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Biomedical subjects

G H Kou

Publications and source records attributed to G H Kou.

23 records · Page 2Linked to original sources

Genomic structure of the locus encoding protein 4.1. Structural basis for complex combinational patterns of tissue-specific alternative RNA splicing.

Protein 4.1 (P4.1) is a multifunctional protein with heterogeneity in molecular weight, intracellular localization, tissue- and development-specific expression patterns. We have analyzed the genomic structure of the locus encoding mouse P4.1 and have systematically analyzed diverse P4.1 mRNA isoforms expressed in erythroid and nonerythroid tissues. Our results indicate that the mouse protein 4.1 gene, over 90 kilobases long, comprises at least 23 exons (13 constitutive exons, 10 alternative exons) interrupted by 22 introns. The donor and acceptor splice site sequences match the consensus sequences for the exon-intron boundaries of most eukaryotic genes. No significant sequence difference was observed between splice junctions of alternative and constitutive exons. Apparently, most alternative exon-encoded peptides are located within particular functional domains of the P4.1 protein: two peptides encoded by alternative exons 4 and 5 are located near or within the glycophorin/calmodulin binding domain, whereas three other alternative exon-encoded peptides (19-amino acid encoded by exon 14, 14-amino acid encoded by exon 15, and 21-amino acid encoded by exon 16) are located near or within the spectrin-actin binding domain. Selective use of exon 2', which carries an upstream translation initiation codon (AUG), may produce an elongated P4.1 isoform (135 kDa) that is predominantly expressed in nonerythroid tissues. Combinatorial splicing of these exons may generate different isoforms that exhibit complicated tissue-specific expression patterns.

3T3 Cells↗

Purification and amplification of DNA from Penaeus monodon-type baculovirus (MBV).

The purpose of this paper was to purify and amplify the DNA fragment of Penaeus monodon-type baculovirus (MBV). Using 30-50% caesium chloride gradients, MBV virions and occlusion bodies with density parameters of 1.28-1.29 and 1.32-1.33 g/ml, respectively, were purified. Two oligonucleotide primers have been successfully designed and utilized for the amplification of a DNA fragment of MBV. After 35 amplification cycles of the MBV DNA fragment, a large amount of amplified product with an approximate molecular weight of 600 bp was obtained. This is the first successfully published work on the amplification of MBV using the polymerase chain reaction (PCR). Using the same primers, DNA extracted from MBV noninfected P. monodon, P. japonicus, and P. orientalis had a negative PCR response. However, a positive PCR response was obtained from DNA extracted from MBV-infected postlarval P. monodon. DIG-dot blot hybridization technique using PCR product obtained from the present study as a probe further confirmed that the product is originated from a portion of MBV polyhedrin gene. It is also suggested that PCR product may be beneficial for an accurate and early diagnosis of MBV infection in larval shrimp.

Animals↗

Establishment of a cell line derived from top-minnow (Gambusia patruelis).

A cell line, derived from top-minnow (Gambusia patruelis), has been transferred for 114 times in Leibovitz L-15 medium plus 10% FCS (GM-L-15) at a temperature of 31 degrees C and designated as TM. The results of a chromosome analysis of 100 cells at the metaphase stage, show a bimodal distribution of the chromosome number ranged from 21 to 68 with a modal number of 38. At a low seeding density, the plating efficiency of TM cells was 11-12.4%. TM cells are susceptible to EVE, EVA, EVEX, IPNV and LV-1 at 18 degrees C. The result of a sterility test showed that the TM cell line was free of bacterial, fungal and mycoplasmic contamination. The presence of numerous microvilli on the surface of TM cells in the micrographs of normal TM cell. The microvilli are replaced by blebs at the late stage of cytokinesis of the cells.

Animals↗

The small subunit ribosomal RNA gene sequence of Pleistophora anguillarum and the use of PCR primers for diagnostic detection of the parasite.

Using the polymerase chain reaction (PCR) and two primers for conserved regions of the small subunit ribosomal RNA (SSU-rRNA) of Microsporidia, a DNA segment about 1,195 base pairs long was amplified from a DNA template prepared from purified spores of the microsporidian species Pleistophora anguillarum. These spores had been isolated from adult eels (Anguilla japonica) with "Beko Disease." A comparison of sequence data from other microsporidian species showed P. anguillarum SSU-rRNA to be most similar to Vavraia oncoperae. When juvenile eels were artificially infected with P. anguillarum, enzyme-linked immunosorbent assay could detect a positive infection only 12 days post-infection. However, when suitable PCR primers were used, a DNA fragment of about 0.8 kb was detected from these juvenile eels after only 3 days post infection. No PCR product was obtained with templates prepared from clinically healthy control animals.

Anguilla↗