Analysis the Detailed Process of Glomerular Capillary Formation Using Immunofluorescence Perform With Ultrathick Section

Background Glomerular capillary formation is one of the fundamental mysteries in renal developmental biology. However, there are still debates on this issue, and its detailed formation process has not been clarified. Results To resolve this problem, we performed antibody staining with ultra-thick section on embryonic and postnatal mouse kidneys to detect and analyze the development of glomerular capillaries. We found that blood vessel of the fetal kidneys expanded through proliferation and sprouting. During the comma-stage and S-shaped stages, 3-4 capillaries began to bud and migrate into the glomerular cleft, forming a capillary bed in the Bowman’s capsule. Then, the capillary bed expanded into mature glomerular capillary by intussusceptive angiogenesis. The afferent and efferent arterioles were formed through pruning. The distribution of VEGFA in the nephron epithelial cells but not only in podocytes, induced multiple capillaries sprouted into the glomerular cleft. And CXCR4 played an important role in the differentiation and expansion of capillary bed into glomerular capillary. Conclusions Immunofluorescence performed with ultra-thick section allowed us to investigate the development of complex structure tissues systematically and comprehensively.