• Korean Journal of Veterinary Service
• /
• v.47 no.1
• /
• pp.9-17
• /
• 2024

Porcine epidemic diarrhea (PED) is a highly contagious enteric viral disease of pigs with watery diarrhea in piglets, which ultimately results in huge economic losses in the swine industry. The spike (S) protein plays an important role in viral pathogenicity, tissue tropism, infection, dissemination and the trypsin-dependent proliferation of the PED virus (PEDV). In the present study, we determined the full-length spike (S) gene sequences of twenty PEDV field strains detected in Jeonbuk province in 2022. Phylogenetic analysis showed that the twenty PEDV field strains were classified into G2b group and shared 98.6~100% of nucleotide homology and 97.4~100% of amino acid homology with each other. Mutations of amino acid sequences on the neutralizing epitope of S protein were observed in the twenty field strains compared to the previous vaccine strain SM-98-1 (G1a group). Therefore, these amino acid mutations in the PEDV S protein may result in a new genotype of the virus and highly pathogenic virus, so continuous monitoring is required.

• Journal of Microbiology
• /
• v.33 no.2
• /
• pp.136-141
• /
• 1995

From a cluster of structural rRNA genes which has previsouly been cloned (Hwang and Kim, in submission; J. Microbiol. Biotechnol.), a 1.0-kb Eco RI fragment of DNA which shows significant homology to the 25S and rRNA s of Tricholoma matsutake was used for sequence analysis. Nucleotide sequence was bidirectionally determined using delection series of the DNA fragment. Comparing the resultant 1016-base sequence with sequences in the database, both the 3'end of 25S-rRNA gene and 5S rRNA gene were searched. The 5S rRNA gene is 118-bp in length and is located 158-bp downstream of 3'end of the 25S rRNA gene. IGSI and IGS2 (partial) sequences are also contained in the fragment. Multiple alignment of the 5S rRNA sequences was carried out with 5S rRNA sequences from some members of the subdivision Basidiomycotina obtained from the database. Polygenetic analysis with distance matrix established by Kimura's 2-parameter method and phylogenetic tree by UPGMA method proposed that T. matsutake is closely related to efibulobasidium allbescens. Secondary structure of 5S rRNA was also hypothesized to show similar topology with its generally accepted eukaryotic counterpart.

• Journal of Microbiology
• /
• v.44 no.6
• /
• pp.607-616
• /
• 2006

Molecular characterization of ten marine cyanobacterial isolates belonging to the order Oscillatoriales was carried out using the phycocyanin locus (cpcBA-IGS) and the 16S-23S internally transcribed spacer region. DNA sequences from the phycocyanin operon discriminated ten genotypes, which corresponded to seven morphotypes identified by traditional microscopic analysis. The cpcB coding region revealed 17% nucleotide variation, while cpcA exhibited 29% variation across the studied species. Phylogenetic analyses support the conclusion that the Phormidium and Leptolyngbya genera are not monophyletic. The nucleotide variations were heterogeneously distributed with no or minimal informative nucleotides. Our results suggest that the discriminatory power of the phycocyanin region varies across the cyanobacterial species and strains. The DNA sequence analysis of the 16S-23S internally transcribed spacer region also supports the polyphyletic nature of the studied oscillatorian cyanobacteria. This study demonstrated that morphologically very similar strains might differ genotypically. Thus, molecular approaches comprising different gene regions in combination with morphological criteria may provide better taxonomical resolution of the order Oscillatoriales.

• Journal of Veterinary Science
• /
• v.21 no.6
• /
• pp.73.1-73.10
• /
• 2020

Background: Bovine papilloma is a neoplastic disease caused by bovine papillomaviruses (BPVs), which were recently divided into 5 genera and at least 24 genotypes. Objectives: The complete genome sequence of BPV type 15 (BPV Aks-02), a novel putative BPV type from skin samples from infected cows in Southern Xinjiang China, was determined by collecting warty lesions, followed by DNA extraction and amplicon sequencing. Methods: DNA was analyzed initially by polymerase chain reaction (PCR) using the degenerate primers FAP59 and FAP64. The complete genome sequences of the BPV Aks-02 were amplified by PCR using the amplification primers and sequencing primers. Sequence analysis and phylogenetic analysis were performed using bio-informatic software. Results: The nucleotide sequence of the L1 open reading frame (ORF) of BPV Aks-02 was 75% identity to the L1 ORF of BPV-9 reference strain from GenBank. The complete genome consisted of 7,189 base pairs (G + C content of 42.50%) that encoded 5 early (E8, E7, E1, E2, and E4) and 2 late (L1 and L2) genes. The E7 protein contained a consensus CX₂CX₂₉CX₂C zinc-binding domain and a LxCxE motif. Among the different members of this group, the percentages of the complete genome and ORFs (including 5 early and 2 late ORFs) sequence identity of BPV Aks-02 were closer to the genus Xipapillomavirus 1 of the Xipapillomavirus genus. Phylogenetic analysis and sequence similarities based on the L1 ORF of BPV Aks-02 revealed the same cluster. Conclusions: The results suggest that BPV type (BPV Aks-02) clustered with members of the Xipapillomavirus genus as BPV 15 and were closely related to Xipapillomavirus 1.

• Parasites, Hosts and Diseases
• /
• v.53 no.3
• /
• pp.253-258
• /
• 2015

Toxoplasma gondii, an obligate intracellular protozoan parasite of the phylum Apicomplexa, can infect all warm-blooded vertebrates, including humans, livestock, and marine mammals. The aim of this study was to investigate whether superoxide dismutase (SOD) of T. gondii can be used as a new marker for genetic study or a potential vaccine candidate. The partial genome region of the SOD gene was amplified and sequenced from 10 different T. gondii isolates from different parts of the world, and all the sequences were examined by PCR-RFLP, sequence analysis, and phylogenetic reconstruction. The results showed that partial SOD gene sequences ranged from 1,702 bp to 1,712 bp and A + T contents varied from 50.1% to 51.1% among all examined isolates. Sequence alignment analysis identified total 43 variable nucleotide positions, and these results showed that 97.5% sequence similarity of SOD gene among all examined isolates. Phylogenetic analysis revealed that these SOD sequences were not an effective molecular marker for differential identification of T. gondii strains. The research demonstrated existence of low sequence variation in the SOD gene among T. gondii strains of different genotypes from different hosts and geographical regions.

• Korean Journal of Plant Taxonomy
• /
• v.53 no.3
• /
• pp.237-241
• /
• 2023

The genus Scrophularia L. (Scrophulariaceae) comprises 200-270 species worldwide and is a taxonomically challenging lineage, displaying morphological diversity and hybridization. S. kakudensis is morphologically similar to the closely related taxa S. kakudensis var. microphylla, S. pilosa, and S. cephalantha. Therefore, the purpose of this study was to sequence the chloroplast (cp) genome of S. kakudensis using next-generation sequencing and compare it to those of related taxa. The complete cp genome sequence of Scrophularia kakudensis was found to be 152,355 bp long, consisting of a pair of inverted repeats of 25,485 bp that separate a large single-copy (LSC) of 83,479 bp from small single-copy regions of 17,909 bp. The cp genome contained 78 protein-coding genes, 30 tRNAs, and four rRNAs. A phylogenetic analysis based on 78 protein-coding genes from six Scrophularia species showed S. kakudensis and S. cephalantha formed with 100% bootstrap values. We compared the complete cp genomes of S. kakudensis and S. cephalantha and identified seven sequence divergence regions: matK/rps16, rps16/trnQ, trnS/trnG, rpoB/trnC, trnS/trnG, rpl32/trnL, and ndhD/psaC. These regions may be useful for determining the phylogenetic relationships among S. kakudensis-related species.

• Parasites, Hosts and Diseases
• /
• v.42 no.3
• /
• pp.129-135
• /
• 2004

We compared the DNA sequences of the genus Metagonimus: M. yokogawai, M. takahashii, and M. miyatai. We obtained 288 D1 ribosomal DNA (rDNA) and mitochondrial cytochrome c oxidase subunit I (mtCOI) fragments from the adult worms by PCR, that were cloned and sequenced. Phylogenetic relationships inferred from the nucleotide sequences of the 28S D1 rDNA and mtCOI gene. M. takahashii and M. yokogawai are placed in the same clade supported by DNA sequence and phylogenie tree analysis in 28S D1 rDNA and mtCOI gene region. The above findings tell us that M. takahashii is closer to M. yokogawai than to M. miyatai genetically. This phylogenetic data also support the nomination of M. miyatai as a separate species.

• Animal Systematics, Evolution and Diversity
• /
• v.28 no.4
• /
• pp.269-278
• /
• 2012

Gobiids are hyperdiverse compared with other teleost groups, with about 2,000 species occurring in marine, freshwater, and blackish habitats, and they show a remarkable variety of morphologies and ecology. Testing the effectiveness of DNA barcodes on species that have emerged as a result of radiation remains a major challenge in evolutionary biology. Here, we used the cytochrome c oxidase subunit 1 (COI) sequences from 144 species of gobies and related species to evaluate the performance of distance-based DNA barcoding and to conduct a phylogenetic analysis. The average intra-genus genetic distance was considerably higher than that obtained in previous studies. Additionally, the interspecific divergence at higher taxonomic levels was not significantly different from that at the intragenus level, suggesting that congeneric gobies possess substantial interspecific sequence divergence in their COI gene. However, levels of intragenus divergence varied greatly among genera, and we do not provide sufficient evidence for using COI for cryptic species delimitation. Significantly more nucleotide changes were observed at the third codon position than that at the first and the second codons, revealing that extensive variation in COI reflects synonymous changes and little protein level variation. Despite clear signatures in several genera, the COI sequences did resolve genealogical relationships in the phylogenetic analysis well. Our results support the validity of COI barcoding for gobiid species identification, but the utilization of more gene regions will assist to offer a more robust gobiid species phylogeny.

• Korean Journal of Agricultural Science
• /
• v.38 no.2
• /
• pp.249-255
• /
• 2011

This study was performed to investigate the characterization of infectious BLV env gene isolated form Korean Holstein Cattle and to determine its incoming origin. Gp51 region of BLV env gene known as having important role in immunological function was characterized using PCR-RFLP sequencing and phylogenetic analysis. BLV env gene was grouped into PCR-RFLP patterns with three restriction endonucleases including Pvu II, BamHI and Hae III, and we identified two new RFLP patterns from nucleotide sequences of each group. Phylogenetic analysis showed that 80% of the Korean Holstein was included in the USA and Japanese group. These results here can provide a valuable information about the character of the BLV env gene and research on infection route of BLV.

• The Plant Pathology Journal
• /
• v.23 no.3
• /
• pp.151-154
• /
• 2007

Phytoplasma was identified from leaf lettuce (Lactuca sativa) cultivated in commercial green-house in Korea. Diseased leaf lettuce revealed proliferation of shoots, and yellowing and shrinking of leaves (lettuce proliferation-K). Polymerase chain reaction (PCR) with universal primer pair P1/P6, and aster yellows (AY) specific primer pair R16F1/R1 amplified 1.5kb and 1.1kb length of DNA fragments, respectively. Nucleotide sequences of 16S rRNA gene were determined (Gen Bank accession no EF489024). Phylogenetic analysis of 16S rDNA showed the closest relationship with AY phytoplasma (GenBank accession no. AY389822 and AY389826), indicating that lettuce proliferation-K is a member of AY. Phytoplasma bodies were detected in phloem sieve tubes of diseased lettuce by transmission electron microscopy. The structures had round or pleomorphic shapes with a diameter of 130-300nm. Phylogenetic analysis of 16S rRNA gene, microscopic observation of phytoplasma bodies and symptomatology indicated that lettuce proliferation-K is caused by phytoplasma in the AY group. This is the first report of phytoplasma disease in lettuce in Korea.