Chad A Blanksma US EPA Great Lakes Toxicology and Ecology Division Histotechnologist

6201 Congdon Blvd. Duluth MN 55804 USA

blanksma.chad@epa.gov 0009-0001-8811-8083 An ovary in a 15 week old female medaka sectioned along the sagittal plane. The microtomy procedure produced 4 regions in the parasagittal plane, and this section represents region 2 of 4. Microtomy proceeded from the left side to the right for this sample. Populations of oogenic cell types that can be identified in this image include perinucleolar, cortical alveolar, and vitellogenic oocytes. Early and late development vitellogenic oocytes can be identified. This image was created by stitching several 10x images together. Scale bar = 1 millimeter. Medaka Adult Whole ovary Sagittal plane Perinucleolar oocyte Cortical alveolar oocyte Vitellogenic oocyte Oogenesis Vitellogenesis This information is released under the Creative Commons license - Attribution - CC BY (https://creativecommons.org/licenses/by/4.0/). The consumer of these data ("Data User" herein) is required to cite it appropriately in any publication that results from its use. The Data User should realize that these data may be actively used by others for ongoing research and that coordination may be necessary to prevent duplicate publication. The Data User is urged to contact the authors of these data if any questions about methodology or results occur. Where appropriate, the Data User is encouraged to consider collaboration or co-authorship with the authors. The Data User should realize that misinterpretation of data may occur if used out of context of the original study. While substantial efforts are made to ensure the accuracy of data and associated documentation, complete accuracy of data sets cannot be guaranteed. All data are made available "as is." The Data User should be aware, however, that data are updated periodically and it is the responsibility of the Data User to check for new versions of the data. The data authors and the repository where these data were obtained shall not be liable for damages resulting from any use or misinterpretation of the data. Thank you. 2015 Kingdom Animalia animals 202423 Subkingdom Bilateria triploblasts 914154 Infrakingdom Deuterostomia 914156 Phylum Chordata chordates 158852 Subphylum Vertebrata vertebrates 331030 Infraphylum Gnathostomata 914179 Superclass Actinopterygii ray-finned fishes 161061 Class Teleostei 161105 Superorder Acanthopterygii 166082 Order Beloniformes needlefishes 553128 Suborder Adrianichthyoidei 553156 Family Adrianichthyidae adrianichthyids 165623 Subfamily Oryziinae 645103 Genus Oryzias 165616 Species Oryzias latipes Japanese killifish 165622 Chad A Blanksma US EPA Great Lakes Toxicology and Ecology Division Histotechnologist blanksma.chad@epa.gov 0009-0001-8811-8083 Image collection device Diagnostic Instruments, Inc. SPOT Insight 12.3 Mp sCMOS/ 4K UHD Camera System Image collection software Diagnostic Instruments, Inc. SPOT Advanced Software Image analysis software Media Cybernetics Image-Pro Premier 9.3 Graphics Editing Software Corel Corporation CorelDraw Graphics Suite 2022 Kevin Flynn US EPA Great Lakes Toxicology and Ecology Division Biologist flynn.kevin@epa.gov 0000-0001-8658-5633 Corresponding author The Medaka Extended One Generation Reproduction Test (MEOGRT) is a Tier 2 test within U.S. Environmental Protection Agency's (USEPA) Endocrine Disruptor Screening Program (EDSP), designed to characterize the potential adverse effects to fish of exposure to chemical that can cause disruption of the endocrine system. The MEOGRT focuses primarily on adverse effects to reproduction while collecting information regarding effects on growth, survival, and endocrine-related endpoints. However, the risk assessment process for fish, as mandated by legislation such as the Federal Insecticide, Fungicide, and Rodenticide Act (FIFRA) or the Toxic Substances Control Act (TSCA), could benefit from a more detailed assessment of effects on growth. Typically, fish growth data in support of risk assessment are obtained from full life-cycle tests or early life stage tests using the fathead minnow. As an alternative to these tests, a modified MEOGRT was conducted to assess the effects of diazinon on the various parameters measured in the MEOGRT. Diazinon is an organophosphate insecticide that is detected in the environment, and whose efficacy is a result of inhibition of the acetylcholine esterase enzyme at neuromuscular junctions and synapses of the nervous system. Diazinon (2.9, 5.2, 10.3, 19.8, and 40.2 μg/L) was tested with the MEOGRT protocol, and the lowest observable effect concentrations of 2.9 μg/L for fecundity and 5.2 μg/L for growth were determined. Additional growth measurements were added to the MEOGRT protocol to more robustly define growth rates and to determine the impact size has on reproductive performance. Fish size starting at the first measurement day (i.e. 21 days post-fertilization), and continuing through the duration of the test was reduced with exposure to 5.2 μg/L and higher, and asymptotic size predicted from growth modeling was reduced at 10.3 μg/L and higher. By simply adding non-destructive growth measurements at two additional time points, the MEOGRT provided enough data for the parameterization of growth models, which could be used to characterize the reproductive implications of growth impairment. Flynn K, Lothenbach D, Whiteman F, Hammermeister D, Swintek J, Etterson M, Johnson R. The effects of continuous diazinon exposure on growth and reproduction in Japanese medaka using a modified Medaka Extended One Generation Reproduction Test (MEOGRT). Ecotoxicol Environ Saf. 2018 Oct 30;162:438-445. doi: 10.1016/j.ecoenv.2018.06.088. Epub 2018 Jul 14. PMID: 30015190. Diaz1402_F1_Repro_T1R2_2C_10x_Stitched_Cropped_Finished2 Diaz1402_F1_Repro_T1R2_2C_10x_Stitched_Cropped_Finished2.tif tif histology USEPA_GLTED_OL_MEOGRT_Diaz1402_F1_Repro_T1R2 female 105 adult 1 ovary unspecified 1B 5 microns Nikon Eclipse TE 300