Fetal XXXX Gubernaculum Mesenchymal Cells Adopt Myogenic and Myofibroblast-Like Phenotypes.

@entity10081 @entity10080 @entity10944 @entity35 @entity22060
PURPOSE: Gubernaculum-cremaster complex development is hormonally regulated and abnormal in a cryptorchid @entity35 model. Using cell tracking techniques and imaging we studied myogenic phenotypes and fates in the fetal @entity35 gubernaculum-cremaster complex. MATERIALS AND METHODS: Embryonic day 17 gubernaculum-cremaster complexes were labeled with CellTracker    or the DNA synthesis marker @entity10081 ( @entity10080 ), or immobilized in Matrigel   and grown in culture. Embryonic day 17 to 21 gubernaculum-cremaster complex sections and cells were imaged using wide field and deconvolution immunofluorescence microscopy, and muscle and/or myofibroblast specific antibodies. Deconvolved image stacks were used to create a 3-dimensional model of embryonic day 21 gubernaculum-cremaster complex muscle. RESULTS: @entity22060 ( @entity22060 ) positive and myogenin positive muscle precursors were visible in a @entity10944 -rich myogenic zone between muscle layers that elongated and became thicker during development. Gubernaculum-cremaster complex inner mesenchymal cells expressed @entity10944 and aSMA (a smooth muscle actin) at lower levels than in the myogenic zone. After pulse labeling with  CellTracker or @entity10081 mesenchymal cells became incorporated into differentiated muscle. Conversely, mesenchymal cells migrated beyond Matrigel immobilized gubernaculum-cremaster complexes, expressed @entity22060 and fused to form striated myotubes. Mesenchymal gubernaculum-cremaster complex cell lines proliferated more than 40 passages and showed contractile behavior but did not form striated muscle. Our 3-dimensional gubernaculum-cremaster complex model had 2 orthogonal ventral layers and an arcing inner layer of muscle. CONCLUSIONS: Our data suggest that mesenchymal cells in the peripheral myogenic zone of the fetal gubernaculum-cremaster complex contribute to formation of a distinctively patterned cremaster muscle. Nonmyogenic, @entity10944 and aSMA positive gubernaculum-cremaster complex mesenchymal cells proliferate and have a myofibroblast-like phenotype in culture. Intrinsic mechanical properties of these divergent cell types may facilitate perinatal inversion of the gubernaculum-cremaster complex.
