Abstract:

Recent studies by our lab have shown that oil exposure increases oxygen consumption of developing mahi-mahi larvae and that this increased metabolic demand is likely fueled by increased protein catabolism, as evidenced by increased nitrogenous waste excretion. Additionally, a recent RNA-seq study by our lab and others revealed a number of oil-responsive genes in early life stage mahi-mahi associated with nitrogenous waste excretion. Similar to other teleosts, mahi-mahi avoid the toxic build-up of ammonia by being ureotelic during the embryonic stage and gradually switch to being ammoniotelic around hatch. Thus, any disruption in the timing of these processes could indicate significant physiological impacts with implications for survival. In this dataset, the mRNA expression changes for different transporters (Rhag, Rhbg, Rhcg1, Rhcg2, Nhe2, Nhe3, EF1a, UT) are provided for mahi embryos and larvae at different time points. Additionally, results from in situ hybridization experiments to localize the tissue-specific expression of these genes are provided.

Suggested Citation:

Wang, Y.. 2018. Developmental gene expression analysis of the impacts of crude oil toxicity on nitrogenous waste excretion in mahi-mahi (Coryphaena hippurus) early life stages. Distributed by: GRIIDC, Harte Research Institute, Texas A&M University–Corpus Christi. doi:10.7266/N7J38QZP

Publications:

Wang, Y., Pasparakis, C., Mager, E. M., Stieglitz, J. D., Benetti, D., & Grosell, M. (2019). Ontogeny of urea and ammonia transporters in mahi-mahi (Coryphaena hippurus) early life stages. Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology, 229, 18–24. doi:10.1016/j.cbpa.2018.11.018

Purpose:

Finding the baseline information about how ammonia and urea excretion rates and relative transporters changes during the early life stages of mahi-mahi.

Data Parameters and Units:

Ammonia and urea excretion rates (pmol N indiv-1 min 1) at different time points (6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 72, 78, 84, 90, 96, 102 hpf) data found in ‘NW Excretion Complies Data’ folder. mRNA expression of different transporters (Rhag, Rhbg, Rhcg1, Rhcg2, Nhe2, Nhe3, EF1a, UT) were quantified in mahi embryos and larvae in different time points (6, 12, 18, 24, 30, 36, 42, 48, 54, 60, 66, 78, 90, 102 hpf), data found in ‘qPCR data’ folder. The curve data was calculated by the software and included under each gene file. Images taken to localize where the transporters are at 60 and 102 hpf – data found in ‘In situ Hybridization Pics’. The first number in the image file names indicate the biological replicate number; for example: the first larvae, the second larvae. The second number indicates the number of pictures taken from the same larvae.

Methods:

Ammonia and urea excretion rates: Micromodified Indophenol Blue and Diacetyl Monoxime methods. mRNA expression raw data analysis was performed with the qPCR Miner software (Zhao and Fernald, 2005) and normalized to EF1 mRNA expression. The in situ hybridization protocol was based on the work of Thisse (Thisse et al., 2008).

Instruments:

qPCR - Stratagene Mx3005P; in situ hybridization - Leica inverted microscope

Provenance and Historical References:

Zhao, S., & Fernald, R. D. (2005). Comprehensive algorithm for quantitative real-time polymerase chain reaction. Journal of computational biology, 12(8), 1047-1064. Thisse, C., & Thisse, B. (2008). High-resolution in situ hybridization to whole-mount zebrafish embryos. Nature protocols, 3(1), 59.

Individual Files: