Multihost saprobes are facultative pathogens of bullfrog Lithobates catesbeianus eggs.

Pathogens that infect more than one host species create complex linkages in ecological communities. We tested whether saprobes that grow on multiple host species in aquatic systems can be facultative pathogens of amphibian eggs. We isolated oomycetes from dead arthropods, vertebrates, plant leaves, and frog eggs that coexisted in a small pond.

Duplication, concerted evolution and purifying selection drive the evolution of mosquito vitellogenin genes.

Background: Mosquito vitellogenin (Vtg) genes belong to a small multiple gene family that encodes the major yolk protein precursors required for egg production. Multiple Vtg genes have been cloned and characterized from several mosquito species, but their origin and molecular evolution are poorly understood.

Results: Here we used in silico and molecular cloning techniques to identify and characterize the evolution of the Vtg gene family from the genera Culex, Aedes/Ochlerotatus, and Anopheles.