MANZON, R.G.*; DENVER, R.J.; University of Regina, SK, Canada; University of Michigan, Ann Arbor, USA: Regulation of pituitary thyrotropin during Xenopus metamorphosis: beyond type II deiodinase. Several hypotheses have been proposed to explain the paradoxical increase and sustained expression of pituitary thyrotropin (TSH) in the presence of elevated thyroid hormone (TH) levels at metamorphic climax […]

WU, X*; DURICA, DAVID/S; HOPKINS, PENNY/M; University of Oklahoma; University of Oklahoma; University of Oklahoma: Physical characterization of the ecdysteroid and retinoid X receptors (UpEcR and UpRXR) in the fiddler crab, Uca pugilator and their distribution patterns in regenerating limbs during the molt cycle Several UpRXR cDNA variants were found in regions that could potentially […]

MURDOCK, C.A.*; WIBBELS, T.; University of Alabama, Birmingham; University of Alabama, Birmingham: Dmrt1 mRNA levels during development in a turtle with temperature-dependent sex determination Vertebrates exhibit a variety of sex determination systems, which include both genotypic and temperature-dependent sex determination (TSD). A number of genes have been identified in these sex determination systems, and some […]

DONG, Ying; FRIEDRICH, Markus; Wayne State University; Wayne State University: The effect of ecdysteroids on eye development in the grasshopper Schistocerca americana The metamorphosis of holometabolous insects is controlled by the steroids hormone ecdysone and the lipid juvenile hormone. Ecdysone is secreted from the prothorathic gland and converted in peripheral tissues to the active form […]

NEVITT, Gabrielle ; LEMA, Sean; Univ. of California, Davis; Univ. of California, Davis: Testing a new model for olfactory imprinting in salmon: Evidence for proliferation of olfactory receptor neurons in response to thyroid hormone. Salmon are famous for their ability to imprint and home to natal stream odors, yet the mechanisms driving olfactory imprinting remain […]

LOVERN, M.B.*; WADE, J.; Michigan State Univ., East Lansing; Michigan State Univ., East Lansing: Relationship among sex steroid levels in breeding female plasma, yolk, and embryonic tissue in green anole lizards Sex steroids have been documented in the egg yolks of numerous birds and reptiles, but why they are there remains an open question. Steroids […]

TUBERTY, S. R.; GLAS, P.S.; Appalachian State University, Boone, NC; The Citadel, Charleston, SC: Free Ecdysteroid Levels in Grass Shrimp Embryos Relate to Embryonic Envelope Elevation Ecdysteroids, the hormones responsible for stimulating arthropod molting, are secreted by Y-organs in eyestalks of adult crustaceans. Ecdysteroids have been identified in crab (Okazaki and Chang, 1991) lobster (Goudeau, […]

WILLIAMS, T.D. *; VEZINA, F.; KITAYSKY, A.S.; Simon Fraser University, Burnaby; Simon Fraser University, Burnaby; University of Washington, Seattle: Estradiol: a neglected hormone in maternal modification of offspring phenotype? Many current studies suggest that transfer of maternal steroid hormones to the developing embryo might play a role in non-genetic modification of offspring phenotype. However, to […]

VEZINA, F.; WILLIAMS, T.D.; Simon Fraser University, Burnaby, B.C., Canada: What Drives the Metabolic Costs of Egg Production in Birds? Body composition in vertebrates is known to show phenotypic plasticity, and changes in organ masses are usually rapid and reversible. One of the most rapid and reversible change is the transformation of the female avian […]

KIEHN, L.*; SALEUDDIN, A.S.M.; MUKAI, S.T.; York University, Toronto, Ontario; York University, Toronto, Ontario; York University, Toronto, Ontario: The Role of Calcium in Protein Secretion in the Albumen Gland of Helisoma duryi (Mollusca) The albumen gland of the freshwater pulmonate snail Helisoma duryi produces and secretes the perivitelline fluid, which coats fertilized eggs and provides […]