According to the Virginia-Maryland Regional College of Veterinary Medicine, the sustentacular cells perform the function of caring and nurturing spermatocytes in the developing stages. The branches of the cells enfold these forming sperm throughout the stages of development.
Sustentacular cells located at a base are positioned on seminiferous tubule against the boundary of the cell layer. The lowest branches reach out to various other sustentacular cells. When these cells make contact, they fuse and form occluding junctions that divide the tubule, and two compartments develop. The compartments each have a different type of physiologic environment. The barrier between the compartments allows different environments to support the various stages of development for the sperm.