Methylation-based enrichment facilitates low-cost, noninvasive genomic scale sequencing of populations from feces

Obtaining high-quality samples from wild animals is a major obstacle for genomic studies of many taxa, particularly at the population level, as collection methods for such samples are typically invasive. DNA from feces is easy to obtain noninvasively, but is dominated by bacterial and other non-host DNA. The high proportion of non-host DNA drastically reduces the efficiency of high-throughput sequencing for host animal genomics. To address this issue, we developed an inexpensive capture method for enriching host DNA from noninvasive fecal samples. Our method exploits natural differences in CpG-methylation density between vertebrate and bacterial genomes to preferentially bind and isolate host DNA from majority-bacterial samples. We demonstrate that the enrichment is robust, efficient, and compatible with downstream library preparation methods useful for population studies (e.g., RADseq). Compared to other enrichment strategies, our method is quick and inexpensive, adding only a negligible cost to sample preparation. In combination with downstream methods such as RADseq, our approach allows for cost-effective and customizable genomic-scale genotyping that was previously feasible in practice only with invasive samples. Because feces are widely available and convenient to collect, our method empowers researchers to explore genomic-scale population-level questions in organisms for which invasive sampling is challenging or undesirable

The use (and misuse) of phylogenetic trees in comparative behavioral analyses

Abstract Phylogenetic comparative methods play a critical role in our understanding of the adaptive origin of primate behaviors. To incorporate evolutionary history directly into comparative behavioral research, behavioral ecologists rely on strong, wellresolved phylogenetic trees. Phylogenies provide the framework on which behaviors can be compared and homologies can be distinguished from similarities due to convergent or parallel evolution. Phylogenetic reconstructions are also of critical importance when inferring the ancestral state of behavioral patterns and when suggesting the evolutionary changes that behavior has undergone. Improvements in genome sequencing technologies have increased the amount of data available to researchers. Recently, several primate phylogenetic studies have used multiple loci to produce robust phylogenetic trees that include hundreds of primate species. These trees are now commonly used in comparative analyses and there is a perception that we have a complete picture of the primate tree. But how confident can we be in those phylogenies? And how reliable are comparative analyses based on such trees? Herein, we argue that even recent molecular phylogenies should be treated cautiously because they rely on many assumptions and have many shortcomings. Most phylogenetic studies do not model gene tree diversity and can produce misleading results, such as strong support for an incorrect species tree, especially in the case of rapid and recent radiations. We discuss implications that incorrect phylogenies can have for reconstructing the evolution of primate behaviors and we urge primatologists to be aware of the current limitations of phylogenetic reconstructions when applying phylogenetic comparative methods

ACE2 and TMPRSS2 variation in savanna monkeys (Chlorocebus spp.): potential risk for zoonotic/anthroponotic transmission of SARS-CoV-2 and a potential model for functional studies

The COVID-19 pandemic, caused by the coronavirus SARS-CoV-2, has devastated health infrastructure around the world. Both ACE2 (an entry receptor) and TMPRSS2 (used by the virus for spike protein priming) are key proteins to SARS-CoV-2 cell entry, enabling progression to COVID-19 in humans. Comparative genomic research into critical ACE2 binding sites, associated with the spike receptor binding domain, has suggested that African and Asian primates may also be susceptible to disease from SARS-CoV-2 infection. Savanna monkeys (Chlorocebus spp.) are a widespread non-human primate with well-established potential as a bi-directional zoonotic/anthroponotic agent due to high levels of human interaction throughout their range in sub-Saharan Africa and the Caribbean. To characterize potential functional variation in savanna monkey ACE2 and TMPRSS2, we inspected recently published genomic data from 245 savanna monkeys, including 163 wild monkeys from Africa and the Caribbean and 82 captive monkeys from the Vervet Research Colony (VRC). We found several missense variants. One missense variant in ACE2 (X:14,077,550; Asp30Gly), common in Ch. sabaeus, causes a change in amino acid residue that has been inferred to reduce binding efficiency of SARS-CoV-2, suggesting potentially reduced susceptibility. The remaining populations appear as susceptible as humans, based on these criteria for receptor usage. All missense variants observed in wild Ch. sabaeus populations are also present in the VRC, along with two splice acceptor variants (at X:14,065,076) not observed in the wild sample that are potentially disruptive to ACE2 function. The presence of these variants in the VRC suggests a promising model for SARS-CoV-2 infection and vaccine and therapy development. In keeping with a One Health approach, characterizing actual susceptibility and potential for bi-directional zoonotic/anthroponotic transfer in savanna monkey populations may be an important consideration for controlling COVID-19 epidemics in communities with frequent human/non-human primate interactions that, in many cases, may have limited health infrastructure.P40 OD010965 - NIH HHSPublished versio

An integrative skeletal and paleogenomic analysis of stature variation suggests relatively reduced health for early european farmers

Human culture, biology, and health were shaped dramatically by the onset of agriculture ∼12,000 y B.P. This shift is hypothesized to have resulted in increased individual fitness and population growth as evidenced by archaeological and population genomic data alongside a decline in physiological health as inferred from skeletal remains. Here, we consider osteological and ancient DNA data from the same prehistoric individuals to study human stature variation as a proxy for health across a transition to agriculture. Specifically, we compared “predicted” genetic contributions to height from paleogenomic data and “achieved” adult osteological height estimated from long bone measurements for 167 individuals across Europe spanning the Upper Paleolithic to Iron Age (∼38,000 to 2,400 B.P.). We found that individuals from the Neolithic were shorter than expected (given their individual polygenic height scores) by an average of −3.82 cm relative to individuals from the Upper Paleolithic and Mesolithic (P = 0.040) and −2.21 cm shorter relative to post-Neolithic individuals (P = 0.068), with osteological vs. expected stature steadily increasing across the Copper (+1.95 cm relative to the Neolithic), Bronze (+2.70 cm), and Iron (+3.27 cm) Ages. These results were attenuated when we additionally accounted for genome-wide genetic ancestry variation: for example, with Neolithic individuals −2.82 cm shorter than expected on average relative to pre-Neolithic individuals (P = 0.120). We also incorporated observations of paleopathological indicators of nonspecific stress that can persist from childhood to adulthood in skeletal remains into our model. Overall, our work highlights the potential of integrating disparate datasets to explore proxies of health in prehistory.info:eu-repo/semantics/publishedVersio

Genome-wide coancestry reveals details of ancient and recent male-driven reticulation in baboons

[INTRODUCTION] As a widespread but comparatively young clade of six parapatric species, the baboons (Papio sp.) exemplify a frequently observed pattern of mammalian diversity. In particular, they provide analogs for the population structure of the multibranched prehuman lineage that occupied a similar geographic range before the hegemony of “modern” humans, Homo sapiens. Despite phenotypic and genetic differences, interspecies hybridization has been described between baboons at several locations, and population relationships based on mitochondrial DNA (mtDNA) do not correspond with relationships based on phenotype. These previous studies captured the broad outlines of baboon population genetic structure and evolutionary history but necessarily used data that were limited in genomic and geographical coverage and therefore could not adequately document inter- and intrapopulation variation. In this study, we analyzed whole-genome sequences of 225 baboons representing all six species and 19 geographic sites, with 18 local populations represented by multiple individuals.[RATIONALE] Recent studies have identified several mammalian species groups in which genetically distinct lineages have hybridized to generate complex reticulate phylogenies. Baboons provide a valuable context for studying processes generating such population and phylogenetic complexity because extant parapatric species form hybrid zones in several regions of Africa, allowing for direct observation of ongoing introgression. Furthermore, prior studies of nuclear and mtDNA and phenotypic diversity have demonstrated gene flow among differentiated lineages but were unable to develop the detailed picture of process and history that is now possible using whole-genome sequences and modern computational methods. To address these questions, we designed a study that would provide a more fine-grained picture of recent and ancient genetic reticulation by comparing phenotypes and autosomal, X and Y chromosomal, and mtDNA sequences, along with polymorphic insertions of repetitive elements across multiple baboon populations.[RESULTS] Using deep whole-genome sequence data from 225 baboons representing multiple populations, we identified several previously unknown geographic sites of gene flow between genetically distinct populations. We report that yellow baboons (P. cynocephalus) from western Tanzania are the first nonhuman primate found to have received genetic input from three distinct lineages. We compared the ancestry shared among individuals, estimated separately from the X chromosome and autosomes, to distinguish shared ancestry due to ancestral population relationships from coancestry as a result of recent male-biased immigration and gene flow. This reveals directionality and sex bias of recent gene flow in several locations. Analyses of population differences within species quantified different degrees of interspecies introgression among populations with an essentially identical phenotype.[CONCLUSION] The population genetic structure and history of introgression among baboon lineages are even more complex than predicted from observed phenotypic diversity and prior studies of limited genetic data. Single populations can carry genetic contributions from more than two ancestral sources. Populations that appear homogeneous on the basis of observable phenotype can display different levels of interspecies introgression. The evolutionary dynamics and current structure of baboon population diversity indicate that other mammals displaying differentiated and geographically separate species may also have more-complex histories than anticipated. This may also be true for the morphologically defined hominin taxa from the past 4 million years.This work was funded by “la Caixa” Foundation (ID 100010434), fellowship code LCF/BQ/PR19/11700002 (M.K.); the Vienna Science and Technology Fund (WWTF) (10.47379/VRG20001) (M.K.); German Research Foundation grants FI707/9-1, KN1097/3-1/3-1, KN1097/4-1, ZI548/5-1, and RO3055/2-1 (J.F., S.K., D.Z., and C.R.); Novo Nordisk Foundation grant 0058553 (E.F.S. and K.M.); R01 GM59290 (M.A.B.); and internal funding from Baylor College of Medicine (J.R.). T.M.B. is supported by funding from the European Research Council under the European Union's Horizon 2020 research and innovation programme (grant 864203), PID2021-126004NB-100 (MICIIN/FEDER, UE) and Secretaria d'Universitats i Recerca and CERCA Programme del Departament d'Economia i Coneixement de la Generalitat de Catalunya (GRC 2021 SGR 00177).Peer reviewe

Awash baboon hybrid zone map

Map of baboon groups in the Awash Hybrid Zone in Awash Ethiopia

Relationship between genome‐wide and MHC class I and II genetic diversity and complementarity in a nonhuman primate

Although mate choice is expected to favor partners with advantageous genetic properties, the relative importance of genome-wide characteristics, such as overall heterozygosity or kinship, versus specific loci, is unknown. To disentangle genome-wide and locus-specific targets of mate choice, we must first understand congruence in global and local variation within the same individual. This study compares genetic diversity, both absolute and relative to other individuals (i.e., complementarity), assessed across the genome to that found at the major histocompatibility complex (MHC), a hyper-variable gene family integral to immune system function and implicated in mate choice across species. Using DNA from 22 captive olive baboons (Papio anubis), we conducted double digest restriction site-associated DNA sequencing to estimate genome-wide heterozygosity and kinship, and sequenced two class I and two class II MHC loci. We found that genome-wide diversity was not associated with MHC diversity, and that diversity at class I MHC loci was not correlated with diversity at class II loci. Additionally, kinship was a significant predictor of the number of MHC alleles shared between dyads at class II loci. Our results provide further evidence of the strong selective pressures maintaining genetic diversity at the MHC in comparison to other randomly selected sites throughout the genome. Furthermore, our results indicate that class II MHC disassortative mate choice may mediate inbreeding avoidance in this population. Our study suggests that mate choice favoring genome-wide genetic diversity is not always synonymous with mate choice favoring MHC diversity, and highlights the importance of controlling for kinship when investigating MHC-associated mate choice.National Science Foundation of Sri Lanka https://doi.org/10.13039/501100008982New York University https://doi.org/10.13039/10000673

Transcriptomic and small RNA response to Mayaro virus infection in Anopheles stephensi mosquitoes

Mayaro virus (MAYV) is an arboviral pathogen in the genus Alphavirus that is circulating in South America with potential to spread to naïve regions. MAYV is also one of the few viruses with the ability to be transmitted by mosquitoes in the genus Anopheles, as well as the typical arboviral transmitting mosquitoes in the genus Aedes. Few studies have investigated the infection response of Anopheles mosquitoes. In this study we detail the transcriptomic and small RNA responses of An. stephensi to infection with MAYV via infectious bloodmeal at 2, 7, and 14 days post infection (dpi). 487 unique transcripts were significantly regulated, 78 putative novel miRNAs were identified, and an siRNA response is observed targeting the MAYV genome. Gene ontology analysis of transcripts regulated at each timepoint shows a number of proteases regulated at 2 and 7 dpi, potentially representative of Toll or melanization pathway activation, and repression of pathways related to autophagy and apoptosis at 14 dpi. These findings provide a basic understanding of the infection response of An. stephensi to MAYV and help to identify host factors which might be useful to target to inhibit viral replication in Anopheles mosquitoes

Deflating the "Good Genes Hypothesis": Asymmetry may not be an honest indicator of genetic quality in humans

edition: https://onlinelibrary.wiley.com/doi/abs/10.1002/ajpa.23210status: publishe