Hong-Shik Oh

Length difference between equine ZFX and ZFY genes and its application for molecular sex determination

PurposeWe analyzed the sex chromosome-encoding ZFX-ZFY genes and tested molecular sexing using the amplification patterns of intron 9 of ZFX-ZFY in the horse.Methods and resultsThe amplification of the ZFX-ZFY produced two distinct patterns, reflecting sexual dimorphism based on a length difference between the X and Y chromosomes. The amplification products from foals showed two distinct bands: one was common to all foals and mares, indicating that this band was amplified from ZFX, while the other was specific to some foals, indicating that it was from ZFY. The result based on the PCR assay was identical to the results of amplification of the Y chromosome-specific SRY gene and those of investigations of the phenotypic gender in three different horse populations.ConclusionWe suggest that this PCR strategy for determining sexes by comparing the amplification patterns of ZFX-ZFY genes is a convenient and precise method for discriminating sexes in horses.

Molecular phylogeny of Crocidura shrews in northeastern Asia: A special reference to specimens on Cheju Island, South Korea

Molecular phylogeny of crocidurine shrews (Insectivora, Soricidae) in northeastern Asia was investigated to confirm the taxonomic status of unidentified specimens ofCrocidura from Cheju Island, South Korea. Phylogenetic trees were constructed by neighbor-joining (NJ) and maximum likelihood (ML) methods, based on mitochondrial cytochromeb gene sequences (402 base pairs) of 37 individuals of seven crocidurine species and three unidentified specimens from 31 localities mainly in northeastern Asia. Phylogenetic position of the three unidentified specimens from Cheju Island were compared with those of Suncus murinus,C. attenuata, C. dsinezumi, C. lasiura, C. sibirica, C. suaveolens, andC. watasei. Both in NJ and ML trees, the three unidentified specimens were included in the cluster ofC. dsinezumi and were obviously different fromC. suaveolens on Cheju Island. Thus, the present investigation demonstrated that bothC. suaveolens andC. dsinezumi exist on Cheju Island.

Porcine SPP1 gene polymorphism association with phenotypic traits in the Landrace × Jeju (Korea) black pig F2 population

This study examined polymorphisms of the secreted phosphoprotein 1 (SPP1) gene and its association with growth and carcass traits in the F2 population of the crossbred Landracexa0×xa0Jeju (Korea) Black pig. The authors detected the presence/absence polymorphisms of short interspersed nuclear element in the SPP1 intron 6 of the population; they then designated the longer fragment as allele A and the shorter one as allele B. The SPP1A/B heterozygous pigs evidenced significantly heavier body weight at birth and on days 21 and 70, and a higher level of average daily gain during the early developmental period than was seen in the A/A and B/B homozygous pigs (Pxa0<xa00.05). Further, the SPP1A/B heterozygous pigs evidenced significantly greater body length, less backfat thickness measured at three different sites, and larger loin muscle area than the homozygotes (Pxa0<xa00.05). On the other hand, the levels of late average daily gain, 140th-day body weight, and marbling score were not significantly associated (Pxa0>xa00.05). The results of this study reveal faster growth rate and differences in pig productivity according to genotypes of the SPP1 gene. These findings demonstrate that SPP1 genotypes may effectively function as molecular genetic markers for the improvement of Jeju Black pig-related crossbreeding systems.

Karyotype and RFLP of the nuclear rDNA of Crocidura sp. on Cheju Island, South Korea (Mammalia, Insectivora)

Nous avons revise le statut taxonomique dune musaraigne a dents blanches (Mammalia, Insectivora) de lile Cheju, Coree du Sud, qui a ete consideree comme la musaraigne japonaise a dents blanches Crocidura dsinezumi dapres lanalyse de son caryotype et de restructuration du polymorphisme dun fragment de longueur (RFLP) pour les regions plus espacees du gene ribosomal nucleaire RNA (rDNA). Le caryotype dun specimen de Crocidura de lile Cheju etait le meme que celui de la petite Crocidura, C. suaveolens, de lile Tsushima et du continent eurasien qui a 2n = 40 et NF = 46, tandis que C. dsinezumi des iles japonaises a 2n = 40 et NF = 52. Le rDNA-RFLP a ete examine dans deux specimens de Crocidura de lile Cheju, deux C. dsinezumi du Japon (Honshu et Kyushu), et un C. suaveolens de la peninsule de Coree, utilisant six sites de restriction avec la sonde rDNA 285 de la souris. Les musaraignes de lile Cheju presentent quatre sites de restriction en commun avec C. suaveolens de la peninsule de Coree, mais seulement un site en commun avec C. dsinezumi, ce qui indique que les musaraignes de lile de Cheju sont genetiquement plus proches mais distinctes des populations de C. suaveolens de la peninsule de Coree. Dapres les resultats du caryotype de RFLP et de rDNA, les specimens de lile de Cheju peuvent etre regardes comme des C. suaveolens.

SINE indel polymorphism of AGL gene and association with growth and carcass traits in Landrace × Jeju black pig F2 population

Genetic polymorphisms in the glycogen debrancher enzyme (AGL) gene were assessed with regard to their association with growth and carcass traits in the F2 population crossbred Landrace and Jeju (Korea) Black pig. Three genotypes representing the insertion and/or deletion (indel) polymorphisms of short interspersed nuclear element were detected at frequencies of 0.278 (L/L), 0.479 (L/S), and 0.243 (S/S), respectively. The AGL S allele-containing pigs evidenced significantly heavier body weights at birth, the 3rd week, 10th week, and 20th week during developmental stages and higher average daily gains during the late period than were noted in the L/L homozygous pigs (Pxa0<xa00.05), respectively. However, average daily gains during the early period were not significantly associated with genotype distribution (Pxa0>xa00.05). With regard to the carcass traits, the S allele pigs (S/-) evidenced significantly heavier carcass weights and thicker backfat than was measured in L/L homozygous pigs (Pxa0<xa00.05). However, body lengths, meat color, and marbling scores were all found not to be statistically significant (Pxa0>xa00.05). Consequently, the faster growth rate during the late period and backfat deposition rather than intramuscular fat deposition cause differences in pig productivity according to genotypes of the AGL gene. These findings indicate that the AGL genotypes may prove to be useful genetic markers for the improvement of Jeju Black pig-related crossbreeding systems.

Migration route estimation of the Jeju striped field mouse Apodemus agrarius chejuensis (Rodentia, Muridae)

The taxonomic relationship between two Korean field mice species, Apodemus agrarius coreae and A. a. chejuensis, as well as their possible historic migration routes, was examined by molecular genetic analysis of the complete mitochondrial cytochrome b gene of 73 mice collected from the Korean Peninsula and Jeju Island. Our findings suggest that A. a. coreae and A. a. chejuensis populations expanded and dispersed rapidly. Bayesian and network analysis showed that A. a. chejuensis is a clearly distinct population, and that A. a. chejuensis originated from the ancestral lineage of A. a. coreae. Based on our data, we hypothesize that the A. a. coreae population originated from eastern China or elsewhere. After the last glacial epoch, the lineage isolated from A. a. coreae had adapted to the new environment of Jeju Island, and with the reproductive isolation caused by the geographic barrier, this lineage eventually became a distinct population.

Adiaspiromycosis of an Apodemus agrarius captured wild rodent in Korea

Adiaspiromycosis is caused by pulmonary infection with Emmonsia. Inhalated spores of Emmonsia cause asymptomatic infection to necrogranulomatous pneumonia, depending on the burden of adiaspore and host immunity. For disease monitoring of wild rodents captured on Jeju Island in Korea, we examined the lung tissue of wild rodents histopathologically. Spores composed of thick three-layered walls were found following histopathological examination and were diagnosed as adiaspiromycosis. Adiaspiromycosis has been found in mammals in many parts of the world. To our knowledge, this is the first report of adiaspiromycosis of an Apodemus agrarius captured in Korea.

First detection of West Nile virus in domestic pigeon in Korea

West Nile virus (WNV) is a mosquito-borne zoonotic pathogen that has spread throughout Europe and the United States. Recently, WNV spread to East and Southeast Asia, and great efforts have been made in South Korea to prevent the spread of WNV from neighboring countries. In this study, we diagnosed the first case of WNV in pigeons (Columba livia domestica) residing in cities using a competitive enzyme-linked immunosorbent assay and confirmed it with nested reverse transcription polymerase chain reaction analysis and sequencing. This is the first report to provide convincing evidence that WNV is present within South Korea.

Detection and Molecular Characterization of Cryptosporidium spp. from Wild Rodents and Insectivores in South Korea

In order to examine the prevalence of Cryptosporidium infection in wild rodents and insectivores of South Korea and to assess their potential role as a source of human cryptosporidiosis, a total of 199 wild rodents and insectivore specimens were collected from 10 regions of South Korea and screened for Cryptosporidium infection over a period of 2 years (2012-2013). A nested-PCR amplification of Cryptosporidium oocyst wall protein (COWP) gene fragment revealed an overall prevalence of 34.2% (68/199). The sequence analysis of 18S rRNA gene locus of Cryptosporidium was performed from the fecal and cecum samples that tested positive by COWP amplification PCR. As a result, we identified 4 species/genotypes; chipmunk genotype I, cervine genotype I, C. muris, and a new genotype which is closely related to the bear genotype. The new genotype isolated from 12 Apodemus agrarius and 2 Apodemus chejuensis was not previously identified as known species or genotype, and therefore, it is supposed to be a novel genotype. In addition, the host spectrum of Cryptosporidium was extended to A. agrarius and Crosidura lasiura, which had not been reported before. In this study, we found that the Korean wild rodents and insectivores were infected with various Cryptosporidium spp. with large intra-genotypic variationa, indicating that they may function as potential reservoirs transmitting zoonotic Cryptosporidium to livestock and humans.

Identifying the species of origin in commercial sausages in South Korea

ABSTRACT This study aimed to develop a rapid and reliable method for identifying the species origin of the meat in commercial sausages using amplification patterns for mitochondrial DNA (mtDNA). Forty commercial sausages were purchased from retail markets and subjected to mtDNA analysis. Two mtDNA markers were used for amplifying the meat source DNA. To optimize the PCR conditions, gradient PCR reactions were carried out to determine the primer annealing temperatures, and real-time PCR was done to check the minimal amount of DNA solution and to examine the cross-reaction. PCR products were observed on the gels suggesting that DNA molecules may be useful in the identification of the meat source in processed sausages. A similarity search of the DNA sequences showed that they were from pig, chicken, and fish, as described on the product labels. The real-time PCR results showed that the PCR products were observed above 10 fg (0.01 pg)/μl concentrations in pig, chicken, and processed fish meat DNA. No significant amplification was found in cross-species. This PCR-based molecular method using mtDNA markers may provide useful information for food safety and traceability purposes by supplying molecular evidence for detecting and identifying the meat sources used in sausage production.