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Full-Text Articles in Life Sciences

Proliferation, Migration, And Survival Of Cells In The Telencephalon Of The Ball Python, Python Regius, Thomas B. Bales Jul 2014

Proliferation, Migration, And Survival Of Cells In The Telencephalon Of The Ball Python, Python Regius, Thomas B. Bales

Master's Theses and Project Reports

Reptiles exhibit neurogenesis throughout the brain during adulthood. However, very few studies have quantified telencephalon-wide neurogenesis in adulthood, and no studies have performed these investigations in snakes. Quantifying neurogenesis in the adult snake is essential to understanding class-wide adult neurogenesis and providing insight into the evolution of this trait. The thymidine analog 5-bromo-2’-deoxyuridine (BrdU) was used to quantify cell proliferation, migration, and survival in the ball python (Python regius). First, to determine the proper dose of BrdU for injection we subcutaneously injected 50mg/kg, 100mg/kg, and 250mg/kg into 15 adult male P. regius. We found the 250mg ...


Tissue-Specific Thyroid Hormone Regulation Of Gene Transcripts Encoding Iodothyronine Deiodinases And Thyroid Hormone Receptors In Striped Parrotfish (Scarus Iseri), Kaitlin M. Johnson, Sean C. Lema Jul 2011

Tissue-Specific Thyroid Hormone Regulation Of Gene Transcripts Encoding Iodothyronine Deiodinases And Thyroid Hormone Receptors In Striped Parrotfish (Scarus Iseri), Kaitlin M. Johnson, Sean C. Lema

Biological Sciences

In fish as in other vertebrates, the diverse functions of thyroid hormones are mediated at the peripheral tissue level through iodothyronine deiodinase (dio) enzymes and thyroid hormone receptor (tr) proteins. In this study, we examined thyroid hormone regulation of mRNAs encoding the three deiodinases dio1, dio2 and dio3 – as well as three thyroid hormone receptors trαA, trαB and trβ – in initial phase striped parrotfish (Scarus iseri). Parrotfish were treated with dissolved phase T3 (20 nM) or methimazole (3 mM) for 3 days. Treatment with exogenous T3 elevated circulating T3, while the methimazole treatment depressed plasma T4 ...


Dietary Exposure To 2,2´,4,4´-Tetrabromodiphenyl Ether (Pbde-47) Alters Thyroid Status And Thyroid Hormone–Regulated Gene Transcription In The Pituitary And Brain, Sean C. Lema, Jon T. Dickey, Irvin R. Schultz, Penny Swanson Dec 2008

Dietary Exposure To 2,2´,4,4´-Tetrabromodiphenyl Ether (Pbde-47) Alters Thyroid Status And Thyroid Hormone–Regulated Gene Transcription In The Pituitary And Brain, Sean C. Lema, Jon T. Dickey, Irvin R. Schultz, Penny Swanson

Biological Sciences

No abstract provided.


Neural Defects And Cardiac Arrhythmia In Fish Larvae Following Embryonic Exposure To 2,2',4,4'-Tetrabromodiphenyl Ether (Pbde 47), Sean C. Lema, Irvin R. Schultz, Nathaniel L. Scholz, John P. Incardona, Penny Swanson May 2007

Neural Defects And Cardiac Arrhythmia In Fish Larvae Following Embryonic Exposure To 2,2',4,4'-Tetrabromodiphenyl Ether (Pbde 47), Sean C. Lema, Irvin R. Schultz, Nathaniel L. Scholz, John P. Incardona, Penny Swanson

Biological Sciences

Polybrominated diphenyl ethers (PBDEs) are added to plastics, polyurethane foam, and textiles as a flame retardant. While PBDEs play a key role in reducing loss of human life and property from fires, these flame retardants have become pervasive organic contaminants in the environment and in the tissues of fish, birds, marine mammals, and humans. Levels of PBDEs in wildlife and humans continue to rise, raising concerns about potential ecological and health risks associated with exposure to these chemicals. Nevertheless, there is little currently known about the toxicological effects of PBDE exposure. Here, we examined the developmental toxicity of the PBDE ...


Environmental Rearing Conditions Produce Forebrain Differences In Wild Chinook Salmon Oncorhynchus Tshawytscha, R. L. Kihslinger, Sean C. Lema, G. A. Nevitt Oct 2006

Environmental Rearing Conditions Produce Forebrain Differences In Wild Chinook Salmon Oncorhynchus Tshawytscha, R. L. Kihslinger, Sean C. Lema, G. A. Nevitt

Biological Sciences

Recent studies suggest that hatchery-reared fish can have smaller brain-to-body size ratios than wild fish. It is unclear, however, whether these differences are due to artificial selection or instead reflect differences in rearing environment during development. Here we explore how rearing conditions influence the development of two forebrain structures, the olfactory bulb and the telencephalon, in juvenile Chinook salmon (Oncorhynchus tshawytscha) spawned from wild-caught adults. First, we compared the sizes of the olfactory bulb and telencephalon between salmon reared in a wild stream vs. a conventional hatchery. We next compared the sizes of forebrain structures between fish reared in an ...