Terminal drought is one of the major constraints to crop production in chickpea (Cicer arietinum L.). In order to map drought tolerance related traits at high resolution, we sequenced multi-parent advanced generation intercross (MAGIC) population using whole genome resequencing approach and phenotyped it under drought stress environments for two consecutive years (2013-14 and 2014-15). A total of 52.02 billion clean reads containing 4.67 TB clean data were generated on the 1136 MAGIC lines and eight parental lines. Alignment of clean data on to the reference genome enabled identification of a total, 932,172 of SNPs, 35,973 insertions, and 35,726 deletions among the parental lines. A high-density genetic map was constructed using 57,180 SNPs spanning a map distance of 1606.69 cM. Using compressed mixed linear model, genome-wide association study (GWAS) enabled us to identify 737 markers significantly associated with days to 50% flowering, days to maturity, plant height, 100 seed weight, biomass, and harvest index. In addition to the GWAS approach, an identity-by-descent (IBD)-based mixed model approach was used to map quantitative trait loci (QTLs). The IBD-based mixed model approach detected major QTLs that were comparable to those from the GWAS analysis as well as some exclusive QTLs with smaller effects. The candidate genes like FRIGIDA and CaTIFY4b can be used for enhancing drought tolerance in chickpea. The genomic resources, genetic map, marker-trait associations, and QTLs identified in the study are valuable resources for the chickpea community for developing climate resilient chickpeas.

Lung adenocarcinoma (LUAD) usually contains heterogeneous histological subtypes, among which the micropapillary (MIP) subtype was associated with poor prognosis while the lepidic (LEP) subtype possessed the most favorable outcome. However, the genomic features of the MIP subtype responsible for its malignant behaviors are substantially unknown. In this study, eight FFPE samples from LUAD patients were micro-dissected to isolate MIP and LEP components, then sequenced by whole-exome sequencing. More comprehensive analyses involving our samples and public validation cohorts on the two subtypes were performed to better decipher the key biological and evolutionary mechanisms. As expected, the LEP and MIP subtypes exhibited the largest disease-free survival (DFS) differences in our patients. EGFR was found with the highest mutation frequency. Additionally, shared mutations were observed between paired LEP and MIP components from single patients, and recurrent mutations were verified in the Lung-Broad, Lung-OncoSG, and TCGA-LUAD cohorts. Distinct biological processes or pathways were involved in the evolution of the two components. Besides, analyses of copy number variation (CNV) and intratumor heterogeneity (ITH) further discovered the possible immunosurveillance escape, the discrepancy between mutation and CNV level, ITH, and the pervasive DNA damage response and WNT pathway gene alternations in the MIP component. Phylogenetic analysis of five pairs of LEP and MIP components further confirmed the presence of ancestral EGFR mutations. Through comprehensive analyses combining our samples and public cohorts, PTP4A3, NAPRT, and RECQL4 were identified to be co-amplified. Multi-omics data also demonstrated the immunosuppression prevalence in the MIP component. Our results uncovered the evolutionary pattern of the concomitant LEP and MIP components from the same patient that they were derived from the same initiation cells and the pathway-specific mutations acquired after EGFR clonal mutation could shape the subtype-specificity. We also confirmed the immunosuppression prevalence in the MIP subtype by multi-omics data analyses, which may have resulted in its unfavorable prognosis.

Objective:. The genomic landscapes of metastatic colorectal cancer (mCRC) have been extensively studied; however, the genetic mechanisms underlying the locoregional recurrence (LR) of CRC remain unclear. The objective of our study was to investigate genomic evolution during LR in CRC using high-throughput sequencing. Methods:. Twenty-three CRC patients with matched primary and LR tissues were recruited from Nanfang Hospital and Zhejiang Cancer Hospital between January 2011 and December 2018. The last date of follow-up was March 2020. Tissue samples were analyzed by whole-exome sequencing and the genomic profiles were depicted by single nucleotide variation, mutational signature, copy number variation, clonal architecture, and other features. The evolutionary process was speculated with comparison of the genetic variations between primary and LR lesions. The disseminating clusters from primary to LR lesions were identified by variant allele frequency dynamics. Furthermore, the early-recurrent biomarker was explored by comparing the indel signature between early- and late-recurrent patients. The study was approved by the Institutional Review Board of Nanfang Hospital of Southern Medical University (approval No. 2020010) on September 11, 2020. Results:. The results highlighted distinct origins of LR between patients with high microsatellite instability and microsatellite stability. LR lesions evolved independently in patients with high microsatellite instability, while LR lesions were highly clonally related to the primary lesions in patients with microsatellite stability. Late-acquired variations in LR lesions encompassed a wide range of driver genes involved in histone methylation, DNA replication, T cell activation, PDCD1 gain, and LMNA loss. Furthermore, clonal analysis of the disseminating cells identified a dominant polyclonal seeding pattern during LR. The indel signature ID4 was associated with significantly shorter disease-free survival in patients with relapsed CRC according to a public dataset. Conclusion:. These findings pose a challenge for the development of new approaches targeting the interactions of multiple clones in the establishment of LR and in terms of optimizing the clinical management of susceptible patients.

Background: Lung adenocarcinoma (LUAD) usually contain heterogeneous histological subtypes, among which the micropapillary (MIP) subtype was associated with poor prognosis while the lepidic (LEP) subtype possessed the most favorable outcome. A more comprehensive analysis involving discovery and public validation cohorts on the two subtypes could better decipher the key biological and evolutionary mechanisms. Methods: We firstly retrospectively studied the survival status of 286 LUAD patients with different subtypes. MIP and LEP components were micro-dissected for whole-exome sequencing (WES). Shared and private alterations as well as genomic alternation characteristics between the two components were investigated. Four public cohorts containing LEP and MIP samples were further selected for genomic profile comparison, novel therapeutic target investigation and immune infiltration quantification. Results: LEP and MIP subtypes exhibited largest disease free survival (DFS) in our patients. A total of 2035 SNV and 2757 InDels were identified in the sequenced LEP and MIP components. EGFR was found with highest mutation frequency. Distinct biological processes or pathways were involved in the evolutionary of the two components. Besides, analyses on copy number variation (CNV) and intratumor heterogeneity further discovered the possible immunosurveillance escape, the discrepancy between mutation and CNV level ITH and the pervasive DNA Damage Response as well as WNT pathway gene alternations in MIP component. Phylogenetic analysis on 5 pairs of LEP and MIP components further confirmed the presence of ancestral EGFR mutations. Through comprehensive analysis in our samples and public cohorts, PTP4A3 , NAPRT and RECQL4 were identified as novel therapeutic and diagnostic targets in MIP subtype. Immunosuppression prevalence in MIP component was finally confirmed by multi-omics data. Conclusion: We identified genetic differences responsible for variated prognosis. The subtype evolution trajectory was additionally unraveled. Novel gene targets and the immunological analyses also provided therapeutic suggestions for MIP subtype.

Primary malignant melanoma of the esophagus (PMME) is a rare gastrointestinal melanoma with a high rate of recurrence and metastasis. The standard of care for PMME has not been established yet due to a lack of understanding of its clinical and molecular pathogenesis. Thus, we performed genomic profiling on a recurrent PMME case to seek novel opportunities for the management of this rare disease. Between 2013 and 2016, 6 tissue samples including 3 from the primary tumors, 2 from the relapsed tumors, and 1 from a normal control were collected from a patient diagnosed with PMME and were subjected to whole-exome sequencing to track the dynamic genetic changes. Additionally, we also analyzed a cohort of 398 samples obtained from the TCGA skin cutanesous melanoma (TCGA-SKCM) dataset to assess the frequency and determine the clinical implications of genomic events found in the presented study. ARHGAP35 (p.L1022M) was the only mutation shared across temporal PMME lesions. The PMME samples showed higher levels of genetic instability and intra-tumor heterogeneity. They also shared several concordant copy number variations (CNV). All lesions were concordant with the evolution trajectory, and shrinkage of the founding clone caused the subclonal population to become dominant in PT1c, which was likely the reason behind metastatic seeding. ARHGAP35 mutations were found in 6% of the TCGA-SKCM cohort samples. The presence of the mutations was associated with poor progression-free survival (PFS) by both univariate and multivariate Cox regression analyses. Our study showed that the primary tumor clone disseminates earlier in PMME. This highlights the need to understand the mechanism involved in the early PMME recurrence to optimize treatment.

Although eusociality evolved independently within several orders of insects, research into the molecular underpinnings of the transition towards social complexity has been confined primarily to Hymenoptera (for example, ants and bees). Here we sequence the genome and stage-specific transcriptomes of the dampwood termite Zootermopsis nevadensis (Blattodea) and compare them with similar data for eusocial Hymenoptera, to better identify commonalities and differences in achieving this significant transition. We show an expansion of genes related to male fertility, with upregulated gene expression in male reproductive individuals reflecting the profound differences in mating biology relative to the Hymenoptera. For several chemoreceptor families, we show divergent numbers of genes, which may correspond to the more claustral lifestyle of these termites. We also show similarities in the number and expression of genes related to caste determination mechanisms. Finally, patterns of DNA methylation and alternative splicing support a hypothesized epigenetic regulation of caste differentiation.

Bladder cancer is one of the most common cancers worldwide, with transitional cell carcinoma (TCC) being the predominant form. Here we report a genomic analysis of TCC by both whole-genome and whole-exome sequencing of 99 individuals with TCC. Beyond confirming recurrent mutations in genes previously identified as being mutated in TCC, we identified additional altered genes and pathways that were implicated in TCC. Notably, we discovered frequent alterations in STAG2 and ESPL1, two genes involved in the sister chromatid cohesion and segregation (SCCS) process. Furthermore, we also detected a recurrent fusion involving FGFR3 and TACC3, another component of SCCS, by transcriptome sequencing of 42 DNA-sequenced tumors. Overall, 32 of the 99 tumors (32%) harbored genetic alterations in the SCCS process. Our analysis provides evidence that genetic alterations affecting the SCCS process may be involved in bladder tumorigenesis and identifies a new therapeutic possibility for bladder cancer.