Evolutionary origin of peptidoglycan recognition proteins in vertebrate innate immune system.

Background: Innate immunity is the ancient defense system of multicellular organisms against microbial infection. The basis of this first line of defense resides in the recognition of unique motifs conserved in microorganisms, and absent in the host. Peptidoglycans, structural components of bacterial cell walls, are recognized by Peptidoglycan Recognition Proteins (PGRPs).

Evolution of the A+T-rich region of mitochondrial DNA in the melanogaster species subgroup of Drosophila.

We determined the nucleotide sequences of two regions in the A+T-rich region of mitochondrial DNA (mtDNA) in the siI and siII types of D. simulans, the maII type of D. mauritiana, and D.