Development of the Gubernaculum During Testicular Descent in the Rat
Version of Record online: 25 MAY 2011
Copyright © 2011 Wiley-Liss, Inc.
The Anatomical Record
Volume 294, Issue 7, pages 1249–1260, July 2011
How to Cite
Nation, T.R., Buraundi, S., Farmer, P.J., Balic, A., Newgreen, D., Southwell, B.R. and Hutson, J.M. (2011), Development of the Gubernaculum During Testicular Descent in the Rat. Anat Rec, 294: 1249–1260. doi: 10.1002/ar.21393
- Issue online: 15 JUN 2011
- Version of Record online: 25 MAY 2011
- Manuscript Accepted: 22 FEB 2011
- Manuscript Revised: 16 FEB 2011
- Manuscript Received: 5 JUL 2010
- testicular descent;
- genitofemoral nerve;
- mammary bud
Gubernacular elongation during inguinoscrotal testicular descent and cremaster muscle development remains poorly described in mammals. The role of the genitofemoral nerve (GFN) remains elusive. We performed detailed histological analysis of testicular descent in normal rats to provide a comprehensive anatomical description for molecular studies. Fetuses and neonatal male offspring (5–10 per group) from time-mated Sprague-Dawley dams (embryonic days 15, 16, and 19; postnatal days 0, 2, and 8) were prepared for histology. Immunohistochemistry was performed for nerves (Class III tubulin, Tuj1) and muscle (desmin). At embryonic days 15 and 16, the gubernaculum and breast bud are adjacent and both supplied by the GFN. By embryonic day 19, the breast bud has regressed and the gubernacular swelling reaction is completed. Postnatally, the gubernacular core regresses, except for a cranial proliferative zone. The cremaster is continuous with internal oblique and transversus abdominis. By postnatal day 2 (P2), the gubernaculum has everted, locating the proliferative zone caudally and the residual mesenchymal core externally. Eversion creates the processus vaginalis, with the everted gubernaculum loose in subcutaneous tissue but still remote from the scrotum. By P8, the gubernaculum has nearly reached the scrotum with fibrous connections attaching the gubernaculum to the scrotal skin. A direct link between GFN, gubernaculum, and breast bud suggests that the latter may be involved in gubernacular development. Second, the cremaster muscle is continuous with abdominal wall muscles, but most of its growth occurs in the distal gubernacular tip. Finally, gubernacular eversion at birth brings the cranial proliferative zone to the external distal tip, enabling gubernacular elongation similar to a limb bud. Anat Rec, 2011. © 2011 Wiley-Liss, Inc.