Experimental data-sets on sex reversal and histopathological assessment of potential endocrine disrupting effects of graphene oxide on Japanese medaka (Oryzias latipes) larvae at the onset of maturity

Abstract

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...

Histopathological evaluation of the interrenal gland (adrenal homolog) of Japanese medaka (Oryzias latipes) exposed to graphene oxide

“…16 Our laboratory has been evaluating GO, as a potential EDC using Japanese medaka fish (Oryzias latipes), as our experimental model. [17][18][19][20][21][22][23] We have demonstrated that the males of medaka fish are more sensitive to GO than the females. From our histopathological evaluation of the gonadal structures and thyroid follicles, we found that the damages observed after GO administration was mainly due to aggregation/agglomeration of GO on or within the organs rather than directly acting as an EDC.…”

“…The solution of GO (both 20 and 2000 mg/L) was sonicated for 5 min (2 s on -1 s off pulse, 225 w) using a probe sonicator (ultrasonicator LPX 750, Cole Palmer, Chicago, IL) in ice temperature and further diluted to desired concentration when necessary (for larvae). The sonicated nanomaterial was further checked by transmission electronmicroscope at the Electron Microscopy Core laboratory at the Jackson State University, Jackson, MS. [18][19][20][21]…”

“…18,19,22,23 Our other investigation of GO effect on the sex reversal (SR) of medaka larvae showed no apparent EDC effect. 20,21 In the present study, we have extended our investigations on the histopathology of the IRG of medaka adults and larvae exposed to different concentrations/doses of GO either by a single intraperitoneal (IP) injection or by 96 h continuous immersion (IMR). In fish, the IRG is considered as the adrenomedullary homolog of the mammalian adrenal gland.…”

Experimental data sets on the evaluation of graphene oxide as a thyroid endocrine disruptor and a modulator of gas gland cells in Japanese medaka (Oryzias latipes) larvae at the onset of maturity

“…The animal maintenance and details of the medaka colony maintained at the Medaka fish culture facility at the Jackson State University were described previously [1] , [2] – 3 , 5 , 6] . Briefly, the breeding colony of Japanese medaka fish (orange red varieties, Hd-rR strain) was maintained in the Aquatic Toxicology Laboratory at the Plant Science building at Jackson State University, Jackson, MS, USA.…”

“…The trunk was used for studies on gas gland cells. The phenotypic sex was determined by gonad histology and genotypic sex by genotyping sex-specific male gene dmy [1] , [2] , [3] . Description of data collection GO was obtained from Sigma (St. louis MO), and sonicated in ERM.…”