Targets and terminology for comparative genomics in mammalian hibernators

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Comparative Biochemistry and Physiology, Part C j o u r n a l h o m e p a g e : w w w. e l s ev i e r. c o m / l o c a t e / c b p c

International Conference of Comparative Physiology, Biochemistry and Toxicology, and 6th Chinese Comparative Physiology Conference TARGETS AND TERMINOLOGY FOR COMPARATIVE GENOMICS IN MAMMALIAN HIBERNATORS Brian M. Barnes Institute of Arctic Biology, University of Alaska, Fairbanks, Alaska, 99775, USA E-mail: [email protected] Mammalian hibernators display profound metabolic flexibility and regulated capacities to withstand levels of prolonged hypothermia and ischemia that are pathological in non-hibernating species. The genetic and molecular mechanisms that regulate hibernation and provide protection to tissues from extreme conditions, however, are still relatively unknown. Genomic and proteomic approaches are increasingly being used to investigate these mechanisms, but the relevance of species, sex, and age cohort differences, the appropriate choices of seasonal and hibernation cycle sampling times, and concepts of suitable controls are still unknown or controversial. Our field and lab investigations of hibernation in a medium-sized hibernator, the arctic ground squirrel (∼1 kg), have shown phenotypic changes in reproductive state, body temperature regulation, metabolic rate, body mass and composition, behavior, and stages in life histories that may inform when and what comparisons may be relevant to which questions. This presentation will describe traits of seasonal and hibernation cycle changes in arctic ground squirrels, suggest a terminology for consistency in sample selection, and review alternatives and the logic for selecting comparisons within and between species in genomic approaches to hibernation. doi:10.1016/j.cbpc.2008.10.004

COMPARATIVE PHYSIOLOGY AND TOXICOLOGY OF COPPER AND SILVER IN EURYHALINE INVERTEBRATES: A BIOTIC LIGAND MODEL APPROACH Adalto Bianchinia, Mariana M. Lauerb, Mariana S. Pedrosob, Indianara F. Barcarollic, Samantha E.G. Martinsc, Aline F.A. de Limac, Grasiela L.L. Pinhoc a Departamento de Ciências Fisiológicas, Fundação Universidade Federal do Rio Grande (FURG), Rio Grande, RS, 96201-900, Brazil b Pós-Graduação em Ciências Fisiológicas, FURG, Rio Grande, RS, 96201-900, Brazil c Pós-Graduação em Oceanografia Biológica, FURG, Rio Grande, RS, 96201-900, Brazil E-mail: [email protected] The premise behind the Biotic Ligand Model (BLM) approach is that exist a correlation between the metal binding at the sites of toxicity in the biotic ligand and the corresponding metal toxicity. Physiological studies have demonstrated that the key mechanism of copper and silver toxicity is associated with ionorregulatory disturbances in both freshwater (fish and invertebrates) and marine (fish) osmoregulators. However, few studies have been developed in estuarine and marine osmoconformers. Furthermore, the key mechanism of copper and silver toxicity in these animals is still not well established. In the present study, possible ionoregulatory impairments at the hemolymph (crab and clam) or whole body level (isopod and copepod) were evaluated as the key mechanism of acute copper and silver toxicity in different euryhaline invertebrate species. Most studies were performed in a wide range of salinity in both the absence and the presence of food in the

water. Data obtained indicate that animal's response to acute metal exposure depends on metal and species under consideration, as well as on salinity and presence of food in the water. When osmoconforming, euryhaline invertebrates (crab, isopod, copepod and clam) were not significantly affected by copper or silver exposure. On the other hand, significant ionoregulatory impairments at the hemolymph (crab) or whole body level (isopod and copepod) were generally observed after exposure to copper or silver in osmoregulating euryhaline invertebrates. However, some effects were only observed in the absence of food. These results indicate that the mechanism of both copper and silver in osmoregulating invertebrates is similar to that observed in freshwater fish and crustaceans, i.e. an ionoregulatory impairment associated with an inhibition of the gill or whole body Na+,K+-ATPase. They also suggest that other mechanism(s) is (are) associated with copper and silver toxicity in osmoconforming euryhaline invertebrates. Therefore, findings presented here are quite important when modeling the physiological effects of metals in euryhaline animals and will certainly contribute for a future extension of the BLM for estuarine and marine conditions. doi:10.1016/j.cbpc.2008.10.005

SALINITY TOLERANCE OF THE ENDANGERED LAKE QINGHAI SCALELESS CARP, GYMNOCYPRIS PRZEWALSKII C.J. Braunera, J.G. Richardsa, V. Mateyb, C.M. Woodc, J. Rogersc, B. Murrayd, X.-Q. Chene, J.-Z. Due, Y.-X. Wangf a Department of Zoology, University of British Columbia, Vancouver, B.C., Canada V6T 1Z4 b Department of Biology, San Diego State University, San Diego, CA, USA c Department of Biology, McMaster University, Hamilton, Ontario, Canada L8S 4K1 d Ecosystem Science and Management Program, University of Northern British Columbia, Prince George, B.C., Canada V2N 4Z9 e Department of Biotechnology, Life Science College, Zhejiang University, Hangzhou, Zhejiang, PR China, 310027 f Department of Biology, Queen's University, Kingston, Ontario, Canada K7P 3N6 E-mail: [email protected] Lake Qinghai is the largest lake in China (4200 km2) historically supporting a fishery for scale-less carp (28000 tons/year in 1961). The lake resides at 3600 m and is saline (presently 11 ppt) due to no outflow and high evaporative water loss. Fish currently living in this lake are isosmotic with their environment. Because of extensive water diversion for agricultural use, the water level is decreasing 10 cm/year, and the salinity is increasing. Carp in general, have limited ability to hypoosmoregulate, and the scale-less carp appear to be no exception. While living in lake water at the current salinity appears to be metabolically favorable relative to freshwater (Wood et al., 2007), an increase in salinity above current levels by 4 ppt or higher resulted in severe osmoregulatory disturbances leading to mortality or severe loss of equilibrium within 3 days. An increase of as little as 2 ppt over current lake salinity resulted in an osmoregulatory disturbance within 24 h that was exacerbated over the following 48–72 h which was associated with 10% mortality and an additional 30% loss of equilibrium by 3 days. Minor changes in gill morphology and gill Na+, K+-ATPase were observed at higher salinities indicating that this species has a very limited ability to hypoosmoregulate. Taken together these data indicate