Tankyrase 2 promotes lung cancer cell malignancy.

BACKGROUND: Tankyrase 2 (TNKS2) is a potential candidate molecular target for the prognosis and treatment of non-small cell lung cancer (NSCLC), but its biological functions are unclear. AIM: To investigate the biological functions of TNKS2 in NSCLC. METHODS: Using a lentiviral vector, we generated H647 model cells with TNKS2 knockdown by RNA interference and A549 model cells with TNKS2 overexpression by transfection with a TNKS2 overexpressing plasmid. Increased and decreased expression levels of TNKS2 in the two cell lines were verified using real-time reverse transcriptase-polymerase chain reaction and Western blot analyses. Cell apoptosis, proliferation, and migration were determined using flow cytometry, carboxyfluorescein succinimidyl ester staining, and scratch assay, respectively. Immunofluorescence staining was conducted to examine TNKS2 and ß-catenin expression levels in the two transfected cell lines and the non-transfected cells. RESULTS: TNKS2 mRNA and protein expression was significantly higher in the highly malignant NCI-H647 cells, while it remained at a low level in the less malignant A549 cells. Lentivirus-mediated overexpression of TNKS2 in A549 cells resulted in a 3-fold increase in gene expression and a 1.7-fold increase in protein expression (P < 0.01). Conversely, shRNA interference targeting TNKS2 Led to an 8-fold decrease in gene expression and a 3-fold decrease in protein expression (P < 0.01) in NCI-H647 cells. Furthermore, the cell apoptosis rate was significantly reduced (50%) and cell migration rate was increased (35%) in the TNKS2 overexpression group than in the control group (P < 0.05). In contrast, shTNKS2 promoted apoptosis by more than one fold and reduced migration by 60% (P < 0.05). Immunofluorescence analysis revealed enhanced nuclear localization of ß-catenin fluorescence signal associated with high TNKS2 expression levels. Western blot analysis investigating TNKS2/ß-catenin-related proteins indicated consistent changes between TNKS2 and ß-catenin expression in lung cancer cells, whereas Axin displayed an opposite trend (P < 0.05). CONCLUSION: The obtained results revealed that TNKS2 may serve as an adverse prognostic factor and a potential therapeutic target in NSCLC.

Functional characterization of a geranylgeranyl diphosphate synthase in the leaf beetle Monolepta hieroglyphica.

Geranylgeranyl diphosphate synthase (GGPPS) as the short-chain prenyltransferases for catalyzing the formation of the acyclic precursor (E)-GGPP has been extensively investigated in mammals, plants, and microbes, but its functional plasticity is poorly understood in insect species. Here, a single GGPPS in leaf beetle Monolepta hieroglyphica, MhieGGPPS, was functionally investigated. Phylogenetic analysis showed that MhieGGPPS was clustered in one clade with homologs and had six conserved motifs. Molecular docking results indicated that binding sites of dimethylallyl diphosphate (DMAPP), (E)-geranyl pyrophosphate (GPP), and (E)-farnesyl pyrophosphate (FPP) were in the chain-length determination region of MhieGGPPS, respectively. In vitro, recombiant MhieGGPPS could catalyze the formation of (E)-geranylgeraniol against different combinations of substrates including isopentenyl pyrophosphate (IPP)/DMAPP, IPP/(E)-GPP, and IPP/(E)-FPP, suggesting that MhieGGPPS could not only use (E)-FPP but also (E)-GPP and DMAPP as the allylic cosubstrates. In kinetic analysis, the (E)-FPP was most tightly bound to MhieGGPPS than that of others. It was proposed that MhieGGPPS as a multifunctional enzyme is differentiated from the other GGPPSs in the animals and plants, which only accepted (E)-FPP as the allylic cosubstrate. These findings provide valuable insights into understanding the functional plasticity of GGPPS in M. hieroglyphica and the novel biosynthesis mechanism in the isoprenoid pathway.

n-octyl acrylate is a candidate sex pheromone component involved in courtship in parasitoid wasp Microplitis mediator.

Sex pheromones are considered to play critical roles in partner communication of most parasitic Hymenoptera. However, the identification of sex pheromone components remains limited to a few families of parasitoid wasps. In this study, we functionally characterized a candidate sex pheromone component in Microplitis mediator (Hymenoptera: Braconidae), a solitary parasitoid of Noctuidae insects. We found that the body surface extract from female wasps could significantly stimulate courtship behavior of males. Gas chromatography-electroantennographic detection (GC-EAD) analysis revealed that a candidate semiochemical from extract triggered significant electrophysiological response of antennae of males. By performing gas chromatography-mass spectrometer (GC-MS) measurement, GC-EAD active compound was identified as n-octyl acrylate, a candidate sex pheromone component in female M. mediator. In electroantennogram (EAG) tests, antennae of male wasps showed significantly higher electrophysiological responses to n-octyl acrylate than those of females. Y-tube olfactometer assays indicated that male wasps significantly chose n-octyl acrylate compared with the control. Furthermore, male wasps showed a remarkable preference for n-octyl acrylate in a simulated field condition behavioral trial; simultaneously, n-octyl acrylate standard could also trigger significant courtship behavior in males. We propose that n-octyl acrylate, as a candidate vital sex pheromone component, could be utilized to design behavioral regulators of M. mediator to implement the protection and utilization of natural enemies.

Genome-wide identification and analysis of a cotton secretome reveals its role in resistance against Verticillium dahliae.

BACKGROUND: The extracellular space between the cell wall and plasma membrane is a battlefield in plant-pathogen interactions. Within this space, the pathogen employs its secretome to attack the host in a variety of ways, including immunity manipulation. However, the role of the plant secretome is rarely studied for its role in disease resistance. RESULTS: Here, we examined the secretome of Verticillium wilt-resistant Gossypium hirsutum cultivar Zhongzhimian No.2 (ZZM2, encoding 95,327 predicted coding sequences) to determine its role in disease resistance against the wilt causal agent, Verticillium dahliae. Bioinformatics-driven analyses showed that the ZZM2 genome encodes 2085 secreted proteins and that these display disequilibrium in their distribution among the chromosomes. The cotton secretome displayed differences in the abundance of certain amino acid residues as compared to the remaining encoded proteins due to the localization of these putative proteins in the extracellular space. The secretome analysis revealed conservation for an allotetraploid genome, which nevertheless exhibited variation among orthologs and comparable unique genes between the two sub-genomes. Secretome annotation strongly suggested its involvement in extracellular stress responses (hydrolase activity, oxidoreductase activity, and extracellular region, etc.), thus contributing to resistance against the V. dahliae infection. Furthermore, the defense response genes (immunity marker NbHIN1, salicylic acid marker NbPR1, and jasmonic acid marker NbLOX4) were activated to varying degrees when Nicotina benthamiana leaves were agro-infiltrated with 28 randomly selected members, suggesting that the secretome plays an important role in the immunity response. Finally, gene silencing assays of 11 members from 13 selected candidates in ZZM2 displayed higher susceptibility to V. dahliae, suggesting that the secretome members confer the Verticillium wilt resistance in cotton. CONCLUSIONS: Our data demonstrate that the cotton secretome plays an important role in Verticillium wilt resistance, facilitating the development of the resistance gene markers and increasing the understanding of the mechanisms regulating disease resistance.

Pan-genome of Citrullus genus highlights the extent of presence/absence variation during domestication and selection.

The rich genetic diversity in Citrullus lanatus and the other six species in the Citrullus genus provides important sources in watermelon breeding. Here, we present the Citrullus genus pan-genome based on the 400 Citrullus genus resequencing data, showing that 477 Mb contigs and 6249 protein-coding genes were absent in the Citrullus lanatus reference genome. In the Citrullus genus pan-genome, there are a total of 8795 (30.5%) genes that exhibit presence/absence variations (PAVs). Presence/absence variation (PAV) analysis showed that a lot of gene PAV were selected during the domestication and improvement, such as 53 favorable genes and 40 unfavorable genes were identified during the C. mucosospermus to C. lanatus landrace domestication. We also identified 661 resistance gene analogs (RGAs) in the Citrullus genus pan-genome, which contains 90 RGAs (89 variable and 1 core gene) located on the pangenome additional contigs. By gene PAV-based GWAS, 8 gene presence/absence variations were found associated with flesh color. Finally, based on the results of gene PAV selection analysis between watermelon populations with different fruit colors, we identified four non-reference candidate genes associated with carotenoid accumulation, which had a significantly higher frequency in the white flesh. These results will provide an important source for watermelon breeding.

[Progress on the researches of acupuncture preconditioning before surgery].

This paper reviews the researches on acupuncture preconditioning before surgery in recent years and explores its application value from three aspects, i.e. relieving preoperative anxiety, preventing from postoperative cognitive dysfunction, and preventing from postoperative gastrointestinal dysfunction. As a relatively safe non-drug treatment, acupuncture has the underlying advantages in participating into multidisciplinary coordination in the enhanced recovery after surgery (ERAS). By building up higher-quality medical evidences and revealing the effect mechanism of acupuncture from multi-dimenisonal aspects, it is expected that acupuncture technology can be coordinated with ERAS to optimize the clinical path in the perioperative period, and boost the development of the perioperative medicine ultimately.

Effects of the Extraction Solvents on Dissolution Rate and Antioxidant Capacity of Auricularia auricula (Agaricomycetes) Polysaccharides In Vitro and In Vivo.

This paper reports the effects of solvents on the dissolution rate and antioxidant capacity of Auricularia auricula polysaccharides (AAPs). The ultra-low temperature combined with microwave extraction (UME) was used to compare the dissolution rates and molecular weights of AAPs using deionized water and deep eutectic solvents (DES) as solvents, respectively. Scanning electron microscope (SEM) was used to observe the effects of water extract (AAPs-FW) and DES extract (AAPs-FD) on the cell wall of A. auricula. The antioxidant capacity of polysaccharide extracts in vitro was assessed by using various methods (DPPH, ABTS, and hydroxyl radicals). In addition, in vivo oxidative stress was assessed using Caenorhabditis elegans models. The extract yield of AAPs varied among the extracts and was 19.58% ± 0.56% in AAPs-FW. Whereas DES-UME increased the yield of polysaccharides (AAPs-FD) by 9.81% in the extraction medium containing triethylene glycol-choline chloride, under the optimum conditions of 60 min freezing time, 350 W, and 90 s microwave time. The microstructure of the cell wall shown by SEM was consistent with the results of polysaccharide yields. The molecular weights of AAPs-FW and AAPs-FD were found to be 398.107 kDa and 89.099 kDa, respectively. The results demonstrated that AAPs-FD exhibited potent radical scavenging activity against DPPH and a weaker scavenging ability for ABTS and OH radicals compared to AAPs-FW. In addition, both polysaccharide extracts increased the survival rate of C. elegans under methyl viologen induced oxidative stress at specific concentrations (p < 0.05), and the antioxidant capacity of AAPs-FD was higher than that of AAPs-FW at low concentrations (0.125 mg/mL). This indicated that both polysaccharides had a protective effect against damage induced by intracellular free radical generators (methyl viologen).

Methimazole and sodium perchlorate exert anti-thyroidal effects in the T3-induced Xenopus laevis metamorphosis assay: A rapid assay for screening thyroid disrupting chemicals.

Thyroid disrupting chemicals (TDCs) have received much attention due to their potential adverse effects on animal and human health, which calls for rapid screen assays to identify them. The triiodothyronine (T3)-induced Xenopus metamorphosis assay (TiXMA) we developed previously has been successfully applied to the detection of the TDCs disrupting thyroid hormone (TH) signaling. Here, we attempted to expand the application of the TiXMA to the screening of the TDCs interfering with the hypothalamic-pituitary-thyroid (HPT) axis. Two well-known TH synthesis inhibitors methimazole (MMI) and sodium perchlorate (SP) were employed to test the sensitivity of the TiXMA to the TDCs interfering with the HPT axis. As expected, we observed that the two chemicals concentration-dependently antagonized T3-induced morphological changes and body weight reduction of X. laevis tadpoles following 96 h-exposure, in parallel with blocked thyroid development and down-regulated tshß expression in the brain. All the data show that both MMI and SP exert inhibitory effects on T3-induced metamorphosis, indicating that the TiXMA is capable of screening the TDCs interfering with the HPT axis. In comparison with Amphibian Metamorphosis Assay (AMA), a 21-day assay for screening the TDCs interfering with the HPT axis, the TiXMA has a remarkable advantage of shorter exposure duration (96 h).

Risk factors combine in a complex manner in assessment for macrosomia.

BACKGROUND: Macrosomia is a serious public health concern. This study aimed to examine the combined effects of various risk factors on macrosomia. METHODS: The China Labor and Delivery Survey was a multicenter cross-sectional study that included 96 hospitals. Logistic regression analysis was performed to examine the combined effects of the risk factors for macrosomia. The population attributable risk percentage (PAR%) was calculated for the risk factors. RESULTS: A total of 64,735 live births, including 3,739 neonates with macrosomia, were used for the analysis. The weighted prevalence of macrosomia was 5.8%. Pre-pregnancy overweight/obesity, diabetes, and gestational hypertension have a synergistic effect on increasing the rate of macrosomia in mothers aged < 36 years. The highest odds ratio (36.15, 95% CI: 34.38-38.02) was observed in female fetuses whose mothers had both gestational hypertension and diabetes. However, in mothers aged ≥ 36 years, the synergistic effect of gestational hypertension and other factors did not exist, and the risk for macrosomia was reduced by 70% in female fetuses of mothers with both gestational hypertension and overweight/obesity. Pre-pregnancy risk factors (pre-pregnancy overweight/obesity and advanced maternal age) contributed the most to macrosomia (23.36% of the PAR%), and the single largest risk factor was pre-pregnancy overweight/obesity (17.43% of the PAR%). CONCLUSION: Macrosomia was related to several common, modifiable risk factors. Some factors have combined effects on macrosomia (e.g., pre-pregnancy overweight/obesity and diabetes), whereas gestational hypertension varies by maternal age. Strategies based on pre-pregnancy risk factors should be given more attention to reduce the burden of macrosomia.

Multiple variation patterns of terpene synthases in 26 maize genomes.

Terpenoids are important compounds associated with the pest and herbivore resistance mechanisms of plants; consequently, it is essential to identify and explore terpene synthase (TPS) genes in maize. In the present study, we identified 31 TPS genes based on a pan-genome of 26 high-quality maize genomes containing 20 core genes (present in all 26 lines), seven dispensable genes (present in 2 to 23 lines), three near-core genes (present in 24 to 25 lines), and one private gene (present in only 1 line). Evaluation of ka/ks values of TPS in 26 varieties revealed that TPS25 was subjected to positive selection in some varieties. Six ZmTPS had ka/ks values less than 1, indicating that they were subjected to purifying selection. In 26 genomes, significant differences were observed in ZmTPS25 expression between genes affected by structural variation (SV) and those not affected by SV. In some varieties, SV altered the conserved structural domains resulting in a considerable number of atypical genes. The analysis of RNA-seq data of maize Ostrinia furnacalis feeding revealed 10 differentially expressed ZmTPS, 9 of which were core genes. However, many atypical genes for these responsive genes were identified in several genomes. These findings provide a novel resource for functional studies of ZmTPS.

Genome Resource for the Verticillium Wilt Resistant Gossypium hirsutum Cultivar Zhongzhimian No. 2.

Verticillium wilt, caused by the fungal pathogen Verticillium dahliae, is the major cause of disease-related yield losses in cotton (Gossypium hirsutum). Despite these losses, the major cultivars of G. hirsutum remain highly susceptible to Verticillium wilt. The lack of understanding on the genetic basis for Verticillium wilt resistance may further hinder progress in deploying elite cultivars with proven resistance, such as the wilt resistant G. hirsutum cultivar Zhongzhimian No. 2. To help remedy this knowledge gap, we sequenced the whole genome of Zhongzhimian No. 2 and assembled it from a combination of PacBio long reads, Illumina short reads, and high-throughput chromosome conformation capture technologies. The final assembly of the genome was 2.33 Gb, encoding 95,327 predicted coding sequences. The GC content was 34.39% with 99.2% of the bases anchored to 26 pseudo-chromosomes that ranged from 53.8 to 127.7 Mb. This resource will help gain a detailed understanding of the genomic features governing high yield and Verticillium wilt resistance in this cultivar. Comparative genomics will be particularly helpful, since there are several published genomes of other Gossypium species. [Formula: see text] Copyright © 2022 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.

A female-biased odorant receptor tuned to the lepidopteran sex pheromone in parasitoid Microplitis mediator guiding habitat of host insects.

INTRODUCTION: The parasitoid wasp Microplitis mediator is an important natural enemy of the turnip moth Agrotis segetum and other Noctuidae pests. In our field observation, it was fortuitously discovered that sex pheromone traps used for A. segetum also attract female wasps, verified by a simulated field condition dual-choice laboratory assay. Therefore, it was hypothesized that olfactory recognition could be crucial in this process. In this regard, a female-biased odorant receptor of the wasp, MmedOR49, attracted our attention. OBJECTIVES: To unravel the significance of the female-biased MmedOR49 regulating host pheromone recognition. METHODS: Expression analysis (fluorescence in situ hybridization; quantitative realtime PCR), in vitro (two-electrode voltage-clamp recordings) and in vivo (RNAi combined with behavioral assessments) functional studies, and bioinformatics (structural modeling and molecular docking) were carried out to investigate the characteristics of MmedOR49. RESULTS: MmedOR49 expression was detected in the antennae of females by FISH. Quantification indicated that the expression level of MmedOR49 increased significantly after adult emergence. In vitro functional study revealed that MmedOR49 was specifically tuned to cis-5-decenyl acetate (Z5-10:Ac), the major sex pheromone component of A. segetum. Molecular docking showed that Z5-10:Ac strongly bound to the key amino acid residues His 80, Ile 81, and Arg 84 of MmedOR49 through hydrogen bonding. Behavioral assays indicated that female wasps were significantly attracted by Z5-10:Ac in a three-cage olfactometer. RNAi targeting further confirmed that MmedOR49 was necessary to recognize Z5-10:Ac, as female wasps lost their original behavioral responses to Z5-10:Ac after down-regulation of the MmedOR49 transcript. CONCLUSION: Although M. mediator is a larval endoparasitoid, female wasps have a behavioral preference for a sex pheromone component of lepidopteran hosts. In this behavior, for female M. mediator, MmedOR49 plays an important role in guiding the habitat of host insects. These data provide a potential target for enhancing natural enemy utilization and pest control.

Preference and performance of the green peach aphid, Myzus persicae on three Brassicaceae vegetable plants and its association with amino acids and glucosinolates.

The green peach aphid, Myzus persicae (Sulzer) is a generalist pest of various host plants, whose feeding preference and growth performance mainly depends on the quantity and quality of nutrients and defensive metabolites in host plants. Here, we studied the preference and performance of M. persicae on three major Brassicaceae vegetables in China and measured nutrient (amino acids) and defensive metabolites (glucosinolates) in these plants. We found that M. persicae preferred and performed better on Chinese cabbage than cabbage and radish, which may be due to the relatively higher concentration of amino acids and lower levels of indole glucosinolates in their leaves. The glucosinolates level in cabbage leaves was ten times higher than the other two plants, while the amino acid concentration in radish was only half of the cabbage or Chinese cabbage. The higher concentration of indole glucosinolates in cabbage and lower levels of amino acids in radish may account for the poorer preference and growth of M. persicae on these two plants. These results suggest that both amino acids and glucosinolates in plants may play important roles in the preference and performance of M. persicae, which provide new knowledge for the cultivation and breeding of Brassicaceae vegetables.

Plant volatile compound methyl benzoate is highly effective against Spodoptera frugiperda and safe to non-target organisms as an eco-friendly botanical-insecticide.

Recent studies have indicated that the plant volatile methyl benzoate (MB) exhibits significant insecticidal bioactivity against several common insects. However, the potential environmental hazards of MB and its safety to non-target organisms is poorly understood. In the present study, these characteristics were investigated through laboratory experiments and field investigations. The results revealed that MB was highly toxic to the agricultural pest, fall armyworm Spodoptera frugiperda. Compared with the commercial pesticide lambda-cyhalothrin, the toxicities of MB against S. frugiperda larvae and adults were comparable and 3.41 times higher, respectively. Behavioral bioassays showed that the percentage repellency of MB to S. frugiperda larvae was 56.72 %, and MB induced 69.40 % oviposition deterrence rate in S. frugiperda female adults. Furthermore, in terms of median lethal concentration (LC50) and median lethal doses (LD50), MB exhibited non-toxic effects on non-target animals with 3-d LC50 of > 1 % to natural predators (Coccinella septempunctata and Harmonia axyridis), 3-d LD50 of 467.86 µg/bee to the bumblebee Bombus terrestris, 14-d LC50 of 971.09 mg/kg to the earthworm Eisenia fetida, and 4-d LC50 of 47.30 mg/L to the zebrafish Brachydanio rerio. The accumulation of MB in the soil and earthworms was found to be extremely limited. Our comparative study clearly demonstrated that MB is effective as a selective botanical pesticide against S. frugiperda and it is safe to use in the tested environment, with no toxic effects on non-target animals and natural predators.

The main component of the aphid alarm pheromone (E)-ß-farnesene affects the growth and development of Spodoptera exigua by mediating juvenile hormone-related genes.

The (E)-ß-farnesene (EßF) is one of the most important secondary metabolites in some plants and provides indirect defense against aphids. However, the direct effect of EßF against pests is still unclear. In this study, various concentrations of EßF (0.16, 0.8, and 4 g/kg) were provided in an artificial diet to determine the direct effects of EßF on Spodoptera exigua. The results showed that an artificial diet containing 4 g/kg of EßF reduced the final survival of the S. exigua larvae and per female fecundity of adults significantly when compared with CK and SC controls (p < 0.05), then ultimately it also significantly affected the intrinsic rate of increase (p < 0.05). Furthermore, the results of the EßF bioassay in an artificial diet also indicated that the proliferation of the S. exigua population was inhibited by the ingestion of EßF in a dose-dependent manner. Combined differential RNA-seq data and RT-qPCR analysis, it was found that four key genes involved in juvenile hormone degradation significantly upregulated in S. exigua larvae treated by EßF at a dose of 0.8 and 4 g/kg when compared with two controls (p < 0.05). This indicated that EßF could disturb the normal function of juvenile hormones and reduce the survival rate of S. exigua larvae. Additionally, two key genes that regulate per fecundity of S. exigua females, including SeVg and SeVgR, were significantly downregulated in adult females (p < 0.05) when they were treated with 0.8 and 4 g/kg of EßF at the larval stage, relative to the expression of these genes after treatment with controls. These findings suggested that EßF first disturbed the normal function of juvenile hormone by upregulating key degradation genes, and then inhibited the expression of SeVg/SeVgR genes and proteins, thus reducing the population size of S. exigua by increasing larval mortality and inhibiting per female fecundity.

Terpene Synthases in Rice Pan-Genome and Their Responses to Chilo suppressalis Larvae Infesting.

Terpene synthase (TPS) catalyzes the synthesis of terpenes and plays an important role in plant defense. This study identified 45 OsTPS genes (32 core genes and 13 variable genes) based on the high-quality rice gene-based pan-genome. This indicates limitations in OsTPS gene studies based on a single reference genome. In the present study, through collinearity between multiple rice genomes, one OsTPS gene absent in the reference (Nipponbare) genome was found and two TPS genes in the reference genome were found to have atypical structures, which would have been ignored in single genome analysis. OsTPS genes were divided into five groups and TPS-b was lost according to the phylogenetic tree. OsTPSs in TPS-c and TPS-g were all core genes indicating these two groups were stable during domestication. In addition, through the analysis of transcriptome data, some structural variations were found to affect the expression of OsTPS genes. Through the Ka/Ks calculation of OsTPS genes, we found that different OsTPS genes were under different selection pressure during domestication; for example, OsTPS22 and OsTPS29 experienced stronger positive selection than the other OsTPS genes. After Chilo suppressalis larvae infesting, 25 differentially expressed OsTPS genes were identified, which are involved in the diterpene phytoalexins precursors biosynthesis and ent-kaurene biosynthesis pathways. Overall, the present study conducted a bioinformatics analysis of OsTPS genes using a high-quality rice pan-genome, which provided a basis for further study of OsTPS genes.

Pan-Genome Analysis Reveals the Abundant Gene Presence/Absence Variations Among Different Varieties of Melon and Their Influence on Traits.

Melon (Cucumismelo L.) is an important vegetable crop that has been subjected to domestication and improvement. Several varieties of melons with diverse phenotypes have been produced. In this study, we constructed a melon pan-genome based on 297 accessions comprising 168 Mb novel sequences and 4,325 novel genes. Based on the results, there were abundant genetic variations among different melon groups, including 364 unfavorable genes in the IMP_A vs. LDR_A group, 46 favorable genes, and 295 unfavorable genes in the IMP_M vs. LDR_M group. The distribution of 709 resistance gene analogs (RGAs) was also characterized across 297 melon lines, of which 603 were core genes. Further, 106 genes were found to be variable, 55 of which were absent in the reference melon genome. Using gene presence/absence variation (PAV)-based genome-wide association analysis (GWAS), 13 gene PAVs associated with fruit length, fruit shape, and fruit width were identified, four of which were located in pan-genome additional contigs.