scholarly journals Higher Rates of Processed Pseudogene Acquisition in Humans and Three Great Apes Revealed by Long-Read Assemblies

2021 ◽  
Author(s):  
Xiaowen Feng ◽  
Heng Li
Keyword(s):  
Reference Genome ◽  
Great Apes ◽  
Accurate Method ◽  
Protein Coding ◽  
Short Reads ◽  
Long Read ◽  
Processed Pseudogene ◽  
Processed Pseudogenes ◽  
Exon Junctions ◽  
Flanking Regions

Abstract LINE-1-mediated retrotransposition of protein-coding mRNAs is an active process in modern humans for both germline and somatic genomes. Prior works that surveyed human data mostly relied on detecting discordant mappings of paired-end short reads, or exon junctions contained in short reads. Moreover, there have been few genome-wide comparisons between gene retrocopies in great apes and humans. In this study, we introduced a more sensitive and accurate method to identify processed pseudogenes. Our method utilizes long-read assemblies, and more importantly, is able to provide full-length retrocopy sequences as well as flanking regions which are missed by short-read based methods. From 22 human individuals, we pinpointed 40 processed pseudogenes that are not present in the human reference genome GRCh38 and identified 17 pseudogenes that are in GRCh38 but absent from some input individuals. This represents a significantly higher discovery rate than previous reports (39 pseudogenes not in the reference genome out of 939 individuals). We also provided an overview of lineage-specific retrocopies in chimpanzee, gorilla, and orangutan genomes.

scholarly journals Higher rates of processed pseudogene acquisition in humans and three great apes revealed by long read assemblies

2020 ◽  
Author(s):  
Xiaowen Feng ◽  
Heng Li
Keyword(s):  
Great Apes ◽  
Comprehensive Analysis ◽  
Active Process ◽  
Protein Coding ◽  
Short Read ◽  
Short Reads ◽  
Human Data ◽  
Genome Wide ◽  
Long Read ◽  
Processed Pseudogene

AbstractLINE-1 mediated retrotransposition of protein-coding mRNAs is an active process in modern humans for both germline and somatic genomes. Prior works that surveyed human data or human cohorts mostly relied on detecting discordant mappings of paired-end short reads, or assumed L1 hallmarks such as polyA tails and target site duplications. Moreover, there has been few genome-wide comparison between gene retrocopies in great apes and humans. In this study, we introduced a more sensitive and accurate approach to the discovery of processed pseudogene. Our method utilizes long read assemblies, and more importantly, is able to provide full retrocopy sequences as well as the neighboring sequences which are missed by short-read based methods reads. We provided an overview of novel gene retrocopies of 40 events (38 parent genes) in 20 human assemblies, a significantly higher discovery rate than previous reports (39 events of 36 parent genes out of 939 individuals). We also performed comprehensive analysis of lineage specific retrocopies in chimpanzee, gorilla and orangutan genomes.

scholarly journals Recovery of non-reference sequences missing from the human reference genome

BMC Genomics ◽  
2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Ran Li ◽  
Xiaomeng Tian ◽  
Peng Yang ◽  
Yingzhi Fan ◽  
Ming Li ◽  
...  
Keyword(s):  
Human Genome ◽  
Tandem Repeats ◽  
Reference Genome ◽  
De Novo ◽  
Precise Location ◽  
Protein Coding ◽  
Human Reference Genome ◽  
Mhc Haplotype ◽  
Reference Sequences ◽  
Flanking Regions

Abstract Background The non-reference sequences (NRS) represent structure variations in human genome with potential functional significance. However, besides the known insertions, it is currently unknown whether other types of structure variations with NRS exist. Results Here, we compared 31 human de novo assemblies with the current reference genome to identify the NRS and their location. We resolved the precise location of 6113 NRS adding up to 12.8 Mb. Besides 1571 insertions, we detected 3041 alternate alleles, which were defined as having less than 90% (or none) identity with the reference alleles. These alternate alleles overlapped with 1143 protein-coding genes including a putative novel MHC haplotype. Further, we demonstrated that the alternate alleles and their flanking regions had high content of tandem repeats, indicating that their origin was associated with tandem repeats. Conclusions Our study detected a large number of NRS including many alternate alleles which are previously uncharacterized. We suggested that the origin of alternate alleles was associated with tandem repeats. Our results enriched the spectrum of genetic variations in human genome.

scholarly journals Dog10K_Boxer_Tasha_1.0: A Long-Read Assembly of the Dog Reference Genome

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 847
Author(s):  
Vidhya Jagannathan ◽  
Christophe Hitte ◽  
Jeffrey M. Kidd ◽  
Patrick Masterson ◽  
Terence D. Murphy ◽  
...  
Keyword(s):  
Reference Genome ◽  
Gene Annotation ◽  
Domestic Dog ◽  
Genetic Studies ◽  
Protein Coding ◽  
Canine Genetics ◽  
Long Read ◽  
And Behavior ◽  
New Protein ◽  
Initial Assembly

The domestic dog has evolved to be an important biomedical model for studies regarding the genetic basis of disease, morphology and behavior. Genetic studies in the dog have relied on a draft reference genome of a purebred female boxer dog named “Tasha” initially published in 2005. Derived from a Sanger whole genome shotgun sequencing approach coupled with limited clone-based sequencing, the initial assembly and subsequent updates have served as the predominant resource for canine genetics for 15 years. While the initial assembly produced a good-quality draft, as with all assemblies produced at the time, it contained gaps, assembly errors and missing sequences, particularly in GC-rich regions, which are found at many promoters and in the first exons of protein-coding genes. Here, we present Dog10K_Boxer_Tasha_1.0, an improved chromosome-level highly contiguous genome assembly of Tasha created with long-read technologies that increases sequence contiguity >100-fold, closes >23,000 gaps of the CanFam3.1 reference assembly and improves gene annotation by identifying >1200 new protein-coding transcripts. The assembly and annotation are available at NCBI under the accession GCF_000002285.5.

scholarly journals Construction of a new chromosome-scale, long-read reference genome assembly of the Syrian hamster, Mesocricetus auratus

2021 ◽  
Author(s):  
R. Alan Harris ◽  
Muthuswamy Raveendran ◽  
Dustin T Lyfoung ◽  
Fritz J Sedlazeck ◽  
Medhat Mahmoud ◽  
...  
Keyword(s):  
Genome Assembly ◽  
Syrian Hamster ◽  
Reference Genome ◽  
Sequence Data ◽  
Mesocricetus Auratus ◽  
Protein Coding ◽  
Protein Coding Genes ◽  
Sequencing Technologies ◽  
Long Read ◽  
Short Read Sequence

Background The Syrian hamster (Mesocricetus auratus) has been suggested as a useful mammalian model for a variety of diseases and infections, including infection with respiratory viruses such as SARS-CoV-2. The MesAur1.0 genome assembly was published in 2013 using whole-genome shotgun sequencing with short-read sequence data. Current more advanced sequencing technologies and assembly methods now permit the generation of near-complete genome assemblies with higher quality and higher continuity. Findings Here, we report an improved assembly of the M. auratus genome (BCM_Maur_2.0) using Oxford Nanopore Technologies long-read sequencing to produce a chromosome-scale assembly. The total length of the new assembly is 2.46 Gbp, similar to the 2.50 Gbp length of a previous assembly of this genome, MesAur1.0. BCM_Maur_2.0 exhibits significantly improved continuity with a scaffold N50 that is 6.7 times greater than MesAur1.0. Furthermore, 21,616 protein coding genes and 10,459 noncoding genes were annotated in BCM_Maur_2.0 compared to 20,495 protein coding genes and 4,168 noncoding genes in MesAur1.0. This new assembly also improves the unresolved regions as measured by nucleotide ambiguities, where approximately 17.11% of bases in MesAur1.0 were unresolved compared to BCM_Maur_2.0 in which the number of unresolved bases is reduced to 3.00%. Conclusions Access to a more complete reference genome with improved accuracy and continuity will facilitate more detailed, comprehensive, and meaningful research results for a wide variety of future studies using Syrian hamsters as models.

scholarly journals Recovery of non-reference sequences missing from the human reference genome

2019 ◽  
Author(s):  
Ran Li ◽  
Xiaomeng Tian ◽  
Peng Yang ◽  
Yingzhi Fan ◽  
Ming Li ◽  
...  
Keyword(s):  
Tandem Repeats ◽  
Reference Genome ◽  
De Novo ◽  
Precise Location ◽  
Protein Coding ◽  
Human Reference Genome ◽  
Protein Coding Genes ◽  
Mhc Haplotype ◽  
Reference Sequences ◽  
Flanking Regions

Abstract The non-reference sequences (NRS) represent structure variations in human genome with potential functional significance. However, besides the known insertions, it is currently unknown whether other types of structure variations with NRS exist. Here, we compared 31 human de novo assemblies with the current reference genome to identify the NRS and their location. We resolved the precise location of 6,113 NRS adding up to 12.8 Mb. Besides 1,571 insertions, we detected 3,041 alternate alleles, which were defined as having less than 90% (or none) identity with the reference alleles. These alternate alleles overlapped with 1,143 protein-coding genes including a putative novel MHC haplotype. Further, we demonstrated that the alternate alleles and their flanking regions had high content of tandem repeats, indicating that their origin was associated with tandem repeats. Our study enriched the spectrum of human genetic variations.

scholarly journals Recovery of non-reference sequences missing from the human reference genome

2019 ◽  
Author(s):  
Ran Li ◽  
Xiaomeng Tian ◽  
Peng Yang ◽  
Yingzhi Fan ◽  
Ming Li ◽  
...  
Keyword(s):  
Human Genome ◽  
Tandem Repeats ◽  
Reference Genome ◽  
De Novo ◽  
Precise Location ◽  
Protein Coding ◽  
Human Reference Genome ◽  
Mhc Haplotype ◽  
Reference Sequences ◽  
Flanking Regions

Abstract Background The non-reference sequences (NRS) represent structure variations in human genome with potential functional significance. However, besides the known insertions, it is currently unknown whether other types of structure variations with NRS exist. Results Here, we compared 31 human de novo assemblies with the current reference genome to identify the NRS and their location. We resolved the precise location of 6,113 NRS adding up to 12.8 Mb. Besides 1,571 insertions, we detected 3,041 alternate alleles, which were defined as having less than 90% (or none) identity with the reference alleles. These alternate alleles overlapped with 1,143 protein-coding genes including a putative novel MHC haplotype. Further, we demonstrated that the alternate alleles and their flanking regions had high content of tandem repeats, indicating that their origin was associated with tandem repeats. Conclusions Our study detected a large number of NRS including many alternate alleles which are previously uncharacterized. We suggested that the origin of alternate alleles was associated with tandem repeats. Our results enriched the spectrum of genetic variations in human genome.

scholarly journals Chromosomal-level assembly of the blood clam, Scapharca (Anadara) broughtonii, using long sequence reads and Hi-C

GigaScience ◽  
2019 ◽  
Vol 8 (7) ◽  
Author(s):  
Chang-Ming Bai ◽  
Lu-Sheng Xin ◽  
Umberto Rosani ◽  
Biao Wu ◽  
Qing-Chen Wang ◽  
...  
Keyword(s):  
Reference Genome ◽  
De Novo ◽  
Marine Bivalve ◽  
Protein Coding ◽  
Long Reads ◽  
Oxford Nanopore ◽  
The Pacific ◽  
The Family ◽  
Long Read ◽  
Blood Clam

Abstract Background The blood clam, Scapharca (Anadara) broughtonii, is an economically and ecologically important marine bivalve of the family Arcidae. Efforts to study their population genetics, breeding, cultivation, and stock enrichment have been somewhat hindered by the lack of a reference genome. Herein, we report the complete genome sequence of S. broughtonii, a first reference genome of the family Arcidae. Findings A total of 75.79 Gb clean data were generated with the Pacific Biosciences and Oxford Nanopore platforms, which represented approximately 86× coverage of the S. broughtonii genome. De novo assembly of these long reads resulted in an 884.5-Mb genome, with a contig N50 of 1.80 Mb and scaffold N50 of 45.00 Mb. Genome Hi-C scaffolding resulted in 19 chromosomes containing 99.35% of bases in the assembled genome. Genome annotation revealed that nearly half of the genome (46.1%) is composed of repeated sequences, while 24,045 protein-coding genes were predicted and 84.7% of them were annotated. Conclusions We report here a chromosomal-level assembly of the S. broughtonii genome based on long-read sequencing and Hi-C scaffolding. The genomic data can serve as a reference for the family Arcidae and will provide a valuable resource for the scientific community and aquaculture sector.

scholarly journals Recovery of non-reference sequences missing from the human reference genome

2019 ◽  
Author(s):  
Ran Li ◽  
Xiaomeng Tian ◽  
Peng Yang ◽  
Yingzhi Fan ◽  
Ming Li ◽  
...  
Keyword(s):  
Human Genome ◽  
Tandem Repeats ◽  
Reference Genome ◽  
De Novo ◽  
Precise Location ◽  
Protein Coding ◽  
Human Reference Genome ◽  
Mhc Haplotype ◽  
Reference Sequences ◽  
Flanking Regions

Abstract Background The non-reference sequences (NRS) represent structure variations in human genome with potential functional significance. However, besides the known insertions, it is currently unknown whether other types of structure variations with NRS exist. Results Here, we compared 31 human de novo assemblies with the current reference genome to identify the NRS and their location. We resolved the precise location of 6,113 NRS adding up to 12.8 Mb. Besides 1,571 insertions, we detected 3,041 alternate alleles, which were defined as having less than 90% (or none) identity with the reference alleles. These alternate alleles overlapped with 1,143 protein-coding genes including a putative novel MHC haplotype. Further, we demonstrated that the alternate alleles and their flanking regions had high content of tandem repeats, indicating that their origin was associated with tandem repeats. Conclusions Our study detected a large number of NRS including many alternate alleles which are previously uncharacterized. We suggested that the origin of alternate alleles was associated with tandem repeats. Our results enriched the spectrum of genetic variations in human genome.

scholarly journals High quality, phased genomes of Phytophthora ramorum clonal lineages NA1 and EU1

2021 ◽  
Author(s):  
Nicholas C Carleson ◽  
Caroline M Press ◽  
Niklaus J Grunwald
Keyword(s):  
Reference Genome ◽  
Phytophthora Ramorum ◽  
Sudden Oak Death ◽  
Valuable Resource ◽  
High Quality ◽  
Total Size ◽  
Protein Coding ◽  
Protein Coding Genes ◽  
Live Oak ◽  
Long Read

Phytophthora ramorum is the causal agent of sudden oak death in West Coast forests and currently two clonal lineages, NA1 and EU1, cause epidemics in Oregon forests. Here, we report on two high-quality genomes of individuals belonging to the NA1 and EU1 clonal lineages respectively, using PacBio long-read sequencing. The NA1 strain Pr102, originally isolated from coast live oak in California, is the current reference genome and was previously sequenced independently using either Sanger (P. ramorum v1) or PacBio (P. ramorum v2) technology. The EU1 strain PR-15-019 was obtained from tanoak in Oregon. These new genomes have a total size of 57.5 Mb, with a contig N50 length of ~3.5-3.6 Mb and encode ~15,300 predicted protein-coding genes. Genomes were assembled into 27 and 28 scaffolds with 95% BUSCO scores and are considerably improved relative to the current JGI reference genome with 2,575 or the PacBio genomes with 1,512 scaffolds. These high-quality genomes provide a valuable resource for studying the genetics, evolution, and adaptation of these two clonal lineages.

scholarly journals Positive natural selection of N6-methyladenosine on the RNAs of processed pseudogenes

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Liqiang Tan ◽  
Weisheng Cheng ◽  
Fang Liu ◽  
Dan Ohtan Wang ◽  
Linwei Wu ◽  
...  
Keyword(s):  
De Novo ◽  
Rna Degradation ◽  
Rna Modification ◽  
Protein Coding ◽  
Nonsense Mediated Decay ◽  
Protein Coding Genes ◽  
Processed Pseudogene ◽  
Processed Pseudogenes ◽  
Cognate Protein

Abstract Background Canonical nonsense-mediated decay (NMD) is an important splicing-dependent process for mRNA surveillance in mammals. However, processed pseudogenes are not able to trigger NMD due to their lack of introns. It is largely unknown whether they have evolved other surveillance mechanisms. Results Here, we find that the RNAs of pseudogenes, especially processed pseudogenes, have dramatically higher m6A levels than their cognate protein-coding genes, associated with de novo m6A peaks and motifs in human cells. Furthermore, pseudogenes have rapidly accumulated m6A motifs during evolution. The m6A sites of pseudogenes are evolutionarily younger than neutral sites and their m6A levels are increasing, supporting the idea that m6A on the RNAs of pseudogenes is under positive selection. We then find that the m6A RNA modification of processed, rather than unprocessed, pseudogenes promotes cytosolic RNA degradation and attenuates interference with the RNAs of their cognate protein-coding genes. We experimentally validate the m6A RNA modification of two processed pseudogenes, DSTNP2 and NAP1L4P1, which promotes the RNA degradation of both pseudogenes and their cognate protein-coding genes DSTN and NAP1L4. In addition, the m6A of DSTNP2 regulation of DSTN is partially dependent on the miRNA miR-362-5p. Conclusions Our discovery reveals a novel evolutionary role of m6A RNA modification in cleaning up the unnecessary processed pseudogene transcripts to attenuate their interference with the regulatory network of protein-coding genes.

Sign in / Sign up

Export Citation Format

Share Document