Presence of male determining factors found on three autosomes in the house fly, Musca domestica

SEX is determined by the presence of X and Y sex chromosomes in the house fly, Musca domestica L. (males are heterogametic), and the Y chromosome determines maleness. Aneuploid house flies with from one to six X chromosomes (and with the normal five pairs of autosomes) are females if no Y chromosome is present and males if one or more Y chromosomes are present1.