During male gonadal sex determination in mammals, the sex-determining gene SRY activates Sox9, which encodes a pivotal transcription factor essential for orchestrating Sertoli cell differentiation and maintenance within the testis. SOX9 plays a multifaceted role by regulating downstream genes crucial in the development of various organs and tissues including the testis, where the loss of SOX9 results in male-to-female sex reversal and male infertility in mice. We hypothesised that SOX9 divides its labour among its numerous target genes within the testis. Here we investigated a potential SOX9 target gene, Tyro3, along with its family members, Axl and Mertk (TAM family). Inhibition of the TAM family in E11.5 ex vivo cultured male mouse gonads led to reduced germ cell numbers caused by reduced proliferation and increased apoptosis of the germ cells. Tyro3 knockout mice exhibited reduced expression levels of the germ cell genes Ddx4, Dazl and Pou5f1 and increased expression levels of the Sertoli cell genes Sox9 and Amh at E12.5. However, by E14.5, the expression of Ddx4, Dazl, Sox9 and Amh had returned to normal levels in Tyro3 knockout testes. Tyro3 knockout testes displayed normal morphology and structures during foetal testis development. Moreover, knockdown of Tyro3 in mouse Sertoli cell lines using siRNA did not affect cell adhesion or proliferation. In summary, our results suggest that TAM family members have redundant roles in regulating germ cell development during early testis development and that SOX9 mediates germ cell development in part via Tyro3.