Flightin is a 20kDa protein that is only expressed in the indirect flight muscle (IFM) of the fruit fly Drosophila melanogaster. This gene is essential for the flight behavior in the fruit fly and its known that maintain the integrity of the sarcomere in the IFM. In the past it was tough that flightin was an orphan gene but recent examination of the different genomes available has revealed that different organisms has flightin like sequences. These flightin like sequences share a common region of about 55 amino acids named WYR (because 9 amino acids are conserved tryptophan, tyrosine and arginine). We hypothesize that this region is the region responsible to bind myosin. One aspect of my research is delimiting the region in flightin that is responsible to bind myosin. Also, from the examination of these flightin like sequence we found two striking results. The first is that some sequences come from insects that are very primitive which lack wings and in other cases the insect have only synchronous muscle. The second, and for our surprise is that some of the sequences comes from crustacean. These results suggest that flightin maybe has other function than the one already reported in the IFM of Drosophila. The other aspect of my research deals with the examination of the expression of flightin in different tissues from organisms that represent the crustaceans and the hexapods.