title: Overexpression of Anti-Müllerian Hormone Disrupts Gonadal Sex Differentiation, Blocks Sex Hormone Synthesis, and Supports Cell Autonomous Sex Development in the Chicken.
abstract: The primary role of Anti-Müllerian hormone (AMH) during mammalian development is the regression of Müllerian ducts in males. This highly conserved function is retained in birds and is supported by the high levels of AMH expression in developing testes. Mammalian AMH expression is regulated by a combination of transcription factors, the most important being Sry-type high-mobility-group box transcription factor-9 (SOX9). In the chicken embryo, however, AMH mRNA expression precedes that of SOX9, leading to the view that AMH may play a more central role in avian testicular development. To define its role in chicken gonadal development, AMH was overexpressed using the RCASBP viral vector. AMH caused the gonads of both sexes to develop as small and undeveloped structures at both embryonic and adult stages. Molecular analysis revealed that although female gonads developed testis-like cords, gonads lacked Sertoli cells and were incapable of steroidogenesis. A similar gonadal phenotype was also observed in males, with a complete loss of both Sertoli cells, disrupted SOX9 expression and gonadal steroidogenesis. At sexual maturity both sexes showed a female external phenotype but retained sexually dimorphic body weights that matched their genetic sexes. These data suggest that AMH does not operate as an early testis activator in the chicken but can affect downstream events, such as sex steroid hormone production. In addition, this study provides a unique opportunity to assess chicken sexual development in an environment of sex hormone deficiency, demonstrating the importance of both hormonal signaling and direct cell autonomous factors for somatic sex identity in birds.
authors.affiliation: Murdoch Childrens Research Institute (L.S.L., K.L.A., A.H.S., A.D.C.), Royal Children's Hospital, Melbourne, Victoria 3052, Australia; Department of Paediatrics (K.L.A., A.H.S., A.D.C.), The University of Melbourne, Melbourne, Victoria 3010, Australia; Commonwealth Scientific and Industrial Research Organisation Biosecurity Flagship (K.M., T.G.W., T.O., D.W., Y.C., T.J.D.), Australian Animal Health Laboratory, Geelong, Victoria 3217, Australia; and Department of Anatomy and Developmental Biology (C.A.S.), Monash University, Clayton, Victoria 3168, Australia.
authors.forename: Luke S
authors.initials: LS
authors.lastname: Lambeth
authors.affiliation: Murdoch Childrens Research Institute (L.S.L., K.L.A., A.H.S., A.D.C.), Royal Children's Hospital, Melbourne, Victoria 3052, Australia; Department of Paediatrics (K.L.A., A.H.S., A.D.C.), The University of Melbourne, Melbourne, Victoria 3010, Australia; Commonwealth Scientific and Industrial Research Organisation Biosecurity Flagship (K.M., T.G.W., T.O., D.W., Y.C., T.J.D.), Australian Animal Health Laboratory, Geelong, Victoria 3217, Australia; and Department of Anatomy and Developmental Biology (C.A.S.), Monash University, Clayton, Victoria 3168, Australia.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Morris
authors.affiliation: Murdoch Childrens Research Institute (L.S.L., K.L.A., A.H.S., A.D.C.), Royal Children's Hospital, Melbourne, Victoria 3052, Australia; Department of Paediatrics (K.L.A., A.H.S., A.D.C.), The University of Melbourne, Melbourne, Victoria 3010, Australia; Commonwealth Scientific and Industrial Research Organisation Biosecurity Flagship (K.M., T.G.W., T.O., D.W., Y.C., T.J.D.), Australian Animal Health Laboratory, Geelong, Victoria 3217, Australia; and Department of Anatomy and Developmental Biology (C.A.S.), Monash University, Clayton, Victoria 3168, Australia.
authors.forename: Katie L
authors.initials: KL
authors.lastname: Ayers
authors.affiliation: Murdoch Childrens Research Institute (L.S.L., K.L.A., A.H.S., A.D.C.), Royal Children's Hospital, Melbourne, Victoria 3052, Australia; Department of Paediatrics (K.L.A., A.H.S., A.D.C.), The University of Melbourne, Melbourne, Victoria 3010, Australia; Commonwealth Scientific and Industrial Research Organisation Biosecurity Flagship (K.M., T.G.W., T.O., D.W., Y.C., T.J.D.), Australian Animal Health Laboratory, Geelong, Victoria 3217, Australia; and Department of Anatomy and Developmental Biology (C.A.S.), Monash University, Clayton, Victoria 3168, Australia.
authors.forename: Terry G
authors.initials: TG
authors.lastname: Wise
authors.affiliation: Murdoch Childrens Research Institute (L.S.L., K.L.A., A.H.S., A.D.C.), Royal Children's Hospital, Melbourne, Victoria 3052, Australia; Department of Paediatrics (K.L.A., A.H.S., A.D.C.), The University of Melbourne, Melbourne, Victoria 3010, Australia; Commonwealth Scientific and Industrial Research Organisation Biosecurity Flagship (K.M., T.G.W., T.O., D.W., Y.C., T.J.D.), Australian Animal Health Laboratory, Geelong, Victoria 3217, Australia; and Department of Anatomy and Developmental Biology (C.A.S.), Monash University, Clayton, Victoria 3168, Australia.
authors.forename: Terri
authors.initials: T
authors.lastname: O'Neil
authors.affiliation: Murdoch Childrens Research Institute (L.S.L., K.L.A., A.H.S., A.D.C.), Royal Children's Hospital, Melbourne, Victoria 3052, Australia; Department of Paediatrics (K.L.A., A.H.S., A.D.C.), The University of Melbourne, Melbourne, Victoria 3010, Australia; Commonwealth Scientific and Industrial Research Organisation Biosecurity Flagship (K.M., T.G.W., T.O., D.W., Y.C., T.J.D.), Australian Animal Health Laboratory, Geelong, Victoria 3217, Australia; and Department of Anatomy and Developmental Biology (C.A.S.), Monash University, Clayton, Victoria 3168, Australia.
authors.forename: Susanne
authors.initials: S
authors.lastname: Wilson
authors.affiliation: Murdoch Childrens Research Institute (L.S.L., K.L.A., A.H.S., A.D.C.), Royal Children's Hospital, Melbourne, Victoria 3052, Australia; Department of Paediatrics (K.L.A., A.H.S., A.D.C.), The University of Melbourne, Melbourne, Victoria 3010, Australia; Commonwealth Scientific and Industrial Research Organisation Biosecurity Flagship (K.M., T.G.W., T.O., D.W., Y.C., T.J.D.), Australian Animal Health Laboratory, Geelong, Victoria 3217, Australia; and Department of Anatomy and Developmental Biology (C.A.S.), Monash University, Clayton, Victoria 3168, Australia.
authors.forename: Yu
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Murdoch Childrens Research Institute (L.S.L., K.L.A., A.H.S., A.D.C.), Royal Children's Hospital, Melbourne, Victoria 3052, Australia; Department of Paediatrics (K.L.A., A.H.S., A.D.C.), The University of Melbourne, Melbourne, Victoria 3010, Australia; Commonwealth Scientific and Industrial Research Organisation Biosecurity Flagship (K.M., T.G.W., T.O., D.W., Y.C., T.J.D.), Australian Animal Health Laboratory, Geelong, Victoria 3217, Australia; and Department of Anatomy and Developmental Biology (C.A.S.), Monash University, Clayton, Victoria 3168, Australia.
authors.forename: Andrew H
authors.initials: AH
authors.lastname: Sinclair
authors.affiliation: Murdoch Childrens Research Institute (L.S.L., K.L.A., A.H.S., A.D.C.), Royal Children's Hospital, Melbourne, Victoria 3052, Australia; Department of Paediatrics (K.L.A., A.H.S., A.D.C.), The University of Melbourne, Melbourne, Victoria 3010, Australia; Commonwealth Scientific and Industrial Research Organisation Biosecurity Flagship (K.M., T.G.W., T.O., D.W., Y.C., T.J.D.), Australian Animal Health Laboratory, Geelong, Victoria 3217, Australia; and Department of Anatomy and Developmental Biology (C.A.S.), Monash University, Clayton, Victoria 3168, Australia.
authors.forename: Andrew D
authors.initials: AD
authors.lastname: Cutting
authors.affiliation: Murdoch Childrens Research Institute (L.S.L., K.L.A., A.H.S., A.D.C.), Royal Children's Hospital, Melbourne, Victoria 3052, Australia; Department of Paediatrics (K.L.A., A.H.S., A.D.C.), The University of Melbourne, Melbourne, Victoria 3010, Australia; Commonwealth Scientific and Industrial Research Organisation Biosecurity Flagship (K.M., T.G.W., T.O., D.W., Y.C., T.J.D.), Australian Animal Health Laboratory, Geelong, Victoria 3217, Australia; and Department of Anatomy and Developmental Biology (C.A.S.), Monash University, Clayton, Victoria 3168, Australia.
authors.forename: Timothy J
authors.initials: TJ
authors.lastname: Doran
authors.affiliation: Murdoch Childrens Research Institute (L.S.L., K.L.A., A.H.S., A.D.C.), Royal Children's Hospital, Melbourne, Victoria 3052, Australia; Department of Paediatrics (K.L.A., A.H.S., A.D.C.), The University of Melbourne, Melbourne, Victoria 3010, Australia; Commonwealth Scientific and Industrial Research Organisation Biosecurity Flagship (K.M., T.G.W., T.O., D.W., Y.C., T.J.D.), Australian Animal Health Laboratory, Geelong, Victoria 3217, Australia; and Department of Anatomy and Developmental Biology (C.A.S.), Monash University, Clayton, Victoria 3168, Australia.
authors.forename: Craig A
authors.initials: CA
authors.lastname: Smith
mesh_terms: D000818:Animals; D054304:Anti-Mullerian Hormone / Q000235:genetics*; D049628:Body Size / Q000235:genetics; D001835:Body Weight / Q000235:genetics; D002642:Chick Embryo; D002645:Chickens; D004958:Estradiol / Q000096:biosynthesis; D005260:Female; D005455:Fluorescent Antibody Technique; D018507:Gene Expression Regulation, Developmental; D055879:Gene Knock-In Techniques; D005835:Genitalia / Q000196:embryology / Q000254:growth & development; D012739:Gonadal Steroid Hormones / Q000096:biosynthesis*; D006066:Gonads / Q000196:embryology* / Q000254:growth & development; D017403:In Situ Hybridization; D008297:Male; D060888:Real-Time Polymerase Chain Reaction; D055758:SOX9 Transcription Factor / Q000235:genetics / Q000378:metabolism; D019849:Sex Determination Processes / Q000235:genetics*; D012733:Sex Differentiation / Q000235:genetics*; D046468:Sexual Development / Q000235:genetics; D013739:Testosterone / Q000096:biosynthesis
chemical_list: D012739:Gonadal Steroid Hormones; D055758:SOX9 Transcription Factor; D013739:Testosterone; D004958:Estradiol; D054304:Anti-Mullerian Hormone