title: Expression pattern of acetylated alpha-tubulin in porcine spermatogonia.
abstract: Mammalian spermatogonial stem cells reside on the basement membrane of the seminiferous tubules. The mechanisms responsible for maintenance of spermatogonia at the basement membrane are unclear. Since acetylated alpha-tubulin (Ac-alpha-Tu) is a component of long-lived, stable microtubules and deacetylation of alpha-tubulin enhances cell motility, we hypothesized that acetylation of alpha-tubulin might be associated with positioning of spermatogonia at the basement membrane. The expression pattern of Ac-alpha-Tu at different stages of testis development was characterized by immunohistochemistry for Ac-alpha-Tu and spermatogonia-specific proteins (PGP 9.5, DAZL). In immature pig testes, Ac-alpha-Tu was present exclusively in gonocytes at 1 week of age, and in a subset of spermatogonia at 10 weeks of age. At this age, spermatogonia are migrating toward the tubule periphery and Ac-alpha-Tu appeared polarized toward the basement membrane. In adult pig testes, Ac-alpha-Tu was detected in few single or paired spermatogonia at the basement membrane as well as in spermatids and spermatozoa. Only undifferentiated (DAZL-), proliferating (determined by BrdU incorporation) spermatogonia expressed high levels of Ac-alpha-Tu. Comparison with the expression pattern of beta-tubulin and tyrosinated alpha-tubulin confirmed that only Ac-alpha-Tu is specific to germ cells. The unique pattern of Ac-alpha-Tu in undifferentiated germ cells during postnatal development suggests that posttranslational modifications of microtubules may play an important role in recruiting and anchoring spermatogonia at the basement membrane. Mol. Reprod. Dev. 77: 348-352, 2010. (c) 2009 Wiley-Liss, Inc.
authors.affiliation: Center for Animal Transgenesis and Germ Cell Research, Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA.
authors.forename: Jinping
authors.initials: J
authors.lastname: Luo
authors.forename: Jose Rafael
authors.initials: JR
authors.lastname: Rodriguez-Sosa
authors.forename: Lin
authors.initials: L
authors.lastname: Tang
authors.forename: Alla
authors.initials: A
authors.lastname: Bondareva
authors.forename: Susan
authors.initials: S
authors.lastname: Megee
authors.forename: Ina
authors.initials: I
authors.lastname: Dobrinski
mesh_terms: D000107:Acetylation; D000595:Amino Acid Sequence; D000818:Animals; D008297:Male; D008870:Microtubules / Q000378:metabolism; D008969:Molecular Sequence Data; D016415:Sequence Alignment; D013093:Spermatogonia / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D013234:Stem Cells / Q000166:cytology / Q000378:metabolism*; D034421:Sus scrofa / Q000033:anatomy & histology / Q000196:embryology; D014404:Tubulin / Q000235:genetics / Q000378:metabolism*; D043222:Ubiquitin Thiolesterase / Q000378:metabolism
chemical_list: D014404:Tubulin; D043222:Ubiquitin Thiolesterase