Trypanosoma brucei: Two mitogen activated protein kinase kinases are dispensable for growth and virulence of the bloodstream form

► Two MAP kinase kinase (MKK) genes were disrupted in bloodstream Trypanosoma brucei. ► The knockout parasites grew similarly to wild type in vitro and in vivo. ► Δmkk1 parasites showed decreased growth at 39 °C. ► Unlike Δmkkl Leishmania mexicana, Δmkkl T. brucei do not have shortened flagella.