Normal and shortened photoperiods in liver, ovary, and pituitarty
Ontology highlight
ABSTRACT:
ORGANISM(S): Oncorhynchus mykiss
SUBMITTER: Sharon Hook
PROVIDER: E-GEOD-19478 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:This study compared changes in gene expression in an oviparous female fish, the rainbow trout (Oncorhynchus mykiss), under two different photoperiod treatments, a natural photoperiod (NP) and a shortened photoperiod (SP; 60% of NP). Gene expression in the liver, ovary and pituitary were measured at one-four week intervals over the course of the reproductive cycle in each treatment. Total RNA was harvested from these tissues, cDNA prepared, and hybridized on the 16K GRASP cDNA microarray. Established indices of reproductive development (ovulation, gonadosomatic index, mean oocyte diameter, and plasma hormone levels) were also measured. The SP fish failed to ovulate and their reproductive trajectory was clearly different from the NP group, which ovulated as expected. A comparative examination of the reproductive indices in both groups shows that ovarian development initiated in the SP group and proceeded relatively normally for about two-thirds of the reproductive cycle. Plasma follicle-stimulating hormone levels were higher in the SP fish from the cycle onset. This may have dampened E2 synthesis, preventing the positive feedback signal on the pituitary for the normal, rapid increase in luteinizing hormone late in the cycle. Transcriptome analysis used an unsupervised k-means hierarchical clustering method to visualize changes in gene expression in the different organs from the NP fish that were assumed to represent the normal pattern leading to successful ovary development. In the NP, fish four, five, and six unique gene clusters were identified in the liver, ovary, and pituitary, respectively. These clusters ranged in size from 22 genes in one of the pituitary clusters to 302 genes in the liver. These clusters were then applied to the SP fish to determine if and how they were altered. The expression patterns of most genes in the SP fish were notably altered from the first time point. A SP in female rainbow trout initiated a rapid change in tr anscript levels within the liver, ovary, and pituitary, leading to ovarian failure and apparently disrupting normal endocrine signaling between the pituitary and ovary.
2009-12-15 | GSE19478 | GEO
Project description:Metabolic processes and sexual maturation closely interact during the long-distance reproductive migration of many fish species to their spawning grounds. In the present study, we have for the first time used exercise experimentally to investigate the effects on sexual maturation in rainbow trout. Pubertal autumn-spawning seawater-raised female rainbow trout Oncorhynchus mykiss (n=26; 50-cm, 1.5-kg) were rested or swum at a near optimal speed of 0.75 body-lengths per second in a 6,000 L swim-flume under natural reproductive conditions (16 °C fresh-water, starvation, 8h-light:16h-dark photoperiod). Fish were sampled after arrival and subsequently after 10 days (resting or swimming 307 km) and 20 days (resting or swimming 636 km). Ovarian development was significantly reduced in the swimmers. Analysis of the expression of key factors in the reproductive axis included pituitary kiss1-receptor, lh and fsh and ovarian lh-receptor, fsh-receptor, aromatase and vitellogenin-receptor (vtgr). Swimmers had lower pituitary lh and ovarian vtgr expression than resters. Furthermore, the number of late vitellogenic oocytes was lower in swimmers than in resters, probably resulting from the lower vtgr expression, and vitellogenin plasma levels were higher. Therefore, swimming exercise suppresses oocyte development possibly by inhibiting vitellogenin uptake. Transcriptomic changes that occurred in the ovary of exercised fish were investigated using a salmonid cDNA microarray platform. Protein biosynthesis and energy provision were among the sixteen functional categories that were all down-regulated in the ovary. Down-regulation of the transcriptomic response in the ovary illustrates the priority of energy reallocation and will save energy to fuel exercise. A swimming-induced ovarian developmental suppression at the start of vitellogenesis during long-term reproductive migration may be a strategy to avoid precocious muscle atrophy.
2010-02-05 | GSE20131 | GEO
Project description:Metabolic processes and sexual maturation closely interact during the long-distance reproductive migration of many fish species to their spawning grounds. In the present study, we have for the first time used exercise experimentally to investigate the effects on sexual maturation in rainbow trout. Pubertal autumn-spawning seawater-raised female rainbow trout Oncorhynchus mykiss (n=26; 50-cm, 1.5-kg) were rested or swum at a near optimal speed of 0.75 body-lengths per second in a 6,000 L swim-flume under natural reproductive conditions (16 °C fresh-water, starvation, 8h-light:16h-dark photoperiod). Fish were sampled after arrival and subsequently after 10 days (resting or swimming 307 km) and 20 days (resting or swimming 636 km). Ovarian development was significantly reduced in the swimmers. Analysis of the expression of key factors in the reproductive axis included pituitary kiss1-receptor, lh and fsh and ovarian lh-receptor, fsh-receptor, aromatase and vitellogenin-receptor (vtgr). Swimmers had lower pituitary lh and ovarian vtgr expression than resters. Furthermore, the number of late vitellogenic oocytes was lower in swimmers than in resters, probably resulting from the lower vtgr expression, and vitellogenin plasma levels were higher. Therefore, swimming exercise suppresses oocyte development possibly by inhibiting vitellogenin uptake. Transcriptomic changes that occurred in the ovary of exercised fish were investigated using a salmonid cDNA microarray platform. Protein biosynthesis and energy provision were among the sixteen functional categories that were all down-regulated in the ovary. Down-regulation of the transcriptomic response in the ovary illustrates the priority of energy reallocation and will save energy to fuel exercise. A swimming-induced ovarian developmental suppression at the start of vitellogenesis during long-term reproductive migration may be a strategy to avoid precocious muscle atrophy. In order to simulate the natural reproductive conditions of anadromous salmonids, experiments were performed with sea water-raised rainbow trout, Oncorhynchus mykiss. Resters and swimmers were starved during the experiment, seawater was replaced by fresh water and photoperiod was changed. These changes were expected to affect reproductive parameters but as âbackgroundâ effect because both resters as swimmers were experiencing these conditions at the same time in the same set-up. Any additional effects in swimming fish would thus be caused by swimming only. Pubertal autumn spawning rainbow trout (n=26; ~50 cm, ~1.5 kg) were purchased from a Danish exporter (Frederiksvaerk Aleexport) where they had been raised for 2 years in freshwater followed by 4 months in sea water cages at 10 â°. They were transferred by truck within 16 h to Spakenburg (Spakenburg Paling, The Netherlands) and subsequently in the same water in a similar holding tank to the swim-flume at Leiden University (The Netherlands). The next day, 5 randomly chosen fish were sampled as âstartâ-group while others were randomly divided into a ârestâ-group (n=10) and a âswimâ-group (n=11). During the following 4 days, the brackish 10 â° water was stepwise replaced by freshwater at 16 °C and photoperiod was changed from 16L:8D to 8L:16D. Fish were then acclimatized for two days to their new conditions. Subsequently, swimmers were first swum at a speed of 0.33 body-lengths per second (BL/s) which was increased the next day to the final, near optimal speed of 0.75 BL/s (0.34 m/s or 29.4 km/day). Fish were sampled after 10 days (5 resters and 5 swimmers) and 20 days (5 resters and 6 swimmers). At sampling, fish were anesthetized using oil of cloves that was commercially purchased from a drugstore (diluted 1:10 in ethanol and used at a dosage of 1.5 ml/l). Fish were euthanized by decapitation and dissected for the ovary which was flash frozen in liquid nitrogen. RNA was isolated from pituitary and ovary samples according to the TRIZOL reagent protocol by Invitrogen (Baro, Spain). Isolated RNA was DNAse treated using RQ1 DNAse Promega (Madison, USA) and reverse transcribed using Superscript IIITM (Baro, Spain) according to the manufacturerâs protocol. Microarray analyses were performed on ovarian tissue for 20-days-swimmers vs. 20-days-resters. A rainbow trout cDNA microarray platform was used that was previously validated and described by Koskinen et al., 2004ab, Krasnov et al., 2005, MacKenzie et al., 2006ab, 2008 and Djordjevic et al., 2009, and deposited in GEO under accession number GPL1212, the original cDNA microarray (SFA2.0 chip), and GPL6154; the updated 1.8 K platform. This platform compromises 1818 genes representing 366 functional categories. Total RNA was extracted from flash frozen samples from experimental fish of the 20-days-swim group (n=5) and 20-days-rest group (n=5) like described before. Total RNA corresponding to pooled samples from the swim or rest groups was labeled with Cye3 and Cye5-dCTP (GE Healthcare, Barcelona, Spain) using SuperScript III reverse transcriptase (Invitrogen, Baro, Spain) and oligo(dT) primer. In our experience, reverse labeling combined with multiple replication of spots provide robust normalization and high statistical power of analyses. cDNA was purified with MicroconYM30 (Millipore). The slides were pretreated with 1% BSA(fraction V), 20 à SSC, 10% SDS (30 min at 50°C) and washed with 2 à SSC (3 min) and 0.2 à SSC (3 min) and hybridized overnight in cocktail containing 50 à Denhardt's, 20 à SSC, 10% SDS, 10μg/μl polyadenylate and 10 μg/μl yeast tRNA. All chemicals were from Sigma-Aldrich. Scanning was performed with ScanArray 5000 and images were processed with QuantArray (GSI Luminomics). The measurements in spots were filtered by criteria I/B ⥠3 and (I-B)/(SI + SB) ⥠0.6, where I and B are the mean signal and background intensities and SI, SB are the standard deviations. After subtraction of mean background, LOWESS normalization was performed. To assess differential expression of genes, the normalized log intensity ratios (expression ratio) were analyzed with Student's t-test (P <0.05). Validation of the microarray was performed by Q-PCR of 6 differentially expressed genes (DEGs) as described above. The used primers were either published (Alpha-globin I-1: Donate Jimeno, 2008) or designed, again by using the Genamics software.
2010-06-24 | E-GEOD-20131 | biostudies-arrayexpress
Project description:Foxl2 is a forkhead transcription factor essential for proper reproductive function in females. It is expressed in the somatic cell population of the gonad (granulosa cells) which forms the follicles of the ovary, the structures responsible for embedding and nurturing the oocytes during their development. FOXL2 directly regulate the aromatase that synthesizes estrogens CYP19A1, thus promoting female differentiation, as well as acting as a repressor of the male factors SOX9 and DMRT1.Expression is also found in the eyelids, pituitary gland and uterus. In the goat, frog and many fish species FOXL2 is a sex-determining gene which, when deleted, leads to female-to-male sex reversal.
2022-07-11 | PXD024439 | Pride
Project description:We sequenced mRNA from four biological replicates of each tissue before (T1) and after the onset of maturation (T2, T3, T4). A total of 3.2 billion paired-end reads were mapped against the Atlantic salmon reference genome with 72% mapping efficiency to create an average depth of 50 million reads per library. The number of differentially expressed genes (DEGs) increased with elapsed time following the onset of the long light photoperiod for the two BPG axis tissues (pituitary and ovary). Of these, the ovary underwent the most dramatic remodelling over time with 403, 1,709 and then 3,497 DEGs observed at timepoints T2, T3 and T4 respectively. This increasing trajectory of differential ngene expression, coupled with the elevated GSI following the light stimuli, strongly suggests the experimental approach successfully initiated the onset of maturation. Next, we identified clusters of DEGs in each of the analysed tissues, which describe their physiological roles. The identity of the DEGs, in response to the onset of maturation, revealed the key players involved in the earliest triggers into maturation. Among these, upregulation of genes encoding specififc pituitary hormones such as gonadotropins along with genes encoding transcription factors (such as GATA2) are significant in controlling onset of maturation. In addition, genes encoding pituitary hormone receptors and follicular development were upregulated in ovary.
2020-08-28 | GSE157001 | GEO
Project description:Senegalese sole males born and raised in captivity (F1 males) do not spawn naturally and typically display lower gamete quality when compared with wild individuals. Broodstock nutrition is an important aspect when dealing with reproduction because it influences not only fish health, but also gamete and progeny quality. The usage of dietary algae antioxidants to improve fish reproduction is under-explored, especially in terms of the male reproductive system. In this experiment, 6 % of a blended meal of Phaeodactylum tricornutum and Gracilaria gracilis was incorporated in Senegalese sole broodstock feed, to evaluate the effects on sperm quality of F1 males throughout the breeding season. RNA-seq was employed to assess differences in the gonadal tissue of fish fed the algae supplemented diets.
2024-08-01 | E-MTAB-14218 | biostudies-arrayexpress
Project description:Triclocarban (TCC) is a widely used antimicrobial agent that is routinely detected in surface waters. The present study was designed to examine TCC’s efficacy and mode of action as a reproductive toxicant in fish. Reproductively mature Pimephales promelas were continuously exposed to either 1 or 5 μg TCC/L, 0.5 μg 17β-trenbolone (TRB)/L or a mixture (MIX) of 5 μg TCC and 0.5 μg TRB/L for 22 d and a variety of reproductive and endocrine-related endpoints were examined. The data were evaluated to answer several key questions: first, whether exposure to TCC could be linked with an ecologically-relevant adverse outcome, i.e., impaired reproduction; second, whether the present study provided additional support for augmentation of androgen action as an endocrine-disrupting mode of action for TCC; and third, whether there were any novel and/or plausible linkages between changes in the ovarian transcriptome and the apical responses observed in females that could support adverse outcome pathway development and/or further hypothesis-driven testing. Fathead minnows were randomly paired (one male, one female) and placed in tanks at a density of two pairs per tank with six replicate tanks per treatment. Pairs were separated by a water permeable mesh divider and each pair had its own breeding substrate. The fish were held in the test system, receiving UV-treated, filtered Lake Superior (control) water only, for a 21 d acclimation period during which the fecundity and fertility of each pair were assessed daily. After 21 d, exposures were initiated with pairs that had spawned successfully during acclimation. Fish were exposed continuously to target test concentrations of 0 (Lake Superior control), TCC (1 and 5 µg/L), TRB (0.5 μg/L), or a mixture of the two chemicals (5 μg TCC and 0.5 μg TRB/L) for 22 d. Water concentrations of TCC and TRB were determined in stock solutions and all exposure tanks every two to three days. General water quality characteristics (mean ± SD) measured regularly over the course of the Experiment were: temperature, 24.8 ± 0.7 oC; pH, 7.87 ± 0.04; dissolved oxygen, 6.8 ± 0.35 mg/L. Ovary RNA samples from twenty four fish (n=5 for all treatments except TRB alone; n=4) were selected for microarray analysis.
2015-07-31 | E-GEOD-64291 | biostudies-arrayexpress
Project description:2,3,7,8-TCDD (TCDD) is a reproductive toxicant and endocrine disruptor in nearly all vertebrates, yet the mechanisms by which TCDD induces these reproductive alterations have not been fully characterized. Fish are among the most sensitive vertebrates to the toxic effects of TCDD, and even subtle physiologic changes induced by TCDD can impair reproduction. Previously, we have shown that chronic, sub-lethal exposure to TCDD decreased reproductive capacity, reduced serum estradiol and vitellogenin concentrations, and altered follicular development. Here we investigate the transcriptional changes in zebrafish ovary as they relate to observed attenuated estradiol concentrations and ovarian development. We used quantitative RT-PCR to assess TCDDâs effects on the expression of several candidate genes important in the regulation of follicular development and steroidogenesis. Additionally, global changes in gene expression in the ovary caused by TCDD exposure were identified using Affymetrix Gene Chip Analysis. Our data suggest that TCDD may inhibit follicle maturation via attenuated gonadotropin responsiveness and/or depressed estradiol biosynthesis. Additionally, genes involved in glucose and lipid metabolism, regulation of transcription, and immune function were dysregulated by at least 2-fold suggesting that TCDD alters various integrated networks of signaling pathways. Approximately 89% of dysregulated transcripts contain putative AHR response elements (AHRE) within 5kb upstream of the predicted transcriptional start site suggesting ovarian toxicity is AHRE driven. Furthermore, approximately 49% of dysregulated transcripts contain putative estrogen response elements (ERE) suggesting that dysregulation of estrogen-responsive genes may also contribute to TCDD-induced attenuated follicular development. Patterns in gene expression were correlated with putative EREs and AHREs, and suggest that impacts on the regulation of transcription may play a large role in TCDDâs ovarian toxicity. Taken together, these data illustrate the complexity of TCDDâs ovarian toxicity. Experiment Overall Design: A total of eight samples were analyzed including three TCDD doses (10, 40, 100 ppb, dietary exposure) and vehicle control samples. cRNA targets were synthesized from pooled total RNA isolated from five ovaries from different individuals in each treatment group. Each individual contributed equally to a given pool. Two technical replicates were run for each treatment group. Several genes of interest arising from this microarray study were validated by Quantitative RT-PCR with individual ovary samples to assess biological variability.
2009-04-30 | E-GEOD-4859 | biostudies-arrayexpress
Project description:African clawed frog Xenopus sp. is used extensively for developmental biology and toxicology research. Amid concerns of environmental pollutants disrupting endocrine systems and causing altered reproductive development in wildlife, eco-toxicology research has led to a focus on linking molecular initiating events to population-level effects. As such, efforts to better understand reproductive development at the molecular level in these model species are warranted. To that end, transcriptomes were characterized in differentiating Xenopus tropicalis gonad tissues at Nieuwkoop and Faber (NF) stage 58 (pro-metamorphosis), NF66 (completion of metamorphosis), one week post-metamorphosis (1WPM), and two weeks post-metamorphosis (2WPM). Differential expression analysis between tissue types at each developmental stage revealed a substantial divergence of ovary and testis transcriptomes starting between NF58 and NF66; transcriptomes continued to diverge through 2WPM. Generally, testis-enriched transcripts were expressed at relatively constant levels, while ovary-enriched transcripts were up-regulated within this developmental period. Functional analyses of differentially expressed transcripts allowed linkages to be made between their putative human orthologues and specific cellular processes associated with differentiating gonad tissues. In ovary tissue, genetic programs direct germ cells through meiosis to the diplotene stage when maternal mRNAs are transcribed and trafficked to oocytes for translation following fertilization. In the testis, gene expression is consistent with connective tissue development, tubule formation, and germ cell support (Leydig and Sertoli cells). This dataset exhibited remarkable consistency with transcript profiles previously described in gonad tissues across species, and emphasizes the universal importance of certain transcripts for germ cell development and preparation of these tissues for reproduction. Four developmental time-points were considered for global expression analysis: NF58 (pro-metamorphosis), NF66 (completion of metamorphosis), one week post-metamorphosis (1WPM), and two weeks post-metamorphosis (2WPM). Gonad tissues were time-matched and stage-matched, so collection occurred on a single day for each developmental time-point and all animals used were from the same spawn. For the 1WPM and 2WPM time-points, all animals reached NF66 on the same day and were separated from the rest of the spawn until sample collection one and two weeks later respectively. On the day of tissue collection, animals were developmentally staged (Nieuwkoop and Faber, 1994) and euthanized by submersion in a lethal concentration of tricane methanesulfonate ([MS-222], Argent Chemical Laboratories, Redmond, WA, USA) buffered with sodium bicarbonate. Gonad tissues were then excised independently of any other tissues (i.e. “pure” gonad tissue) and transferred to a separate vial for each individual, homogenized in lysis buffer from an RNeasy micro kit (Qiagen Inc., Valencia, CA, USA), and immediately frozen on dry ice until samples could be moved to -80oC storage. Tail or toe tissue was also collected from each individual for genetic sex determination using methods previously described by Olmstead et al. (2010). Once genetic sex was determined for each individual, testes and ovaries were randomly assigned to pools of four individuals (eight gonads per pool) to make a total of five pools of testis tissue and five pools of ovary tissue at each developmental time-point, with the exception of NF58 which had four pools of testis tissue and four pools of ovary tissue (38 total sample pools).
2014-07-31 | E-GEOD-58612 | biostudies-arrayexpress
Project description:The experiment is designed to assess the impact of winter length on epigenetic status of key genes related to smoltification. Transferring fish from constant light (LL) to short photoperiod (SP) for different durations and then returning to constant light (LL) for 8 weeks to stimulate smoltification. Three histone marks were assessed: H3K4me3, H3K27me3 and H3K27ac.
2023-10-27 | E-MTAB-11091 | biostudies-arrayexpress