Marsh-Armstrong, N.*; Brown, D.D.: Transgenic studies of metamorphic changes in the nervous system of Xenopus laevis During Xenopus laevis metamorphosis, herbivorous filter feeding tadpoles that swim by flicking their tails are transformed into carnivorous frogs that use their arms to shovel in food and their legs to swim. The nervous system changes during metamorphosis to […]

DENVER, R.J.: Transcriptional Regulatory Networks Induced by Thyroid Hormone During Metamorphosis of the Amphibian Central Nervous System Thyroid hormone (T3) induces multiple molecular, biochemical and morphological changes in the tadpole CNS. These changes prepare the animal for the transition from larval to adult life. At the cellular level, T3-induces cell proliferation, death, migration, processelaboration and […]

WASSERSUG, R.J.: Problems in Metamorphosis Above the Molecular Level Tadpoles from a single clutch, which hatch at approximately equal size, can vary in size by nearly an order of magnitude by the time they metamorphose. This observation has led to extensive research by ecologists on social and environmental factors that influence metamorphosis. Independently, molecular biologists […]

Furlow, J.D.*; Lim, W.; Ermio, D.J.; Chiellini, G.; Scanlan, T.S.: Molecular mechanisms underlying thyroid hormone induced gene expression cascades during amphibian metamorphosis Amphibian metamorphosis is an excellent system to understand nuclear receptor function during development. Thyroid hormone (TH) induces a wide range of morphological changes by regulating gene expression via a pair of nuclear receptors, […]

SHI, Y.B.: Mechanism and developmental function of gene regulation by thyroid hormone receptors in Xenopus laevis. Thyroid hormone (T3) receptors (TRs) are the presumed mediators of the effects of T3 during metamorphosis. Interestingly, these receptors are expressed not only during metamorphosis but also in premetamorphic tadpoles when there is no T3. To investigate the roles […]

BUCHHOLZ, D.*; HAYES, T.: Evolution of Diversity in Anuran Tadpoles: Accelerated metamorphosis in spadefoot toads Spadefoot toads exhibit a large diversity in larval period and size at metamorphosis. We used growth and development data to examine evolutionary, physiological, and morphological aspects of this diversity. To obtain comparable data across taxa, we reared tadpoles under laboratory […]

MENON J.*; FRESSE, D.: Effects of hormones/morphogens in anuran metamorphosis Retinoids, a large family of natural and synthetic compounds related to vitamin A, have pleiotropic effects on embryonic development. The role of retinoids in processes such as cell proliferation, differentiation and apoptosis is well documented. Heterodimerization of retinoid X receptors (RXRs) with receptors of thyroid […]

WRIGHT, M.L.: Circadian aspects of hormonal regulation of metamorphosis in Rana catesbeiana. Most hormones exhibit a circadian, or 24-hr, rhythm synchronized by the light/dark (LD) cycle. Hormones such as melatonin (ML), adrenal cortical steroids, and prolactin may synergize with, or antagonize, the thyroid hormones (TH) which induce metamorphosis. Consequently, the relationship of their diurnal profiles […]

KALTENBACH, J.C.: ATPase immunoreactivity and lectin binding in gills of larval amphibians and fish Strong Na+/K+ ATPase activity is a characteristic of chloride cells (mitochondria-rich cells) in fish gills. Such cells have an important role in ion transport. To determine if similar cells are also present in the internal gills of amphibian tadpoles, paraffin sections […]