Comparative study of the expression of the native,modified, and hybrid <Emphasis Type="Italic">cry</Emphasis>3a genes of <Emphasis Type="Italic">Bacillus thuringiensis</Emphasis> in prokaryotic and eukaryotic cells

The cry3a gene of Bacillus thuringiensis was cloned. Based on sequence analysis of this gene, a modified gene, cry3aM, was constructed, which has the optimal codon composition for effective expression in eukaryotic cells. Hybrid genes cry3a-licBM2 and cry3aM-licBM2 were constructed, in which the sequences of the native and modified genes are fused with the reporter gene for thermostable lichenase in the reading frame. We have shown that the expression levels of hybrid genes cry3a-licBM2 and cry3aM-licBM2 in Escherichia coli are comparable, being 5% of those for reporter gene licBM2. In cells of a lower eukaryote Saccharomyces cerevisiae, the expression of hybrid gene cry3aM-licBM2, which contains the modified gene, considerably exceeded the level of expression of cry3a-licBM2 containing the native gene. The presence of lichenase in the composition of hybrid proteins was shown to facilitate selection and analysis of the expression level of hybrid proteins in transgenic organisms.Translated from Genetika, Vol. 41, No. 2, 2005, pp. 171–177.Original Russian Text Copyright © 2005 by Salehi Jozani, Komakhin, Piruzian.     

Cadmium and lead in rice grains and wheat breads in Isfahan (Iran) and human health risk assessment

This study was conducted to survey the levels of cadmium (Cd) and lead (Pb) in the main foods of Isfahan province (central Iran). The rice grains and wheat breads were collected from Isfahan city and villages around the Isfahan and Mobarakeh Steel companies. The food samples were wet-ashed by heating in the presence of concentrated nitric acid and hydrogen peroxide. The concentrations of Cd and Pb were determined by inductively coupled plasma-optical emission spectrometer (ICP-OES). The potential exposure risks were then estimated. Levels of Cd in the rice grains and Pb in the investigated foods (except Sangak beard) were above the maximum levels as set by the Codex Alimentarius and National standards of Iran. The wheat bread samples in Isfahan city and Mobarakeh Steel regions presented higher estimated weekly intake (EWI) of Pb (40.93 and 35.35 µg kg^–1 body weight, respectively) compared to other foods. The EWI for Cd and Pb in most samples was considerably above than the provisional tolerable weekly intake. In most cases, the target hazard quotients values were above one and consequently the consumption of foods in the investigated regions was a potentially serious health risk caused by exposure to the crops contaminated with Cd and Pb.     

Nano silver: a novel nanomaterial for removal of bacterial contaminants in valerian (Valeriana officinalis L.) tissue culture

Bacterial contamination is a serious problem in plant tissue culture procedures. An experiment was conducted to evaluate the potential of nano silver (NS) to remove bacterial contaminants of valerian nodal explants. This experiment was conducted as a completely randomized design in a factorial arrangement with four replications and each replicate with ten explants. Treatments involved NS at two stages (before and after surface sterilization along with control) with three rates (25, 50 and 100 mg l⁻¹) at three times of soaking (30, 60 and 180 min). Explants were cultured on MS medium supplemented with 5 mg l⁻¹ Kin and 0.1 mg l⁻¹ NAA. Results showed that using 100 mg l⁻¹ of NS solution after surface sterilization resulted in the highest percentage (89%) of disinfected explants. Nano silver solution did not affect the characters measured. On the basis of the data obtained in this experiment, it was concluded that NS had a good potential for removing of the bacterial contaminants in plant tissue culture procedures. As this is the first report on application of NS in in vitro culture techniques, further investigations on other plant species are needed to clarify the effectiveness of NS for the removal of bacterial contaminants in tissue culture of other crops.     

First International Workshop on Porcine Chromosome 6

Recent advances in the use of microsatellite markers and the development of comparative gene mapping techniques have made the construction of high resolution genetic maps of livestock species possible. Framework and comprehensive genetic linkage maps of porcine chromosome 6 have resulted from the first international effort to integrate genetic maps from multiple laboratories. Eleven highly polymorphic genetic markers were exchanged and mapped by four independent laboratories on a total of 583 animals derived from four reference populations. The chromosome 6 framework map consists of 10 markers ordered with high local support. The average marker interval of the framework map is 15.1 cM (sex averaged). The framework map is 135, 175 and 109 cM in length (for sex averaged, female and male maps, respectively). The comprehensive map includes a total of 48 type I and type II markers with a sex averaged interval of 3.5 cM and is 166, 196 and 126 cM (for sex averaged, female and male maps, respectively). Additional markers within framework map marker intervals can thus be selected from the comprehensive map for further analysis of quantitive trait loci (QTL) located on chromosome 6. The resulting maps of swine chromosome 6 provide a valuable tool for analysing and locating QTL.     

Thermostable lichenase as a translational reporter

Hybrid genes containing the reporter gene for thermostable lichenase and model genes recA, recA1, cry3a, cry3aM, and ssp1 were constructed. The expression of these genes was studied in prokaryotic and eukaryotic cells. The presence of lichenase in the hybrid proteins was shown to facilitate analysis of the hybrid protein expression in transgenic organisms. Owing to high relative activity and thermostability of lichenase, the activity of this enzyme can be measured by simple, rapid and sensitive qualitative and quantitative methods that do not require costly equipment and reagents. Using the zymograms method, molecular masses of the lichenase-containing hybrid proteins can be precisely estimated. This method is proposed instead of Western blotting using lichenase as a translational reporter. Our results showed that the use of thermostable lichenase as a translational reporter yields the data that are problematic to obtain using traditional methods of gene expression analysis, which is of importance for fundamental and applied research.Translated from Genetika, Vol. 41, No. 1, 2005, pp. 30–39.Original Russian Text Copyright © 2005 by Komakhin, Abdeeva, Salehi Dzhuzani, Goldenkova, Zhuchenko.     

Characterization of a Phytoplasma Associated with Pear Decline in Iran

Symptoms of pear decline (PD) were observed in several pear growing regions of Iran. Pear trees with typical symptoms of PD from Estahban (Fars Province) were examined for phytoplasma infection using polymerase chain reaction (PCR) assay. Graft inoculation of healthy pear trees with scions from diseased trees resulted in production of PD symptoms and transmission of phytoplasma as verified by PCR. Target DNA was amplified from symptomatic pear trees with fO1/rO1, an apple proliferation (AP) group-specific primer pair. Physical and putative restriction fragment length polymorphism (RFLP) analyses of fO1/rO1 primed PCR products showed profiles corresponding to AP group, 16SrX-C subgroup ( Candidatus Phytoplasma pyri). Percent similarity values and phylogenetic analysis of fO1/rO1 primed sequences confirmed that, as a member of AP subclade, Estahban PD phytoplasma has a closer relationship to PD and peach yellow leaf roll phytoplasmas than to AP ( Ca . Phytoplasma mali) and European stone fruit yellows ( Ca . Phytoplasma prunorum) phytoplasmas. This is the first report of PD phytoplasma in the eastern Mediterranean.     

Comparative analysis of cost factors in sturgeon fingerling production in Iranian hatcheries (2000–2004)

Production cost analysis in aquaculture is an essential exercise to assist farm managers. Economic assessment of a farm operation also provides the basis to formulate governmental aquaculture and enhancement policies in many regions. The present study employed questionnaires and interviewed managers while also using governmental statistics to gain insight into production cost variables in Iranian sturgeon hatcheries. Within a decade, production of sturgeon fingerlings for release and stock enhancement increased in Iran to more than 21 million fingerlings by 2004. Costs and contributions of various production factors were determined using data obtained from a questionnaire involving all hatcheries between 2000 and 2004. A team of experts completed the questionnaire data sets while conducting interviews at all sturgeon centres and other related departments. From 2000 to 2004 the contribution of A. persicus was 79% of the total number of sturgeon fingerlings produced followed by A. nudiventris with 7.5% and Huso huso with 6.6%. Among the various expenditures between 2000 and 2004, the costs for permanent and part‐time employees contributed the greatest share of total costs, averaging 44%, with a noticeable declining trend from 51% in 2000 to 36% in 2004. Obtaining and incubating fertilized eggs averaged 22% of total costs, increasing during the same time period from 6 to 35%, respectively. On average, the 2000–2004 production cost for a single sturgeon fingerling was estimated at Rials 1667 (US$ 0.20), increasing from Rials 992 (US$ 0.12) to Rials 2623 (US$ 0.29) over these 4 years. Permanent staff at a hatchery was determined as being the principal cost, followed by costs for obtaining fertilized eggs (including broodstock handling). Over the 5‐year study period the results indicated that costs for part‐time labour declined yearly and, conversely, the costs of obtaining broodstocks as well as fertilizing and incubating eggs increased. Considering the background of hatchery production and stock enhancement of sturgeon species and the results of fishing data, it is possible to arrive at a first estimate of the potential contribution of Persian sturgeon farming to the total catch in Iranian waters; it is assumed that these increases were most likely through stock enhancement.