scholarly journals 11-Deoxycorticosterone Is a Potent Agonist of the Rainbow Trout (Oncorhynchus mykiss) Mineralocorticoid Receptor

Endocrinology ◽  
2005 ◽  
Vol 146 (1) ◽  
pp. 47-55 ◽  
Author(s):  
A. Sturm ◽  
N. Bury ◽  
L. Dengreville ◽  
J. Fagart ◽  
G. Flouriot ◽  
...  
Keyword(s):  
Amino Acids ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Mineralocorticoid Receptor ◽  
Head Kidney ◽  
Luciferase Reporter ◽  
Similar Response ◽  
Hormonal Stimulation ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Juvenile Trout

The teleost fish are thought to lack the mineralocorticoid hormone aldosterone but possess mineralocorticoid receptor (MR) homologs. Here we describe the characterization of two rainbow trout (Oncorhynchus mykiss) MRs, called rtMRa and rtMRb. The open reading frame of rtMRa cDNA encoded a protein of 1041 amino acids. The rtMRb predicted protein sequence is similar, differing in only 10 amino acids in the nonconserved A/B domain and lacking a three-amino acid insertion between the two zinc fingers of the C domain. Expression of rtMR mRNA (sum of both forms), measured in juvenile trout by real-time RT-PCR, shows that the transcripts are ubiquitous. Expression was significantly higher in brain than the other tissues studied (eye, trunk kidney, head kidney, gut, gills, liver, spleen, ovary, heart, white muscle, skin). Hormonal stimulation of receptor transactivation activity was studied in COS-7 cells transiently cotransfected with receptor cDNA and a mouse mammary tumor virus-luciferase reporter. The mineralocorticoids 11-deoxycorticosterone and aldosterone were more potent enhancers of rtMRa transcriptional activity (EC50 = 1.6 ± 0.5 × 10−10 and 1.1 ± 0.4 × 10−10m, respectively) than the glucocorticoids cortisol and 11-deoxycortisol (EC50 = 1.1 ± 0.3 × 10−9 and 3.7 ± 1.9 × 10−9m, respectively). A similar response was observed in transactivation assays with rtMRb. These results are discussed in the view of reported circulating levels of corticosteroids in trout.

DETERMINATION OF PROTEIN SYNTHESIS IN RAINBOW TROUT, ONCORHYNCHUS MYKISS, USING A STABLE ISOTOPE

1994 ◽  
Vol 189 (1) ◽  
pp. 279-284
Author(s):  
C Carter ◽  
S Owen ◽  
Z He ◽  
P Watt ◽  
C Scrimgeour ◽  
...  
Keyword(s):  
Amino Acids ◽  
Protein Synthesis ◽  
Rainbow Trout ◽  
Amino Acid ◽  
Oncorhynchus Mykiss ◽  
Considerable Proportion ◽  
Published Data ◽  
Short Term ◽  
Terrestrial Mammals ◽  
Rainbow Trout Oncorhynchus Mykiss

It has been suggested (Houlihan, 1991) that the consumption of 1 g of protein in a variety of species of fish stimulates the synthesis of, approximately, an equal amount of protein. Although synthesis of protein may account for as much as 40 % of the whole-animal oxygen consumption (Lyndon et al. 1992), only about 30 % of the synthesized proteins are retained as growth (Houlihan et al. 1988; Carter et al. 1993a,b). Thus, one focus of attention is the potential advantage gained by fish in allocating a considerable proportion of assimilated energy to protein turnover in contrast to relatively low-cost, low-turnover protein growth (Houlihan et al. 1993). Rates of protein synthesis in several species of fish have been measured using radioactively labelled amino acids, frequently given as a flooding dose (reviewed by Fauconneau, 1985; Houlihan, 1991). These measurements cannot be made for longer than a few hours because of the decline in specific radioactivity in the amino acid free pool. However, as protein synthesis rates vary during the course of a day as a result of the post-prandial stimulation, and since radiolabelled amino acid methodology is invasive, short-term and terminal, it has been difficult to be certain of the relationship between protein growth measured in the long term and protein synthesis rates measured in the short term. This paper addresses these problems by developing a method using 15N in orally administered protein to measure protein synthesis rates in fish over relatively long periods, the aim being to use procedures that are as non-invasive and repeatable as possible. The use of stable isotopes to measure protein metabolism is well established in terrestrial mammals (see Rennie et al. 1991; Wolfe, 1992), but to our knowledge the only published data for aquatic ectotherms are on the blue mussel (Mytilus edulis L.) (Hawkins, 1985). In the present study, rates of protein synthesis of individual rainbow trout [Oncorhynchus mykiss (Walbaum)] were calculated from the enrichment of excreted ammonia with 15N over the 48 h following the feeding of a single meal (dose) containing protein uniformly labelled with 15N by use of an end-point stochastic model (Waterlow et al. 1978; Wolfe, 1992). Application of this type of modelling would appear to be ideal for measuring ammonotelic fish nitrogen metabolism since, unlike the situation in mammals, the catabolic flux of amino acids through urea is very small. Further, ammonia is excreted directly into the surrounding water via the gills and is not stored for any length of time, in contrast to the situation in mammals, so the rate of tracer appearance is easily measurable.

scholarly journals Optimisation of the lymphocyte proliferation assay in rainbow trout (Oncorhynchus mykiss)

2019 ◽  
Vol 64 (No. 12) ◽  
pp. 547-557
Author(s):  
H Minarova ◽  
M Palikova ◽  
J Mares ◽  
E Syrova ◽  
J Blahova ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Bovine Serum ◽  
Lymphocyte Proliferation ◽  
Head Kidney ◽  
Pokeweed Mitogen ◽  
Lymphocyte Proliferation Assay ◽  
Proliferation Assay ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Foetal Bovine Serum

The lymphocyte proliferation assay is a valuable method used for the evaluation of the fish immune system. However, there are many variations and optimal results are not always obtained. Unification is necessary to ensure the comparability between different studies. The aim of this study was to optimise the lymphocyte proliferation assay in rainbow trout (Oncorhynchus mykiss). This goal included the determination of the optimal incubation length, serum type, incubation temperature, type of mitogen and its concentration, and anticoagulant. The peripheral blood and head kidney lymphocytes were isolated by density gradient centrifugation. Subsequently, the cells were incubated for 3–8 days with different mitogens (pokeweed mitogen 5, 10 and 50 µg/ml, concanavalin A 1, 10 and 20 µg/ml, phytohaemagglutinin 25, 50 and 100 µg/ml, lipopolysaccharide 1, 50 and 100 µg/ml). The use of the different serum types (foetal bovine serum, trout serum), incubation temperatures (10–20 °C) and anticoagulants (heparin, EDTA) was compared. Labelled thymidine was used to evaluate the assay. The best results were obtained after seven days of incubation at 15 °C with foetal bovine serum (FBS). The head kidney lymphocytes showed the highest proliferative response with 50 µg/ml phytohaemagglutinin. With the peripheral blood lymphocytes (heparin and EDTA), the best results were obtained with 50 µg/ml pokeweed mitogen. The highest proliferation levels were detected with heparinised blood. In conclusion, optimisation of this assay contributes to the improved assessment of the rainbow trout immune function.

Transcriptomic responses to heat stress in rainbow trout Oncorhynchus mykiss head kidney

2018 ◽  
Vol 82 ◽  
pp. 32-40 ◽  
Author(s):  
Jinqiang Huang ◽  
Yongjuan Li ◽  
Zhe Liu ◽  
Yujun Kang ◽  
Jianfu Wang
Keyword(s):  
Heat Stress ◽  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Head Kidney ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Transcriptomic Responses

scholarly journals Draft Genome Sequence of Epilithonimonas sp. FP211-J200, Isolated from an Outbreak Episode on a Rainbow Trout (Oncorhynchus mykiss) Farm

2017 ◽  
Vol 5 (37) ◽  
Author(s):  
Manuel Ayala ◽  
Cristopher Segovia ◽  
Rodrigo Rojas ◽  
Claudio Miranda ◽  
Javier Santander
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Genome Sequence ◽  
Draft Genome ◽  
Head Kidney ◽  
Fish Host ◽  
Draft Genome Sequence ◽  
Kidney Cells ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Head Kidney Cells

ABSTRACT Here, we report the draft genome sequence of Epilithonimonas sp. FP211-J200, isolated from rainbow trout head kidney cells. The size of the genome is 4,110,772 bp, with a G+C content of 37.1%. The Epilithonimonas sp. FP211-J200 genome has genes related to tetracycline and β-lactam resistance. This is the first reported Epilithonimonas species genome isolated from a fish host.

Sign in / Sign up

Export Citation Format

Share Document