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1. Parenting moderates the etiology of callous‐unemotional traits in middle childhood

   https://doi.org/10.1111/jcpp.13542  

   Tomlinson, Rachel C. ; Hyde, Luke W. ; Dotterer, Hailey L. ; Klump, Kelly L. ; Burt, S. Alexandra ( November 2021 , Journal of Child Psychology and Psychiatry)

   Callous‐unemotional (CU) traits are associated with chronic and escalating trajectories of antisocial behavior. Extant etiologic studies suggest that heritability estimates for CU traits vary substantially, while also pointing to an environmental association between parenting and CU traits.

   We used twin modeling to estimate additive genetic (A), shared environmental (C), and nonshared environmental (E) influences on CU traits, measured with the Inventory of Callous‐Unemotional Traits (ICU) and its subscales. Our sample included 600 twin pairs (age 6–11, 230 monozygotic) from neighborhoods with above‐average levels of family poverty, a risk factor for antisocial behavior. We examined the extent to which correlations between parenting, measured via parent and child report on the Parental Environment Questionnaire, and CU traits reflected genetic versus environmental factors. Then, we tested whether parenting moderated the heritability of CU traits.

   In the context of lower‐income neighborhoods, CU traits were moderately to highly heritable (A = 54%) with similar moderate‐to‐high nonshared environmental influences (E = 46%). Bivariate models revealed that associations between CU traits andwarmparenting were genetic (rA = .22) and environmental (rE = .19) in origin, whereas associations between CU traits andharshparenting were largely genetic in origin (rA = .70). The heritability of CU traits decreased with increasing parental warmth and decreasing harshness.

   Callous‐unemotional traits are both genetic and environmental in origin during middle childhood, but genetic influences are moderated by parenting quality. Parenting may be an important target for interventions, particularly among youth with greater genetic risk.

    

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2. Tolerance traits related to climate change resilience are independent and polygenic

   https://doi.org/10.1111/gcb.14386  

   Healy, Timothy M. ; Brennan, Reid S. ; Whitehead, Andrew ; Schulte, Patricia M. ( August 2018 , Global Change Biology)

   The resilience of organisms to climate change through adaptive evolution is dependent on the extent of genetically based variation in key phenotypic traits and the nature of genetic associations between them. For aquatic animals, upper thermal tolerance and hypoxia tolerance are likely to be a important determinants of sensitivity to climate change. To determine the genetic basis of these traits and to detect associations between them, we compared naturally occurring populations of two subspecies of Atlantic killifish,Fundulus heteroclitus, that differ in both thermal and hypoxia tolerance. Multilocus association mapping demonstrated that 47 and 35 single nucleotide polymorphisms (SNPs) explained 43.4% and 51.9% of variation in thermal and hypoxia tolerance, respectively, suggesting that genetic mechanisms underlie a substantial proportion of variation in each trait. However, no explanatory SNPs were shared between traits, and upper thermal tolerance varied approximately linearly with latitude, whereas hypoxia tolerance exhibited a steep phenotypic break across the contact zone between the subspecies. These results suggest that upper thermal tolerance and hypoxia tolerance are neither phenotypically correlated nor genetically associated, and thus that rates of adaptive change in these traits can be independently fine‐tuned by natural selection. This modularity of important traits can underpin the evolvability of organisms to complex future environmental change.

    

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3. Genomic variation in the American pika: signatures of geographic isolation and implications for conservation

   https://doi.org/10.1186/s12862-020-01739-9  

   Klingler, Kelly B. ; Jahner, Joshua P. ; Parchman, Thomas L. ; Ray, Chris ; Peacock, Mary M. ( January 2021 , BMC Ecology and Evolution)

   Distributional responses by alpine taxa to repeated, glacial-interglacial cycles throughout the last two million years have significantly influenced the spatial genetic structure of populations. These effects have been exacerbated for the American pika (Ochotona princeps), a small alpine lagomorph constrained by thermal sensitivity and a limited dispersal capacity. As a species of conservation concern, long-term lack of gene flow has important consequences for landscape genetic structure and levels of diversity within populations. Here, we use reduced representation sequencing (ddRADseq) to provide a genome-wide perspective on patterns of genetic variation across pika populations representing distinct subspecies. To investigate how landscape and environmental features shape genetic variation, we collected genetic samples from distinct geographic regions as well as across finer spatial scales in two geographically proximate mountain ranges of eastern Nevada.

   Our genome-wide analyses corroborate range-wide, mitochondrial subspecific designations and reveal pronounced fine-scale population structure between the Ruby Mountains and East Humboldt Range of eastern Nevada. Populations in Nevada were characterized by low genetic diversity (π = 0.0006–0.0009; θ_W = 0.0005–0.0007) relative to populations in California (π = 0.0014–0.0019; θ_W = 0.0011–0.0017) and the Rocky Mountains (π = 0.0025–0.0027; θ_W = 0.0021–0.0024), indicating substantial genetic drift in these isolated populations. Tajima’sDwas positive for all sites (D = 0.240–0.811), consistent with recent contraction in population sizes range-wide.

   Substantial influences of geography, elevation and climate variables on genetic differentiation were also detected and may interact with the regional effects of anthropogenic climate change to force the loss of unique genetic lineages through continued population extirpations in the Great Basin and Sierra Nevada.

    

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4. Markers of Environmental Enteric Dysfunction Are Associated With Neurodevelopmental Outcomes in Tanzanian Children

   https://doi.org/10.1097/MPG.0000000000001978  

   Etheredge, Analee J. ; Manji, Karim ; Kellogg, Mark ; Tran, Hao ; Liu, Enju ; McDonald, Christine M. ; Kisenge, Rodrick ; Aboud, Said ; Fawzi, Wafaie ; Bellinger, David ; et al ( June 2018 , Journal of Pediatric Gastroenterology and Nutrition)

   Chronic exposure to enteropathogens may result in environmental enteric dysfunction (EED), a subclinical condition associated with poor child growth. Growth faltering is strongly associated with poor neurodevelopment, and occurs during sensitive periods of postnatal brain development. We investigated the role of novel EED biomarkers, systemic inflammation, and micronutrient status on neurodevelopment in Tanzanian children.

   Non‐stunted subjects with 6‐week and 6‐month blood samples and neurodevelopmental measures (n = 107) were included in this study. Samples were tested for biomarkers of gastrointestinal function (citrulline, antibodies to lipopolysaccharide, and flagellin), micronutrient status (iron, retinol binding protein [RBP], and vitamin D), systemic inflammation (C‐reactive protein [CRP] and alpha‐1‐acid glycoprotein), and growth (insulin‐like growth factor and insulin‐like growth factor binding protein 3).

   Cognitive scores at 15 months were associated with higher concentrations of 6‐month anti‐lipopolysaccharide IgG (β = 1.95,P= 0.02), anti‐flagellin IgA (β = 2.41,P= 0.04), and IgG (β = 2.99,P= 0.009). Higher receptive language scores were positively associated with anti‐flagellin IgG (β = 0.95,P= 0.05), and receptive language and gross motor scores were positively associated with citrulline at 6 months (β = 0.09,P= 0.02; β = 0.10,P= 0.03, respectively). Gross motor scores were positively associated with RBP at 6 months (β = 1.70,P= 0.03). Markers of systemic inflammation were not significantly associated with neurodevelopment.

   Plasma citrulline, a marker of gastrointestinal mucosal surface area, and vitamin A status were associated with higher gross motor development scores. Novel markers for EED, but not inflammation, were positively associated with cognitive scores, suggesting a possible mechanistic pathway involving immune response and neuroprotection.

    

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5. Leave no stone unturned: individually adapted xerotolerant Thaumarchaeota sheltered below the boulders of the Atacama Desert hyperarid core

   https://doi.org/10.1186/s40168-021-01177-9  

   Hwang, Yunha ; Schulze-Makuch, Dirk ; Arens, Felix L. ; Saenz, Johan S. ; Adam, Panagiotis S. ; Sager, Christof ; Bornemann, Till L. V. ; Zhao, Weishu ; Zhang, Ying ; Airo, Alessandro ; et al ( November 2021 , Microbiome)

   The hyperarid core of the Atacama Desert is an extremely harsh environment thought to be colonized by only a few heterotrophic bacterial species. Current concepts for understanding this extreme ecosystem are mainly based on the diversity of these few species, yet a substantial area of the Atacama Desert hyperarid topsoil is covered by expansive boulder accumulations, whose underlying microbiomes have not been investigated so far. With the hypothesis that these sheltered soils harbor uniquely adapted microbiomes, we compared metagenomes and geochemistry between soils below and beside boulders across three distantly located boulder accumulations in the Atacama Desert hyperarid core.

   Genome-resolved metagenomics of eleven samples revealed substantially different microbial communities in soils below and beside boulders, despite the presence of shared species. Archaea were found in significantly higher relative abundance below the boulders across all samples within distances of up to 205 km. These key taxa belong to a novel genus of ammonia-oxidizingThaumarchaeota,CandidatusNitrosodeserticola. We resolved eight mid-to-high quality genomes of this genus and used comparative genomics to analyze its pangenome and site-specific adaptations.Ca.Nitrosodeserticola genomes contain genes for ammonia oxidation, the 3-hydroxypropionate/4-hydroxybutyrate carbon fixation pathway, and acetate utilization indicating a chemolithoautotrophic and mixotrophic lifestyle. They also possess the capacity for tolerating extreme environmental conditions as highlighted by the presence of genes against oxidative stress and DNA damage. Site-specific adaptations of the genomes included the presence of additional genes for heavy metal transporters, multiple types of ATP synthases, and divergent genes for aquaporins.

   We provide the first genomic characterization of hyperarid soil microbiomes below the boulders in the Atacama Desert, and report abundant and highly adaptedThaumarchaeaotawith ammonia oxidation and carbon fixation potential.Ca.Nitrosodeserticola genomes provide the first metabolic and physiological insight into a thaumarchaeal lineage found in globally distributed terrestrial habitats characterized by various environmental stresses. We consequently expand not only the known genetic repertoire ofThaumarchaeotabut also the diversity and microbiome functioning in hyperarid ecosystems.

    

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