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77. Evolution and developmental expression of the sodium–iodide symporter (NIS, slc5a5) gene family: Implications for perchlorate toxicology.

Author

Petersen, Ann M., Small, Clayton M., Yan, Yi‐Lin, Wilson, Catherine, Batzel, Peter, Bremiller, Ruth A., Buck, C. Loren, von Hippel, Frank A., Cresko, William A., and Postlethwait, John H.

Subjects
GONADS, GENE families, THREESPINE stickleback, GENITALIA, GERM cells, CONNECTIVE tissues, CARTILAGE cells
Abstract

The vertebrate sodium–iodide symporter (NIS or SLC5A5) transports iodide into the thyroid follicular cells that synthesize thyroid hormone. The SLC5A protein family includes transporters of vitamins, minerals, and nutrients. Disruption of SLC5A5 function by perchlorate, a pervasive environmental contaminant, leads to human pathologies, especially hypothyroidism. Perchlorate also disrupts the sexual development of model animals, including threespine stickleback (Gasterosteus aculeatus) and zebrafish (Danio rerio), but the mechanism of action is unknown. To test the hypothesis that SLC5A5 paralogs are expressed in tissues necessary for the development of reproductive organs, and therefore are plausible candidates to mediate the effects of perchlorate on sexual development, we first investigated the evolutionary history of Slc5a paralogs to better understand potential functional trajectories of the gene family. We identified two clades of slc5a paralogs with respect to an outgroup of sodium/choline cotransporters (slc5a7); these clades are the NIS clade of sodium/iodide and lactate cotransporters (slc5a5, slc5a6, slc5a8, slc5a8, and slc5a12) and the SGLT clade of sodium/glucose cotransporters (slc5a1, slc5a2, slc5a3, slc5a4, slc5a10, and slc5a11). We also characterized expression patterns of slc5a genes during development. Stickleback embryos and early larvae expressed NIS clade genes in connective tissue, cartilage, teeth, and thyroid. Stickleback males and females expressed slc5a5 and its paralogs in gonads. Single‐cell transcriptomics (scRNA‐seq) on zebrafish sex‐genotyped gonads revealed that NIS clade‐expressing cells included germ cells (slc5a5, slc5a6a, and slc5a6b) and gonadal soma cells (slc5a8l). These results are consistent with the hypothesis that perchlorate exerts its effects on sexual development by interacting with slc5a5 or its paralogs in reproductive tissues. These findings show novel expression domains of slc5 genes in stickleback and zebrafish, which suggest similar functions across vertebrates including humans, and provide candidates to mediate the effects of perchlorate on sexual development. [ABSTRACT FROM AUTHOR]

Published
2022
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80. Patterns of cortisol and corticosterone concentrations in humpback whale (Megaptera novaeangliae) baleen are associated with different causes of death

Author

Lowe, Carley L, primary, Hunt, Kathleen E, additional, Robbins, Jooke, additional, Seton, Rosemary E, additional, Rogers, Matthew, additional, Gabriele, Christine M, additional, Neilson, Janet L, additional, Landry, Scott, additional, Teerlink, Suzie S, additional, and Buck, C Loren, additional

Published
2021
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84. Retrospective analysis of the lifetime endocrine response of southern right whale calves to gull wounding and harassment: A baleen hormone approach

Author

Fernández Ajó, Alejandro A., primary, Hunt, Kathleen E., additional, Giese, A. Carolina, additional, Sironi, Mariano, additional, Uhart, Marcela, additional, Rowntree, Victoria J., additional, Marón, Carina F., additional, Dillon, Danielle, additional, DiMartino, Matias, additional, and Buck, C. Loren, additional

Published
2020
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89. Potential endocrine correlation with exposure to domoic acid in Southern Right Whale (Eubalaena australis) at the Península Valdés breeding ground.

Author

D'Agostino, Valeria C., Fernández Ajó, Alejandro, Degrati, Mariana, Krock, Bernd, Hunt, Kathleen E., Uhart, Marcela M., and Buck, C. Loren

Subjects
MATING grounds, DOMOIC acid, MARINE mammals, ENZYME-linked immunosorbent assay, LACTATION, SYMPTOMS, WHALES
Abstract

In waters off Península Valdés (PV), Argentina, southern right whales (SRW, Eubalaena australis) are occasionally exposed to domoic acid (DA), a neurotoxin produced by diatoms of the genus Pseudo-nitzschia. Domoic acid toxicity in marine mammals can cause gastrointestinal and neurological clinical signs, alterations in hematologic and endocrine variables, and can be fatal in extreme cases. In this study, we validated an enzyme immunoassay to quantify fecal glucocorticoid metabolites (fGCm) in 16 SRW fecal samples from live and dead stranded whales in PV from 2013 to 2018 and assessed fGCm levels associated with DA exposure. Overall, fGCm levels were significantly lower in SRWs with detectable fecal DA (n = 3) as compared to SRWs with undetectable fecal DA levels (n = 13). The highest fecal DA was observed in a live lactating female, which had low fGCm compared to the other lactating females studied. The highest fGCm was observed in a lactating female with undetectable DA; interestingly, at the time of sample collection, this female was sighted with two calves, an extremely unusual occurrence in this species. Though the sample size of these exceptionally rare breeding-season fecal samples was unavoidably small, our study provides evidence of potential adrenal alterations in whales exposed to an environmental neurotoxin such as DA. [ABSTRACT FROM AUTHOR]

Published
2022
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90. Resetting the clock: after hibernation, arctic ground squirrels may need the light of day to reactivate body rhythms

Author

Williams, Cory T. and Buck, C. Loren

Subjects
Ground squirrels -- Physiological aspects -- Environmental aspects, Zoological research, Circadian rhythms -- Environmental aspects, Anthropology/archeology/folklore, Biological sciences, Earth sciences, Science and technology, Zoology and wildlife conservation
Abstract

As the farthest-north hibernating small mammals in North America, arctic ground squirrels (Urocitellus parryii) are exposed to profound seasonal changes in light and ambient temperature. Their annual cycle includes a [...]

Published
2015

100. Multi-year patterns in testosterone, cortisol and corticosterone in baleen from adult males of three whale species

Author

Hunt, Kathleen E., Lysiak, Nadine S. J., Matthews, Cory J. D., Lowe, Carley, Ajo, Alejandro Fernández, Dillon, Danielle, Willing, Cornelia, Heide-Jørgensen, Mads Peter, Ferguson, Steven H., Moore, Michael J., Buck, C. Loren, Hunt, Kathleen E., Lysiak, Nadine S. J., Matthews, Cory J. D., Lowe, Carley, Ajo, Alejandro Fernández, Dillon, Danielle, Willing, Cornelia, Heide-Jørgensen, Mads Peter, Ferguson, Steven H., Moore, Michael J., and Buck, C. Loren

Abstract

© The Author(s), 2018. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Conservation Physiology 6 (2018): coy049, doi:10.1093/conphys/coy049., Male baleen whales have long been suspected to have annual cycles in testosterone, but due to difficulty in collecting endocrine samples, little direct evidence exists to confirm this hypothesis. Potential influences of stress or adrenal stress hormones (cortisol, corticosterone) on male reproduction have also been difficult to study. Baleen has recently been shown to accumulate steroid hormones during growth, such that a single baleen plate contains a continuous, multi-year retrospective record of the whale’s endocrine history. As a preliminary investigation into potential testosterone cyclicity in male whales and influences of stress, we determined patterns in immunoreactive testosterone, two glucocorticoids (cortisol and corticosterone), and stable-isotope (SI) ratios, across the full length of baleen plates from a bowhead whale (Balaena mysticetus), a North Atlantic right whale (Eubalaena glacialis) and a blue whale (Balaenoptera musculus), all adult males. Baleen was subsampled at 2 cm (bowhead, right) or 1 cm (blue) intervals and hormones were extracted from baleen powder with methanol, followed by quantification of all three hormones using enzyme immunoassays validated for baleen extract of these species. Baleen of all three males contained regularly spaced peaks in testosterone content, with number and spacing of testosterone peaks corresponding well to SI data and to species-specific estimates of annual baleen growth rate. Cortisol and corticosterone exhibited some peaks that co-occurred with testosterone peaks, while other glucocorticoid peaks occurred independent of testosterone peaks. The right whale had unusually high glucocorticoids during a period with a known entanglement in fishing gear and a possible disease episode; in the subsequent year, testosterone was unusually low. Further study of baleen testosterone patterns in male whales could help clarify conservation- and management-related questions such as age of sexual maturity, location and season, This work was supported by (1) the Arizona Board of Regents Technology Research Initiative Fund; (2) the Center for Bioengineering Innovation at Northern Arizona University; (3) the Greenland Institute of Natural Resources; (4) the Woods Hole Oceanographic Institution Ocean Life Institute and (5) Fisheries and Ocean Canada’s (DFO) Priorities and Partnership Strategic Initiatives Fund and Oceans Protection Plan.

Published
2018

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