Meeting Abstract

P2.143  Wednesday, Jan. 5  Investigating Hypothalamic Control of Puberty in Zebra Finches GUARDADO, D.*; BENTLEY , G.E.; PERFITO, N.; University of California, Berkeley ; University of California, Berkeley ; University of California, Berkeley daisy.guard@gmail.com

The mechanisms controlling the onset of puberty in vertebrates are not fully understood. Our study aims to identify and understand the molecular and neuroendocrine mechanisms that signal the onset of puberty. To this aim, we used an avian species, the Zebra Finch (Taeniopygia guttata ). Zebra Finches are an excellent model to study for this purpose because they breed very easily in captivity and have a long pre-pubescent period, which enables us to identify the beginning of puberty clearly. Although we do not fully understand the mechanisms controlling puberty, an increase in release of the hypothalamic neuropeptide, gonadotropin-releasing hormone (GnRH) is primarily responsible for the increase of gonadotropin release from the pituitary, and subsequent gonadal growth. We hypothesize that an enzyme called type 2-iodothyronine deiodinase (Dio2) is involved in the initial release of GnRH, which signals the start of puberty. In adults of seasonally breeding species, Dio2 is involved in the activation of the reproductive system at the start of the breeding season, but nobody has studied Dio2 in the context of puberty. In this study, we sampled pre-pubescent and post-pubescent zebra finches to identify if Dio2 was expressed in the hypothalamus and the pars tubularis of the pituitary. If the enzyme Dio2 is implicated in the onset of puberty, we expect that Dio2 will not be expressed in pre-pubescent birds as they are not yet reproductively active. In contrast, we do expect to see increased Dio2 expression in post-pubescent birds that are breeding. Data from this study will provide us with fundamental information about the neuroendocrine events that indicate the onset of puberty in vertebrates as a whole.