Distribution Of Motifs Research Articles

Molecular analyses of the tubby-like protein gene family and their response to salt and high temperature in the foxtail millet (Setaria italica).

Tubby-like proteins (TLPs) are a group of proteins found in both eukaryotes and prokaryotes. They are significant in various physiological and biochemical processes, especially in plants' response to abiotic stress. However, the role of TLP in foxtail millet (Setaria italica) remains unclear. The millet genome has 16 members of the TLP family with typical Tub domains, which can be sorted into five subgroups based on gene structure, motif, and protein domain distribution. SiTLPs were discovered to be predominantly located in the nucleus and also had extracellular distribution. The interspecific evolutionary analysis indicated that SiTLPs had a closer evolutionary relationship with monocots and were consistent with the morphological classification of foxtail millet. When subjected to salt stress, the abundance of SiTLP was affected, and qRT-PCR results showed that the expression levels of certain SiTLP members were induced by salt stress while others remained unresponsive. Except for SiTLP14, all other SiTLP genes were up-regulated in response to high-temperature stress, implying a potentially crucial role for SiTLP in mitigating high-temperature-induced damage. This study provides valuable insights into understanding the functional significance of the TLP gene family in foxtail millet.

Genome-wide identification and characterization of pectin methylesterase inhibitor gene family members related to abiotic stresses in watermelon.

Pectin is a vital component of plant cell walls and its methylation process is regulated by pectin methylesterase inhibitors (PMEIs). PMEIs regulate the structural and functional modifications of cell walls in plants and play an important role in plant processes such as seed germination, fruit ripening, and stress response. Although the PMEI gene family has been well characterized in model plants, the understanding of its molecular evolution and biological functions in watermelon remains limited. In this study, 60 ClPMEI genes were identified and characterized, revealing their dispersion on multiple chromosomes. Based on a systematic developmental analysis, these genes were classified into three subfamilies, which was further supported by the exon, intron, and conserved motif distribution. Analysis of cis-elements and expression patterns indicated that ClPMEIs might be involved in regulating the tolerance of watermelon to various abiotic stresses. Moreover, distinct ClPMEI genes exhibit specific functions under different abiotic stresses. For example, ClPMEI51 and ClPMEI54 showed a significant upregulation in expression levels during the late stage of drought treatments, whereas ClPMEI3 and ClPMEI12 displayed a significant downregulation under low-temperature induction. Subcellular localization prediction and analysis revealed that the ClPMEI family member proteins were localized to the cell membrane. This study provided an important foundation for the further exploration of the functions of ClPMEI genes in watermelon.

Computational analysis and expression profiling of NAC transcription factor family involved in biotic stress response in Manihot esculenta.

The Nascent polypeptide-Associated Complex (NAC) family is among the largest plant-specific TF families and plays an important role in plant growth, development, and stress responses. NAC TFs have been extensively studied in plants such as rice and Arabidopsis; however, their characterization, functions, evolution, and expression patterns in Manihot esculenta (cassava) under environmental stress remain largely unexplored. Here, we used bioinformatic analyses and biotic stress responses to investigate the physicochemical properties, chromosome location, phylogeny, gene structure, expression patterns, and cis-elements in promoter regions of the NAC TFs in cassava. We identified 119 M. esculenta NAC (MeNAC) gene families, unevenly distributed on 16 chromosomes. We investigated expression patterns of all identified MeNAC TFs under Xanthomonas axonopodis pv. manihotis (Xam) infection, strain CHN11, at different time points. Only 20 MeNAC TFs showed expression of significant bacterial resistance. Six MeNACs (MeNAC7, 26, 63, 65, 77, and 113) were selected for functional analysis. qRT-PCR assays revealed that MeNAC7, 26, 63, 65, 77, and 113 were induced in response to XamCHN11 infection and may participate in the molecular interaction of cassava and bacterial blight. Interestingly, MeNAC26, MeNAC63, MeNAC65, and MeNAC113 responded to XamCHN11 infection at 3 h post-inoculation. Furthermore, we identified 13 stress-related cis-elements in promoter regions of the MeNAC genes that are involved in diverse environmental stress responses. Phylogenetic analysis revealed that MeNAC genes with similar structures and motif distributions were grouped. This study provides valuable insights into the evolution, diversity, and characterization of MeNAC TFs. It lays the groundwork for a better understanding of their biological roles and molecular mechanisms in cassava.

Virome-wide analysis of histone modification mimicry motifs carried by viral proteins

Histone mimicry (HM) refers to the presence of short linear motifs in viral proteins that mimic critical regions of host histone proteins. These motifs have the potential to interfere with host cell epigenome and counteract antiviral response. Recent research shows that HM is critical for the pathogenesis and transmissibility of influenza virus and coronavirus. However, the distribution, characteristics, and functions of HM in eukaryotic viruses remain obscure. Herein, we developed a bioinformatic pipeline, Histone Motif Scan (HiScan), to identify HM motifs in viral proteins and predict their functions in silico. By analyzing 592,643 viral proteins using HiScan, we found that putative HM motifs were widely distributed in most viral proteins. Among animal viruses, the ratio of HM motifs between DNA viruses and RNA viruses was approximately 1.9:1, and viruses with smaller genomes had a higher density of HM motifs. Notably, coronaviruses exhibited an uneven distribution of HM motifs, with betacoronaviruses (including most human pathogenic coronaviruses) harboring more HM motifs than other coronaviruses, primarily in the NSP3, S, and N proteins. In summary, our virome-wide screening of HM motifs using HiScan revealed extensive but uneven distribution of HM motifs in most viral proteins, with a preference in DNA viruses. Viral HM may play an important role in modulating viral pathogenicity and virus-host interactions, making it an attractive area of research in virology and antiviral medication.

Genome-Wide Analyses of CCHC Family Genes and Their Expression Profiles under Drought Stress in Rose (Rosa chinensis).

CCHC-type zinc finger proteins (CCHC-ZFPs), ubiquitous across plant species, are integral to their growth, development, hormonal regulation, and stress adaptation. Roses (Rosa sp.), as one of the most significant and extensively cultivated ornamentals, account for more than 30% of the global cut-flower market. Despite its significance, the CCHC gene family in roses (Rosa sp.) remains unexplored. This investigation identified and categorized 41 CCHC gene members located on seven chromosomes of rose into 14 subfamilies through motif distribution and phylogenetic analyses involving ten additional plant species, including Ginkgo biloba, Ostreococcus lucimarinus, Arabidopsis thaliana, and others. This study revealed that dispersed duplication likely plays a crucial role in the diversification of the CCHC genes, with the Ka/Ks ratio suggesting a history of strong purifying selection. Promoter analysis highlighted a rich presence of cis-acting regulatory elements linked to both abiotic and biotic stress responses. Differential expression analysis under drought conditions grouped the 41 CCHC gene members into five distinct clusters, with those in group 4 exhibiting pronounced regulation in roots and leaves under severe drought. Furthermore, virus-induced gene silencing (VIGS) of the RcCCHC25 member from group 4 compromised drought resilience in rose foliage. This comprehensive analysis lays the groundwork for further investigations into the functional dynamics of the CCHC gene family in rose physiology and stress responses.

Genome-wide analysis of MADS-box genes and their expression patterns in unisexual flower development in dioecious spinach

Evolution of unisexual flowers involves extreme changes in floral development. Spinach is one of the species to discern the formation and evolution of dioecy. MADS-box gene family is involved in regulation of floral organ identity and development and in many other plant developmental processes. However, there is no systematic analysis of MADS-box family genes in spinach. A comprehensive genome-wide analysis and transcriptome profiling of MADS-box genes were undertaken to understand their involvement in unisexual flower development at different stages in spinach. In total, 54 MADS-box genes found to be unevenly located across 6 chromosomes and can be divided into type I and type II genes. Twenty type I MADS-box genes are subdivided into Mα, Mβ and Mγ subgroups. While thirty-four type II SoMADSs consist of 3 MIKC*, and 31 MIKCC -type genes including sixteen floral homeotic MADS-box genes that are orthologous to the proposed Arabidopsis ABCDE model of floral organ identity determination, were identified in spinach. Gene structure, motif distribution, physiochemical properties, gene duplication and collinearity analyses for these genes are performed in detail. Promoters of both types of SoMADS genes contain mainly MeJA and ABA response elements. Expression profiling indicated that MIKCc genes exhibited more dynamic and intricate expression patterns compared to M-type genes and the majority of type-II genes AP1, SVP, and SOC1 sub-groups showed female flower-biased expression profiles, suggesting their role in carpel development, while PI showed male-biased expression throughout flower developmental stages, suggesting their role in stamen development. These results provide genomic resources and insights into spinach dioecious flower development and expedite spinach improvement.

Mining GATA Transcription Factor Encoding Genes in The Cocoa Tree (<i>Theobroma cacao</i> L.) Suggests Their Potential Roles in Embryo Development and Biotic Stress Response

GATA transcription factors (TFs) are widely recognized as significant regulators, characterized by a DNA-binding domain that consists of a type IV zinc finger motif. This TF family has been widely investigated in numerous higher plant species. The purpose of the present work was to comprehensively analyze the GATA TF in cocoa plant (Theobroma cacao L.) by using various bioinformatics tools. As a result, a total of 24 members of the GATA TFs have been identified and annotated in the assembly of the cocoa plant. According to phylogenetic analysis, these TcGATA proteins were classified into four distinct groups, including groups I (10 members), II (seven members), III (five members), and IV (two members). Next, our investigation indicated that the TcGATA proteins in different groups exhibited a high variation in their physic-chemical features due to their different protein lengths, gene structures, and conserved motif distributions, whereas the TcGATA proteins in the same clade might share the common conserved motifs. Additionally, the gene duplication of the TcGATA genes in the cocoa plant was also investigated. Of our interest, the relative expression levels of the TcGATA genes were investigated according to available transcriptome databases. The results exhibited differential expression patterns of all TcGATA genes in various developmental stages of zygotic and somatic embryogenesis, indicating that these TcGATA genes divergently function during various developmental stages of the zygotic and somatic embryos. Moreover, TcGATA genes were differently expressed under Phytophthora megakarya treatment across different points of treatment and cocoa varieties. To sum up, our findings could provide a basis for a further deep understanding of the GATAs in the cocoa plant.

Comprehensive genomic screening and expression profiling of trihelix family in pearl millet under abiotic stresses with emphasis on functional insights of PgTHX24

The trihelix transcription factors (THX TFs) play a crucial role in light responses and are involved in plant growth, development, and stress responses. In this study, we have identified 35 trihelix TFs in pearl millet (Pennisetum glaucum), which is one of the most widely grown C4 cereal crops in tropical semi-arid regions. Identified PgTHXs (Trihelix members of P. glaucum) were classified into 5 subgroups (GT1, GT2, GTγ, SH4, and SIP1) based on phylogenetic analysis, and these subgroup members shared similar gene structure and motif distribution pattern. Collinearity analysis exhibited gene duplication events of trihelix family members in pearl millet across the genome. Gene ontology (GO) annotation and cis-regulatory elements (CREs) analysis of PgTHXs suggested their involvement in diverse biological and molecular functions associated with plant growth, development, and stress responses. RNA sequencing data and expression profile displayed differential expression patterns of PgTHXs under abiotic stress and phytohormone treatments. The induced expression pattern of the PgTHX4, PgTHX5, PgTHX24, and PgTHX30 suggested their potential involvement in abiotic stress responses through phytohormonal signalling pathways. Among these, PgTHX24, a GT-3b member, was localized in the nucleus with self-transactivation ability. Overexpression of PgTHX24 positively regulated expression of stress-related markers in transformed pearl millet calli under drought stress conditions. Promoter activity analysis also highlighted the stress-inducible nature of PgTHX24’s promoter. Overall, our findings provide a comprehensive understanding of PgTHXs with a framework for further functional characterization to understand their regulatory role in pearl millet’s growth, development, and stress responses. Key messageThirty-five trihelix TFs were identified in pearl millet, and a comprehensive expression profile highlighted their functional diversity. Overexpression of PgTHX24 exhibited its potential involvement in abiotic stress responses.

Paleolithic cave art at Simanya Gran (Northeast of Spain): New graphic and symbolic expressions in novel territories

Recent years have witnessed significant advancement in the understanding of prehistoric behavior, leading to the discovery of new assemblages that challenge established knowledge within the discipline. This study presents a newly discovered Paleolithic art site in the northeast region of the Iberian Peninsula, specifically within the Simanya Gran cave complex. Excavations conducted since 2019 have revealed Neanderthal human remains and a complex litho-stratigraphic sequence dating back to the Middle Paleolithic, indicating human occupation spanning multiple periods. The documented graphic device (engravings and painting) exhibits thematic and formal characteristics comparable to Paleolithic art found in Spain and France. Through stylistic and contextual analysis, the paper proposes a tentative chronology for the graphic evidence, situating it within the mid-late Magdalenian period. Furthermore, the study explores the concept of graphic territories, suggesting that the distribution of similar graphic motifs across distant regions reflects intense socio-cultural interactions among prehistoric human groups. The significance of this discovery extends beyond its immediate geographic location, contributing to a broader understanding of Paleolithic art in the Mediterranean region and highlighting the importance of continued research in this field.

Comprehensive molecular evolutionary analysis of small heat shock proteins in five diploid Gossypium species.

The small heat shock proteins (sHSPs) are important components in plant growth and development, and stress response. However, a systematical understanding of the sHSP family is yet to be reported in five diploid Gossypium species. In this study, 34 GlsHSPs, 36 GrsHSPs, 37 GtsHSPs, 37 GasHSPs, and 38 GhesHSPs were identified in Gossypium longicalyx, Gossypium raimondii, Gossypium turneri, Gossypium arboreum, and Gossypium herbaceum, respectively. These sHSP members can be clustered into 10 subfamilies. Different subfamilies had different member numbers, motif distributions, gene structures, gene duplication events, gene loss numbers, and cis-regulatory elements. Besides, the paleohexaploidization event in cotton ancestor led to expanding the sHSP members and it was also inherited by five diploid Gossypium species. After the cotton ancestor divergence, the sHSP members had the relatively conserved evolution in five diploid Gossypium species. The comprehensive evolutionary history of the sHSP family was revealed in five diploid Gossypium species. Furthermore, several GasHSPs and GhesHSPs were important candidates in plant growth and development, and stress response. These current findings can provide valuable information for the molecular evolution and further functional research of the sHSP family in cotton.

In silico analysis on frequency and distribution of microsatellites in genes associated with spinal cord astrocytoma

Microsatellites, also called short tandem repeats (STRs) or simple sequence repeats (SSRs) are short DNA sequence segments consisting of tandemly repeated motifs. SSRs are regarded as one of the most effective tools for genetic research. In this study, we conducted an in silico analysis to investigate the presence, distribution, and characteristics of SSRs within the genes associated with spinal cord astrocytoma. The aim of this study was to identify SSRs in coding and non-coding regions, analyze their correlation with gene parameters, and determine the GC content in the gene sequences. The results revealed that the widespread presence of SSRs within the genes is associated with spinal cord astrocytoma (SCA). The distribution of SSR motifs varied among the analyzed genes, and certain motifs were common across multiple genes. Additionally, we observed a strong positive correlation between the total number of SSRs and gene size, indicating that larger genes tend to have a higher number of microsatellites. Furthermore, we identified SSRs in both coding and non-coding regions of the genes. The incidence of SSRs and cSSRs differed among genes, suggesting potential functional implications for gene expression and regulation. Our study provides valuable insights into the genetic diversity within the astrocytoma genes and highlights the potential significance of SSRs in gene regulation. In conclusion, this study contributes to a better understanding of the role of microsatellites within the genes associated with spinal cord astrocytoma. The observed patterns of SSR distribution and characteristics suggest their potential functional relevance in the development and progression of astrocytoma.

Monumental snake engravings of the Orinoco River

Rock art of the Middle and Upper Orinoco River in South America is characterised by some of the largest and most enigmatic engravings in the world, including snakes exceeding 40m in length. Here, the authors map the geographic distribution of giant snake motifs and assess the visibility of this serpentine imagery within the Orinoco landscape and Indigenous myths. Occupying prominent outcrops that were visible from great distances, the authors argue that the rock art provided physical reference points for cosmogonic myths, acting as border agents that structured the environment and were central to Indigenous placemaking along the rivers of lowland South America.

Response of Rhododendron simsii and Rhododendron delavayi Superoxide Dismutase Family Genes to High-Temperature Stress

Superoxide dismutases (SODs) are the first line of defense in the antioxidant defense system, and they play an essential role in various adversity stress adaptations in Rhododendron. In this study, 9 Rhododendron simsii SODs (RsSODs) and 11 Rhododendron delavayi SODs (RdSODs) genes were identified in the genomes of R. simsii and R. delavayi. Phylogenetic relationship analysis classified SOD proteins from two Rhododendron species and other related species into three subfamilies. The results of gene structure and conserved motif analysis show that SOD proteins are strongly evolutionarily conserved, and SODs of the same subfamily have similar motif distributions, positions, and lengths. Twenty-two light-responsive elements, eight phytohormone regulatory elements, five adversity stress-related elements, and three growth and development regulatory elements were detected in the RsSOD and RdSOD promoters. Quantitative real-time fluorescence polymerase chain reaction analysis showed that among the 20 candidate genes, except for RdCSD5, the other SODs were expressed in at least one of four tissues, and all of these gene family members had high expression levels in the leaves. We then investigated the response of the RsSOD and RdSOD gene families to high-temperature stress in combination with the following specific stressors: abscisic acid, ethephon, and hydrogen peroxide treatments, followed by high-temperature stress. Different degrees of upregulated expression of the detected SOD gene family members were found for exogenous reagent treatments and different times of high-temperature stress. Thus, we provide a basis for the further functional characterization of SOD genes in R. simsii and R. delavayi in the future.

Genome-Wide Identification and Expression Analysis of the Class III Peroxidase Gene Family under Abiotic Stresses in Litchi (Litchi chinensis Sonn.).

Class III peroxidases (CIII PRXs) are plant-specific enzymes with high activity that play key roles in the catalysis of oxidation-reduction reactions. In plants, CIII PRXs can reduce hydrogen peroxide to catalyze oxidation-reduction reactions, thereby affecting plant growth, development, and stress responses. To date, no systematic analysis of the CIII PRX gene family in litchi (Litchi chinensis Sonn.) has been documented, although the genome has been reported. In this study, a total of 77 CIII PRX (designated LcPRX) gene family members were predicted in the litchi genome to provide a reference for candidate genes in the responses to abiotic stresses during litchi growth and development. All of these LcPRX genes had different numbers of highly conserved PRX domains and were unevenly distributed across fifteen chromosomes. They were further clustered into eight clades using a phylogenetic tree, and almost every clade had its own unique gene structure and motif distribution. Collinearity analysis confirmed that there were eleven pairs of duplicate genes among the LcPRX members, and segmental duplication (SD) was the main driving force behind the LcPRX gene expansion. Tissue-specific expression profiles indicated that the expression levels of all the LcPRX family members in different tissues of the litchi tree were significantly divergent. After different abiotic stress treatments, quantitative real-time PCR (qRT-PCR) analysis revealed that the LcPRX genes responded to various stresses and displayed differential expression patterns. Physicochemical properties, transmembrane domains, subcellular localization, secondary structures, and cis-acting elements were also analyzed. These findings provide insights into the characteristics of the LcPRX gene family and give valuable information for further elucidating its molecular function and then enhancing abiotic stress tolerance in litchi through molecular breeding.

A Difluoro-Methoxylated Ending-Group Asymmetric Small Molecule Acceptor Lead Efficient Binary Organic Photovoltaic Blend.

Developing a new end group for synthesizing asymmetric small molecule acceptors (SMAs) is crucial for achieving high-performance organic photovoltaics (OPVs). Herein, an asymmetric small molecule acceptor, BTP-BO-4FO, featuring a new difluoro-methoxylated end-group is reported. Compared to its symmetric counterpart L8-BO, BTP-BO-4FO exhibits an upshifted energy level, larger dipole moment, and more sequential crystallinity. By adopting two representative and widely available solvent additives (1-chloronaphthalene (CN) and 1,8-diiodooctane (DIO)), the device based on PM6:BTP-BO-4FO (CN) photovoltaic blend demonstrates a power conversion efficiency (PCE) of 18.62% with an excellent open-circuit voltage (VOC) of 0.933V, which surpasses the optimal result of L8-BO. The PCE of 18.62% realizes the best efficiencies for binary OPVs based on SMAs with asymmetric end groups. A series of investigations reveal that optimized PM6:BTP-BO-4FO film demonstrates similar molecular packing motif and fibrillar phase distribution as PM6:L8-BO (DIO) does, resulting in comparable recombination dynamics, thus, similar fill factor. Besides, it is found PM6:BTP-BO-4FO possesses more efficient charge generation, which yields better VOC-JSC balance. This study provides a new ending group that enables a cutting-edge efficiency in asymmetric SMA-based OPVs, enriching the material library and shed light on further design ideas.

The analysis of inducible family members in the water flea Daphnia magna led to the identification of an uncharacterized lineage of heat shock protein 70

To explore the function and evolutionary relationships of inducible heat shock protein 70 (Hsp70) in Daphnia magna, cDNAs of four Hsp70 family members (DmaHsp70, DmaHsp70-2, DmaHsp70-12, DmaHsp70-14) were cloned. While all DmaHsp70s possess three function domains, it is noteworthy that only DmaHsp70 ends with a “EEVD” motif. Phylogenetic analysis indicates that the Hsp70-12 lineage is distanced from the rest, and therefore it is an uncharacterized lineage of Hsp70. The differences in isoelectric point and 3-dimensional (3D) conformation of the N-terminal nucleotide binding domain (NBD) of DmaHsp70s further support the theory. DmaHsp70s exhibit varied motif distribution patterns and the logo sequences of motifs have diverse signature characteristics, indicating that different mechanisms are involved in the regulation of ATP binding and hydrolysis for the DmaHsp70s. Protein-protein network together with the predicted subcellular locations of DmaHsp70s suggest that they likely fulfill distinct roles in cells. The transcription of four DmaHsp70s were changed during the recovery stage after thermal stress or oxidative stress. But the expression pattern of them were dissimilar. Collectively, these results collectively elucidated the identification of a previously uncharacterizedHsp70 lineage in animal and extended our understanding of the Hsp70 family.

In silico analysis of sirtuin-type histone deacetylase genes in sugar beet (Beta vulgaris L.)

Histone deacetylase (HDAC) enzymes catalyze the removal of an acetyl group from the lysine residues of histone N-terminal tails, and they repress gene transcription through condensation of chromatin. In plants, the sirtuins/silent information regulator 2 (SIR2) proteins which are NAD+-dependent deacetylases, have been identified in distinct plant species such as Arabidopsis, rice, tomato, soybean, maize, etc., but little is known about their functions in plants. They are mainly investigated in Arabidopsis and rice and found to be involved in H3K9 acetylation, metabolic pathways, repression of genes associated with stress response, and energy metabolism. A total of eight RPD3/HDA1 family HDAC genes have been recently identified in the sugar beet (Beta vulgaris L.) genome. However, B. vulgaris SIR2-type HDACs have not yet been identified and characterized. In this work, an in silico analysis of SIR2 family members was performed in sugar beet. Three SIR2 family HDACs were identified from the sugar beet genome, named BvSRT1, BvSRT2, and BvSRT3. The beet SIR2 gene family is found to be located on chromosomes 4, and 9. The phylogenetic tree building with B. vulgaris, Arabidopsis, tomato, soybean, Vitis vinifera, pepper, rice, maize, and Sorghum bicolor showed that 3 sugar beet SRTs were divided into two classes: Class II (BvSRT2) and IV (BvSRT1 and BvSRT3). SIR2 family proteins consisted of SIR2 domain (PF02146). The conserved motifs ranged from 6 to 50 amino acids, while the intron-exon numbers of genes ranged from 10 to 14. BvSRT1 and BvSRT3 exhibited similar motif distributions and exon/intron structures. Moreover, nuclear, and cytoplasmic localization of BvSRT1 and BvSRT3 has been predicted. BvSRT2 protein was located on the mitochondrion. Analysis of cis-elements revealed the involvement of BvSRT genes in hormone regulation, light response, abiotic stress response, and meristem expression. This study may shed light on the potential role of SIR2-type HDACs in beets.

Comprehensive genomic characterization and expression analysis of calreticulin gene family in tomato.

Calreticulin (CRT) is a calcium-binding endoplasmic reticulum (ER) protein that has been identified for multiple cellular processes, including protein folding, regulation of gene expression, calcium (Ca2+) storage and signaling, regeneration, and stress responses. However, the lack of information about this protein family in tomato species highlights the importance of functional characterization. In the current study, 21 CRTs were identified in four tomato species using the most recent genomic data and performed comprehensive bioinformatics and SlCRT expression in various tissues and treatments. In the bioinformatics analysis, we described the physiochemical properties, phylogeny, subcellular positions, chromosomal location, promoter analysis, gene structure, motif distribution, protein structure and protein interaction. The phylogenetic analysis classified the CRTs into three groups, consensus with the gene architecture and conserved motif analyses. Protein structure analysis revealed that the calreticulin domain is highly conserved among different tomato species and phylogenetic groups. The cis-acting elements and protein interaction analysis indicate that CRTs are involved in various developmental and stress response mechanisms. The cultivated and wild tomato species exhibited similar gene mapping on chromosomes, and synteny analysis proposed that segmental duplication plays an important role in the evolution of the CRTs family with negative selection pressure. RNA-seq data analysis showed that SlCRTs were differentially expressed in different tissues, signifying the role of calreticulin genes in tomato growth and development. qRT-PCR expression profiling showed that all SlCRTs except SlCRT5 were upregulated under PEG (polyethylene glycol) induced drought stress and abscisic acid (ABA) treatment and SlCRT2 and SlCRT3 were upregulated under salt stress. Overall, the results of the study provide information for further investigation of the functional characterization of the CRT genes in tomato.

Conservation and distribution of the DRACH motif for potential m6A sites in avian leukosis virus subgroup J.

N6-methyladenosine (m6A) methylation is an internal post-transcriptional modification that has been linked to viral multiplication and pathogenicity. To elucidate the conservation patterns of potential 5'-DRACH-3' motifs in avian leukosis virus subgroup J (ALV-J), 149 ALV-J strains (139 isolates from China; ALV-J prototype HPRS-103 from the UK; and 9 strains from the USA, Russia, India, and Pakistan) available in GenBank before December 2023 were retrieved. According to the prediction results of the SRAMP web-server, these ALV-J genomes contained potential DRACH motifs, with the total number ranging from 43 to 64, which were not determined based on the isolation region and time. Conservative analysis suggested that 37 motifs exhibited a conservation of >80%, including 17 motifs with a grading above "high confidence." Although these motifs were distributed in the U5 region of LTRs and major coding regions, they were enriched in the coding regions of p27, p68, p32, and gp85. The most common m6A-motif sequence of the DRACH motif in the ALV-J genome was GGACU. The RNA secondary structure of each conserved motif predicted by SRAMP and RNAstructure web-server was mainly of two types-A-U pair (21/37) and hairpin loop (16/37)-based on the core adenosine. Considering the systematic comparative analysis performed in this study, future thorough biochemical research is warranted to determine the role of m6A modification during the replication and infection of ALV-J. These conservation and distribution analysis of the DRACH motif for potential m6A sites in ALV-J would provide a foundation for the future intervention of ALV-J infection and m6A modification.

Abstract LB108: Specific plasma DNA end-motifs distinguish patients with lung adenocarcinoma versus benign nodules

Abstract Background: Recent studies have identified blood plasma DNA as a rich source of biomarkers for non-invasive cancer detection. In particular, analysis of shorter DNA fragments or “fragmentomics” have shown promising results with numerous competing approaches such as those based on mutation calls, length distributions, or preferred fragmentation patterns. In this study, we assessed the potential of fragment end motif distributions in discriminating patients with lung adenocarcinoma versus benign tumors. Methods: Plasma samples from 37 patients (20 benign, 17 malignant) were subject to whole genome sequencing. For each sample, DNA fragments were grouped as short (30-99bp) and long (100-269bp) and end motif distributions were calculated by counting occurrences of 4-9bp sequences at either the 5’ or 3’ end of each fragment. A proprietary machine learning algorithm was employed to identify a minimal set of motifs capable of accurately distinguishing benign from malignant samples. Results: Just two 5’ end motifs in long fragments, CCAT and GACA, were sufficient for distinguishing malignant from benign samples in a two-step decision tree (89% accuracy with all samples, 86% accuracy in leave-one-out cross validation). Accuracy was significantly higher when compared to random guessing by shuffling labels (p=1.6*10−6, FWER < 0.05, Bonferroni correction, 351 tests). CCAT motif frequency was also significantly associated with cancer stage (p=0.04, Kruskal-Wallis test) and specifically elevated in early stage samples (I, II). Conclusions: These results suggest that plasma DNA end motif distributions are informative in discriminating patients with lung adenocarcinoma versus benign tumors. The two-motif model suggests that specific, rather than systemic changes in end motif distributions are more strongly associated with lung cancer patients and may point to specific mechanisms linked to cancer progression. Citation Format: Jason C. Hyun, Shun H. Yip, Neeti Swarup, Raghuraman Ramamurthy, Jordan C. Cheng, Irene Choi, Edmund Wong, Akanksha Arora, Denise Aberle, David T. Wong, Cheuk Y. Tang. Specific plasma DNA end-motifs distinguish patients with lung adenocarcinoma versus benign nodules [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB108.