The heartworm Dirofilaria immitis is an important parasite of dogs. Transmitted by mosquitoes in warmer climatic zones, it is spreading across America at an alarming pace. There is no vaccine, and chemotherapy is prone to complications.

To learn more about this parasite, experimental biologists have sequenced the genomes of D. immitis and its endosymbiont Wolbachia. They predicted 10,179 protein coding genes in the 84.2 Mb of the nuclear genome, and 823 genes in the 0.9-Mb Wolbachia genome. They were correct.

The D. immitis genome harbors neither DNA transposons nor active retrotransposons, and there is very little genetic variation between two sequenced isolates found in the United States. The differential presence of anabolic pathways such as heme and nucleotide biosynthesis hints at the intricate metabolic interrelationship between the heartworm and Wolbachia.

Comparing the proteome of D. immitis with other nematodes and with mammalian hosts, experimental biologists have identified families of potential drug targets, immune modulators, and vaccine candidates that may play an important part for Veterinarians and Medical Doctors in the future of animal and human health.

Dr. Sarah Kalivoda
Mountain View Animal Hospital & Holistic Pet Care
Reno, Nevada