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Full-Text Articles in Biology
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
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 …
Physical Habitat And Social Conditions Across A Coral Reef Shape Spatial Patterns Of Intraspecific Behavioral Variation In A Demersal Fish, Meagan N. Schrandt, Kristin M. Hardy, Kaitlin M. Johnson, Sean C. Lema
Physical Habitat And Social Conditions Across A Coral Reef Shape Spatial Patterns Of Intraspecific Behavioral Variation In A Demersal Fish, Meagan N. Schrandt, Kristin M. Hardy, Kaitlin M. Johnson, Sean C. Lema
Biological Sciences
As coral reef ecosystems decline in health worldwide, reef-associated fishes are being impacted by changes to their coral reef habitats. While previous studies have shown coral reef structure to affect the demography of reef fishes, changes in reef conditions may also impact the behavior of reef fishes as they cope with altered habitats. In this study, we examined spatial patterns of intraspecific behavioral variation in the bicolor damselfish (Stegastes partitus) across the fringing reefs of Curaçao (Caribbean Sea), and explored how this behavioral variation associated with physical and social conditions on the reef. Principal components analysis (PCA) condensed …
Diurnal Rhythms Of Behavior And Brain Mrna Expression For Arginine Vasotocin, Isotocin, And Their Receptors In Wild Amargosa Pupfish (Cyprinodon Nevadensis Amargosae), Sean C. Lema, Lauren J. Wagstaff, Nina M. Gardner
Diurnal Rhythms Of Behavior And Brain Mrna Expression For Arginine Vasotocin, Isotocin, And Their Receptors In Wild Amargosa Pupfish (Cyprinodon Nevadensis Amargosae), Sean C. Lema, Lauren J. Wagstaff, Nina M. Gardner
Biological Sciences
Amargosa pupfish (Cyprinodon nevadensis amargosae) occupy remote desert habitats that vary widely in environmental conditions from day to night. In this study, die! patterns of behavior were documented for pupfish in their natural habitat, and examined relative to changes in the abundance of mRNAs encoding prepro-arginine vasotocin (pro-VT), prepro-isotocin (pro-IT), three distinct vasotocin receptors (V1a1, V1a2, and V2), and an isotocin receptor (ITR) in the brain. The behavior of wild pupfish varied diurnally, with frequent aggression from 12:00 to 15:00 h and courtship and spawning most common between 15:00 and 19:00h. Transcript abundance for pro-VT in the brain …
Identification Of Multiple Vasotocin Receptor Cdnas In Teleost Fish: Sequences, Phylogenetic Analysis, Sites Of Expression, And Regulation In The Hypothalamus And Gill In Response To Hyperosmotic Challenge, Sean C. Lema
Biological Sciences
Vasopressin and its homolog vasotocin regulate hydromineral balance, stress responses, and social behaviors in vertebrates. In mammals, the functions of vasopressin are mediated via three classes of membrane-bound receptors: V1a-type, V1b-type and V2-type. To date, however, only a single class of vasotocin receptor has been identified in teleost fish. Here, cDNAs encoding three putative vasotocin receptors – two distinct V1a-type receptor paralogs (V1a1 and V1a2) and a previously undescribed V2- type receptor (V2) – and a single isotocin receptor were isolated and sequenced from the Amargosa pupfish (Cyprinodon nevadensis amargosae). RT-PCR revealed that mRNAs …
Molecular Cloning And Sequence Analysis Of Multiple Cdna Variants For Thyroid-Stimulating Hormone Β Subunit (Tshβ) In The Fathead Minnow (Pimephales Promelas), Sean C. Lema, Jon T. Dickey, Penny Swanson
Molecular Cloning And Sequence Analysis Of Multiple Cdna Variants For Thyroid-Stimulating Hormone Β Subunit (Tshβ) In The Fathead Minnow (Pimephales Promelas), Sean C. Lema, Jon T. Dickey, Penny Swanson
Biological Sciences
We cloned and sequenced full-length cDNAs encoding the β subunit of thyroid-stimulating hormone (TSHβ) from the pituitary of fathead minnow (Piephales promelas)using 5'-and 3'-rapid amplification of cDNA ends (RACE). Three cDNA variants for TSHβ with lengths of 1184-, 1093-, and 818-bp were identified. The cDNA variant of 1184-bp included 453-bp of open-reading frame and 610-bp of 3' UTR followed by a poly(A)site. This cDNA encodes 150 amino acids including a 19 residue signal peptide and a mature TSHβ protein of 131 residues with sequence identities of 97–53% to other fishes and 42–39% to mammals. The 1093-bp cDNA variant …
The Long And Winding Road: Influences Of Intracellular Metabolite Diffusion On Cellular Organization And Metabolism In Skeletal Muscle, Stephen T. Kinsey, Kristin M. Hardy, Bruce R. Locke
The Long And Winding Road: Influences Of Intracellular Metabolite Diffusion On Cellular Organization And Metabolism In Skeletal Muscle, Stephen T. Kinsey, Kristin M. Hardy, Bruce R. Locke
Biological Sciences
A fundamental principle of physiology is that cells are small in order to minimize diffusion distances for O2 and intracellular metabolites. In skeletal muscle, it has long been recognized that aerobic fibers that are used for steady state locomotion tend to be smaller than anaerobic fibers that are used for burst movements. This tendency reflects the interaction between diffusion distances and aerobic ATP turnover rates, since maximal intracellular diffusion distances are ultimately limited by fiber size. The effect of diffusion distance on O2 flux in muscle has been the subject of quantitative analyses for a century, but the …
Environmental Rearing Conditions Produce Forebrain Differences In Wild Chinook Salmon Oncorhynchus Tshawytscha, R. L. Kihslinger, Sean C. Lema, G. A. Nevitt
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 …
Population Divergence In Plasticity Of The Avt System And Its Association With Aggressive Behaviors In A Death Valley Pupfish, Sean C. Lema
Population Divergence In Plasticity Of The Avt System And Its Association With Aggressive Behaviors In A Death Valley Pupfish, Sean C. Lema
Biological Sciences
Behavioral differences can evolve rapidly in allopatry, but little is known about the neural bases of such changes. Allopatric populations of Amargosa pupfish (Cyprinodon nevadensis) vary in aggression and courtship behaviors in the wild. Two of these wild populations were recently found to differ in brain expression of arginine vasotocin (AVT)—a peptide hormone shown previously to modulate aggression in pupfish. These populations have been isolated for less than 4000 years, so it remained unclear whether the differences in behavior and neural AVT phenotype were evolved changes or plastic responses to ecologically dissimilar habitats. Here, I tested whether these …
Proliferation Zones In The Salmon Telencephalon And Evidence For Environmental Influence On Proliferation Rate, Sean C. Lema, Mark J. Hodges, Michael P. Marchetti, Gabrielle A. Nevitt
Proliferation Zones In The Salmon Telencephalon And Evidence For Environmental Influence On Proliferation Rate, Sean C. Lema, Mark J. Hodges, Michael P. Marchetti, Gabrielle A. Nevitt
Biological Sciences
Cell proliferation occurs in the brain of fish throughout life. This mitotic activity contributes new neurons to some brain subdivisions, suggesting potential for plasticity in neural development. Recently we found that the telencephalon in salmonids (salmon, trout) is significantly reduced in fish reared in hatcheries compared to wild fish, and that these differences resulted in part from rearing conditions. Here, we describe localized areas of cell proliferation in the telencephalon of juvenile coho salmon (Oncorhynchus kisutch) and begin to explore whether mitotic activity in these areas is sensitive to environmental conditions. Using the 5-bromo-2'-deoxyuridine (BrdU) cell birthdating technique, …
Exogenous Vasotocin Alters Aggression During Agonistic Exchanges In Male Amargosa River Pupfish (Cyprinodon Nevadensis Amargosae), Sean C. Lema, Gabrielle A. Nevitt
Exogenous Vasotocin Alters Aggression During Agonistic Exchanges In Male Amargosa River Pupfish (Cyprinodon Nevadensis Amargosae), Sean C. Lema, Gabrielle A. Nevitt
Biological Sciences
Pupfishes in the Death Valley region have rapidly differentiated in social behaviors since their isolation in a series of desert streams, springs, and marshes less than 20,000 years ago. These habitats can show dramatic fluctuations in ecological conditions, and pupfish must cope with the changes by plastic physiological and behavioral responses. Recently, we showed differences among some Death Valley populations in brain expression of arginine vasotocin (AVT). As AVT regulates both hydromineral balance and social behaviors in other taxa, these population differences may indicate adaptive changes in osmoregulatory and/or behavioral processes. To test whether AVT is relevant for behavioral shifts …
Longitudinal Variation In Muscle Protein Expression And Contraction Kinetics Of Largemouth Bass Axial Muscle, Tierney M. Thys, Jason M. Blank, David J. Coughlin, Fred Schachat
Longitudinal Variation In Muscle Protein Expression And Contraction Kinetics Of Largemouth Bass Axial Muscle, Tierney M. Thys, Jason M. Blank, David J. Coughlin, Fred Schachat
Biological Sciences
The present study investigates muscle protein expression in largemouth bass Micropterus salmoides through intra- and intermyomeric comparisons of white muscle. Using denaturing SDS-polyacrylamide gel electrophoresis, muscle protein expression in the arm and cone regions of sequential myomeres was compared for three bass. Low percentage (4.75 %) polyacrylamide-SDS gels and cyanogen bromide (CNBr) peptide mapping revealed no obvious intramyomeric differences between the myosin heavy chains of the arm and cone regions. Electrophoresis of myofibrils and muscle homogenates on higher percentage gels also failed to demonstrate any significant differences between arm and cone regions in either the myosin light chains or any …