text: <unk>  is a Gram-negative bacterium in the family Enterobacteriaceae, related to E. coli, which lives in the gut of the tsetse fly.  The bacterium bears the name of the British entomologist who first described it, Sir Vincent Brian Wigglesworth.<unk>  has symbiotically co-evolved with the tsetse fly for millions of years, and is a text book example of a bacterial endosymbiont.  Because of this relationship,<unk>  has lost a large part of its genome and has one of the smallest known genomes of any living organism.  Together with Buchnera aphidicola,<unk>  has been the subject of genetic research into the minimal genome necessary for any living organism.<unk>  also synthesizes key vitamins which the tsetse fly does not get from its diet of blood.  Without the vitamins<unk>  produces, the tsetse fly cannot reproduce.  Since the tsetse fly spreads african sleeping sickness,<unk>  may one day be used to control the spread of this terrible disease.
option_0: Wigglesworthia glossinidia brevipalpis
option_1: Onchocerca volvulus
option_2: Ancylostoma braziliense
option_3: Loa loa filaria
option_4: Gnathostoma hispidum
option_5: Spirometra erinaceieuropaei
option_6: Oesophagostomum
option_7: Wuchereria bancrofti