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[en] An investigation is being carried out on the ribosomal DNA (rDNA) molecular organization of closely related Arphidiinae species belonging to the genus Aphidius Nees, of relevant interest in biological control, with the aim of evaluating the variability within and between species. After construction of a restriction map of the most represented A. ervi rDNA cistrons, the molecular organization of the rDNA repeating units of single individuals and populations was studied in Southern blot analyses. Heterogeneity within the A. ervi rDNA cistrons and between populations of different geographical origin was identified. This approach allowed the conclusion to be reached that differences in the rDNA cistrons can be diagnostic of species and populations, therefore providing a useful tool in biological control programmes. (author). 18 refs, 4 figs
[en] These are slides on genetic algorithm for nuclear data evaluation. The following is covered: initial population, fitness (outer loop), calculate fitness, selection (first part of inner loop), reproduction (second part of inner loop), solution, and examples.
[en] Pleurotus species is an edible mushroom in Malaysia which is commonly known as Oyster mushroom and grow by small holder farmers. This species is important for nutraceutical, pharmaceutical and cosmoceutical industries. However, there is some mis identification due to phenotypic variation in which the species shared some similarities due to environmental factors, and thus create troublesome. Thus, eleven isolates of Pleurotus sample which comprise of 4 different species were collected from different locations in Malaysia were used for strain and species identification including mutant line Pleurotus. Pleurotus pulmonarius coded as ATCC 62887 was used as a reference. Total genomic DNA was extracted, quantified and amplified by using rDNA-ITS (Ribosomal DNA Internal Transcribed Spacers) ITS8-F: 5"'AGTCGTAACAAGGTTTCCGTAGGTG3"' and ITS6-R: 5"'TTCCCGCTTCACTCGC-AGT3"'primers. The PCR products were directly sequenced for BLAST evaluation. Phylogenetic (UPGMA) was constructed by using CLC Sequence Viewer 6.8.1. It clearly shown distinct clades of the Pleurotus species and strains. Pleurotus pulmonarius were found to be grouped in one group while Pleurotus florida and Pleurotus columbinus were in the other different clade. For Pleurotus geesteranus, which has the most nucleotide similarity and morphology with Pleurotus pulmonarius, was grouped in its own clade and was single isolated. Thus, ITS marker found to be reliable, rapid, robust and reproducible approach in screening of Pleurotus species and its variants for taxonomical purposes and phylogenetic analysis. (author)
[en] The fourth international workshop on human chromosome 18 mapping was held in Boston, Massachusetts, USA on October 7-9, 1996. The workshop was attended by 34 participants from 7 countries. The goals of the workshop were to (1) generate integrated genetic and physical maps, (2) update the transcriptional map, (3) assess the syntenic relationships between human chromosome 18 and the mouse genome, and (4) establish a chromosome 18 web site
[en] The Cordoba department of Colombia programmed to establish 200000 ha of forest plantations by year 2025. Teak was priorized by its adaptation, wood quality and value in the asian markets. The objective of this research was to estimate the expected genetic gain, of phenotypically selected pluss trees in 5316 ha plantation in Cordoba, for diameter at breast height, commercial height, commercial volume and log quality traits. The selection based on the pheno typical evaluation of the tree candidate and its four best neighbors within a 20 m radius, qualifying, individually the first four segments of 2.5 m length. Selected trees were classified in list A as determined to be superior in both, volume and quality, according to the selection differential to all its four best neighbors. List B included those plus trees found superior only in commercial volume or in stem quality. Genetic gain was estimated by multiplying selection differential X average narrow sense heritability. We estimated a Selection Index that integrate commercial volume (60%) and stem quality (40%). From 46 selected trees, 18 were classified as plus A. In selecting and cloning the 18 best A plus trees, based on the Selection Index, we expected genetic gains of 5.52% (diameter); 17.50% (height); 41.71% (commercial volume) and 9,59% (stem quality). These results suggest an important genetic progress breeding teak in Cordoba, as long as they broaden the genetic base of the program and verify results with genetic testing in various potential production areas.
[en] Biochemical and molecular markers (RAPD) can be used for population genetics and genome analysis of the Mediterranean fruit fly (medfly), Ceratitis capitata. At the population level, biochemical markers allowed recognition of: (a) the presence of geographical genetic heterogeneity, and (b) provided information on the relative contribution of different types of evolutionary forces during the process of colonization. The polymorphisms in genomic finger-prints, generated by the RAPD approach, provide a tool to improve the significance of the estimates of genetic relatedness between medfly populations, as well as being able to distinguish between slightly divergent flies. For genome organization analysis, biochemical markers provided information on the relationship of genome structure to genome function. The RAPD approach may provide a new tool to explore and completely map the medfly genome. (author). 17 refs, 1 fig
[en] Gene transformation for the control of mosquito transmitted diseases is currently limited by the lack of an efficient method for the transfection and integration of exogenous DNA. The biolistic technique, which uses high velocity DNA coated microprojectiles, has been developed to introduce DNA into embryos of Anopheles gambiae. The biolistic parameters have been characterized and optimized on the basis of transient expression of the luciferase reporter gene placed under the control of the heat shock protein 70 promoter of Drosophila. High luciferase activities were observed for biolistic DNA introduction performed in the early embryonic stages. Because of the very large number of embryos which can easily be transfected biolistically, and because DNA is probably delivered directly into the nuclei, the biolistic method could be useful for obtaining insect genetic transformation, despite the low frequency of exogenous DNA integration. Moreover, this technique has already been proved suitable for embryo transfection in other invertebrates, such as crustaceans. (author). 8 refs