New records and invasion risk of Stenochrus portoricensis Chamberlin, 1922 (Schizomida: Hubbardiidae) in Brazil

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  New records and invasion risk of Stenochrus portoricensis Chamberlin, 1922 (Schizomida: Hubbardiidae) in Brazil Abstract Stenochrus portoricensis Chamberlin, 1922 is a schizomid native to the Caribbean and Central America and is notable for facultative parthenogenesis and a broad synanthropic distribution. It is widely reported as an exotic species in several regions worldwide, with recognized invasive potential. Here, we expand its known distribution in Brazil by documenting the first records from the state of Mato Grosso and new occurrences in tourist caves in Bahia. We also model the species’ potential distribution in South America using the Maximum Entropy (MaxEnt) algorithm under current and future climate scenarios. The models indicate higher habitat suitability in regions characterized by low annual temperature variation and consistent rainfall patterns, conditions typical of tropical and subterranean environments, and predict range expansion under future climate change, p...

Exploring changes in social spider DNA methylation profiles in all cytosine contexts following infection

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Exploring changes in social spider DNA methylation profiles in all cytosine contexts following infection

Abstract

Living at high density and with low genetic diversity are factors that should both increase the susceptibility of organisms to disease. Therefore, group living organisms, especially those that are inbred, should be especially vulnerable to infection and therefore have particular strategies to cope with infection. Phenotypic plasticity, underpinned by epigenetic changes, could allow group living organisms to rapidly respond to infection challenges. To explore the potential role of epigenetic modifications in the immune response to a group-living species with low genetic diversity, we compared the genome-wide DNA methylation profiles of five colonies of social spiders (Stegodyphus dumicola) in their natural habitat in Namibia at the point just before they succumbed to infection to a point at least six months previously where they were presumably healthier. We found increases in genome- and chromosome-wide methylation levels in the CpG, CHG, and CHH contexts, although the genome-wide changes were not clearly different from zero. These changes were most prominent in the CHG context, especially at a narrow region of chromosome 13, hinting at an as-of-yet unsuspected role of this DNA methylation context in phenotypic plasticity. However, there were few clear patterns of differential methylation at the base level, and genes with a known immune function in spiders had mean methylation changes close to zero. Our results suggest that DNA methylation may change with infection at large genomic scales, but that this type of epigenetic change is not necessarily integral to the immune response of social spiders.

Fisher, D.N., Bechsgaard, J. & Bilde, T. Exploring changes in social spider DNA methylation profiles in all cytosine contexts following infection. Heredity (2024). https://doi.org/10.1038/s41437-024-00724-y