR-ABL positive leukemia treatment 1, 5. References 1. Adamia S, Pilarski PM, Natan MB, Stone RM, Griffin JD. Curr Cancer Drug Targets. 2013 Jul 30. [Epub ahead of print]. 2. Gruber FX, Lundán T, Goll R, Silye A, Mikkola I, Rekvig OP et al. Med Oncol. 2012 Mar; 29(1):219-26. 3. van Dongen JJ, Macintyre EA, Gabert JA, Delabesse E, Rossi V, Saglio G et al. Leukemia. 1999 Dec; 13(12):1901-28. 4. Lucas CM, Harris RJ, Giannoudis A, Davies A, Knight K, Watmough SJ, et al. Haematologica. 2009 Oct;94(10):1362-7 5. Chiarella P, Summa V, De Santis S, Signori E, Picardi E, Pesole G et al. Curr Mol Med. 2012 Jun;12(5):547-65. Disclosures: No relevant conflicts of interest to declare.

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MYB Transcription Factors and Its Regulation in Secondary Cell Wall Formation and Lignin Biosynthesis during Xylem Development

International Journal of Molecular Sciences ◽

10.3390/ijms22073560 ◽

2021 ◽

Vol 22 (7) ◽

pp. 3560

Author(s):

Ruixue Xiao ◽

Chong Zhang ◽

Xiaorui Guo ◽

Hui Li ◽

Hai Lu

Keyword(s):

Cell Wall ◽

Transcription Factors ◽

Secondary Wall ◽

Secondary Cell Wall ◽

Lignin Biosynthesis ◽

Cell Wall Formation ◽

Long Distance ◽

Secondary Cell Wall Formation ◽

Myb Transcription Factors ◽

Wall Formation

The secondary wall is the main part of wood and is composed of cellulose, xylan, lignin, and small amounts of structural proteins and enzymes. Lignin molecules can interact directly or indirectly with cellulose, xylan and other polysaccharide molecules in the cell wall, increasing the mechanical strength and hydrophobicity of plant cells and tissues and facilitating the long-distance transportation of water in plants. MYBs (v-myb avian myeloblastosis viral oncogene homolog) belong to one of the largest superfamilies of transcription factors, the members of which regulate secondary cell-wall formation by promoting/inhibiting the biosynthesis of lignin, cellulose, and xylan. Among them, MYB46 and MYB83, which comprise the second layer of the main switch of secondary cell-wall biosynthesis, coordinate upstream and downstream secondary wall synthesis-related transcription factors. In addition, MYB transcription factors other than MYB46/83, as well as noncoding RNAs, hormones, and other factors, interact with one another to regulate the biosynthesis of the secondary wall. Here, we discuss the biosynthesis of secondary wall, classification and functions of MYB transcription factors and their regulation of lignin polymerization and secondary cell-wall formation during wood formation.

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Cardiovascular risks awareness in coaches and amateur athletes

European Journal of Preventive Cardiology ◽

10.1093/eurjpc/zwab061.380 ◽

2021 ◽

Vol 28 (Supplement_1) ◽

Author(s):

A Markovich ◽

O Mironova

Keyword(s):

Physical Activity ◽

Cardiovascular Diseases ◽

Heart Attack ◽

Conflicts Of Interest ◽

The Body ◽

Treadmill Test ◽

Cardiovascular Risks ◽

Sports Cardiology ◽

Long Distance ◽

Endurance Sport

Abstract Funding Acknowledgements Type of funding sources: None. Background Regular physical activity is an important component of therapy for most сardiovascular diseases and is associated with reduced cardiovascular and all-cause mortality. The promotion of the physical activity and regular exercise is an important preventive measure that affects the prognosis. Purpose To assess the awareness of the prevalence of cardiovascular disease in exercising population and its influence on the safety of the patients and healthy adults among coaches and people actively engaged in sports activities. Methods An open non-randomized observation was conducted. The questionnaire created by our team included 45 questions about cardiovascular diseases and sport. 111 athletes and coaches aged from 19 to 46 were enrolled in the study. 61,5% (68) are men and 38,5% (42) of the respondents are women. 30,3% (33) of the respondents are coaches. 45,5% (15) of them have over 5 years of coaching experience. 44% (48) of all respondents prefer endurance sport, 25,7% (28) train strength exercise. 63,6% (70) train 3-8 hours per week, 12,7% (14 [7 women and 7 men]) train more than 8 hours each week. Results 18,5% (20 [6 women and 14 men]) think that ECG is enough for screening for cardiovascular diseases. 20% (4) of them are coaches. Only 69,5% (77) of all respondents know about treadmill test. And 41,6% (32/77) of them know about the necessary screening for arrhythmogenic condition. 13% (10/77) of them train more than 8 hours per week. And only 27,3% (21/77) of people who know about treadmill test, passed it themselves. Also 21,6% (24) of all respondents think that any episode of arrhythmia is the contraindication for any sport. But 96,4% (107) of the respondents know that it is necessary to regularly screen the cardiovascular system, even in the absence of complaints. 9% (10) of the interviewed think that diet is not important for people with cardiovascular diseases. And 18,9% (21) of the respondents don’t know about the effect of electrolytes on the body and the work of the heart muscle. Only 53,2% (59 [21 women and 38 men]) of the respondents trust the doctors more than coaches or themselves. And this is one of the reasons why it is necessary to talk about the basic principles of sports cardiology not only to doctors. 8,1% (9) of the respondents have never heard about any cases of sudden death of an athlete during training or at competitions due to «heart problems». 63,6% (21) of the coaches would not train a person who has suffered a heart attack. 71,8% (56) of the sportsmen would like to return to training after a heart attack. Conclusions Despite the fact that most people prefer a sedentary lifestyle, high-intensity fitness and long-distance endurance sport is getting more popular. Our survey proves the relatively low level of education about the underlying health conditions and possible risks associated with sports not only among athletes but professional coaches as well. There are no conflicts of interest to declare.

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A Classification of Basic Helix-Loop-Helix Transcription Factors of Soybean

International Journal of Genomics ◽

10.1155/2015/603182 ◽

2015 ◽

Vol 2015 ◽

pp. 1-10 ◽

Cited By ~ 16

Author(s):

Karen A. Hudson ◽

Matthew E. Hudson

Keyword(s):

Transcription Factors ◽

Genome Sequence ◽

Search Algorithm ◽

Soybean Genome ◽

Binding Potential ◽

Future Research ◽

Basic Helix Loop Helix ◽

Helix Loop Helix ◽

Bhlh Genes ◽

Wide Range

The complete genome sequence of soybean allows an unprecedented opportunity for the discovery of the genes controlling important traits. In particular, the potential functions of regulatory genes are a priority for analysis. The basic helix-loop-helix (bHLH) family of transcription factors is known to be involved in controlling a wide range of systems critical for crop adaptation and quality, including photosynthesis, light signalling, pigment biosynthesis, and seed pod development. Using a hidden Markov model search algorithm, 319 genes with basic helix-loop-helix transcription factor domains were identified within the soybean genome sequence. These were classified with respect to their predicted DNA binding potential, intron/exon structure, and the phylogeny of the bHLH domain. Evidence is presented that the vast majority (281) of these 319 soybean bHLH genes are expressed at the mRNA level. Of these soybean bHLH genes, 67% were found to exist in two or more homeologous copies. This dataset provides a framework for future studies on bHLH gene function in soybean. The challenge for future research remains to define functions for the bHLH factors encoded in the soybean genome, which may allow greater flexibility for genetic selection of growth and environmental adaptation in this widely grown crop.

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Archaic Origins of the Lowland Maya

Latin American Antiquity ◽

10.7183/1045-6635.21.3.312 ◽

2010 ◽

Vol 21 (3) ◽

pp. 312-352 ◽

Cited By ~ 38

Author(s):

Jon C. Lohse

Keyword(s):

Cultural Change ◽

New Technologies ◽

Cultural Practices ◽

Future Research ◽

Late Archaic ◽

Long Distance ◽

Radiocarbon Data ◽

Cultural Origins ◽

Lines Of Evidence ◽

Lowland Maya

The earliest Lowland Maya are commonly recognized by permanent architecture and the appearance of pottery. However, when other lines of evidence are considered, strong continuities with late Archaic populations can be seen. Reconciling these views relies on more than simply gathering more data. It is also necessary to consider the effect of decades of scholarship that defines the precolumbian Maya as “civilization” rather than considering the historical contexts of important transitions, such as the one that culminated with sedentism, the adoption of new technologies, and participation in long-distance exchange. The Archaic-to-Preclassic transition was relatively brief and largely obscured by the practices of establishing permanent dwellings. Nevertheless, this period must have been extremely dynamic and marked by significant cultural change, making it important to researchers interested in early Mesoamerica. Using three lines of evidence—subsistence, economy and technology, and stratigraphically controlled radiocarbon data—this article argues that the Lowland Maya had their cultural origins at least in the late Archaic and that the case for pottery before ca. 1000 B.C. remains uncertain. Future research is needed to determine precisely how far back in time certain cultural practices that characterize Preclassic and Classic Maya society can be documented.

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