MiRNA transcriptional profiling during rainbow trout ovarian development
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ABSTRACT: The study aimed to characterize miRNA expression in rainbow trout ovary during ovarian development from immature to mature stages. Whole ovary were collected at the following stages: immature pre-vitelogenesis (IMM), mid-vitellogenesis (MV), late vitellogenesis (LV), post-vitellogenesis (PV) and mature while meiotic maturation is in progress (MAT).
Project description:The study aimed to characterize gene expression in rainbow trout ovary during ovarian development from immature to mature stages. Whole ovary were collected at the following stages: immature pre-vitelogenesis (IMM), mid-vitellogenesis (MV), late vitellogenesis (LV), post-vitellogenesis (PV) and mature while meiotic maturation is in progress (MAT).
Project description:The study aimed to characterize gene expression in rainbow trout ovary during ovarian development from immature to mature stages. Whole ovary were collected at the following stages: immature pre-vitelogenesis (IMM), mid-vitellogenesis (MV), late vitellogenesis (LV), post-vitellogenesis (PV) and mature while meiotic maturation is in progress (MAT). Gene expression in rainbow trout ovary was measured at 5 different stages (immature, mid-vitellogenesis, late vitellogenesis, post-vitellogenesis and mature). Three to four biological replicates were used for each stages.
Project description:The study aimed to characterize miRNA expression in rainbow trout ovary during ovarian development from immature to mature stages. Whole ovary were collected at the following stages: immature pre-vitelogenesis (IMM), mid-vitellogenesis (MV), late vitellogenesis (LV), post-vitellogenesis (PV) and mature while meiotic maturation is in progress (MAT). miRNA expression in rainbow trout ovary was measured at 5 different stages (immature, mid-vitellogenesis, late vitellogenesis, post-vitellogenesis and mature). Two to three biological replicates were used for each stages.
Project description:The vertebrate skeleton is mostly composed of three specific cell types: immature chondrocytes (IMM), mature (hypertrophic) chondrocytes (MAT), and osteoblasts (OST). These three cell types are distinct, but they also share the expression of many genes. This overlapping gene expression can be attributed to two transcription factors, SOX9 and RUNX2, which operate near the top of hierarchy of the gene regulatory network (GRN) underlying IMM, MAT, and OST. Sox9 drives IMM differentiation, whereas Runx2 regulates OST differentiation. Importantly, MAT do not form without the function of either Sox9 or Runx2, but little is known about mechanisms of GRN regulation in MAT. During MAT differentiation, the expression of Runx2 increases, and many genes regulated by this transcription such as Spp1, Mef2c, Ibsp, and Alpl are activated. To understand regulatory control of gene expression in mature chondrocytes, ChIP-seq experiments were performed using the mouse chondrogenic cell line ATDC5. These experiments identified in vitro RUNX2 binding sites at different stages of chondrogenesis. RUNX2 appeared to bind in most genes enriched in MAT at both day 3 of differentiation. The ChIP-seq analyses presented here verified the molecular mechanisms predicted here to regulate transcription of the many genomic loci in MAT, proving more insight into regulatory control during cartilage maturation.
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.
Project description:We have constructed a rainbow trout high-density oligonucleotide microarray by using all the available tentative consensus (TC) sequences from the Rainbow Trout Gene Index database (The Computational Biology and Functional Genomics Lab., Dana Farber Cancer Institute and Harvard School of Public Health). The Rainbow Trout Gene Index integrates research data from all available international rainbow trout genomic research projects. The newly designed microarray incorporates 37,394 unique transcript-specific oligonucleotide probes, 60-mer long each. The microarray was printed according to our design by Agilent Technologies using the 4 X 44-design format and contains 1417 Agilent control spots. The performance of the new microarray platform was evaluated by analyzing gene expression associated with the rainbow trout vitellogenesis-induced muscle atrophy. These chips can be ordered from Agilent using design number 016320. This microarray is anticipated to open new avenues of research that will aid in the development of novel strategies to enhance growth efficiency and quality in salmonid species. Keywords: Development of an oligo-array for rainbow trout The performance of the new microarray platform was evaluated by analyzing transcriptome response associated with the rainbow trout vitellogenesis-induced muscle atrophy. Severe muscle deterioration accompanies the physiological responses of the energetic demands of the rainbow trout spawning/vitellogenesis. Atrophying muscle of fertile fish had 11% less extractable muscle (g/bw) and 11% less protein content compared to non-atrophying muscle of sterile fish (p<0.01). The rainbow trout was used to profile changes in gene expression of atrophying muscles. Gene expression levels were determined by comparing the amount of mRNA transcript present in the experimental sample (fertile fish) to the control (sterile fish). RNAs isolated from each experimental fish were run on separate microarrays in independent experiments, with no pooling. A total of 8 fish were used in the microarray experiments (4 replicates x 2 groups). Fluorophors (Cy3 and Cy5) were randomly assigned to RNA from each of the atrophying and nonatrophying muscles to limit the dye effect.
Project description:Trout spermatogenesis proceeds seasonally in a way that all morphological and cellular events tend to be synchronized. We thus used gonads at key stages of the male reproductive cycle together with isolated germ cell populations to study the changes in gene expression underlying testis development. Statistical analysis followed by clustering of expression profiles allowed the discrimination of sequential events of gene activation or repression during testis development and/or throughout the germline. 38 samples covering 6 developmental stages (as defined in Gomez et al. 1998 Biol. Reprod. 58, 483-491) and 3 isolated germ cell populations were analysed. This included: - Testes at early stages containing slowly-dividing type A spermatogonia (Stage_I, n=5) or growing numbers of actively-dividing type B spermatogonia (Stages_IIa, n= 4; Stage_IIb, n= 4) - Maturing testes containing in addition large numbers of meiotic spermatocytes (Stage_IIIb, n=3) and post-meiotic spermatids (Stage_V, n=4) - Spawning testes containing essentially mature spermatozoa (Stage_VIII, n=3) - Fractions of isolated germ cells enriched in spermatogonia (Spermatogonia, N=6), spermatocytes (Spermatocyte, N=6) and spermatids (Spermatid, N=3).