Project description:Bats have attracted considerable interest for their extraordinary longevity and ability to withstand infection by a range of pathogens without major harm. Yet, little is known about the relationship between these two characteristics, or the extent to which they vary between individuals of the same species. We investigated sources of immune variation in wild greater spear-nosed bats, Phyllostomus hastatus, via transcriptome sequencing of blood samples before and after ex vivo exposure to lipopolysaccharide, a membrane component of gram-negative bacteria. We estimated bat ages from a combination of banding records and a methylation clock. We assessed immune variation across both sexes, males of contrasting social status, and the full range of ages in each sex. We observe striking immune variation associated with sex and age, with males and older bats mounting stronger inflammatory responses. These two factors interacted significantly, revealing male-biased slopes of age-related variation in immunity, the magnitude of which is consistent with male-biased ageing, supporting the predicted association between immunity and ageing.
Project description:Primary objectives: The primary objective is to investigate circulating tumor DNA (ctDNA) via deep sequencing for mutation detection and by whole genome sequencing for copy number analyses before start (baseline) with regorafenib and at defined time points during administration of regorafenib for treatment efficacy in colorectal cancer patients in terms of overall survival (OS).
Primary endpoints: circulating tumor DNA (ctDNA) via deep sequencing for mutation detection and by whole genome sequencing for copy number analyses before start (baseline) with regorafenib and at defined time points during administration of regorafenib for treatment efficacy in colorectal cancer patients in terms of overall survival (OS).
Project description:DNA methylation (DNAm) influences when and where genes are expressed or repressed during growth and development. Recently, patterns of DNAm at conserved genomic sites have been discovered that predict chronological age in all mammals. Deviations from these ‘epigenetic clocks’ have been used to identify factors that alter the aging process. In this study, we profile DNAm with a custom microarray for over 330 wild Phyllostomus hastatus, a highly polygynous bat in which unrelated females form long-lasting associations and larger males compete aggressively to control mating access to female groups. DNAm age estimates reveal that females can live more than 1.5 times as long as males. After fitting linear models for age, sex and their interaction we find that DNAm changes 1.4 times faster in males than females at thousands of sites. Therefore, even though age of either sex can be predicted by a common set of sites, the methylome of males is more dynamic than that of females. Sites associated with differences in the rate of change between males and females are sensitive to androgens and enriched on the X chromosome. Those that gain methylation with age in both sexes are associated with active and repressive chromatin states in blood and are enriched in promoters of genes involved in regulation of metabolic processes. In contrast, few sites differ in DNAm rate between males of different reproductive status, though subordinate males exhibit faster DNAm change than dominant males. Thus, males have accelerated physiological processes in comparison to females that likely increase mating success but reduce survival.
2024-12-12 | GSE273259 | GEO
Project description:RNA sequence of Corydoras hastatus