Project description:. Here we provide a deeper insight into Xenopsylla cheopis salivary glands contents pairing transcriptome and proteomic approaches. Sequencing of 99 pairs of salivary glands from adult females X. cheopis yielded a total of 7,432 coding sequences functionally classified into 25 classes, in which the secreted class was found to be the most abundant one. The translated transcripts also served as a reference database for the proteomic study, which identified peptides from 610 different proteins.
Project description:XC-43 is a small peptide identified in the sialome of the flea Xenopsylla cheopis and act as a fast, tight-binding inhibitor of thrombin with a dissociation constant of less than 10 pM. The crystal structure of XC-43 in complex with thrombin shows that despite its substrate-like binding mode, XC-43 is not detectably cleaved by thrombin and that it interacts with the thrombin surface from the enzyme catalytic site through the fibrinogen-binding exosite I. The low rate of hydrolysis is verified in solution experiments with XC-43 which show the substrate to be largely intact after two hours of incubation with thrombin at 37°C. The potential of XC-43 as an anticoagulant is suggested by increased arterial occlusion time, tail bleeding time, and blood coagulation parameters in rat models of thrombosis.
Project description:Xenopsylla cheopis, also called oriental rat flea, is an ectoparasite as well as disease vector for murine typhus and bubonic plague. In the study, the whole mitochondrial genome of X. cheopis was sequenced and assembled, which is the second report of mitochondrial genome in the family Pulicidae and the sixth mitochondrial genome in the order Siphonaptera (fleas). The mitochondrial genome is 18,902 bp in length, consisting of 40% A, 44% T, 6% G, and 10% C. Phylogenetic analysis of all available mitochondrial genomes from Siphonaptera indicated that X. cheopis clustered with Ctenocephalides felis since both species belonged to the family Pulicidae. The complete mitochondrial genome of X. cheopis could serve as useful genetic data for investigating the genetic relationship of fleas.