abnormal reproductive system development abnormal genital tubercle morphology csmith 2012-11-01T02:14:18Z MP:0011771 MPheno.ontology abnormal phallic tubercle morphology any structural anomaly of the embryonic anlage of the external genitalia, which emerges as paired swellings ventral to the cloacal membrane, is proposed to be derived from all three germ layers, and gives rise to the penis, clitoris, scrotum, labia, and foreskin; GT development is indistinguishable in male and female mouse embryos until approximately E16, when the urethral plate begins to be masculinized to form the penile urethra, marking the beginning of an androgen-dependent phase of sexual differentiation