scholarly journals Chromosome-Level Genome Assembly Reveals Significant Gene Expansion in the Toll and IMD Signaling Pathways of Dendrolimus kikuchii

2021 ◽  
Vol 12 ◽  
Author(s):  
Jielong Zhou ◽  
Peifu Wu ◽  
Zhongping Xiong ◽  
Naiyong Liu ◽  
Ning Zhao ◽  
...  
Keyword(s):  
Genome Assembly ◽  
Phylogenetic Analyses ◽  
Repetitive Sequences ◽  
Gene Families ◽  
Thaumetopoea Pityocampa ◽  
High Quality ◽  
Protein Coding ◽  
Peptidoglycan Recognition Protein ◽  
Recognition Protein ◽  
Chromosome Level

A high-quality genome is of significant value when seeking to control forest pests such as Dendrolimus kikuchii, a destructive member of the order Lepidoptera that is widespread in China. Herein, a high quality, chromosome-level reference genome for D. kikuchii based on Nanopore, Pacbio HiFi sequencing and the Hi-C capture system is presented. Overall, a final genome assembly of 705.51 Mb with contig and scaffold N50 values of 20.89 and 24.73 Mb, respectively, was obtained. Of these contigs, 95.89% had unique locations on 29 chromosomes. In silico analysis revealed that the genome contained 15,323 protein-coding genes and 63.44% repetitive sequences. Phylogenetic analyses indicated that D. kikuchii may diverged from the common ancestor of Thaumetopoea. Pityocampa, Thaumetopoea ni, Heliothis virescens, Hyphantria armigera, Spodoptera frugiperda, and Spodoptera litura approximately 122.05 million years ago. Many gene families were expanded in the D. kikuchii genome, particularly those of the Toll and IMD signaling pathway, which included 10 genes in peptidoglycan recognition protein, 19 genes in MODSP, and 11 genes in Toll. The findings from this study will help to elucidate the mechanisms involved in protection of D. kikuchii against foreign substances and pathogens, and may highlight a potential channel to control this pest.

scholarly journals A high-quality chromosome-level genome assembly reveals genetics for important traits in eggplant

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Qingzhen Wei ◽  
Jinglei Wang ◽  
Wuhong Wang ◽  
Tianhua Hu ◽  
Haijiao Hu ◽  
...  
Keyword(s):  
Genome Assembly ◽  
Reference Genome ◽  
Repetitive Sequences ◽  
Gene Families ◽  
Specific Gene ◽  
High Quality ◽  
Total Size ◽  
Protein Coding ◽  
Fruit Length ◽  
Protein Coding Genes

Abstract Eggplant (Solanum melongena L.) is an economically important vegetable crop in the Solanaceae family, with extensive diversity among landraces and close relatives. Here, we report a high-quality reference genome for the eggplant inbred line HQ-1315 (S. melongena-HQ) using a combination of Illumina, Nanopore and 10X genomics sequencing technologies and Hi-C technology for genome assembly. The assembled genome has a total size of ~1.17 Gb and 12 chromosomes, with a contig N50 of 5.26 Mb, consisting of 36,582 protein-coding genes. Repetitive sequences comprise 70.09% (811.14 Mb) of the eggplant genome, most of which are long terminal repeat (LTR) retrotransposons (65.80%), followed by long interspersed nuclear elements (LINEs, 1.54%) and DNA transposons (0.85%). The S. melongena-HQ eggplant genome carries a total of 563 accession-specific gene families containing 1009 genes. In total, 73 expanded gene families (892 genes) and 34 contraction gene families (114 genes) were functionally annotated. Comparative analysis of different eggplant genomes identified three types of variations, including single-nucleotide polymorphisms (SNPs), insertions/deletions (indels) and structural variants (SVs). Asymmetric SV accumulation was found in potential regulatory regions of protein-coding genes among the different eggplant genomes. Furthermore, we performed QTL-seq for eggplant fruit length using the S. melongena-HQ reference genome and detected a QTL interval of 71.29–78.26 Mb on chromosome E03. The gene Smechr0301963, which belongs to the SUN gene family, is predicted to be a key candidate gene for eggplant fruit length regulation. Moreover, we anchored a total of 210 linkage markers associated with 71 traits to the eggplant chromosomes and finally obtained 26 QTL hotspots. The eggplant HQ-1315 genome assembly can be accessed at http://eggplant-hq.cn. In conclusion, the eggplant genome presented herein provides a global view of genomic divergence at the whole-genome level and powerful tools for the identification of candidate genes for important traits in eggplant.

scholarly journals A high-quality chromosome-level genome of wild Rosa rugosa

DNA Research ◽  
2021 ◽  
Vol 28 (5) ◽  
Author(s):  
Fengqi Zang ◽  
Yan Ma ◽  
Xiaolong Tu ◽  
Ping Huang ◽  
Qichao Wu ◽  
...  
Keyword(s):  
Prunus Persica ◽  
Phylogenetic Analyses ◽  
Repetitive Sequences ◽  
Duplication Event ◽  
Genome Sequences ◽  
Rosa Rugosa ◽  
High Quality ◽  
Genome Duplication Event ◽  
Protein Coding ◽  
Chromosome Level

Abstract Rosa rugosa is an important shrub with economic, ecological, and pharmaceutical value. A high-quality chromosome-scale genome for R. rugosa sequences was assembled using PacBio and Hi-C technologies. The final assembly genome sequences size was about 407.1 Mb, the contig N50 size was 2.85 Mb, and the scaffold N50 size was 56.6 Mb. More than 98% of the assembled genome sequences were anchored to seven pseudochromosomes (402.9 Mb). The genome contained 37,512 protein-coding genes, with 37,016 genes (98.68%) that were functionally annotated, and 206.67 Mb (50.76%) of the assembled sequences are repetitive sequences. Phylogenetic analyses indicated that R. rugosa diverged from Rosa chinensis ∼6.6 million years ago, and no lineage-specific whole-genome duplication event occurred after divergence from R. chinensis. Chromosome synteny analysis demonstrated highly conserved synteny between R. rugosa and R. chinensis, between R. rugosa and Prunus persica as well. Comparative genome and transcriptome analysis revealed genes related to colour, scent, and environment adaptation. The chromosome-level reference genome provides important genomic resources for molecular-assisted breeding and horticultural comparative genomics research.

scholarly journals Chromosome-level genome assembly of Scapharca kagoshimensis reveals the expanded molecular basis of heme biosynthesis in ark shell

2021 ◽  
Author(s):  
Teng Weiming ◽  
Xie Xi ◽  
Hongtao Nie ◽  
Yamin Sun ◽  
Liu Xiangfeng ◽  
...  
Keyword(s):  
Genome Assembly ◽  
Molecular Basis ◽  
Molecular Mechanisms ◽  
Heme Biosynthesis ◽  
High Quality ◽  
Protein Coding ◽  
Conserved Genes ◽  
Long Time ◽  
Muddy Sediments ◽  
Chromosome Level

Ark shells are commercially important clam species that inhabit in muddy sediments of shallow coasts in East Asia. For a long time, the lack of genome resources has hindered scientific research of ark shells. Here, we reported a high-quality chromosome-level genome assembly of Scapharca kagoshimensis, with an aim to unravel the molecular basis of heme biosynthesis, and develop genomic resources for genetic breeding and population genetics in ark shells. Nineteen scaffolds corresponding to 19 chromosomes were constructed from 938 contigs (contig N50=2.01 Mb) to produce a final high-quality assembly with a total length of 1.11 Gb and scaffold N50 around 60.64 Mb. The genome assembly represents 93.4% completeness via matching 303 eukaryota core conserved genes. A total of 24,908 protein-coding genes were predicted and 24,551 genes (98.56%) of which were functionally annotated. The enrichment analyses suggested that genes in heme biosynthesis pathways were expanded and positive selection of the hemoglobin genes was also found in the genome of S. kagoshimensis, which gives important insights into the molecular mechanisms and evolution of the heme biosynthesis in mollusca. The valuable genome assembly of S. kagoshimensis would provide a solid foundation for investigating the molecular mechanisms that underlie the diverse biological functions and evolutionary adaptations of S. kagoshimensis.

scholarly journals Chromosome-level genome assembly reveals the unique genome evolution of the swimming crab (Portunus trituberculatus)

GigaScience ◽  
2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Boping Tang ◽  
Daizhen Zhang ◽  
Haorong Li ◽  
Senhao Jiang ◽  
Huabin Zhang ◽  
...  
Keyword(s):  
Genome Assembly ◽  
Repetitive Sequences ◽  
Asia Pacific ◽  
Portunus Trituberculatus ◽  
Swimming Crab ◽  
Protein Coding ◽  
Eukaryotic Genes ◽  
Long Reads ◽  
Commercial Species ◽  
Chromosome Level

Abstract Background The swimming crab, Portunus trituberculatus, is an important commercial species in China and is widely distributed in the coastal waters of Asia-Pacific countries. Despite increasing interest in swimming crab research, a high-quality chromosome-level genome is still lacking. Findings Here, we assembled the first chromosome-level reference genome of P. trituberculatus by combining the short reads, Nanopore long reads, and Hi-C data. The genome assembly size was 1.00 Gb with a contig N50 length of 4.12 Mb. In addition, BUSCO assessment indicated that 94.7% of core eukaryotic genes were present in the genome assembly. Approximately 54.52% of the genome was identified as repetitive sequences, with a total of 16,796 annotated protein-coding genes. In addition, we anchored contigs into chromosomes and identified 50 chromosomes with an N50 length of 21.80 Mb by Hi-C technology. Conclusions We anticipate that this chromosome-level assembly of the P. trituberculatus genome will not only promote study of basic development and evolution but also provide important resources for swimming crab reproduction.

scholarly journals A high-quality genome assembly for the endangered golden snub-nosed monkey (Rhinopithecus roxellana)

GigaScience ◽  
2019 ◽  
Vol 8 (8) ◽  
Author(s):  
Lu Wang ◽  
Jinwei Wu ◽  
Xiaomei Liu ◽  
Dandan Di ◽  
Yuhong Liang ◽  
...  
Keyword(s):  
Single Molecule ◽  
Genome Assembly ◽  
Gene Families ◽  
Rhinopithecus Roxellana ◽  
High Quality ◽  
Chromosome Conformation ◽  
Protein Coding ◽  
A Genome ◽  
Close Relationship ◽  
High Quality Genome

Abstract Background The golden snub-nosed monkey (Rhinopithecus roxellana) is an endangered colobine species endemic to China, which has several distinct traits including a unique social structure. Although a genome assembly for R. roxellana is available, it is incomplete and fragmented because it was constructed using short-read sequencing technology. Thus, important information such as genome structural variation and repeat sequences may be absent. Findings To obtain a high-quality chromosomal assembly for R. roxellana qinlingensis, we used 5 methods: Pacific Bioscience single-molecule real-time sequencing, Illumina paired-end sequencing, BioNano optical maps, 10X Genomics link-reads, and high-throughput chromosome conformation capture. The assembled genome was ∼3.04 Gb, with a contig N50 of 5.72 Mb and a scaffold N50 of 144.56 Mb. This represented a 100-fold improvement over the previously published genome. In the new genome, 22,497 protein-coding genes were predicted, of which 22,053 were functionally annotated. Gene family analysis showed that 993 and 2,745 gene families were expanded and contracted, respectively. The reconstructed phylogeny recovered a close relationship between R. rollexana and Macaca mulatta, and these 2 species diverged ∼13.4 million years ago. Conclusion We constructed a high-quality genome assembly of the Qinling golden snub-nosed monkey; it had superior continuity and accuracy, which might be useful for future genetic studies in this species and as a new standard reference genome for colobine primates. In addition, the updated genome assembly might improve our understanding of this species and could assist conservation efforts.

scholarly journals Chromosome-Level Genome Assembly and Annotation of a Sciaenid Fish, Argyrosomus japonicus

2021 ◽  
Vol 13 (2) ◽  
Author(s):  
Linlin Zhao ◽  
Shengyong Xu ◽  
Zhiqiang Han ◽  
Qi Liu ◽  
Wensi Ke ◽  
...  
Keyword(s):  
Genome Assembly ◽  
Wide Distribution ◽  
High Quality ◽  
Protein Coding ◽  
Repeat Elements ◽  
Long Reads ◽  
The Family ◽  
Solid Foundation ◽  
Genomic Resource ◽  
Chromosome Level

Abstract Argyrosomus japonicus is an economically and ecologically important fish species in the family Sciaenidae with a wide distribution in the world’s oceans. Here, we report a high-quality, chromosome-level genome assembly of A. japonicus based on PacBio and Hi-C sequencing technology. A 673.7-Mb genome containing 282 contigs with an N50 length of 18.4 Mb was obtained based on PacBio long reads. These contigs were further ordered and clustered into 24 chromosome groups based on Hi-C data. In addition, a total of 217.2 Mb (32.24% of the assembled genome) of sequences were identified as repeat elements, and 23,730 protein-coding genes were predicted based on multiple approaches. More than 97% of BUSCO genes were identified in the A. japonicus genome. The high-quality genome assembled in this work not only provides a valuable genomic resource for future population genetics, conservation biology and selective breeding studies of A. japonicus but also lays a solid foundation for the study of Sciaenidae evolution.

scholarly journals Chromosome-level genome assembly of Zizania latifolia provides insights into its seed shattering and phytocassane biosynthesis

2022 ◽  
Vol 5 (1) ◽  
Author(s):  
Ning Yan ◽  
Ting Yang ◽  
Xiu-Ting Yu ◽  
Lian-Guang Shang ◽  
De-Ping Guo ◽  
...  
Keyword(s):  
Genome Assembly ◽  
Wild Rice ◽  
Phylogenetic Analyses ◽  
Repetitive Sequences ◽  
Divergence Time ◽  
Close Relation ◽  
Abscission Layer ◽  
Zizania Latifolia ◽  
Seed Shattering ◽  
Chromosome Level

AbstractChinese wild rice (Zizania latifolia; family: Gramineae) is a valuable medicinal homologous grain in East and Southeast Asia. Here, using Nanopore sequencing and Hi-C scaffolding, we generated a 547.38 Mb chromosome-level genome assembly comprising 332 contigs and 164 scaffolds (contig N50 = 4.48 Mb; scaffold N50 = 32.79 Mb). The genome harbors 38,852 genes, with 52.89% of the genome comprising repetitive sequences. Phylogenetic analyses revealed close relation of Z. latifolia to Leersia perrieri and Oryza species, with a divergence time of 19.7–31.0 million years. Collinearity and transcriptome analyses revealed candidate genes related to seed shattering, providing basic information on abscission layer formation and degradation in Z. latifolia. Moreover, two genomic blocks in the Z. latifolia genome showed good synteny with the rice phytocassane biosynthetic gene cluster. The updated genome will support future studies on the genetic improvement of Chinese wild rice and comparative analyses between Z. latifolia and other plants.

scholarly journals High-quality genome assembly, annotation and evolutionary analysis of the mungbean (Vigna radiata) genome

2020 ◽  
Author(s):  
Qiang Yan ◽  
Qiong Wang ◽  
Cheng Xuzhen ◽  
Lixia Wang ◽  
Prakit Somta ◽  
...  
Keyword(s):  
Genome Assembly ◽  
Vigna Radiata ◽  
Crop Improvement ◽  
Repetitive Sequences ◽  
Gene Families ◽  
Close Relative ◽  
Specific Gene ◽  
Evolutionary Analysis ◽  
High Quality ◽  
High Quality Genome

Mungbean (Vigna radiata [L.]) is an important economic crop grown in South, and East Asia. The low contiguity of the current assembly of V. radiata genome has limited its application. Here, we report a high-quality chromosome-scale assembled genome of V. radiata to facilitate the investigation of its genome characteristics and evolution. By combination of Nanopore long reads, Illumina short reads and Hi-C data, we generated a high-quality genome assembly of V. radiata, with 473.67 megabases assembled into 11 chromosomes with contig N50 and scaffold N50 of 11.3 and 42.4 megabases, respectively. A total of 52.8% of the genome was annotated as repetitive sequences, among which LTRs (long terminal repeats) were predominant (33.9%). The genome of V. radiata was predicted to contain 33,924 genes, 32,470 (95.7%) of which could be functionally annotated. Evolutionary analysis revealed an estimated divergence time of V. radiata from its close relative V. angularis of ~11.66 million years ago. In addition, 277 V. radiata specific gene families, 18 positively selected genes were detected and functionally annotated. This high-quality mungbean genome will provide valuable resources for further genetic analysis and crop improvement of mungbean and other legume species.

scholarly journals The chromosomal-level genome assembly and comprehensive transcriptomes of Chinese razor clam (Sinonovacula constricta) with deep-burrowing life style and broad-range salinity adaptation

2019 ◽  
Author(s):  
Yinghui Dong ◽  
Qifan Zeng ◽  
Jianfeng Ren ◽  
Hanhan Yao ◽  
Wenbin Ruan ◽  
...  
Keyword(s):  
Genome Assembly ◽  
Developmental Stages ◽  
De Novo ◽  
Gene Families ◽  
Sequencing Data ◽  
High Quality ◽  
Protein Coding ◽  
Sinonovacula Constricta ◽  
Razor Clam ◽  
Genomic Resources

AbstractBackgroundThe Chinese razor clam, Sinonovacula constricta, is one of the commercially important marine bivalves with deep-burrowing lifestyle and remarkable adaptability of broad-range salinity. Despite its economic impact and representative of the less-understood deep-burrowing bivalve lifestyle, there are few genomic resources for exploring its unique biology and adaptive evolution. Herein, we reported a high-quality chromosomal-level reference genome of S. constricta, the first genome of the family Solenidae, along with a large amount of short-read/full-length transcriptomic data of whole-ontogeny developmental stages, all major adult tissues, and gill tissues under salinity challenge.FindingsA total of 101.79 Gb and 129.73 Gb sequencing data were obtained with the PacBio and Illumina platforms, which represented approximately 186.63X genome coverage. In addition, a total of 160.90 Gb and 24.55 Gb clean data were also obtained with the Illumina and PacBio platforms for transcriptomic investigation. A de novo genome assembly of 1,340.13 Mb was generated, with a contig N50 of 689.18 kb. Hi-C scaffolding resulted in 19 chromosomes with a scaffold N50 of 57.99 Mb. The repeat sequences account for 50.71% of the assembled genome. A total of 26,273 protein-coding genes were predicted and 99.5% of them were annotated. Phylogenetic analysis revealed that S. constricta diverged from the lineage of Pteriomorphia at approximately 494 million years ago. Notably, cytoskeletal protein tubulin and motor protein dynein gene families are rapidly expanded in the S. constricta genome and are highly expressed in the mantle and gill, implicating potential genomic bases for the well-developed ciliary system in the S. constricta.ConclusionsThe high-quality genome assembly and comprehensive transcriptomes generated in this work not only provides highly valuable genomic resources for future studies of S. constricta, but also lays a solid foundation for further investigation into the adaptive mechanisms of benthic burrowing mollusks.

scholarly journals Reconstruction of ancient homeobox gene linkages inferred from a new high-quality assembly of the Hong Kong oyster (Magallana hongkongensis) genome

BMC Genomics ◽  
2020 ◽  
Vol 21 (1) ◽  
Author(s):  
Yiqian Li ◽  
Wenyan Nong ◽  
Tobias Baril ◽  
Ho Yin Yip ◽  
Thomas Swale ◽  
...  
Keyword(s):  
Hong Kong ◽  
Genome Assembly ◽  
Homeobox Genes ◽  
Homeobox Gene ◽  
Gene Clusters ◽  
Gene Organization ◽  
Recent Analysis ◽  
High Quality ◽  
Protein Coding ◽  
Chromosome Level

Abstract Background Homeobox-containing genes encode crucial transcription factors involved in animal, plant and fungal development, and changes to homeobox genes have been linked to the evolution of novel body plans and morphologies. In animals, some homeobox genes are clustered together in the genome, either as remnants from ancestral genomic arrangements, or due to coordinated gene regulation. Consequently, analyses of homeobox gene organization across animal phylogeny provide important insights into the evolution of genome organization and developmental gene control, and their interaction. However, homeobox gene organization remains to be fully elucidated in several key animal ancestors, including those of molluscs, lophotrochozoans and bilaterians. Results Here, we present a high-quality chromosome-level genome assembly of the Hong Kong oyster, Magallana hongkongensis (2n = 20), for which 93.2% of the genomic sequences are contained on 10 pseudomolecules (~ 758 Mb, scaffold N50 = 72.3 Mb). Our genome assembly was scaffolded using Hi-C reads, facilitating a larger scaffold size compared to the recently published M. hongkongensis genome of Peng et al. (Mol Ecol Resources, 2020), which was scaffolded using the Crassostrea gigas assembly. A total of 46,963 predicted gene models (45,308 protein coding genes) were incorporated in our genome, and genome completeness estimated by BUSCO was 94.6%. Homeobox gene linkages were analysed in detail relative to available data for other mollusc lineages. Conclusions The analyses performed in this study and the accompanying genome sequence provide important genetic resources for this economically and culturally valuable oyster species, and offer a platform to improve understanding of animal biology and evolution more generally. Transposable element content is comparable to that found in other mollusc species, contrary to the conclusion of another recent analysis. Also, our chromosome-level assembly allows the inference of ancient gene linkages (synteny) for the homeobox-containing genes, even though a number of the homeobox gene clusters, like the Hox/ParaHox clusters, are undergoing dispersal in molluscs such as this oyster.

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