title: Primary cilia function regulates the length of the embryonic trunk axis and urogenital field in mice.
abstract: The issues of whether and how some organs coordinate their size and shape with the blueprint of the embryo axis, while others appear to regulate their morphogenesis autonomously, remain poorly understood. Mutations in Ift144, encoding a component of the trafficking machinery of primary cilia assembly, result in a range of embryo patterning defects, affecting the limbs, skeleton and neural system. Here, we show that embryos of the mouse mutant Ift144(twt) develop gonads that are larger than wild-type. Investigation of the early patterning of the urogenital ridge revealed that the anterior-posterior domain of the gonad/mesonephros was extended at 10.5 dpc, with no change in the length of the metanephros. In XY embryos, this extension resulted in an increase in testis cord number. Moreover, we observed a concomitant extension of the trunk axis in both sexes, with no change in the length of the tail domain or somite number. Our findings support a model in which: (1) primary cilia regulate embryonic trunk elongation; (2) the length of the trunk axis determines the size of the urogenital ridges; and (3) the gonad domain is partitioned into a number of testis cords that depends on the available space, rather than being divided a predetermined number of times to generate a specific number of cords.
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, Brisbane QLD 4072, Australia.
authors.forename: Elanor N
authors.initials: EN
authors.lastname: Wainwright
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, Brisbane QLD 4072, Australia.
authors.forename: Terje
authors.initials: T
authors.lastname: Svingen
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, Brisbane QLD 4072, Australia.
authors.forename: Ee Ting
authors.initials: ET
authors.lastname: Ng
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, Brisbane QLD 4072, Australia.
authors.forename: Carol
authors.initials: C
authors.lastname: Wicking
authors.affiliation: Institute for Molecular Bioscience, The University of Queensland, Brisbane QLD 4072, Australia. Electronic address: p.koopman@imb.uq.edu.au.
authors.forename: Peter
authors.initials: P
authors.lastname: Koopman
mesh_terms: D000818:Animals; D019521:Body Patterning / Q000502:physiology*; D002923:Cilia / Q000502:physiology*; D003598:Cytoskeletal Proteins; D005260:Female; D005455:Fluorescent Antibody Technique; D007091:Image Processing, Computer-Assisted; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D051379:Mice; D018613:Microscopy, Confocal; D008954:Models, Biological; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D060888:Real-Time Polymerase Chain Reaction; D060726:Torso / Q000196:embryology*; D014566:Urogenital System / Q000196:embryology*
chemical_list: D003598:Cytoskeletal Proteins; D047908:Intracellular Signaling Peptides and Proteins; D011506:Proteins; C486870:Wdr19 protein, mouse
keywords: Embryo patterning; Gonad; Organogenesis; Ovary; Primary cilia; Testis