The datasets of this article present the experimental parameters resulting from the synthesis and characterization of graphene oxide (GO) using scanning and transmission electron microscopy (SEM, TEM) and spectrophotometric (FTIR, AFM, EDX) methods, and the assessment of its toxicological and endocrine-disrupting effects on the Japanese medaka fish by acute toxicity testing, and histopathological evaluations. These datasets support the article “Reproductive and Developmental Effects of Graphene Oxide on Japanese Medaka ( Oryzias latipes )". GO synthesis was performed following the modified Hummer's method. Its particle diameter and zeta potential were determined using Zeta Sizer Nano ZS analyzer, and characterized by SEM and TEM. After 5 min sonication in water, GO (25–200 µg/g) was injected intraperitoneally to the reproductively active male and female fish maintained as a breeding pair (one male, one female) in 500 mL balanced salt solution (BSS) in glass jars under standard laboratory conditions (25±1 °C; 16L:8D light cycle). The control fish were injected with water. The maximum volume of the injected material is 1 µL/10 mg body weight. To avoid movement, during injection the fish were briefly anesthetized in MS 222 (100 mg/L) and after injection transferred to BSS for recovery. LD 50 values of GO related to fish mortality were determined from the linear regression analysis using a software program. Reproductive activities (fecundity) were determined by daily collection of eggs 7 days before and 21 days after injection from a breeding pair and expressed as percent eggs laid every day post-injection relative to the average (mean of 7 days) eggs laid prior to injection. Developmental abnormalities of the embryos were assessed by culturing the collected fertilized eggs in ERM for a maximum period of 14 day-post fertilization (dpf). The fish that survived after 21days post-injection were sacrificed and the entire fish excluding post-anal tail were cut into three small pieces and fixed in 4% paraformaldehyde containing 0.05% Tween 20. Histopathological evaluations of gonads (ovary and testis), liver, and kidneys were made in 5 µm thick sections stained mainly on hematoxylin and eosin (HE) following the guidelines published by OECD. The Photomicrographs of the sections were made using Olympus B-max 40 microscope attached to a camera with Q-capture Pro 7 software or in Nikon Eclipse 50i microscope attached to Nikon DS-Fi1 camera. Four types of follicles in the stromal compartments of the ovary, perinucleolar (PNO), cortical alveolar (CAO), early vitellogenic (EVO) and late vitellogenic (LVO) were considered as differentiating, and the post ovulatory and atretic follicles were considered as degenerating follicles, and counted in an entire section made through four different regions (anterior, upper middle, lower middle, and anal) of the ovary. The follicular data were expressed as percent follicles (individual follicles or differentiating or degenerating) or as the ...

The datasets of this article present the experimental parameters resulting from the assessment of sex reversal (SR) as a biomarker of endocrine disrupting effect of graphene oxide (GO), together with the histopathological assessment of ovary, testis, liver and kidneys of medaka larvae. These data sets support the published article “Sex-reversal and histopathological assessment of potential endocrine-disrupting effect of graphene oxide on Japanese medaka ( Oryzias larvae ) larvae.” The experiments were conducted on one day-post hatch (dph) Japanese medaka fries (orange-red variety) exposed to different concentrations of GO (2.5–20 mg/L) by immersion in embryo-rearing medium (ERM) for 96 h under laboratory conditions (25 ± 1 °C; light cycle 16 h light: 8 h dark). No food was given during the GO-exposure period. Controls (no GO) were identically maintained in ERM. After treatment, the larvae were maintained in balanced salt solution (BSS) with feeding and allowed to grow for 6 more weeks in a GO-free environment. On 47 dph, the larvae were anesthetized in MS-222, and the total length (mm) and body weight (mg) were recorded. For histopathological and phenotypic sex assessments, after sacrifice, the body excluding post-anal tail was preserved in 4% paraformaldehyde containing 0.05% Tween 20; ovary, testis, liver and kidneys were evaluated in 5 µm thick sections stained on haematoxylin eosin (HE) following OECD guidelines. The photomicrographs of sections were made using either an Olympus B-max 40 microscope attached to a camera with Q-capture Pro 7 software or an Olympus CKX53 inverted microscope with DP22 camera and CellSens software. A minimum 3 images of gonads in different regions were further analysed by imagej software and used for counting spermatogonia (SPG) and spermatocytes (SPT) in testis as well as perinucleolar (PNO) and cortical alveolar (CAO) oocytes in ovary. Data were expressed as number of SPG or SPT/mm 2 testis and % CAO or PNO in an ovary. Preserved tail in TRI reagent was used for genomic DNA extraction and the genetic sex was assessed by genotyping Y chromosome-specific male sex-determining gene dmy . Two different sets of buffers and primers were used and the reactions were conducted in a thermal cycler. The amplified products were separated in 2% agarose gel containing 0.01% ethidium bromide. The gels were viewed on an UV illuminator and the genotypes were identified by visual inspection. The first primer set amplified a 355 bp product for XY genotypes and no amplification for XX. The second set of primers amplified two products; one at 1249 bp and another at 986 bp for XY, and one product at 1249 bp for XX. Experimental data were expressed as means ± SD or SEM, analysed either by one-way analysis of variance (ANOVA) followed by post-hoc Tukey's multiple comparison test or unpaired parametric ‘ t ’ test including Welch's correction, if distributed normally (lengths and weights), or by Kruskal-Walli...

No abstract