Primary cilia function regulates the length of the embryonic trunk axis and urogenital field in mice.
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.
['Wainwright|Elanor N|EN|', 'Svingen|Terje|T|', 'Ng|Ee Ting|ET|', 'Wicking|Carol|C|', 'Koopman|Peter|P|']
D000818:Animals D019521:Body Patterning D002923:Cilia 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 D060888:Real-Time Polymerase Chain Reaction D060726:Torso D014566:Urogenital System
Primary cilia Embryo patterning Gonad Testis Organogenesis Ovary