PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Paleogenomic”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

17 recordsLinked to original sources

[Syphilis and human treponemes: a long evolutionary history revealed by paleogenomics].

Recent discoveries in paleogenomics have revolutionized our understanding of syphilis and other human treponematoses. Far from being a pathogen that suddenly appeared in Europe in the late Middle Ages, we now know that Treponema pallidum has been circulated among human populations for millennia. Ancient genomes recovered from pre-Columbian contexts in the Americas show that major treponemal lineages had already diversified well before the modern era, often in the absence of recognizable skeletal lesions. Genomic analyses further indicate that treponemal diversity is not the result of extensive genetic acquisition, but rather of small-scale modulation of a highly conserved genome, notably via antigenic variation involving the tpr gene family. Combined with data on endemic treponematoses, congenital syphilis, and historical pathology collections, these findings support a model in which syphilis, yaws, and bejel represent context-dependent expressions of an ancient treponemal continuum, with implications for diagnosis, epidemiology, and vaccine design.

Humans↗

Metagenomics to paleogenomics: large-scale sequencing of mammoth DNA.

We sequenced 28 million base pairs of DNA in a metagenomics approach, using a woolly mammoth (Mammuthus primigenius) sample from Siberia. As a result of exceptional sample preservation and the use of a recently developed emulsion polymerase chain reaction and pyrosequencing technique, 13 million base pairs (45.4%) of the sequencing reads were identified as mammoth DNA. Sequence identity between our data and African elephant (Loxodonta africana) was 98.55%, consistent with a paleontologically based divergence date of 5 to 6 million years. The sample includes a surprisingly small diversity of environmental DNAs. The high percentage of endogenous DNA recoverable from this single mammoth would allow for completion of its genome, unleashing the field of paleogenomics.

Animals↗

Paleogenomics of echinoderms.

Paleogenomics propels the meaning of genomic studies back through hundreds of millions of years of deep time. Now that the genome of the echinoid Strongylocentrotus purpuratus is sequenced, the operation of its genes can be interpreted in light of the well-understood echinoderm fossil record. Characters that first appear in Early Cambrian forms are still characteristic of echinoderms today. Key genes for one of these characters, the biomineralized tissue stereom, can be identified in the S. purpuratus genome and are likely to be the same genes that were involved with stereom formation in the earliest echinoderms some 520 million years ago.

Animals↗

"Paleogenomics": looking in the past to the future.

The complete sequence of the human and other vertebrate and nonvertebrate genomes provide a wealth of information on the organization, relationships and evolution of the metazoans. Soon the fine structure of our innermost biological identity will be unveiled and what has so far remained deep and secret will shine like an unearthed treasure and shape and fuel our future quests. A key treasure, for many molecular scientists interested in molecular evolution and development would be the knowledge of the genome of the ancestral precursor of all metazoans. In the absence of fossil DNA, this knowledge will forever remain a yearning for dreamy molecular biologists. And yet, will not the power of deduction and reconstitution of information gained through man's sophisticated technologies one day recreate a "virtual" metazoan ancestor?

Animals↗

Paleogenomic sex inference of mammoth remains sheds light on the anthropogenic nature of bone accumulations.

Whether large accumulations of woolly mammoth (Mammuthus primigenius) bones reflect natural mortality or deliberate human resource exploitation has long been debated, with major implications for understanding Late Pleistocene human-megafaunal interactions.1,2,3,4,5 Here, we use ancient DNA to investigate site-formation hypotheses by comparing genetic sex ratios from mammoth remains recovered in putative anthropogenic bone accumulations and from geographically dispersed, non-anthropogenic contexts. We studied genome-wide data from 521 woolly mammoths-including 100 mammoths from bone accumulation sites and 421 mammoths from natural depositional settings across Eurasia and North America-of which 448 are newly generated. Genetic sex determination reveals a striking contrast between contexts: mammoths from dispersed sites show a male bias (∼66.5%), which is consistent with the heightened vulnerability of solitary males to hazards such as natural traps, where bones are more likely to be preserved, whereas mammoths from anthropogenic bone accumulations are predominantly female (∼70%). This female bias is pervasive across multiple sites, indicating an anthropogenic origin for these accumulations as a result of Upper Paleolithic hunters preferentially exploiting female mammoths, possibly derived from herd contexts. Together, these results provide population-scale genetic evidence that highlights the central role of mammoths in the subsistence and material economies of some Paleolithic communities.

Animals↗

Paleogenomics or the search for remnant duplicated copies of the yeast DUP240 gene family in intergenic areas.

Duplication, resulting in gene redundancy, is well known to be a driving force of evolutionary change. Gene families are therefore useful targets for approaching genome evolution. To address the gene death process, we examined the fate of the 10-member-large S288C DUP240 family in 15 Saccharomyces cerevisiae strains. Using an original three-step method of analysis reported here, both slightly and highly degenerate DUP240 copies, called pseudo-open reading frames (ORFs) and relics, respectively, were detected in strain S288C. It was concluded that two previously annotated ORFs correspond, in fact, to pseudo-ORFs and three additional relics were identified in intergenic areas. Comparative intraspecies analysis of these degenerate DUP240 loci revealed that the two pseudo-ORFs are present in a nondegenerate state in some other strains. This suggests that within a given gene family different loci are the target of the gene erasure process, which is therefore strain dependent. Besides, the variable positions observed indicate that the relic sequence may diverge faster than the flanking regions. All in all, this study shows that short conserved protein motifs provide a useful tool for detecting and accurately mapping degenerate gene remnants. The present results also highlight the strong contribution of comparative genomics for gene relic detection because the possibility of finding short conserved protein motifs in intergenic regions (IRs) largely depends on the choice of the most closely related paralog or ortholog. By mapping new genetic components in previously annotated IRs, our study constitutes a further refinement step in the crucial stage of genome annotation and provides a strategy for retracing ancient chromosomal reshaping events and, hence, for deciphering genome history.

Amino Acid Sequence↗

Paleogenomics and habitat modeling reveal temperate Eurasian origins of woolly rhinoceroses.

The woolly rhinoceros was a prominent Ice Age megafaunal species, and there is limited knowledge regarding its origin and responses to past glacial cycles. We sequenced 29 mitochondrial and 14 nuclear genomes from Pleistocene specimens across Eurasia and modeled the species' habitats over the past 500,000 years. Our results suggest that its maternal genetic diversity mainly evolved in temperate Eurasia around 460 thousand to 420 thousand years ago during a prolonged glacial-interglacial transition. We found that a ~170-thousand-year-old East Asian individual was ancestral to all later populations, indicating East Asia as one possible origin of Late Pleistocene ancestry. We also identified the Altai region as a major climatic refugium. These findings highlight the crucial role of temperate Eurasia in the evolution of woolly rhinoceroses and the diversification of cold-adapted megafauna.

Animals↗

Paleogenomic record of the extinction of human endogenous retrovirus ERV9.

An outstanding question of genome evolution is what stops the invasion of a host genome by transposable elements (TEs). The human genome, harboring the remnants of many extinct TE families, offers an extraordinary opportunity to investigate this problem. ERV9 is an endogenous retrovirus repeatedly mobilized during primate evolution, 15 to 6 million years ago (MYA), which left a trace of over a hundred provirus-like copies and at least 4,000 solitary long terminal repeats (LTRs) in the human genome. Then, its proliferation ceased for unknown reasons, and the family went extinct. We have made a detailed reconstruction of its last active subfamily, ERV9_XII, by examining 115 solitary LTRs from it. These insertions were grouped into 11 sets according to shared nucleotide variants, which could be placed in a sequential order of 10 to 6 MYA. At least 75% of the subfamily was produced 8 to 6 MYA, during a stage of intense proliferation. With new analytical tools, we show that the youngest and most prolific sets may have been produced by effectively instantaneous expansions of corresponding single-sequence variants. The extinction of this family apparently was not a consequence of its slow gradual degeneration, but the outcome of the fixation of specific restrictive alleles in the human-chimpanzee ancestral population. Three species-specific insertions (two in humans and one in chimpanzees) were identified, further supporting that extinction took place when these two species were beginning to diverge. These are the only fixed differences of this kind so far observed between humans and chimpanzees, apart from those belonging to the human endogenous retrovirus K family.

Animals↗

Reconstruction of ancestral plant genomes for inter-crop translational research.

We present Ancestral Genome Reconstruction (AGR), an exploratory framework for the automated inference of "paleogenomes" from large-scale comparative datasets. By analyzing 84 extant angiosperm species, we reconstructed 10 key ancestral angiosperm genomes millions of years old. These reconstructed ancestors were instrumental in (1) estimating when angiosperms emerged, when major botanical families originated, and when shared ancestral whole-genome duplication events occurred; and (2) tracing the evolutionary trajectories of ancestral chromosomes and genes, especially those that may have driven the emergence of key life-history traits (e.g., woody vs. herbaceous, aquatic vs. terrestrial, C3 vs. C4, and symbiotic root-nodulating vs. non-nodulating species). We demonstrated that these paleogenomes serve as tractable backbones for inter-crop translational research. Through an open-access web tool, OrthoViewer, we identified orthologs that have retained the same ancestral genomic context, favoring the identification of genes associated with "phenologs"- orthologous genes across species driving analogous phenotypes, traits, or processes-exemplified by FUWA for yield components, FLC for flowering time, and DDM1 for DNA methylation. Taken together, this study provides a testable paleogenomic workflow, opening novel avenues for integrating evolutionary genomics data into modern climate-smart crop breeding and supporting the agroecological transition.

Genome, Plant↗

Ancient DNA as a temporal lens: reconstructing evolution, migration, and disease dynamics.

Ancient DNA (aDNA) has transformed evolutionary biology and anthropology by providing direct, chronologically validated genetic evidence over millennia. This review synthesizes significant findings from the paleogenomic era (2010-2025), demonstrating how ancient DNA has resolved persistent debates across four interconnected themes: (i) human migration and admixture, revealing complex population transitions from archaic hominins to Holocene expansions; (ii) adaptation, tracking allele frequency changes during domestication and selection; (iii) pathogen history, clarifying the origins of pandemics and the evolution of microbiomes; and (iv) ecosystem dynamics, identifying extinction causes through sedimentary DNA and conservation genomics. We contend that scientific rigor and ethical stewardship are crucial for accurate conclusions, given ancient DNA study requires the destructive collection of culturally significant remains. This review argues that continued advancement will depend on the integration of genomic data with archaeological, isotopic, and proteomic evidence, and highlights the necessity for equitable involvement with descendant communities. By conceptualizing the past as a continuum of dynamic processes rather than static events, ancient DNA provides a revised historical narrative and insights relevant to contemporary concerns in conservation, health, and social justice.

Evolution↗

Empirical analysis of protein insertions and deletions determining parameters for the correct placement of gaps in protein sequence alignments.

To understand how protein segments are inserted and deleted during divergent evolution, a set of pairwise alignments contained exactly one gap, and therefore arising from the first insertion-deletion (indel) event in the time separating the homologs, was examined. The alignments showed that "structure breaking" amino acids (PGDNS) were preferred within and flanking gapped regions, as are two residues with hydrophilic side-chains (QE) that frequently occur at the surface of protein folds. Conversely, hydrophobic residues (FMILYVW) occur infrequently within and flanking the gapped region. These preferences are modestly different in protein pairs separated by an episode of adaptive evolution, than in pairs diverging under strong functional constraints. Surprisingly, regions near an indel have not evolved more rapidly than the sequence pair overall, showing no evidence that an indel event must be compensated by local amino acid replacement. The gap-lengths are best approximated by a Zipfian distribution, with the probability of a gap of length L decreasing as a function of L(-1.8). These features are largely independent of the length of the gap and the extent of divergence (measured by both silent and non-silent sequence changes) separating the two proteins. Surprisingly, amino acid repeats were discovered in more than a third of the polypeptide segments in and around the gap. These correspond to repeats in the DNA sequence. This suggests that a signature of the mechanism by which indels occur in the DNA sequence remains in the encoded protein sequences. These data suggest specific tools to score gap placement in an alignment. They also suggest tools that distinguish true indels from gaps created by mistaken gene finding, including under-predicted and over-predicted introns. By providing mechanisms to identify errors, the tools will enhance the value of genome sequence databases in support of integrated paleogenomics strategies used to extract functional information in a post-genomic environment.

Amino Acid Sequence↗

Short interspersed transposable elements (SINEs) are excluded from imprinted regions in the human genome.

To test whether regions undergoing genomic imprinting have unique genomic characteristics, imprinted and nonimprinted human loci were compared for nucleotide and retroelement composition. Maternally and paternally expressed subgroups of imprinted genes were found to differ in terms of guanine and cytosine, CpG, and retroelement content, indicating a segregation into distinct genomic compartments. Imprinted regions have been normally permissive to L1 long interspersed transposable element retroposition during mammalian evolution but universally and significantly lack short interspersed transposable elements (SINEs). The primate-specific Alu SINEs, as well as the more ancient mammalian-wide interspersed repeat SINEs, are found at significantly low densities in imprinted regions. The latter paleogenomic signature indicates that the sequence characteristics of currently imprinted regions existed before the mammalian radiation. Transitions from imprinted to nonimprinted genomic regions in cis are characterized by a sharp inflection in SINE content, demonstrating that this genomic characteristic can help predict the presence and extent of regions undergoing imprinting. During primate evolution, SINE accumulation in imprinted regions occurred at a decreased rate compared with control loci. The constraint on SINE accumulation in imprinted regions may be mediated by an active selection process. This selection could be because of SINEs attracting and spreading methylation, as has been found at other loci. Methylation-induced silencing could lead to deleterious consequences at imprinted loci, where inactivation of one allele is already established, and expression is often essential for embryonic growth and survival.

CpG Islands↗

FALCON2: compression-based metagenomic classification of ancient viruses.

MOTIVATION: Ancient DNA (aDNA) sequences present unique challenges for taxonomic classification due to extreme fragmentation (reads 20-100 bp), end-biased cytosine deamination, and high contamination rates. Conventional metagenomic classifiers based on exact k-mer matching or alignment lose discriminative power on such short and damaged reads, limiting the analysis of paleogenomic samples. RESULTS: We present FALCON2, a compression-based metagenomic classifier that leverages position-aware finite-context models to maintain high accuracy on degraded viral ancient viruses. FALCON2 consolidates the capabilities of its predecessor, FALCON-meta, into a unified executable with enhanced features including model persistence, direct processing of compressed inputs, multiple file handling, and optional pre-filtering methodologies for contaminated samples. Under controlled benchmarking with database, taxonomy, and thread parity on simulated viral datasets, FALCON2 achieved an Area Under the Curve of Receiver Operating Characteristic (AUC-ROC) of 0.999, an Area Under Precision-Recall Curve (AUPRC) of 0.968, and an F1-score of 0.918, substantially outperforming Centrifuge (AUPRC = 0.625), Kraken2 (AUPRC = 0.184), and CLARK-S (AUPRC = 0.013) on pooled micro-averaged metrics. FALCON2's advantage is most pronounced on ultra-short reads (20-40 bp), where exact k-mers become sparse. FALCON2 pre-filtering at threshold 0.7 improved precision by 10 percentage points with negligible recall loss. FALCON2 runs on systems with 4-8 GB RAM for typical analyses. AVAILABILITY AND IMPLEMENTATION: FALCON2 is freely available at https://github.com/cobilab/FALCON2 under GPL v3 license. Benchmarking data and scripts are archived at DOI: https://doi.org/10.5281/zenodo.17291214.

Metagenomics↗

Evolutionary history of the human endogenous retrovirus family ERV9.

Several distinct families of endogenous retrovirus-like elements (ERVs) exist in the genomes of primates. Despite the important evolutionary consequences that carrying these intragenomic parasites may have for their hosts, our knowledge about their evolution is still scarce. A matter of particular interest is whether evolution of ERVs occurs via a master lineage or through several lineages coexisting over long periods of time. In this work, the paleogenomic approach has been applied to the study of the evolution of ERV9, one of the human endogenous retrovirus families mobilized during primate evolution. By searching the GenBank database with the first 676 bp of the ERV9 long terminal repeat, we identified 156 different element insertions into the human genome. These elements were grouped into 14 subfamilies based on several characteristic nucleotide differences. The age of each subfamily was roughly estimated based on the average sequence divergence of its members from the subfamily consensus sequence. Determination of the sequential order of diagnostic substitutions led to the identification of four distinct lineages, which retained their capacity of transposition over extended periods of evolution. Strong evidence for mosaic evolution of some of these lineages is presented. Taken altogether, the available data indicate that the possibility of ERV9 still being active in the human lineage can not be discarded.

Animals↗

[Polymorphism of mitochondrial genome noncoding regions in the three Kazakh populations inhabited different areas of Kazakhstan and in the samples of DNA from ancient people of Kazakhstan Altai].

Polymorphism of major noncoding region of mitochondrial DNA (mtDNA D-loop, 528 bp in length) from the three modem kazakh populations and from DNA samples of ancient people inhabited modern Kazakhstani Altai were studied. PCR and RFLP analysis of 13 sites of restriction--BamHI, EcoRV, Sau3AI (1 restriction site), KpnI (2 sites), HaeIII (3 sites), RsaI (5 restriction sites), were carried out. The distribution of each site frequencies was determined. Nucleotide diversity (h) and genetic distance between different kazakh population and other populations of world were estimated. The same RFLP analysis of the mitochondrial DNA control region was carried out for the paleogenomic samples. It was shown that two samples of ancient mitochondrial DNA were monomorphous throughout all analyzed restriction sites.

Base Sequence↗

Tracing the evolution and diversity of human parvovirus B19 across human history.

Human parvovirus B19 (B19V) is an ubiquitously spread, exclusively human pathogen, mainly posing risks to children, as well as pregnant and immunocompromised individuals. Despite evidence of B19V infection of human populations as far back as 7,000 years, the evolutionary history of B19V remains poorly understood. In this study, we present B19V genomic data from the remains of 53 globally distributed individuals spanning more than 8,000 years, including 7 children. Our findings suggest that the most recent common ancestor of all present B19V lineages existed around 12,000 years ago, at the end of the last Ice Age. Additionally, we identified an extinct Eurasian clade that participated in the recombination event that led to the emergence of B19V genotype 2 (GT-2). We date this event to ∼3,200-1,800 BP, potentially in the greater Mediterranean area. Our study shows aspects of how ancient parvovirus variants arose, disseminated, and impacted human health through time.

ancient DNA↗

Eastern origin and three-millennia persistence of a founding grapevine lineage in Iberian viticulture.

Viticulture became central to most Mediterranean civilizations a few millennia after the grapevine (Vitis vinifera L.) was domesticated in the South Caucasus/Near East. To elucidate the origins of the grapevines that enabled this westward spread over the past 3,000 years, we analyzed 28 grapevine seeds from seven archaeological sites in the Iberian Peninsula and Sardinia. Ancient DNA recovered from the oldest seeds with domesticated-like morphology (from ∼1,000 BCE), found in southwestern Spain, revealed nuclear and chloroplast genome signatures of Eastern Mediterranean cultivars. Seeds from the same and later Iron Age Iberian sites, however, showed genomic signatures suggesting hybridization between local wild grapevines and eastern-origin cultivars. The genetic makeup of Sardinian and northeastern Spanish seeds supports that local diversification giving rise to the Central European and Iberian wine genetic lineages had already occurred in the early Iron Age. In Iberia, Roman-period seeds were first-degree related to both the earliest eastern-introduced domesticates and a Medieval seed whose genetic makeup matches the extant Iberian variety "Pasa Valenciana." Another Medieval seed was inferred as an offspring of the extant "Heben," indicating that this major founder of Iberian germplasm has been continuously propagated for over 1,100 years. Our results confirm previous evolutionary models indicating that Western Mediterranean viticulture began with introductions of eastern domesticated grapevines, followed by early hybridization with local Iberian wild grapevines that may have facilitated viticulture adaptation to the new environment. The aDNA unveils that these introductions gave rise to extant cultivars through only a few sexual generations and long-term reliance on clonal propagation.

Iberian Peninsula↗