Project description:High dose level dibutyl phthalate (DBP) exposure of fetal rat testes in vivo inhibits testosterone production (i.e. endocrine disruption). Here, fetal testis mRNA levels were profiled following exposure to a DBP dose level that did not significantly reduce testosterone levels. The goal was to identify the constellation of gene expression changes that do not correlate with endocrine disruption.
Project description:High dose level dibutyl phthalate (DBP) exposure of fetal rat testes in vivo inhibits testosterone production (i.e. endocrine disruption). Here, fetal testis mRNA levels were profiled following exposure to a DBP dose level that did not significantly reduce testosterone levels. The goal was to identify the constellation of gene expression changes that do not correlate with endocrine disruption. Fischer 344 rats were exposed via oral gavage of the dam to vehicle (corn oil) or 50 mg/kg (body weight) DBP daily from gestational day (GD) 12 to 20. The day after mating was defined as gestational day 0. Six hours after the final exposure on GD20, fetal testes were dissected and mRNA levels quantified using Affymetrix Rat Expression 230 2.0 microarrays.
Project description:In rodent models, phthalate exposure alters both the fetal and pubertal testis, but the resulting histopathological changes are divergent. This suggests that the underlying molecular and cellular phthalate mechanism may be age-dependent. Using genome-wide expression profiling of acutely-exposed rats, the initial molecular response in pubertal rat testis following in vivo phthalate exposure was determined. For this study, postnatal day 28 rats were exposed to a single dose of 1 g/kg mono-(2-ethyl)hexyl phthalate (MEHP) and assayed at 1, 2, 3, 6, and 12 hrs thereafter using Affymetrix Rat Genome 230 2.0 Arrays. Keywords: Time course, single dose
Project description:In rodent models, phthalate exposure alters both the fetal and pubertal testis, but the resulting histopathological changes are divergent. This suggests that the underlying molecular and cellular phthalate mechanism may be age-dependent. Using genome-wide expression profiling of acutely-exposed rats, the initial molecular response in pubertal rat testis following in vivo phthalate exposure was determined. For this study, postnatal day 28 rats were exposed to a single dose of 1 g/kg mono-(2-ethyl)hexyl phthalate (MEHP) and assayed at 1, 2, 3, 6, and 12 hrs thereafter using Affymetrix Rat Genome 230 2.0 Arrays. Experiment Overall Design: At each timepoint, testes from 3 treated and 3 control (corn oil gavage) were analzyed.
Project description:Aquatic organisms are generally exposed to a mixture of phthalate esters (PAEs) that have been shown to induce reproductive toxicity. However, their potential toxicity mechanisms to aquatic organisms remain unclear. Here male zebrafish were exposed to dibutyl phthalate (DBP), diisobutyl phthalate (DiBP) and their mixtures for 30 days, and their effects on plasma sex hormones, testis histology and testis transcriptomics were investigated. DBP, DiBP and their mixtures could induce the disequilibrating ratio of testosterone (T) and plasma estradiol (E2) in plasma. The percentage of spermatozoa (Sz) was significantly decreased by 30.6% under DBP-1133 exposure and 27.8% under Mix-3 exposure, and widen intercellular spaces appeared under DiBP-1038 exposure. Transcriptome sequencing revealed 2795 differentially expressed genes (DEGs) in the DBP-1133 exposure group, 1613 DEGs in the DiBP-1038 exposure group and 4570 DEGs in the Mix-3 exposure group, indicating that the toxicity of combined exposure was higher than that of single exposure. Cytokine-cytokine receptor interaction was associated with the toxicity mechanism of DBP, DiBP and Mix. While GnRH signaling pathway and MAPK signaling pathway were related to the toxicity mechanism of DBP. ECM-receptor interaction, steroid hormone biosynthesis, retinol metabolism and PPAR signaling pathway were associated with the toxicity mechanism of DiBP and Mix.
Project description:Analysis of gene expression and alternate splicing effects of retinoic acid treatment on gestational day 15 rat fetal testes in whole testis culture Retinoic acid exposure in cultured fetal testis has previously been demonstrated to have significant effects on the histology of the fetal testis in multiple species, as well as to alter the meiotic states of germ cells. However, previous experiments have not analyzed the mechanisms by which retinoic acid exposure leads to altered tubulogenesis and loss of seminiferous cord structure. This experiment demonstrated that retinoic acid exposure activated signaling pathways that promote the ovary development program and oppose normal testis development in mid-gestational rat fetal testes.
Project description:Provided later Pregnant Fisher 344 rats will be purchased from Charles River Laboratories, Inc. and delivered to CIIT on gestational day (GD) 7 (GD0 = day first vaginal plug positive). At gestational day 12 (GD12), the dams will be exposed once/day until GD20 to 50 mg/kg dibutyl phthalate (DBP) in corn oil vehicle via oral gavage. Each dose group will contain 4-6 vehicle control or phthalate treated dams. Groups of animals will be sacrificed at GD20, postnatal day (PND) 35, and PND90 for endpoint analysis. At GD20, treated and control animals will be examined for various endpoints including body weight, testicular histopathology, gene expression profile via microarray analysis, and anogenital distance (AGD). AGD (at parturition; PND1) and nipple number/location (at PND14 and day of sacrifice) will be determined on animals in the postnatal groups. At PND35 or 90, one male from each in utero corn oil vehicle or DBP exposed group will receive a second gavage of either corn oil or 500 mg/kg DBP. 6 hours after the second gavage, the following endpoints will be examined: 1) testis histopathology; 2) spermatid head quantification (PND90 only); 3) testis and body weights; 5) genome-wide gene expression (via microarray); and 6) germ cell apoptosis (TUNEL assay).
Project description:We report the RNAseq-based transcriptome profiles of rat gestation day 20 dam liver, fetal male and female liver, fetal male pituitary, and fetal testis following in utero exposure to either 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or 2,3,7,8-tetrachlorodibenzofuran (TCDF). Two exposure models were examined: 1) pregnant rats exposed to either a dose response series of TCDD or TCDF from gestation day 6 - 20 or 2) pregnant rats exposed to a single dose of TCDD or TCDF on gestation day 15. These data support a mode-of-action for dioxin-induced rat male reproductive toxicity involving key events in both the fetal pituitary (reduced gonadotropin production) and fetal testis (reduced Leydig cell cholesterologenesis and steroidogenesis) which are hypothesized to decrease perinatal Sertoli cell proliferation and culminate in reduced spermatogenesis. The lack of a TCDF effect on proposed key events may be due to a higher rate of metabolic clearance relative to TCDD.
Project description:ChIP microarrays were used to investigate whether dibutylphthalate (DBP)-mediated repression of SF1-regulated genes was associated with changes in transcription factor binding to genes involved in DBP-induced testicular maldevelopment. The repressive effect of DBP on SF1 regulated gene expression in fetal testes correlates with inhibition of SF1 binding to steroidogenic gene promoters. Comparison of control- and DBP- in utero 500mg/Kg treated fetal rat testes