Learn More
Symbiotic associations between animals and microbes are ubiquitous in nature, with an estimated 15% of all insect species harboring intracellular bacterial symbionts. Most bacterial symbionts share many genomic features including small genomes, nucleotide composition bias, high coding density, and a paucity of mobile DNA, consistent with long-term host(More)
We have developed three strategies to discriminate among the three types of tRNA genes with anticodon CAT (tRNA(Ile), elongator tRNA(Met) and initiator tRNA(fMet)) in bacterial genomes. With these strategies, we have classified the tRNA genes from 234 bacterial and several organellar genomes. These sequences, in an aligned or unaligned format, may be used(More)
The present study explored bidirectional excitatory conditioning using the behavior systems assumption that conditioned responding is related to a sequence of search modes preceding and following the unconditioned stimulus. In Experiment 1a, rats were initially trained with either a forward serial conditioned stimulus (CS) (FCS F – FCS I –FCS N —Food; the(More)
BACKGROUND Understanding evolutionary processes that drive genome reduction requires determining the tempo (rate) and the mode (size and types of deletions) of gene losses. In this study, we analysed five endosymbiotic genome sequences of the gamma-proteobacteria (three different Buchnera aphidicola strains, Wigglesworthia glossinidia, Blochmannia(More)
A approximately 2.4-kb imprinting control region (ICR) regulates somatic monoallelic expression of the Igf2 and H19 genes. This is achieved through DNA methylation-dependent chromatin insulator and promoter silencing activities on the maternal and paternal chromosomes, respectively. In somatic cells, the hypomethylated maternally inherited ICR binds the(More)
BACKGROUND Bacterial symbioses are widespread among insects. The early establishment of such symbiotic associations has probably been one of the key factors for the evolutionary success of insects, since it may have allowed access to novel ecological niches and to new imbalanced food resources, such as plant sap or blood. Several genomes of bacterial(More)
We have reconstructed the gene content and order of the last common ancestor of the human pathogens Mycobacterium leprae and Mycobacterium tuberculosis. During the reductive evolution of M. leprae, 1537 of 2977 ancestral genes were lost, among which we found 177 previously unnoticed pseudogenes. We find evidence that a massive gene inactivation took place(More)
BACKGROUND Genome reduction is a common evolutionary process in symbiotic and pathogenic bacteria. This process has been extensively characterized in bacterial endosymbionts of insects, where primary mutualistic bacteria represent the most extreme cases of genome reduction consequence of a massive process of gene inactivation and loss during their evolution(More)
The availability of a large number of complete genome sequences raises the question of how many genes are essential for cellular life. Trying to reconstruct the core of the protein-coding gene set for a hypothetical minimal bacterial cell, we have performed a computational comparative analysis of eight bacterial genomes. Six of the analyzed genomes are very(More)
Bacterial symbioses are widespread among insects, probably being one of the key factors of their evolutionary success. We present the complete genome sequence of Blochmannia floridanus, the primary endosymbiont of carpenter ants. Although these ants feed on a complex diet, this symbiosis very likely has a nutritional basis: Blochmannia is able to supply(More)