Biology subjects

Wu, D.-D.

Publications and source records attributed to Wu, D.-D..

10 recordsLinked to original sources

bioRxiv2024

Comparative and population genomics analyses of eared pheasants inhabiting highly varying altitudes

Oxygen pressure varies dramatically with altitudes on Earth; however, humans and animals thrive at almost all altitudes. To better understand genetic basis underlying adaptation of closely related species to varying altitudes, we annotated and compared the genome of a white eared pheasant (WT) (Crossoptilon crossoptilon) inhabiting high altitudes and the genome of a brown eared pheasant (BR) (C. mantchuricum) inhabiting low altitudes. Moreover, we compared genetic variations in populations of WT and BR as well as of blue eared pheasants (BL) (C. auritum) inhabiting intermediate altitudes, and identified thousands of selective sweeps in each species. Intriguingly, the unique genes and pseudogenes in the two genomes converge on the same set of altitude adaptation-related pathways of four functional categories as genes in selective sweeps in each species. Thus, these species appear to adapt to highly varying altitudes by diverging selection on the same traits via loss-of-function mutations and fine-tuning genes in common pathways.

bioinformatics↗

bioRxiv2024

Large scale loss-of-function mutations during chicken evolution and domestication

Evolution and domestication are often driven by genetic innovations, yet the role of gene loss remains debated. Here, we present comparative genomic analyses of four indigenous chicken breeds from Yunnan Province, China and a reference red jungle fowl genome (GRCg6a). We identify extensive gene presence-absence variation and large numbers of pseudogenes, revealing highly dynamic gene repertoires among closely related chickens. By reconstructing ancestral gene content, we estimate that the common ancestor harbored at least 21,972 genes, of which 7,993 are dispensable. Each lineage has independently lost thousands of genes through both complete gene loss and pseudogenization. These loss-of-function events are non-random: pseudogenization mutations are biased toward gene termini, frequently fixed in populations, and enriched in specific biological pathways. Notably, patterns of gene loss recapitulate phylogenetic relationships, suggesting that loss-of-function mutations are shaped by selection rather than neutral drift. Analysis of four other chicken genomes assembled using PacBio HiFi reads draws the same conclusion. Thus, our results support a model in which large-scale loss-of-function mutations are a major driver of chicken evolution and domestication, consistent with the "less-is-more" hypothesis of adaptive evolution.

bioinformatics↗

bioRxiv2024

Annotations of four high-quality indigenous chicken genomes identify more than one thousand missing genes in sub-telomeric regions with high G/C contents

BackgroundAlthough multiple chicken genomes have been assembled and annotated, the number of protein-coding genes in chicken genomes is still uncertain due to the low quality of these genome assemblies and limited resources used in gene annotations. ResultsTo fill the gap, we annotated our four recently assembled high-quality genomes of four indigenous chickens with distinct traits using a combination of RNA-seq- and homology-based approach. Our annotated genes in the four chickens recovered 51 of the 274 "missing" genes in birds in general and 36 of the 174 "missing" genes in chickens in particular. Intriguingly, based on deeply sequenced RNA-seq data collected in multiple tissues in each chicken breed, we found a total of 1,420 new protein-coding genes in the four chicken genomes, which were missed in the reference chicken genome annotations. These newly annotated genes (NAGs) tend to have high G/C contents and be located in sub-telomeric regions of almost all assembled chromosomes and some unplaced contigs. The NAGs showed tissue-specific expression and we were able to verify 39 (92.9%) of 42 randomly selected ones in various tissues of the four chicken breeds using RT-qPCR experiments. We found that most of the NAGs also are encoded in previously assembled chicken genomes. The NAGs form functional modules with homology-supported genes that are involved in many important biological pathways. We also identified numerous unique genes in each indigenous chicken genome that might be related to the unique traits of each breed. ConclusionThe ubiquitous presence of the NAGs in various chicken genomes indicate that they might play critical roles in chicken physiology. Counting these new genes, chicken genomes harbor more genes than originally thought.

bioinformatics↗

bioRxiv2023

High-quality genome assembly of a white eared pheasant individual and related functional and genetics data resources

White eared pheasant (WT), (Crossoptilon crossoptilon), inhibiting at high altitudes (3000[~]4,300 m), is a Galliformes bird native to the Qinghai, Sichuan, Yunnan and Tibet Province of China. Due to the difficulty of sequencing the precious species, there is no high-quality genome assembly for the species, hampering the understanding of their genetic mechanisms. To fill the gap, we sequenced and assembled a WT individual using Illumina short reads, PacBio long reads and Hi-C reads. With a contig N50 of 19.63 Mb, scaffold N50 of 29.59 Mb, total length of 1.02 Gb and BUSCO completeness of 97.2%, the assembly is highly complete. Evaluation shows that the assembly is at chromosome-level with only six gaps. Thus, our assembly provides a valuable genetic resource for the crossoptilon species. To further provide resources for gene annotation and population genetics analysis, we also sequenced transcriptomes of 20 tissues of the WT individual and re-sequenced another 10 individuals of WT. Our assembled WT genome and the sequencing data can be valuable resources to study the crossoptilon species.

bioinformatics↗

bioRxiv2023

Artificial selection footprints in domestic chicken genomes

Accurate and low-cost next generation sequencing technologies make re-sequencing of large populations of a species possible. Although many studies related to artificial selection signatures of commercial and indigenous chickens have been carried out, quite a small number of genes have been found to be under selection. In this study, we re-sequenced 85 individuals of five indigenous chicken breeds with distinct traits from Yunnan, a southwest province of China. By analyzing these indigenous chickens together with 116 individuals of commercial chickens (broilers and layers) and 35 individuals of red jungle fowl, we find a substantially large number of selective sweeps and affected genes for each chicken breed using a rigorous statistic model than previously reported. We confirm most of previously identified selective sweeps and affected genes. Meanwhile the vast majority ([~]98.3%) of our identified selective sweeps overlap known chicken quantitative trait loci. Thus, our predictions are highly reliable. For each breed, we also identify candidate genes and selective sweeps that might be related to the unique traits of the chickens.

bioinformatics↗

bioRxiv2023

An efficient error correction and accurate assembly tool for noisy long reads

Long read sequencing data, particularly those derived from the Oxford Nanopore (ONT) sequencing platform, tend to exhibit a high error rate. Here, we present NextDenovo, a highly efficient error correction and assembly tool for noisy long reads, which achieves a high level of accuracy in genome assembly. NextDenovo can rapidly correct reads; these corrected reads contain fewer errors than other comparable tools and are characterized by fewer chimeric alignments. We applied NextDenovo to the assembly of high quality reference genomes of 35 diverse humans from across the world using ONT Nanopore long read sequencing data. Based on these de novo genome assemblies, we were able to identify the landscape of segmental duplications and gene copy number variation in the modern human population. The use of the NextDenovo program should pave the way for population-scale long-read assembly, thereby facilitating the construction of human pan-genomes, using Nanopore long read sequencing data.

bioinformatics↗

bioRxiv2020

Integrating Genomic and Transcriptomic Data to Reveal Genetic Mechanisms Underlying Piao Chicken Rumpless Trait

Piao chicken, a rare Chinese native poultry breed, lacks primary tail structures, such as pygostyle, caudal vertebra, uropygial gland and tail feathers. So far, the molecular mechanisms underlying tail absence in this breed have remained unclear. We employed comprehensive comparative transcriptomic and genomic analyses to unravel potential genetic underpinnings of rumplessness in the Piao chicken. Our results reveal many biological factors involved in tail development and several genomic regions under strong positive selection in this breed. These regions contain candidate genes associated with rumplessness, including IRX4, IL-18, HSPB2, and CRYAB. Retrieval of quantitative trait loci (QTL) and gene functions implied that rumplessness might be consciously or unconsciously selected along with the high-yield traits in Piao chicken. We hypothesize that strong selection pressures on regulatory elements might lead to gene activity changes in mesenchymal stem cells of the tail bud and eventually result in tail truncation by impeding differentiation and proliferation of the stem cells. Our study provides fundamental insights into early initiation and genetic bases of the rumpless phenotype in Piao chicken.

genetics↗

bioRxiv2019

Convergent genomic signatures of high altitude adaptation among domestic mammals

Abundant and diverse domestic mammals living on the Tibetan Plateau provide useful materials for investigating adaptive evolution and genetic convergence. Here, we utilized 327 genomes from horses, sheep, goats, cattle, pigs and dogs living at both high and low altitudes, including 73 genomes generated for this study, to disentangle the genetic mechanisms underlying local adaptation of domestic mammals. Although molecular convergence is comparatively rare at the DNA sequence level, we found convergent signature of positive selection at the gene level, particularly EPAS1 gene in these Tibetan domestic mammals. We also reported a potential function in response to hypoxia for the gene C10orf67, which underwent positive selection in three of the domestic mammals. Our data provides insight into adaptive evolution of high-altitude domestic mammals, and should facilitate the search for additional novel genes involved in the hypoxia response pathway.

evolutionary biology↗

bioRxiv2019

The wild species genome ancestry of domestic chickens

Hybridization and/or introgression play a key role in the evolutionary history of animal species. It is commonly observed in several orders in wild birds. The domestic chicken Gallus gallus domesticus is the commonest livestock species exploited for the benefit of mankind. The origin of its diversity remains unsettled. Here, we report a genome-wide analyses for signatures of introgression within domestic village chicken. We first established the genome-wide phylogeny and divergence time across the genus Gallus, showing the sister relationships between Grey junglefowl G. sonneratii and Ceylon junglefowl G. lafayettii and that the Green junglefowl is the first diverging lineage within the genus Gallus. Then, by analysing the whole-genome sequences of geographically diverse chicken populations, we reveal extensive bidirectional introgression between Grey junglefowl and domestic chicken and to a much less extent with Ceylon junglefowl. A single case of Green junglefowl G. varius introgression was identified. These introgressed regions include biological functions related to the control of gene expression. Our results show that while the Red junglefowl is the main ancestral species, introgressive hybridization episodes have impacted the genome and contributed to the diversity of domestic chicken, although likely at different level across its geographic range.

evolutionary biology↗

bioRxiv2016

Evolutionary history of the brown rat: out of southern East Asia and selection

The brown rat (Rattus norvegicus) is found wherever humans live and transmits many diseases, and its breeding produced the laboratory rat used widely in medical research. Here, we sequenced whole genomes from 118 rats to explore the origin and dispersal routes of the brown rat and the domestication of the laboratory rat. We showed that brown rats migrated about 3600 years ago from southern East Asia, rather than Northern Asia as formerly suggested, to the Middle East and then to Europe and Africa. Many genes involved in the immune system experienced positive selection in the wild brown rat, while genes involved in the nervous system and energy metabolism showed evidence of artificial selection during the domestication of laboratory strains. Our findings demystify the puzzling origin and migration of brown rats and reveal the impact of evolution and domestication on this animal.

evolutionary biology↗