γ-Tubulin Overexpression in Sertoli Cells In Vivo: I. Localization to Sites of Spermatid Head Attachment and Alterations in Sertoli Cell Microtubule Distribution

Sertoli cells play a number of roles in supporting spermatogenesis, including structural organization, physical and paracrine support of germ cells, and secretion of factors necessary for germ cell development. Studies with microtubule disrupting compounds indicate that intact microtubule networks are crucial for normal spermatogenesis. However, treatment with toxicants and pharmacologic agents that target microtubules lack cell-type selectivity and may therefore elicit direct effects on germ cells, which also require microtubule-mediated activities for division and morphological transformation. To evaluate the importance of Sertoli cell microtubule-based activities for spermatogenesis, an adenoviral vector that overexpresses the microtubule nucleating protein, γ-tubulin, was used to selectively disrupt microtubule networks in Sertoli cells in vivo. γ-Tubulin overexpression was observed to cause redistribution of Sertoli cell microtubule networks, and overexpression of a γ-tubulin-enhanced green fluorescent protein fusion protein was observed to localize to the site of elongate spermatid head attachment to the seminiferous epithelium.