“…The study of sex-typical patterns of motor organization, together with the study of genetic mutations, provides a rich source of animal models that can be used to elucidate the potential contributions of various neural systems and their interaction with hormonal states in the development of motor control. The testicular feminized mutation model (TFM) has been documented in a number of species including cats (Meyers-Wallen et al, 1989), mice (Lyon & Hawkes, 1970), nonhuman primates (Eli et al, 1980), and humans (Kaufman, Pinsky, & Feder-Hollander, 1981; Keenan, Meyer, Hadjian, Jones, & Midgeon, 1974; Warne, Gyorki, Risbridger, Khalid, & Funder, 1984). Currently, the TFM model is used primarily to study the interplay of genes, gonadal hormones, and development of CNS anatomy (Freeman, Padgett, Prins, & Breedlove, 1995; Freeman, Watson, & Breedlove, 1996; Forger, Wong, & Breedlove, 1995; Monks, Vanston, & Watson, 1999; Monks & Watson, 2001; Watson, Freeman, & Breedlove, 2001).…”