Anti-Müllerian Hormone Is Required for Chicken Embryonic Urogenital System Growth but Not Sexual Differentiation.
In mammals, the primary role of anti-Müllerian hormone (AMH) during development is the regression of Müllerian ducts in males. These structures otherwise develop into fallopian tubes, oviducts, and upper vagina, as in females. This highly conserved function is retained in birds and is supported by the high levels of AMH expression in developing testes. In mammals, AMH expression is controlled partly by the transcription factor, SOX9. However, in the chicken, AMH mRNA expression precedes that of SOX9 , leading to the view that AMH may lie upstream of SOX9 and play a more central role in avian testicular development. To help define the role of AMH in chicken gonad development, we suppressed AMH expression in chicken embryos using RNA interference. In males, AMH knockdown did not affect the expression of key testis pathway genes, and testis cords developed normally. However, a reduction in the size of the mesonephros and gonads was observed, a phenotype that was evident in both sexes. This growth defect occurred as a result of the reduced proliferative capacity of the cells of these tissues, and male gonads also had a significant reduction in germ cell numbers. These data suggest that although AMH does not directly contribute to testicular or ovarian differentiation, it is required in a sex-independent manner for proper cell proliferation and urogenital system growth.
Murdoch Childrens Research Institute, Melbourne, Victoria, Australia luke.lambeth@mcri.edu.au.
Luke S
LS
Lambeth
Murdoch Childrens Research Institute, Melbourne, Victoria, Australia Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia.
Katie
K
Ayers
Murdoch Childrens Research Institute, Melbourne, Victoria, Australia.
Andrew D
AD
Cutting
CSIRO Animal, Food and Health Sciences, Australian Animal Health Laboratory, Geelong, Victoria, Australia.
Timothy J
TJ
Doran
Murdoch Childrens Research Institute, Melbourne, Victoria, Australia Department of Paediatrics, University of Melbourne, Melbourne, Victoria, Australia.
Andrew H
AH
Sinclair
Department of Anatomy and Developmental Biology, Monash University, Clayton, Victoria, Australia.
Craig A
CA
Smith
D000818:Animals; D054304:Anti-Mullerian Hormone / Q000235:genetics* / Q000378:metabolism; D002642:Chick Embryo; D005260:Female; D018507:Gene Expression Regulation, Developmental; D008297:Male; D010053:Ovary / Q000196:embryology* / Q000378:metabolism; D055758:SOX9 Transcription Factor / Q000235:genetics / Q000378:metabolism; D012733:Sex Differentiation / Q000235:genetics*; D013737:Testis / Q000196:embryology* / Q000378:metabolism; D014566:Urogenital System / Q000196:embryology* / Q000378:metabolism
D055758:SOX9 Transcription Factor; D054304:Anti-Mullerian Hormone
RCANBP; RNA interference; anti-Müllerian hormone (AMH); chicken embryo; sex determination; sex development