Project description:Gynogenetic development in fish is induced by activation of eggs with irradiated spermatozoa followed by exposure of the activated eggs to the temperature or high hydrostatic pressure (HHP) shock that prevents 1st cell cleavage. Produced specimens are fully homozygous fish also known as Doubled Haploids. Gynogenetic DH individuals might be used aquaculture and developmental biology unfortunately; the potential application of DHs is limited by a rather low survival rate of such specimens. However, observed variation in the survival rates of the gynogenetic embryos originated from different clutches suggests that eggs from some females have increased ability for gynogenetic development than others. Taking into account that first 10 cell cleavages in the fish embryos rely on the maternal RNA, it is tempting to assume that the ova showing such a vast difference in potential for gynogenesis may have also had different biological characteristics including alterations in maternal gene expression profiles. If so, then genes that up- or down –regulated expression in eggs increases competence for gynogenetic development in trout might be considered as candidate genes for gynogenesis in rainbow trout. Thus, the main goal of the project is identification of genes that increase ability of rainbow trout eggs for gynogenetic development. Within the project, we tried to verify following hypotheses: 1. Eggs from different females have different potential for gynogenesis in rainbow trout. 2. Eggs with different ability for gynogenetic development with all maternal inheritance have different biological characteristics including morphology and anti-ROS enzyme activities. 3. Eggs with increased competence for gynogenesis have altered transcriptomic profiles. 4. There are some particular genes that altered expression in trout eggs enable development of gynogenetic embryos. Gynogenetic rainbow trout specimens were produced in the course of activation of eggs with UV-irradiated spermatozoa and High Hydrostatic Pressure shock (HHP) applied around 1st cell cleavage. Eggs from several females were used in the experiment. Survival rates of gynogenetic rainbow trout was monitored since fertilization. Quality of eggs was examined by assessment of their morphology and activity of anti-ROS (reactive oxygene species) enzymes. Transcriptome of eggs showing increased and decreased developmental competence for gynogenesis was analyzed using RNA-seq approach and results compared to find out any alterations related to survival of gynogenetic trout.
Project description:Bisphenol A (BPA), a widely used chemical in the manufacture of plastics and epoxy resins, is prevalent in the aquatic environment and disrupts endocrine pathways in fish, but the long-term developmental implications are unknown. We demonstrate that BPA in eggs of rainbow trout (Oncorhynchus mykiss), a commercially important species of fish with a long life-cycle, has the potential to reprogram liver metabolism in the offspring and alter the developmental growth phenotype in multiple generations. Specifically, BPA reduces growth during early development, followed by a catch-up growth and obesity phenotype in juveniles. More importantly, we observed a shift in the liver transcripts supporting the transient growth phenotypes observed in the F1 generation and this was also evident in the F2 generation. These results reveal that maternal and/or ancestral exposure to BPA in eggs has long-lasting and multigenerational impacts in trout, with implications on salmonid fisheries and sustainability of ecosystem health.
Project description:Through 8 generations of selection, our group has developed a strain of rainbow trout that exhibits high growth rates on an economically and environmentally sustainable all plant protein, high-soy diet. The selected strain is resistant to development of soy-induced enteritis, an inflammatory intestinal pathology that occurs often in high-value carnivorous aquaculture species. To better characterize the physiological mechanism behind the superior performance of the selected strain we compared the homeostatic intestinal gene expression of the select strain to that of a commercial control line of trout. Samples were collected at early life stages known to be critical in the development of host-microbe interactions in the gut of rainbow trout. All female cohorts of both strains were reared alongside starting from eggs. Intestinal samples from 5 fish per group (2 fish strains; 2 developmental stages; 20 samples total) were used to generate mRNA selected stranded RNA-seq libraries for high throughput sequencing. Reads were quantified at the transcript level prior to evaluating differential transcript usage and differential gene expression between the two strains of trout and the developmental stages.
Project description:Egg quality is an important aspect in rainbow trout farming. Post-ovulatory aging is one of the most important factors affecting egg quality. MicroRNAs (miRNAs) are the major regulators in various biological processes and their expression profiles could serve as reliable biomarkers for various pathological and physiological conditions. Egg samples from 32 females on day 1, day 7, and day 14 post-ovulation (D1PO, D7PO and D14PO), which had the fertilization rates of 91.8%, 73.4% and less than 50%, respectively, were collected and small RNAs isolated from these samples were subjected to deep sequencing using the Illumina platform. Six miRNAs were found to be differentially expressed between D1PO and D14PO eggs. GO analysis of the target genes of the 6 miRNAs that were down-regulated in D14PO eggs revealed significantly enriched GO terms that are related to stress response, cell death, DNA damage, ATP generation, signal transduction and transcription regulation.
Project description:Egg quality is an important aspect in rainbow trout farming. Post-ovulatory aging is one of the most important factors affecting egg quality. MicroRNAs (miRNAs) are the major regulators in various biological processes and their expression profiles could serve as reliable biomarkers for various pathological and physiological conditions. Egg samples from 32 females on day 1, day 7, and day 14 post-ovulation (D1PO, D7PO and D14PO), which had the fertilization rates of 91.8%, 73.4% and less than 50%, respectively, were collected and small RNAs isolated from these samples were subjected to deep sequencing using the Illumina platform. Six miRNAs were found to be differentially expressed between D1PO and D14PO eggs. GO analysis of the target genes of the 6 miRNAs that were down-regulated in D14PO eggs revealed significantly enriched GO terms that are related to stress response, cell death, DNA damage, ATP generation, signal transduction and transcription regulation. Examination of small RNA populations in eggs of different qualities caused by post-ovulatory aging.
Project description:Marker-assisted selective breeding of fish with higher levels of resistance towards specific pathogens has shown successful, but. However, the impact of host genotype on multiple pathogen infections are is still poorly investigated. This study examined the resistance in rainbow trout (Oncorhynchus mykis) towards infection with the eye fluke Diplostomum pseudospathaceum. We used genetically selected rainbow trout, carrying SNPs associated with resistance towards the parasitic ciliate Ichthyophthirius multifiliis, and exposed the fish to eye fluke cercariae. We showed that fish partly resistant to I. multifiliis were more susceptible to eye fluke invasion. Expression The expression of immune relevant genes (encoding innate and adaptive factors) was also affected as these genotypes responded less strongly to a secondary fluke infection. The complexity of genome architecture in disease resistance towards multiple pathogens is discussed. A total of 200 rainbow trout (body weight 14.3-17.7 g, body length 10.2-11.5 cm) were used for the study. Two groups of rainbow trout with high (QTL fish) and low (non-QTL fish) frequency of SNPs associated with I. multifiliis resistance, were hatched from eyed eggs at the disease free recirculated Bornholm Salmon Hatchery, Nexø, Denmark and subsequently reared to the fingerling stage. For this purpose, the first group (QTL-fish) was produced by using sperm from three male genotyped parents carrying SNPs AX-89947214 (Omy17) and AX-89960822 (Omy16), and the other group (non-QTL fish) was produced by using sperm from three other male parents negative for these SNPs. In both cases, sperm was used to fertilize a common pool of eggs stripped from a total of 30 outbred females. Processes of hatching and subsequent rearing of fry to the fingerling stage did not differ between groups of QTL fish and non-QTL fish. From each group (QTL and non-QTL fish) we randomly gathered 100 rainbow trout and transported them (3 h duration) from the hatchery to the infection facility at the University of Copenhagen. Fish were then accommodated and acclimatized 14 d in identical aerated glass tanks with internal biofilters (25 fish per 60 L water, total tank volume 80 L), which were placed in a temperature temperature-controlled room (water temperature constant at 12°C, pH 7.6). We used 30% water change per day to maintain ammonia levels below 0.25. Fish were fed by pelleted feed (1% of fish biomass per day). All fish were genotyped with respect to the two relevant QTLs, one on chomosome 16 and one on chromosome 17. Fish being double heterozugous were excluded from qPCR analysis.
2022-09-21 | GSE213738 | GEO
Project description:Induced androgenetic development of rainbow trout - transcriptome analysis of the irradiated eggs
Project description:As an important cold-water economic fish species, rainbow trout (Oncorhynchus mykiss) exhibits several intra-specific variation in skin pigmentation that can give rise to distinctive phenotypes, and wild-type rainbow trout with black skin (WR) and yellow mutant rainbow trout with yellow skin (YR) are the major two types in the farms, whose distinct skin colors make them suitable model for elucidating the skin pigmentation process. Skin color as a key indicator for selection in rainbow trout farming as well as has a strong visual impact on the consumer when rainbow trout are marketed. Previously, extensive studies have been conducted on skin color in rainbow trout, including the observation of skin spots and the expression analysis of some important pigment genes. However, up to date, no studies have systematically examined the molecular regulation mechanism of skin color difference between WR and YR through a high throughput method. Therefore, the aim of this study was to reveal the molecular regulation mechanism of skin color difference between these two strains at the mRNA and miRNA transcriptome level, and candidate genes, miRNAs and miRNA-mRNA pairs that may be responsible for rainbow trout albinism were obtained.
Project description:The present study aimed at studying the rainbow trout egg transcriptome using 9152-cDNA microarrays after natural or controlled ovulation. The analysis of egg transcriptome after natural or controlled ovulation led to the identification of 26 genes. We observed that both hormonal induction and photoperiod control of ovulation induced significant changes in the egg mRNA abundance of specific genes. We demonstrate that hormonal induction of ovulation has an impact on the egg mRNA abundance of specific genes even though the resulting effects on the developmental potential of the egg is so far unknown. In addition, we also identified 1 gene exhibiting a differential mRNA abundance in eggs of varying developmental potential. Keywords: Egg quality-dependent
2006-10-03 | GSE5928 | GEO
Project description:Maternal and embryonic transcriptome in rainbow trout eggs after parental exposure to zearalenone