Functional genomic insights into the environmental determinants of mammalian fitness

Social status predicts physiological and behavioral responses to chronic stress in rhesus monkeys

Investigating the underlying factors that cause differential individual responses to chronic stress is crucial for developing personalized therapies, especially in the face of pandemics such as COVID-19. However, this question remains elusive, particularly in primates. In the present study, we aimed to address this question by utilizing monkeys as a model to examine the impacts of social rank on stress levels and physiological and behavioral responses to chronic stress primarily caused by social isolation at both the individual and group levels. Our results showed that high-ranking animals were more susceptible to chronic stress. After exposure to chronic stress, although social hierarchies remained the same, the colonies exhibited more harmonious group relationships (e.g., more prosocial behaviors), with notable contributions from low-ranking animals. Overall, this study deepens our understanding of how social status shapes responses to chronic stress and sheds light on developing tailored and personalized therapies for coping with chronic stress.

The "telomereless" erythrocytes and telomere-length dependent erythropoiesis

Approximately 25 trillion erythrocytes (red blood cells) circulate in the bloodstream of an adult human, surpassing the number of circulating leukocytes (white blood cells) by a factor of about 1000. Moreover, the erythrocyte turnover rate accounts for approximately 76% of the turnover rate of all circulating blood cells. This simple math shows that the hematopoietic system principally spends its telomere length-dependent replicative capacity on building and maintaining the erythrocyte blood pool. Erythropoiesis (red blood cell production) is thus the principal cause of telomere shortening with age in hematopoietic cells (HCs), a conclusion that holds significant implications for linking telomere length dynamics in HCs to health and lifespan of modern humans.

Novel genetic variants data for adaptation to hypoxia in native chickens

OBJECTIVE

The genomic response and the role of genetic variants in hypoxia condition are always interesting issues about adaption pathways at genomic level. Herein, we carried out a comparative genomic study between highland and lowland native chickens, in order to identify the adaptive variants in hypoxia condition. We generated more than 20 million genetic variants in highland and lowland chickens. Finally, 3877 SNVs including the mtDNA ones, were discovered as novel adaptive genetic variants. The generated data set can provide new insight about mechanism of adaptation to hypoxia at genomic level.

DATA DESCRIPTION

To investigate the role of genetic variants in adaptation to hypoxia, 10 whole-genome sequencing data sets associated to highland and lowland native chickens were provided. DNA was extracted by salting-out protocol. Paired-end 125 bp short reads were sequenced by Illumina Hiseq 2000. Variants calling of highland and lowland native chickens were performed by fix ploidy algorithm in CLC Genomic Workbench. Total genetic variants of highland chickens were compared to lowland chickens in order to identify the differential genetic variants (DGVs) between highland and lowland chickens. In this way, 3877 novel SNVs (VCF format) including the mtDNA ones, were deposited at EBI database ( https://identifiers.org/ena.embl:ERZ491574 ) for the first time.

Contrasting effects of Western vs Mediterranean diets on monocyte inflammatory gene expression and social behavior in a primate model

Dietary changes associated with industrialization increase the prevalence of chronic diseases, such as obesity, type II diabetes, and cardiovascular disease. This relationship is often attributed to an 'evolutionary mismatch' between human physiology and modern nutritional environments. Western diets enriched with foods that were scarce throughout human evolutionary history (e.g. simple sugars and saturated fats) promote inflammation and disease relative to diets more akin to ancestral human hunter-gatherer diets, such as a Mediterranean diet. Peripheral blood monocytes, precursors to macrophages and important mediators of innate immunity and inflammation, are sensitive to the environment and may represent a critical intermediate in the pathway linking diet to disease. We evaluated the effects of 15 months of whole diet manipulations mimicking Western or Mediterranean diet patterns on monocyte polarization in a well-established model of human health, the cynomolgus macaque (Macaca fascicularis). Monocyte transcriptional profiles differed markedly between diets, with 40% of transcripts showing differential expression (FDR < 0.05). Monocytes from Western diet consumers were polarized toward a more proinflammatory phenotype. The Western diet shifted the co-expression of 445 gene pairs, including small RNAs and transcription factors associated with metabolism and adiposity in humans, and dramatically altered behavior. For example, Western-fed individuals were more anxious and less socially integrated. These behavioral changes were also associated with some of the effects of diet on gene expression, suggesting an interaction between diet, central nervous system activity, and monocyte gene expression. This study provides new molecular insights into an evolutionary mismatch and uncovers new pathways through which Western diets alter monocyte polarization toward a proinflammatory phenotype.

Epigenomics and gene regulation in mammalian social systems

Social epigenomics is a new field of research that studies how the social environment shapes the epigenome and how in turn the epigenome modulates behavior. We focus on describing known gene-environment interactions (GEIs) and epigenetic mechanisms in different mammalian social systems. To illustrate how epigenetic mechanisms integrate GEIs, we highlight examples where epigenetic mechanisms are associated with social behaviors and with their maintenance through neuroendocrine, locomotor, and metabolic responses. We discuss future research trajectories and open questions for the emerging field of social epigenomics in nonmodel and naturally occurring social systems. Finally, we outline the technological advances that aid the study of epigenetic mechanisms in the establishment of GEIs and vice versa.

Social determinants of health and survival in humans and other animals

The social environment, both in early life and adulthood, is one of the strongest predictors of morbidity and mortality risk in humans. Evidence from long-term studies of other social mammals indicates that this relationship is similar across many species. In addition, experimental studies show that social interactions can causally alter animal physiology, disease risk, and life span itself. These findings highlight the importance of the social environment to health and mortality as well as Darwinian fitness-outcomes of interest to social scientists and biologists alike. They thus emphasize the utility of cross-species analysis for understanding the predictors of, and mechanisms underlying, social gradients in health.