Genetic structure of immunologically associated candidate genes suggests arctic rabies variants exert differential selection in arctic fox populations

Patterns of local adaptation can emerge in response to the selective pressures diseases exert on host populations as reflected in increased frequencies of respective, advantageous genotypes. Elucidating patterns of local adaptation enhance our understanding of mechanisms of disease spread and the capacity for species to adapt in context of rapidly changing environments such as the Arctic. Arctic rabies is a lethal disease that largely persists in northern climates and overlaps with the distribution of its natural host, arctic fox. Arctic fox populations display little neutral genetic structure across their North American range, whereas phylogenetically unique arctic rabies variants are restricted in their geographic distributions. It remains unknown if arctic rabies variants impose differential selection upon host populations, nor what role different rabies variants play in the maintenance and spread of this disease. Using a targeted, genotyping-by-sequencing assay, we assessed correlations of arctic fox immunogenetic variation with arctic rabies variants to gain further insight into the epidemiology of this disease. Corroborating past research, we found no neutral genetic structure between sampled regions, but did find moderate immunogenetic structuring between foxes predominated by different arctic rabies variants. FST outliers associated with host immunogenetic structure included SNPs within interleukin and Toll-like receptor coding regions (IL12B, IL5, TLR3 and NFKB1); genes known to mediate host responses to rabies. While these data do not necessarily reflect causation, nor a direct link to arctic rabies, the contrasting genetic structure of immunologically associated candidate genes with neutral loci is suggestive of differential selection and patterns of local adaptation in this system. These data are somewhat unexpected given the long-lived nature and dispersal capacities of arctic fox; traits expected to undermine local adaptation. Overall, these data contribute to our understanding of the co-evolutionary relationships between arctic rabies and their primary host and provide data relevant to the management of this disease.

Mendelian Executive

A “Mendelian” executive is proposed as an image of strategy-making that lies intermediate between the grand strategist suggested by rational choice approaches and a Darwinian process of random variation and market-based differential selection. The Mendelian executive is capable of intentional design efforts in order to explore possible adjacent strategic spaces. Furthermore, the argument developed here highlights the role of intentionality with respect to selection processes within the organization, and the culling and amplification of strategic initiatives. The firm is viewed as operating an “artificial selection” environment in contrast to selection as the direct consequence of the outcome of competitive processes. Examining the nature of the processes generating these experimental variants and the bases of internal selection, and how these selection criteria may themselves change, is argued to be central to the formation of strategy in dynamic environments.

Gendered working environments as a determinant of mental health inequalities: a systematic review of 27 studies

Background‘Gendered working environments’ describes the ways in which (1) differential selection into work, (2) variations in employment arrangements and working hours, (3) differences in psychosocial exposures and (4) differential selection out of work may produce varied mental health outcomes for men and women. The aim of this study was to conduct a systematic review to understand gender differences in mental health outcomes in relation to the components of gendered working environments.MethodsThe review followed a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) search approach and focused on studies published in 2008–2018. The protocol for the review was prospectively registered with PROSPERO (CRD42019124066).FindingsAcross the 27 cohort studies included in the review, we found that (1) there was inconclusive evidence on the effect of occupational gender composition on the mental health of men and women, (2) women’s mental health was more likely to be affected by long working hours than men’s; however, precarious employment was more likely to be negatively associated with men’s mental health, (3) exposure to traditional constructs of psychosocial job stressors negatively affected the mental health of both women and men, and (4) unemployment and retirement are associated with poorer mental health in both genders.InterpretationThe findings from this review indicate that gendered working environments may affect the mental health of both men and women, but the association is dependent on the specific exposure examined. There is still much to be understood about gendered working environments, and future research into work and health should be considered with a gender lens.

Exploring the potential genetic heterogeneity in the incidence of hoof and leg disorders in Austrian Fleckvieh and Braunvieh cattle

BackgroundGenetic heterogeneity denotes the situation when different genetic architectures underlying diverse populations result in the same phenotype. In this study, we explore the nature of differences in the incidence of the number of hoof and leg disorders between Braunvieh and Fleckvieh cattle in the context of genetic heterogeneity between the breeds.ResultsDespite potentially higher power of testing due to twice as large sample size, none of the SNPs was significantly associated with the number of hoof and leg disorders in Fleckvieh, while 16 SNPs were significant in Braunvieh. The most promising candidate genes in Braunvieh are: CBLB on BTA01, which causes arthritis in rats; CAV2 on BTA04, which in effects mouse skeletal muscles; PTHLH on BTA05, which causes disease phenotypes related to the skeleton in humans, mice and zebrafish; SORCS2 on BTA06, which causes decreased susceptibility to injury in the mouse. Some of the significant SNPs (BTA01, BTA04, BTA05, BTA13, BTA16) reveal allelic heterogeneity – i.e. differences due to different allele frequencies between Fleckvieh and Braunvieh. Some of the significant regions (BTA01, BTA05, BTA13, BTA16) correlate to inter-breed differences in LD structure and may thus represent false-positive heterogeneity. However, positions on BTA06 (SORCS2), BTA14 and BTA24 mark Braunvieh-specific regions.ConclusionsWe hypothesise that the observed genetic heterogeneity of hoof and leg disorders is a by-product of multigenerational differential selection of the breeds – towards dairy production in the case of Braunvieh and towards beef production in the case of Fleckvieh. Based on the current data set it is no possibly to unequivocally confirm/exclude the hypothesis of genetic heterogeneity in the susceptibility to leg disorders between Fleckvieh and Braunvieh because only explore it through associations and not the causal mutations. Rationales against genetic heterogeneity comprise a limited power of detection of true associations as well as differences in the length of LD blocks and in linkage phase between breeds. On the other hand, multigenerational differential selection of the breeds and no systematic differences in LD structure between the breeds favour the heterogeneity hypothesis at some of the significant sites.

COLLEGE COMPLETION AS A PROTECTIVE FACTOR FOR LATER-LIFE COGNITION: ISSUES OF SELECTION

Additional years of education is considered a modifiable protective factor against Alzheimer’s disease and related dementias. However, some empirical studies have suggested that linkages between educational attainment and later life cognition are largely a function of differential selection into higher education. Our study uses data from the Wisconsin Longitudinal Study, as one of the longest-running cohort studies in the U.S., to further probe how differential selection into higher education might influence associations between college completion and later life cognition. Using adjusted inverse probability weighting and with particular attention to adolescent IQ, we find evidence that college completion is associated with better language for both men and women at age 65, as well as with better memory for men. Examining heterogeneous treatment effects, we further find that associations between college completion and later life cognition are strongest for men who were least likely as adolescents to attend college.