A human-specific insertion promotes cell proliferation and migration by enhancing TBC1D8B expression.

Human-specific insertions play important roles in human phenotypes and diseases. Here we reported a 446-bp insertion (Insert-446) in intron 11 of the TBC1D8B gene, located on chromosome X, and traced its origin to a portion of intron 6 of the EBF1 gene on chromosome 5. Interestingly, Insert-446 was present in the human Neanderthal and Denisovans genomes, and was fixed in humans after human-chimpanzee divergence. We have demonstrated that Insert-446 acts as an enhancer through binding transcript factors that promotes a higher expression of human TBC1D8B gene as compared with orthologs in macaques. In addition, over-expression TBC1D8B promoted cell proliferation and migration through "a dual finger" catalytic mechanism (Arg538 and Gln573) in the TBC domain in vitro and knockdown of TBC1D8B attenuated tumorigenesis in vivo. Knockout of Insert-446 prevented cell proliferation and migration in cancer and normal cells. Our results reveal that the human-specific Insert-446 promotes cell proliferation and migration by upregulating the expression of TBC1D8B gene. These findings provide a significant insight into the effects of human-specific insertions on evolution.

Target capture sequencing for the first Nigerian genotype I ASFV genome.

African swine fever (ASF) is a contagious viral disease that affects domestic pigs and wild boars, causing significant economic losses globally. After the first Nigerian outbreak in 1997, there have been frequent reports of ASF in pig-producing regions in the country. To facilitate control, it is important to understand the genotype and phylogenetic relationship of ASF viruses (ASFVs). Recent genetic analysis of Nigerian ASFV isolates has revealed the presence of both genotypes I and II; this is based on analysis of a few selected genes. Phylogenetic analysis of ASFV whole genomes highlights virus origins and evolution in greater depth. However, there is currently no information on the ASFV genome from Nigerian isolates. Two ASFV-positive samples were detected during a random survey of 150 Nigerian indigenous pig samples collected in 2016. We assembled near-complete genomes of the two ASFV-positive samples using in-solution hybrid capture sequencing. The genome-wide phylogenetic tree assigned these two genomes into p72 genotype I, particularly close to the virulent Benin 97/1 strain. The two ASFVs share 99.94 and 99.92 % genomic sequence identity to Benin97/1. This provides insight into the origin and relationship of ASFV strains from Nigeria and Italy. The study reports for the first time the determination of near-complete genomes of ASFV using in-solution hybrid capture sequencing, which represents an important advance in understanding the global evolutionary landscape of ASFVs.

African Suid Genomes Provide Insights into the Local Adaptation to Diverse African Environments.

African wild suids consist of several endemic species that represent ancient members of the family Suidae and have colonized diverse habitats on the African continent. However, limited genomic resources for African wild suids hinder our understanding of their evolution and genetic diversity. In this study, we assembled high-quality genomes of a common warthog (Phacochoerus africanus), a red river hog (Potamochoerus porcus), as well as an East Asian Diannan small-ear pig (Sus scrofa). Phylogenetic analysis showed that common warthog and red river hog diverged from their common ancestor around the Miocene/Pliocene boundary, putatively predating their entry into Africa. We detected species-specific selective signals associated with sensory perception and interferon signaling pathways in common warthog and red river hog, respectively, which contributed to their local adaptation to savannah and tropical rainforest environments, respectively. The structural variation and evolving signals in genes involved in T-cell immunity, viral infection, and lymphoid development were identified in their ancestral lineage. Our results provide new insights into the evolutionary histories and divergent genetic adaptations of African suids.

Single-cell RNA Sequencing Reveals Thoracolumbar Vertebra Heterogeneity and Rib-genesis in Pigs.

Development of thoracolumbar vertebra (TLV) and rib primordium (RP) is a common evolutionary feature across vertebrates, although whole-organism analysis of the expression dynamics of TLV- and RP-related genes has been lacking. Here, we investigated the single-cell transcriptome landscape of thoracic vertebra (TV), lumbar vertebra (LV), and RP cells from a pig embryo at 27 days post-fertilization (dpf) and identified six cell types with distinct gene expression signatures. In-depth dissection of the gene expression dynamics and RNA velocity revealed a coupled process of osteogenesis and angiogenesis during TLV and RP development. Further analysis of cell type-specific and strand-specific expression uncovered the extremely high level of HOXA10 3'-UTR sequence specific to osteoblasts of LV cells, which may function as anti-HOXA10-antisense by counteracting the HOXA10-antisense effect to determine TLV transition. Thus, this work provides a valuable resource for understanding embryonic osteogenesis and angiogenesis underlying vertebrate TLV and RP development at the cell type-specific resolution, which serves as a comprehensive view on the transcriptional profile of animal embryo development.

In Situ Perovskitoid Engineering at SnO2 Interface toward Highly Efficient and Stable Formamidinium Lead Triiodide Perovskite Solar Cells.

The black-phase formamidinium lead triiodide (α-FAPbI3) perovskite has turned out to be one of the most efficient light harvesting materials. However, the phase stability of FAPbI3 is a long-standing issue. Herein, we introduce a layer of tetrabutylammonium fluoride (TBAF) on SnO2, which would form an in situ layer of TBAPbI3 perovskitoid at the SnO2/FAPbI3 interface by interacting with PbI2. The results show that this strategy could improve the conductivity of SnO2, passivate the defects in perovskite, improve the phase stability of α-FAPbI3, and retard the nonradiative recombination in the device. As a result, we obtain a champion device with a power conversion efficiency of 23.1% under AM 1.5 G illumination of 100 mW/cm2. The unencapsulated devices can maintain excellent stability under illumination, thermal stress, and humidity conditions, respectively.

Genetic Architecture Underlying Nascent Speciation-The Evolution of Eurasian Pigs under Domestication.

Speciation is a process whereby the evolution of reproductive barriers leads to isolated species. Although many studies have addressed large-effect genetic footprints in the advanced stages of speciation, the genetics of reproductive isolation in nascent stage of speciation remains unclear. Here, we show that pig domestication offers an interesting model for studying the early stages of speciation in great details. Pig breeds have not evolved the large X-effect of hybrid incompatibility commonly observed between "good species." Instead, deleterious epistatic interactions among multiple autosomal loci are common. These weak Dobzhansky-Muller incompatibilities confer partial hybrid inviability with sex biases in crosses between European and East Asian domestic pigs. The genomic incompatibility is enriched in pathways for angiogenesis, androgen receptor signaling and immunity, with an observation of many highly differentiated cis-regulatory variants. Our study suggests that partial hybrid inviability caused by pervasive but weak interactions among autosomal loci may be a hallmark of nascent speciation in mammals.

Ambient Temperature is A Strong Selective Factor Influencing Human Development and Immunity.

Solar energy, which is essential for the origin and evolution of all life forms on Earth, can be objectively recorded through attributes such as climatic ambient temperature (CAT), ultraviolet radiation (UVR), and sunlight duration (SD). These attributes have specific geographical variations and may cause different adaptation traits. However, the adaptation profile of each attribute and the selective role of solar energy as a whole during human evolution remain elusive. Here, we performed a genome-wide adaptation study with respect to CAT, UVR, and SD using the Human Genome Diversity Project-Centre Etude Polymorphism Humain (HGDP-CEPH) panel data. We singled out CAT as the most important driving force with the highest number of adaptive loci (6 SNPs at the genome-wide 1 × 10-7 level; 401 at the suggestive 1 × 10-5 level). Five of the six genome-wide significant adaptation SNPs were successfully replicated in an independent Chinese population (N = 1395). The corresponding 316 CAT adaptation genes were mostly involved in development and immunity. In addition, 265 (84%) genes were related to at least one genome-wide association study (GWAS)-mapped human trait, being significantly enriched in anthropometric loci such as those associated with body mass index (χ2; P < 0.005), immunity, metabolic syndrome, and cancer (χ2; P < 0.05). For these adaptive SNPs, balancing selection was evident in Euro-Asians, whereas obvious positive and/or purifying selection was observed in Africans. Taken together, our study indicates that CAT is the most important attribute of solar energy that has driven genetic adaptation in development and immunity among global human populations. It also supports the non-neutral hypothesis for the origin of disease-predisposition alleles in common diseases.

OrthReg: a tool to predict cis-regulatory elements based on cross-species orthologous sequence conservation.

Cis-regulatory elements play an important role in the development of traits and disease in organisms (Ma et al., 2020; Woolfe et al., 2005) and their annotation could facilitate genetic studies. The Encyclopedia of DNA Elements (ENCODE) (Davis et al., 2018) and Functional Annotation of Animal Genomes (FAANG) (FAANG Consortium et al., 2015) offer pioneering data on regulatory elements in several species. Currently, however, regulatory element annotation data remain limited for most organisms. In this study, we developed a tool (OrthReg) for annotating conserved orthologous cis-regulatory elements in targeted genomes using an annotated reference genome. Cross-species validation of this annotation tool using human and mouse ENCODE data confirmed the robustness of this strategy. To explore the efficiency of the tool, we annotated the pig genome and identified more than 28 million regulatory annotation records using the reference human ENCODE data. With this regulatory annotation, some putative regulatory non-coding variants were identified within domestication sweeps in European and East Asian pigs. Thus, this tool can utilize data produced by ENCODE, FAANG, and similar projects, and can be easily extended to customized experimental data. The extensive application of this tool will help to identify informative single nucleotide polymorphisms (SNPs) in post-genome-wide association studies and resequencing analysis of organisms with limited regulatory annotation data.

Whole genome resequencing reveals an association of ABCC4 variants with preaxial polydactyly in pigs.

BACKGROUND: Polydactyly is one of the most common congenital limb dysplasia in many animal species. Although preaxial polydactyly (PPD) has been comprehensively studied in humans as a common abnormality, the genetic variations in other animal species have not been fully understood. Herein, we focused on the pig, as an even-toed ungulate mammal model with its unique advantages in medical and genetic researches, two PPD families consisting of four affected and 20 normal individuals were sequenced. RESULTS: Our results showed that the PPD in the sampled pigs were not related to previously reported variants. A strong association was identified at ABCC4 and it encodes a transmembrane protein involved in ciliogenesis. We found that the affected and normal individuals were highly differentiated at ABCC4, and all the PPD individuals shared long haplotype stretches as compared with the unaffected individuals. A highly differentiated missense mutation (I85T) in ABCC4 was observed at a residue from a transmembrane domain highly conserved among a variety of organisms. CONCLUSIONS: This study reports ABCC4 as a new candidate gene and identifies a missense mutation for PPD in pigs. Our results illustrate a putative role of ciliogenesis process in PPD, coinciding with an earlier observation of ciliogenesis abnormality resulting in pseudo-thumb development in pandas. These results expand our knowledge on the genetic variations underlying PPD in animals.

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 used 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 the 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 provide an insight into adaptive evolution of high-altitude domestic mammals, and should facilitate the search for additional novel genes involved in the hypoxia response pathway.

CaptureProbe: a java tool for designing probes for capture Hi-C applications.

Many functional elements associated with traits and diseases are located in non-coding regions and act on distant target genes via chromatin looping and folding, making it difficult for scientists to reveal the genetic regulatory mechanisms. Capture Hi-C is a newly developed chromosome conformation capture technology based on hybridization capture between probes and target genomic regions. It can identify interactions among target loci and all other loci in a genome with low cost and high resolution. Here, we developed CaptureProbe, a user-friendly, graphical Java tool for the design of capture probes across a range of target sites or regions. Numerous parameters helped to achieve and optimize the designed probes. Design testing of CaptureProbe showed high efficiency in the design success ratio of target loci and probe specificity. Hence, this program will help scientists conduct genome spatial interaction research. CaptureProbe and source code are available at https://sourceforge.net/projects/captureprobe/.

Maternal genomic variability of the wild boar (Sus scrofa) reveals the uniqueness of East-Caucasian and Central Italian populations.

The phylogeography of the European wild boar was mainly determined by postglacial recolonization patterns from Mediterranean refugia after the last ice age. Here we present the first analysis of SNP polymorphism within the complete mtDNA genome of West Russian (n = 8), European (n = 64), and North African (n = 5) wild boar. Our analyses provided evidence of unique lineages in the East-Caucasian (Dagestan) region and in Central Italy. A phylogenetic analysis revealed that these lineages are basal to the other European mtDNA sequences. We also show close connection between the Western Siberian and Eastern European populations. Also, the North African samples were clustered with the Iberian population. Phylogenetic trees and migration modeling revealed a high proximity of Dagestan sequences to those of Central Italy and suggested possible gene flow between Western Asia and Southern Europe which was not directly related to Northern and Central European lineages. Our results support the presence of old maternal lineages in two Southern glacial refugia (i.e., Caucasus and the Italian peninsula), as a legacy of an ancient wave of colonization of Southern Europe from an Eastern origin.

Population Genomics Analysis Revealed Origin and High-altitude Adaptation of Tibetan Pigs.

Tibetan pig is native to the Qinghai-Tibet Plateau and has adapted to the high-altitude environmental condition such as hypoxia. However, its origin and genetic mechanisms underlying high-altitude adaptation still remain controversial and enigmatic. Herein, we analyze 229 genomes of wild and domestic pigs from Eurasia, including 63 Tibetan pigs, and detect 49.6 million high-quality variants. Phylogenomic and structure analyses show that Tibetan pigs have a close relationship with low-land domestic pigs in China, implying a common domestication origin. Positively selected genes in Tibetan pigs involved in high-altitude physiology, such as hypoxia, cardiovascular systems, UV damage, DNA repair. Three of loci with strong signals of selection are associated with EPAS1, CYP4F2, and THSD7A genes, related to hypoxia and circulation. We validated four non-coding mutations nearby EPAS1 and CYP4F2 showing reduced transcriptional activity in Tibetan pigs. A high-frequency missense mutation is found in THSD7A (Lys561Arg) in Tibetan pigs. The selective sweeps in Tibetan pigs was found in association with selection against non-coding variants, indicating an important role of regulatory mutations in Tibetan pig evolution. This study is important in understanding the evolution of Tibetan pigs and advancing our knowledge on animal adaptation to high-altitude environments.

Genomic and transcriptomic analyses reveal selection of genes for puberty in Bama Xiang pigs.

The Bama Xiang pig (BMX) is a famous early-maturing Chinese indigenous breed with a two-end black coat. To uncover the genetic basis of the BMX phenotype, we conducted comparative genomic analyses between BMX and East Asian wild boars and Laiwu pigs, respectively. Genes under positive selection were enriched in pathways associated with gonadal hormone and melanin synthesis, consistent with the phenotypic changes observed during development in BMX pigs. We also performed differentially expressed gene analysis based on RNA-seq data from pituitary tissues of BMX and Large White pigs. The CTTNBP2NL, FRS2, KANK4, and KATNAL1 genes were under selection and exhibited expressional changes in the pituitary tissue, which may affect BMX pig puberty. Our study demonstrated the positive selection of early maturity in the development of BMX pigs and advances our knowledge on the role of regulatory elements in puberty evolution in pigs.

PigVar: a database of pig variations and positive selection signatures.

Database URL: http://www.ibiomedical.net/pigvar/.

Analysis of the genetic variation in mitochondrial DNA, Y-chromosome sequences, and MC1R sheds light on the ancestry of Nigerian indigenous pigs.

BACKGROUND: The history of pig populations in Africa remains controversial due to insufficient evidence from archaeological and genetic data. Previously, a Western ancestry for West African pigs was reported based on loci that are involved in the determination of coat color. We investigated the genetic diversity of Nigerian indigenous pigs (NIP) by simultaneously analyzing variation in mitochondrial DNA (mtDNA), Y-chromosome sequence and the melanocortin receptor 1 (MC1R) gene. RESULTS: Median-joining network analysis of mtDNA D-loop sequences from 201 NIP and previously characterized loci clustered NIP with populations from the West (Europe/North Africa) and East/Southeast Asia. Analysis of partial sequences of the Y-chromosome in 57 Nigerian boars clustered NIP into lineage HY1. Finally, analysis of MC1R in 90 NIP resulted in seven haplotypes, among which the European wild boar haplotype was carried by one individual and the European dominant black by most of the other individuals (93%). The five remaining unique haplotypes differed by a single synonymous substitution from European wild type, European dominant black and Asian dominant black haplotypes. CONCLUSIONS: Our results demonstrate a European and East/Southeast Asian ancestry for NIP. Analyses of MC1R provide further evidence. Additional genetic analyses and archaeological studies may provide further insights into the history of African pig breeds. Our findings provide a valuable resource for future studies on whole-genome analyses of African pigs.