However, the recent sequencing of two strains of T. princeps from P. citri (PCIT and PCVAL) has shown that it is, in fact, the smallest (139 kb) and most simplified bacterial genome described to date [16, 19]. Functional analysis reveals that the genetic repertoire of T. princeps is Selleckchem AZD7762 unable to sustain cellular life, according to Gil et al. (2004) [20], and that it entirely depends on M. endobia for many essential functions. Even though most of its genome is occupied by ribosomal

genes and genes involved in the biosynthesis of essential amino acids, T. princeps likely depends on its symbiotic consortium partner to build its own ribosomes and for amino acid production [16, 19]. The work published by McCutcheon and von Dohlen [16] mainly focused Selleck Bioactive Compound Library on the analysis of the T. princeps genome and detangling the amino acid biosynthetic pathways in which all three partners (T. princeps, M. endobia and the

host) appear to be involved. However, the characteristics and functionality of the M. endobia genome, as well as other possible modes of complementation between the two endosymbionts, have remained largely unexplored. In this work we present Topoisomerase inhibitor a comprehensive analysis of the predicted consortium functional capabilities and interactions, thus offering new insights into how this bacterial consortium may function internally. Additionally, we have performed a comparative analysis of both endosymbiont genomes in two P. citri strains, PCIT [16] and PCVAL ([19] and this work). Our analysis suggests that both genomes have undergone reductive evolution, albeit with some unusual genomic Methamphetamine features, probably as a consequence of their unprecedented compartmentalized organization. Results and discussion Main features and genomic variability between two

strains of P. citri nested endosymbionts The main molecular features of the genomes of T. princeps str. PCVAL [19] and PCIT [16], and M. endobia str. PCVAL (this work) and PCIT [16] are summarized in Table 1. It is worth mentioning that differences in CDS numbers and coding density between both strains are due to differences in the annotation criteria used, since the number of polymorphisms detected between the two sequenced strains of T. princeps and M. endobia is minimal (see Additional file 1 for a list of annotation differences in CDS and tRNA genes). Table 1 Main genomic features of the two strains of the P. citri endosymbiotic consortium already sequenced   T. princeps PCVAL T. princeps PCIT M. endobia PCVAL M.