|Department:||Biological Sciences, UI|
|Credentials:||1991 - Ph.D., Memorial University of Newfoundland, Canada|
University of Idaho
Fish Reproductive Biology
The Nagler Laboratory studies how the environment interacts with reproduction in fishes. A major ongoing study is a partnership with the Columbia River Inter-Tribal Fish Commission (CRITFC) to understand the reproductive physiology of iteroparity in wild, female steelhead (kelts). The main objective is to investigate whether steelhead kelts that would normally return to the ocean after spawning, before making a second trip to the Clearwater River to spawn, can be “reconditioned” by holding the fish over in freshwater. If this reconditioning strategy is possible it would short circuit the need for an oceanic migration and increase the number of these endangered fish currently surviving to spawn again. Luke Caldwell, a doctoral graduate student candidate, working in conjunction with the CRITFC project, has been studying the energy and endocrine interplay in post-spawned female rainbow trout as a surrogate for steelhead. Another research project, in collaboration with the Battelle Pacific Northwest National Laboratory, the University of Washington, and the Northwest Marine Fisheries Service is modeling how endocrine disrupting chemicals affect the reproductive axis (brain-pituitary-ovary-liver) of the female rainbow trout. This work will build on questions we have been asking about other environmental factors (e.g., photoperiod) we have studied and earlier iterations of our female trout model. A third area of research is the influence of cortisol-mediated stress in post-spawned female rainbow trout used for brood stock in aquaculture. A consistent proportion of these females are sub-fertile and the molecular basis of this condition and an environmental link are being investigated.
Selected Publications 2008-2014
Bangs PD, Nagler JJ (2014) A comparison of nonlethal methods for evaluating the reproductive status of female coastal cutthroat trout. J. Fish Wild. Manag.5(1):183-190.
Sundling K, Craciun G, Schultz I, Hook S, Nagler J, Cavileer T, Verducci J, Liu Y, Kim J, Hayton W (2014) Modeling the endocrine control of vitellogenin production in female rainbow trout. Math. Biosci. Engineer. 11(3):621-639.
Caldwell LK, Pierce AL, Nagler JJ (2013) Plasma nesfatin-1 is not affected by long-term food restriction and does not predict rematuration among iteroparous female rainbow trout (Oncorhynchus mykiss). PLOS One 10.1371/journal.pone.0085700
Caldwell LK, Pierce AL, Nagler JJ (2013) Metabolic endocrine factors involved in spawning recovery and rematuration of iteroparous Oncorhynchus mykiss. Gen. Comp. Endocrinol.194:124-132.
Nagler JJ, Cavileer T, Verducci J, Schultz I, Hook S, Hayton W (2012) Estrogen receptor mRNA expression patterns in the liver and ovary of female rainbow trout over a complete reproductive cycle. Gen. Comp. Endocrinol. 178: 556-561.
Nagler JJ, Cavileer T, Hunter S, Drew R, OkutsuT, Sakamoto T, Yoshizaki G (2011) Non-sex specific genes associated with the secondary mitotic period of primordial germ cell proliferation in the gonads of embryonic rainbow trout (Oncorhynchus mykiss). Mol. Reprod. Develop. 78:181-187
Shyu C, Cavileer TD, Nagler JJ, Ytreberg FM (2011) Computational estimation of rainbow trout estrogen receptor binding affinities for environmental estrogens. Toxicol. Appl. Pharmacol. 250:322-326.
Hook S, Nagler JJ, Cavileer T, Verducci J, Liu Y, Hayton W, Schultz I (2011) Relationships between the transcriptome and physiological indicators of reproduction in female rainbow trout over an annual cycle. Environ. Toxicol. Chem. 30:309-318.
Nagler JJ, Davis TL, Modi N, Vijayan MM, Schultz I (2010) Intracellular, not membrane, estrogen receptors control vitellogenin synthesis in the rainbow trout (Oncorhynchus mykiss). Gen. Comp. Endocrinol. 167: 326-330.
Cavileer T, Hunter S, OkutsuT, Yoshizaki G, Nagler JJ (2009) Identification of novel genes associated with molecular sex differentiation in the embryonic gonads of rainbow trout (Oncorhynchus mykiss). Sexual Develop. 3:214-224.
Brown KH, Schultz IR, Nagler JJ (2009) Lack of a heritable reproductive defect in the offspring of male rainbow trout exposed to the environmental estrogen 17α-ethynylestradiol. Aquat. Toxicol. 91:71-74.
Brown KH, Schultz IR, Cloud JG, Nagler JJ (2008) Aneuploid sperm formation in rainbow trout exposed to the environmental estrogen 17α-ethynylestradiol. PNAS (USA) 105:19786-19791.