title: Molecular genetic cascades for external genitalia formation: an emerging organogenesis program.
abstract: External genitalia are anatomical structures located at the posterior embryonic region as part of several urogenital/reproductive organs. The embryonic anlage of the external genitalia, the genital tubercle (GT) develops as a bud-shaped structure with an initial urethral plate and later urethra. Embryonic external genitalia are considered to be one of the appendages. Recent experiments suggest that essential regulatory genes possess similar functions for the outgrowth regulation of the GT and limb appendages. The transient embryonic epithelia located in the distal GT are called the distal urethral epithelium (DUE) regulating, at least in part, the (distal) GT development. This review covers the available data about early patterning of GT and discusses the molecular developmental similarities and points of divergence between the different appendages. Development of the male and female external genitalia is also reviewed.
authors.affiliation: Center for Animal Resources and Development (CARD), Graduate School of Medical and Pharmaceutical Sciences, Kumamoto University, Kumamoto, Japan. gen@kaiju.medic.kumamoto-u.ac.jp
authors.forename: G
authors.initials: G
authors.lastname: Yamada
authors.forename: K
authors.initials: K
authors.lastname: Suzuki
authors.forename: R
authors.initials: R
authors.lastname: Haraguchi
authors.forename: S
authors.initials: S
authors.lastname: Miyagawa
authors.forename: Y
authors.initials: Y
authors.lastname: Satoh
authors.forename: M
authors.initials: M
authors.lastname: Kamimura
authors.forename: N
authors.initials: N
authors.lastname: Nakagata
authors.forename: H
authors.initials: H
authors.lastname: Kataoka
authors.forename: A
authors.initials: A
authors.lastname: Kuroiwa
authors.forename: Y
authors.initials: Y
authors.lastname: Chen
mesh_terms: D000818:Animals; D002987:Clitoris / Q000196:embryology; D005121:Extremities / Q000196:embryology; D005260:Female; D005835:Genitalia / Q000196:embryology* / Q000378:metabolism; D006133:Growth Substances / Q000096:biosynthesis / Q000235:genetics; D008297:Male; D051379:Mice; D038081:Organogenesis / Q000235:genetics; D010413:Penis / Q000196:embryology; D012733:Sex Differentiation; D015398:Signal Transduction; D014521:Urethra / Q000196:embryology
chemical_list: D006133:Growth Substances