TNFRSF13B Genetic variability an anthropological - evolutionary approach to Biomedical Research

In the recent years TNFRSF13B coding variants have been implicated by clinical genetics studies in Common Variable Immunodeficiency (CVID), the most common clinically relevant primary immunodeficiency in individuals of European ancestry, but their functional effects in relation to the development of the disease have not been entirely established. To examine the potential contribution of such variants to CVID, the more comprehensive perspective of an evolutionary approach was applied in this study, underling the belief that evolutionary genetics methods can play a role in dissecting the origin, causes and diffusion of human diseases, representing a powerful tool also in human health research. For this purpose, TNFRSF13B coding region was sequenced in 451 healthy individuals belonging to 26 worldwide populations, in addition to 96 control, 77 CVID and 38 Selective IgA Deficiency (IgAD) individuals from Italy, leading to the first achievement of a global picture of TNFRSF13B nucleotide diversity and haplotype structure and making suggestion of its evolutionary history possible. A slow rate of evolution, within our species and when compared to the chimpanzee, low levels of genetic diversity geographical structure and the absence of recent population specific selective pressures were observed for the examined genomic region, suggesting that geographical distribution of its variability is more plausibly related to its involvement also in innate immunity rather than in adaptive immunity only. This, together with the extremely subtle disease/healthy samples differences observed, suggests that CVID might be more likely related to still unknown environmental and genetic factors, rather than to the nature of TNFRSF13B variants only.

Land use change to perennial energy crops in Northern Italy: Effects on soil organic carbon sequestration and distribution, soil enzyme activities and microbial communities.

Studies on soil organic carbon (SOC) sequestration in perennial energy crops are available for North-Central Europe, while there is insufficient information for Southern Europe. This research was conducted in the Po Valley, a Mediterranean-temperate zone characterised by low SOC levels, due to intensive management. The aim was to assess the factors influencing SOC sequestration and its distribution through depth and within soil fractions, after a 9-year old conversion from two annual systems to Miscanthus (Miscanthus × giganteus) and giant reed (Arundo donax). The 13C natural abundance was used to evaluate the amount of SOC in annual and perennial species, and determine the percentage of carbon derived from perennial crops. SOC was significantly higher under perennial species, especially in the topsoil (0-0.15 m). After 9 years, the amount of C derived from Miscanthus was 18.7 Mg ha-1, mostly stored at 0-0.15 m, whereas the amount of C derived from giant reed was 34.7 Mg ha-1, evenly distributed through layers. Physical soil fractionation was combined with 13C abundance analysis. C derived from perennial crops was mainly found in macroaggregates. Under giant reed, more newly derived-carbon was stored in microaggregates and mineral fraction than under Miscanthus. A molecular approach based on denaturing gradient gel electrophoresis (DGGE) allowed to evaluate changes on microbial community, after the introduction of perennial crops. Functional aspects were investigated by determining relevant soil enzymes (β-glucosidase, urease, alkaline phosphatase). Perennial crops positively stimulated these enzymes, especially in the topsoil. DGGE profiles revealed that community richness was higher in perennial crops; Shannon index of diversity was influenced only by depth. In conclusion, Miscanthus and giant reed represent a sustainable choice for the recovery of soils exhausted by intensive management, also in Mediterranean conditions and this is relevant mainly because this geographical area is notoriously characterised by a rapid turnover of SOC.