The Evolution of Host Specialization in the Vertebrate Gut Symbiont Lactobacillus reuteri

Recent research has provided mechanistic insight into the important contributions of the gut microbiota to vertebrate biology, but questions remain about the evolutionary processes that have shaped this symbiosis. In the present study, we showed in experiments with gnotobiotic mice that the evolution of Lactobacillus reuteri with rodents resulted in the emergence of host specialization. To identify genomic events marking adaptations to the murine host, we compared the genome of the rodent isolate L. reuteri 100-23 with that of the human isolate L. reuteri F275, and we identified hundreds of genes that were specific to each strain. In order to differentiate true host-specific genome content from strain-level differences, comparative genome hybridizations were performed to query 57 L. reuteri strains originating from six different vertebrate hosts in combination with genome sequence comparisons of nine strains encompassing five phylogenetic lineages of the species. This approach revealed that rodent strains, although showing a high degree of genomic plasticity, possessed a specific genome inventory that was rare or absent in strains from other vertebrate hosts. The distinct genome content of L. reuteri lineages reflected the niche characteristics in the gastrointestinal tracts of their respective hosts, and inactivation of seven out of eight representative rodent-specific genes in L. reuteri 100-23 resulted in impaired ecological performance in the gut of mice. The comparative genomic analyses suggested fundamentally different trends of genome evolution in rodent and human L. reuteri populations, with the former possessing a large and adaptable pan-genome while the latter being subjected to a process of reductive evolution. In conclusion, this study provided experimental evidence and a molecular basis for the evolution of host specificity in a vertebrate gut symbiont, and it identified genomic events that have shaped this process

Lipstick, lace, and longing : constructions of femininity inside a Russian prison

This paper examines the construction of femininity within Russian women's prisons. On the basis of fieldwork carried out in three women's prisons in the secure and restricted penal zone within Mordovia, Russian Federation, we present unique and original qualitative data, as well as a critical engagement with contemporary Russian press sources. Starting from the assumption that the (free) female body is a particular target of Foucauldian disciplinary power, in that gender is a discipline which produces bodies and identities and operates as an effective form of social control, we examine the ways in which this disciplinary power of gender is compounded by bodily imprisonment. Criminal women are often considered not only to have broken the law but also to have offended against their culturally specific gender role expectations, and punishment applied to women prisoners is grounded not on what women are like, but on how women 'ought' to behave in a particular cultural context, with interventions coercing or persuading women to reintegrate into a recognisably 'feminine' form.We uncover Russia's exceptional and exclusionary geography of women's imprison- ment, and rehabilitative and educational processes, including a beauty pageant, which seek to rescript criminal women toward a predetermined 'ideal' of Russian womanhood, and also explore the ways in which women seek to resist