Localization of insulin-like growth factor-I-like immunoreactivity in the reproductive tract of the vitellogenic female American alligator, Alligator mississippiensis.
Insulin-like growth factor I (IGF-I) is a 70 amino acid, mitogenic polypeptide, which, in mammals, acts through an endocrine, paracrine, and/or autocrine pathway to regulate growth and development. The primary goal of this study was to determine whether or not IGF-I-like immunoreactivity is present in the oviduct of the vitellogenic American alligator, Alligator mississippiensis, and if immunoreactivity patterns vary among the three functional oviducal regions: the albumen-secreting tube region, the anterior, fiber-secreting uterus, and the posterior, calcium-secreting uterus. Immunolocalization of IGF-I-like immunoreactivity was accomplished using a polyclonal antihuman rabbit antiserum with an immunoperoxidase staining system. IGF-I-like immunoreactivity was detected in all three oviducal regions of the vitellogenic alligator. The presence of IGF-I-like immunoreactivity in the oviduct suggests this hormone could function in the growth and proliferation of the alligator oviduct. Furthermore, the presence of IGF-I-like immunoreactivity in the tubal glands, which secrete components of the egg white, suggests that growth factors such as IGF-I may be synthesized by these glands and incorporated into the albumen during egg formation.
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Department of Zoology, University of Florida, Gainesville 32611.
Guillette
L J
LJ
D000489:Alligators and Crocodiles; D000818:Animals; D046508:Culture Techniques; D004848:Epithelium / Q000737:chemistry / Q000648:ultrastructure; D005260:Female; D007334:Insulin-Like Growth Factor I / Q000032:analysis*; D010057:Oviducts / Q000737:chemistry* / Q000648:ultrastructure; D014818:Vitellogenesis
D007334:Insulin-Like Growth Factor I