Donaldson Strain Research Articles

Thermal tolerance of a thermally selected strain of rainbow trout Oncorhynchus mykiss and the pedigrees of its F1 and F2 generations indicated by their critical thermal maxima

A thermally selected strain of rainbow trout has been established by selective breeding since 1966 in Miyazaki, Japan. In the present study, we compared the critical thermal maxima (CTMs), the temperatures at which organisms reach a predefined sublethal endpoint and lose their equilibrium, between a thermally selected and two normal (Donaldson) strains of rainbow trout. The CTM of one normal strain from Nikko (Nikko strain) acclimated to 20 °C (29.7 °C) was significantly lower than those of the thermally selected strain (30.0 °C) and the other Donaldson strain from Aomori (29.9 °C) (P 0.05) for fish acclimated to 20 °C, suggesting that the F1 offspring inherited the thermal tolerance trait from one thermally selected strain parent irrespective of whether it was the male or female. F2 offspring of F1T or F1N also showed the thermal tolerance trait. The coefficients of variation for CTM were also compared among all the datasets obtained in the present study and their values for F1 hybrids were lower than those of the parental generation of the Nikko strain (P < 0.05). In contrast, the coefficients of variation of F2s were the same as those of their parental generation. Furthermore, the thermally selected strain and Nikko strain as a reference family provide a F2 generation for segregating phenotypes, which is required for in-depth genetic analysis of the thermally selected rainbow trout strain.

Multivariate Diallel Cross-Analyses for Body Weight of Rainbow Trout,Oncorhynchus mykiss, in China

Crossbreeding is a common technical approach for the development of new commercial fish strains characterized by high performance and a short generation time, for the Chinese market. Here, five strains – Bohai, Denmark, Donaldson, Norway, and California – of rainbow trout were used in a complete diallel cross, along with self-breeding within each strain, to estimate general combining ability; specific combining ability (SCA); and linebred, maternal, and reciprocal effects. These strains were defined based on their location of origin; the Bohai strain was domesticated and has been maintained since 1959 by the Bohai cold-water fish experimental station in China. Applying univariate and multivariate genetic analyses for body weight using the data set from this complete diallel cross experiment, we found that the cross combination with the Donaldson strain exhibited the most positive growth performance, whereas the Bohai ♀ × Donaldson ♂ cross was the highest performing cross combination in the experiment. Multiple significance tests showed that 40% (4 of 10) of the significant SCA based on univariate analyses (P 0.05). These results suggested that multivariate genetic analyses may provide more reliable reference guidelines for decision making by managers of breeding programs.

Junctional Adhesion Molecule (JAM)-B protein is modulated by progesterone signaling and differentially expressed in mouse placentae of different mating combinations

In rainbow trout there is only one dominant classical MHC class I locus, Onmy-UBA, for which four very different allelic lineages have been described. The purpose of the present study was to determine if Onmy-UBA polymorphism could be used for strain characterisation. This was performed by lineage-specific PCR investigation of 30 fish, each of the Nikko and Donaldson strains, and by sequence analysis of 25 of the amplified DNA fragments. Two new MHC class I lineages were detected in addition to the four previously described lineages, thus six distinct lineages were observed within the fish examined (Sal-MHCIa*A–F). The distribution of lineages appeared to be strain-specific. For example, the lineage Sal-MHCIa*A was very common in the Nikko strain but could not be detected in the Donaldson strain. Analysis of MHC class I variation may help to elucidate relationships between strains and the roles of MHC alleles in disease resistance.

Different gene expression profiles between normal and thermally selected strains of rainbow trout, Oncorhynchus mykiss, as revealed by comprehensive transcriptome analysis

A high-temperature selected (HT) strain of rainbow trout was established from the Donaldson (DS) strain by traditional selective breeding in Japan. The aim of this study is to investigate genes related to upper temperature tolerance in this strain utilizing next generation sequencer (NGS), and to establish comprehensive and comparable datasets in brain, liver, muscle, heart and gill tissues between the HT and DS strains. After assembling, clustering and filtering, 242,530 contigs were obtained. Among them, 7624 transcripts had at least 10 counts in expression analysis in all tissues and used as references. BLASTX homology search showed that 7329 transcripts matched with known genes. Compared to the DS strain, the HT strain expressed 90, 775, 349, 188 and 194 genes 2 folds or more in brain, liver, muscle, heart, and gill, respectively in the case of fish before heat-exposure treatment. Meanwhile, the HT strain expressed 292, 363, 433, 322 and 211 genes 2 folds or more in brain, liver, muscle, heart, and gill, respectively in case of fish after heat-exposure treatment. Many of heat shock protein family genes and transcription factor AP-1 related genes were highly expressed in all tissues of the HT strain compared with the DS strain. These results suggest that these genes play key roles in upper temperature tolerance. These comprehensive and comparable datasets will offer broad visions for upper temperature tolerance in fish species.

Global gene expression analysis of gill tissues from normal and thermally selected strains of rainbow trout

The objective of the study reported here was to investigate genes related to upper temperature tolerance in rainbow trout Oncorhynchus mykiss, a cold-water species with considerable economic importance, by global gene expression analysis using a next generation sequencing system. Fifty million paired sequences were collected from the gill tissues of each of five individuals of a thermally selected strain developed by selective breeding and from the gill tissues of a standard Donaldson strain and assembled into transcripts. The data of both strains were integrated, and a BLASTX search identified 13,092 independent, known genes. A back-mapping of raw reads from both strains onto the genes, conducted to investigate their frequency of expression, revealed that 324 genes showed at least a twofold higher expression in the thermally selected strain than in the Donaldson strain. In addition, 44.4 % of commonly expressed genes were categorized into 38 functional groups by annotation. Genes encoding heat shock proteins and c-fos-related proteins were highly expressed in the thermally selected strain. Our strategy to employ next generation sequencing proved to be very useful to find genes responsible for upper temperature tolerance of rainbow trout.

GAMETOCYTEMIA AND FEVER IN HUMAN MALARIA INFECTIONS

We examine the charts of 408 malaria-naive neurosyphilis patients given malaria therapy at the South Carolina USPHS facility, with daily records encompassing at least 93% of the duration of infection, and focus on the 152 patients infected with the St. Elizabeth strain of Plasmodium vivax, 82 with the McLendon strain of Plasmodium filciparum, 36 with the USPHS strain of Plasmodium malariae, and 15 with the Donaldson strain of Plasmodium ovale in whom gametocytes appeared before drug, or other, intervention. In P. vivax infections, fever and parasitemia were higher after gametocytes were first detected than before; in P. malariae infections, parasitemia was higher. In P. ovale infections, fever and parasitemia were similar before and after. In P. falciparum infections, fever, parasitemia, and fever frequency were lower after gametocytes were first detected than before. Parasitemia and temperature correlated in P. vivax infections, before and after gametocytes were first detected; parasitemia and temperature at first fever were not correlated in infections with any species. Gametocyte density correlated with parasitemia in P. malariae and sporozoite-induced P. falciparum and P. vivax infections. Fevers and detected gametocytemia coincided more often than expected by chance with P. vivax and P. ovale; fever temperature and gametocyte density were not correlated in infections with any species.

Increased Levels of Mitochondrial Gene Transcripts in the Thermally Selected Rainbow Trout (Oncorhynchus mykiss) Strain During Embryonic Development

To investigate molecular mechanisms involved in thermal resistance of rainbow trout, Oncorhynchus mykiss, embryos from thermally selected strain in various developmental stages were treated at 22 degrees C for 30 min and subsequently developed at 12 degrees C using the Donaldson strain as a reference. The embryos were evaluated for their hatching rate along with the ratio of embryos having an abnormal appearance and subjected to mRNA arbitrarily primed reverse transcription-polymerase chain reaction (RAP RT-PCR). One of the genes dominantly expressed in the thermally selected strain (COX II) coded for cytochrome c oxidase subunit II. Northern blot analysis revealed that the accumulated levels of COX II transcripts were more abundant in embryos and unfertilized eggs from the thermally selected strain than those from the Donaldson strain. Furthermore, the differential expression patterns of the ATPase 6-8 gene were similar to those of the COX II gene, whereas the ATP synthase beta-subunit gene showed no significant differences between the two strains.

Does differential selection on the 5S rDNA explain why the rainbow trout sex chromosome heteromorphism is not linked to the SEX locus?

Many but not all rainbow trout strains have morphologically distinguishable sex chromosomes. In these strains, the short arm of the X has multiple copies of 5S rDNA and a bright DAPI band near the centromere, both of which are missing from the Y chromosome, which has a very small short arm. We examined the presence of these markers using fluorescence in situ hybridization (FISH) in four different YY clonal lines derived from different strains and compared the results with sexed fish of the Donaldson strain with the normal X/Y heteromorphism. The Y chromosome in two of the YY clonal lines (Arlee and Swanson) is indistinguishable from the X chromosome and it is positive for 5S rDNA and the DAPI bright band. On the other hand, both 5S rDNA sequences and the DAPI band were not found on the Y chromosome in Hot Creek and Clearwater which have the normal Y. Thus the presence of these two cytogenetic markers may account for the size difference between the short arm of the X and Y chromosome found in most rainbow trout strains. In fishes the expression of one type of 5S rRNA is restricted to oocytes and previous work suggests that although XX males are fairly common, XY females are rare, implying a selective disadvantage for XY females. A hypothesis is presented to explain why this sex chromosome heteromorphism is not closely linked to the SEX locus, which is found on the long arm of the Y chromosome in rainbow trout.

Growth Rate, Maturation Level and Flesh Quality of Three Strains of Large Rainbow Trout (Oncorhynchus Mykiss) Reared in Estonia

Three all-female strains of large rainbow trout imported to Estonia (Danish, Finnish and Donaldson strain) were evaluated in a communal rearing experiment in tanks. The fish had been reared on different fish farms before the experiment started and they had an initial weight of 400–500 g. There were no significant genetic differences between the investigated strains on the basis of three allozyme loci. The total weight gain of the strains during the trial was similar but differences were revealed between seasons. The growth rate of the Finnish trout was high during the first autumn but decreased during the second summer of the trial, probably due to infestation by eye fluke Diplostomum sp. The strains differed in the percentage of immature fish and in the level of gonad development at the age of 2.5–3 years. The Donaldson strain had the highest number of immature fish of the studied strains. Mature females of the Finnish strain had the smallest gonads but also the lowest percentage of immature fish. The level of maturation was the main factor determining the quality – slaughter yield and flesh color.

Differences in MHC class I genes between strains of rainbow trout ( Oncorhynchus mykiss)

In rainbow trout there is only one dominant classical MHC class I locus, Onmy-UBA, for which four very different allelic lineages have been described. The purpose of the present study was to determine if Onmy-UBA polymorphism could be used for strain characterisation. This was performed by lineage-specific PCR investigation of 30 fish, each of the Nikko and Donaldson strains, and by sequence analysis of 25 of the amplified DNA fragments. Two new MHC class I lineages were detected in addition to the four previously described lineages, thus six distinct lineages were observed within the fish examined (Sal-MHCIa*A–F). The distribution of lineages appeared to be strain-specific. For example, the lineage Sal-MHCIa*A was very common in the Nikko strain but could not be detected in the Donaldson strain. Analysis of MHC class I variation may help to elucidate relationships between strains and the roles of MHC alleles in disease resistance.

Occurrence and synthesis of a non-thionein, zinc-binding protein in the rainbow trout ( Salmo gairdneri)

1. A non-thionein, Zn-binding protein (ZBP) was induced in Donaldson strain rainbow trout ( Salmo gairdneri) by 7 mg/kg, i.p. injections of divalent Zn ion. 2. The Sephacryl S-200 used for supernatant fractionation had to be saturated with Zn to recover quantitatively the Zn-ZBP complex. 3. The ZBP was present in liver and kidney, but was absent from gill and spleen. 4. The apparent molecular weights of the liver and kidney ZBP as estimated by gel filtration were 17,300 ± 1300 (SD; N = 11) and 18,100 ( N = 1), respectively. 5. Starvation induced hepatic ZBP synthesis whereas cycloheximide inhibited hepatic ZBP synthesis. The quantity of hepatic ZBP synthesized varied with the temperature of the water in which the trout resided. The maximum quantity of ZBP in the liver following a single 7 mg/kg Zn injection (17 μg Zn/g liver wet weight) occurred at 24 hr.

Isolation and partial characterization of a non-thionein, zinc-binding protein from the liver of rainbow trout ( Salmo gairdneri)

1. A Zn-binding protein (ZBP) was induced in the liver of Donaldson strain rainbow trout by 7 mg/kg i.p. injections of divalent Zn ions. ZBP synthesis was inhibited (74%) by cycloheximide. 2. ZBP had a minimum molecular weight of 16,900 and was composed of two subunits with apparent molecular weights of 9650 and 6050. 3. Purified ZBP contained 4% phenylalanine, 4% isoleucine, 5–6% leucine and 3.48% Zn. Each protein molecule bound nine Zn atoms and contained at least four sulfhydryl groups. 4. Molecular weight, two subunits and the presence of aromatic amino acids suggested that ZBP was not metallothionein.

The Donaldson strain of malaria. 1. History and characteristics of the infection in man.

The Donaldson strain of malaria. 1. History and characteristics of the infection in man.

The Donaldson strain of malaria. 4. An evaluation and status.

Summary and ConclusionsThe Donaldson strain of malaria, which was recovered from a veteran returning from the Pacific area, has been intensively studied. All available evidence indicates that it belongs to the species, Plasmodium ovale.This parasite is immunologically distinct from the native vivax malarias, it can be spread by native anophelines, and both Negro and white races are susceptible to infection. This indicates that this species which has never become established in the United States so far as known, could become established under favorable conditions.

The Donaldson strain of malaria. 2. Morphology of the erythrocytic parasites.

The Donaldson strain of malaria. 2. Morphology of the erythrocytic parasites.

The Donaldson strain of malaria. 3. The infection in the mosquito.

The Donaldson strain of malaria. 3. The infection in the mosquito.