MRG-1/MRG15 is a barrier for germ cell to neuron reprogramming in Caenorhabditis elegans

Chromatin regulators play important roles in the safeguarding of cell identities by opposing the induction of ectopic cell fates and, thereby, preventing forced conversion of cell identities by reprogramming approaches. Our knowledge of chromatin regulators acting as reprogramming barriers in living organisms needs improvement as most studies use tissue culture. We used C. elegans as an in vivo gene discovery model and automated solid-phase RNAi screening, by which we identified 10 chromatin-regulating factors that protect cells against ectopic fate induction. Specifically, the chromodomain protein MRG-1 safeguards germ cells against conversion into neurons. MRG-1 is the ortholog of mammalian MRG15 (MORF-related gene on chromosome 15) and is required during germline development in C. elegans. However, MRG-1's function as a barrier for germ cell reprogramming has not been revealed previously. Here, we further provide protein-protein and genome interactions of MRG-1 to characterize its molecular functions. Conserved chromatin regulators may have similar functions in higher organisms and, therefore, understanding cell fate protection in C. elegans may also help to facilitate reprogramming of human cells

Molecular Epidemiology of Rickettsial Diseases

This chapter summarizes the classical methods used to investigate rickettsioses initially discovered and characterized in the United States with an emphasis on their role in understanding their epidemiology. More recent molecular methodologies used to diagnose and characterize rickettsioses and rickettsial agents are then presented. New epidemiological insights into rickettsioses that have been obtained by using these molecular tools are then reviewed. Finally, the limitations of contemporary tools used in the molecular epidemiology of rickettsioses are examined and discussed in the context of new opportunities for improvement of these current approaches