• Journal of Embryo Transfer
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• v.26 no.4
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• pp.229-235
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• 2011

Sloan-Kettering virus gene product of a cellular protooncogene c-Ski is an unique nuclear pro-oncoprotein and belongs to the Ski/Sno proto-oncogene family. Ski plays multiple roles in a variety of cell types, it can induce both oncogenic transformation and terminal muscle differentiation when expressed at high levels. Ski protein is implicated in proliferation/differentiation in a variety of cells. The alternative fate of granulosa cells other than apoptosis is to differentiate to luteal cells, however, it is unknown whether Ski is expressed and has a role in granulosa cells undergoing luteinization. Thus, the aim of this study was, by means of immunohistochemical methods, to locate Ski protein in the rat ovaries during ovulation and corpora lutea (CL) formation to predict the possible involvement of Ski in luteinization. In addition, we performed to examine whether the initiation of luteinization with luteinizing hormone (LH) directly regulates expression of Ski in the luteinized granulosa and luteal cells after ovulation by in vivo models. In order to examine the expression pattern of Ski protein along with the progress of luteinization, follicular growth was induced by administration of equine chorionic gonadtropin to immature female rat, and luteinization was induced by human chorionic gonadtropin treatment to mimic luteinizing hormone (LH) surge. While no Ski-positive granulosa cells were present in preovulatory follicle, Ski protein expression was induced in response to LH surge, and was maintained after the formation of corpus luteum (CL). These results indicate that Ski is profoundly expressed in the luteinized granulosa cells and luteal cells of CL during luteinization, and suggest that Ski may play a role in luteinization of granulosa cells.

• Animal cells and systems
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• v.15 no.1
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• pp.37-43
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• 2011

The Korean freshwater crayfish, Cambaroides similis, has recently suffered from range reduction and habitat degradation caused by environmental changes and water pollution. For the conservation and restoration of this species, it is necessary to understand the current population structures of Korean C. similis using estimation of their genetic variation. In this study, eight micro satellite loci were developed and characterized from 49 individuals collected from four locations: one population from Mt. Bukhan (BH) and three populations from Mt. Gwanak (GA) in Seoul, Korea. As a result, the number of alleles per locus ranged from 2 to 12. The observed heterozygosities and expected heterozygosities ranged from 0.000 to 0.833 and from 0.125 to 0.943, respectively, and the former values were significantly lower than the latter ones expected under the Hardy-Weinberg equilibrium. No significant linkage disequilibrium was revealed between any of the locus pairs after Bonferroni correction. From the pairwise Fst results over all samples, higher differentiation between GA-BH population pairs (mean 0.1789) was observed than between GA population pairs (mean 0.0454). This was also supported by Mantel's test showing that the genetic distances of these crayfish populations were significantly correlated with geographic distances. This result may show the regional differentiation caused by restricted gene flow between northern (BH) and southern (GA) populations within Seoul. These micro satellite markers have the potential for use in analyses of the genetic diversity and population structure of C. similis species, with implications for its conservation and management plans.

• Korean journal of applied entomology
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• v.47 no.3
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• pp.201-208
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• 2008

Spring phonology of the oriental fruit moth, Grapholita molesta, was monitored using sex pheromone traps in apple cultivating areas. Their occurrence was earlier in southern areas and their population sizes were significantly different among orchards even in a local cultivating zone. The overwintering populations appeared to move between local orchards, based on the fact that monitoring data obtained at the sites between orchards were similar to those of nearby orchards. However, within orchards, these adult movements appeared to decrease and showed skewed occurrences at the side of upwind direction or close to neighboring orchards. At initial occurrence peak(April 20-25), the ovenvintering populations of the different localities were collected and analyzed in their genetic distances. PCR-RAPD analysis indicated that there were significant genetic differences among the overwintering populations of G. molesta. This genetic differentiation of overwinterin populations may be due to genetic bottleneck following differential selection pressures against the subpopulations of G. molesta during winter on the basis of the RAPD analysis that each early spring population was significantly different to its previous fall population in the same locality.

• Journal of Life Science
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• v.19 no.6
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• pp.711-719
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• 2009

We determined a portion of mitochondrial 16S rRNA gene sequences (416 bp) to investigate the genetic structure of the octopus (Octopus minor Ssaki) population in Korea and China. Samples were obtained from Korea (Yeosu, Namhae, Jindo, Muan, Geomundo and Seosan) and China (Sandong) during the period of August 2006 to September 2007. Sequence analyses of 28 individual specimens collected from 7 localities revealed 11 haplotypes, ranging in a sequence divergence of 0.2% - 1.2%. Phylogenetic analyses using PHYLIP and networks subdivided the octopus into two clades (termed clade A and B) and the nucleotide divergence between them was 0.4%. This haplotype subdivision was in accordance with geographic separation: one at Yeosu, Namhae, Muan and Jindo, and the other at Seosan, Geomundo and Sandong. On the basis of hierarchial genetic analysis, genetic distance between localities in Korea and China were also found, but a significant population differentiation was not shown in this study (p>0.05). Consequently, most of the octopus populations in Korea had considerable distribution due to the mitochondrial gene flow that resulted in a formation of a genetically homogenous structure, whereas some of the Korean and Chinese populations had different genetic structures. Gene flow among populations may be restricted due to impassable geographic barriers that promote genetic differentiation.

• Animal Systematics, Evolution and Diversity
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• v.26 no.1
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• pp.15-19
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• 2010

The Russian ratsnake, Elaphe schrenckii, is found in Russia, China, and Korea, and is considered to be an endangered species by the Ministry of Environment in South Korea. Due to habitat loss and use in oriental medicine, their population has been severely decimated. In South Korea, two subspecies of E. schrenckii has been defined according to body color: E. s. schrenckii (blackish) and E. s. anomala (yellow-brownish). Molecular genetic studies on Elaphe schrenckii are very scarce and the taxonomy of Elaphe schrenckii subspecies is uncertain. From the present study, we attempted to identify the genetic differences of these two subspecies using species-specific microsatellites developed from the genomic library of E. schrenckii. Nine polymorphic loci were tested on 19 individuals from E. s. schrenckii (n=10) and E. s. anomala (n=9) in South Korea. The mean number of alleles was 3.78 in E. s. schrenckii and 4.11 in E. s. anomala. The average expected heterozygosity was 0.542 and 0.511 in E. s. schrenckii and E. s. anomala, respectively. We found a lack of genetic structure between two subspecies ($F_{ST}=0.016$) and no genetic discrimination between two subspecies was found. Based on the present findings by microsatellites, two subspecies can be considered as one species, E. schrenckii. However, further investigations on taxonomical status using mitochondrial and nuclear DNA sequences need to be performed and morphological & ecological data should be revised. The genetic markers should benefit future studies of the endangered species of other Elaphe species for the study of genetic diversity and potential conservation management.

• BMB Reports
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• v.42 no.8
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• pp.529-534
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• 2009

Marbling score (MS) is the major trait that affects carcass quality in beef cattle. In this study, we investigated the association between genetic polymorphisms of the adipose differentiation-related protein gene (ADFP) and carcass traits in Korean cattle (also known as Hanwoo). Using direct DNA sequencing in 24 unrelated Korean cattle, 25 novel polymorphisms were identified within all exons and their flanking regions of ADFP, including the promoter region (1.5 kb). Among them, 21 polymorphic sites were selected for genotyping in the beef cattle (n = 425). Statistical analyses revealed that one promoter polymorphism (c.-56-18A > G) was associated with MS (P = 0.009). The 'A' allele of c.-56-18A > G exerted a lowering effect on MS, e.g., the lowest MS was found in 'A/A' (MS = 2.09 ${\pm}$ 1.23), intermediate in 'A/G' (MS = 2.11 ${\pm}$ 1.31), and the highest in 'G/G' (MS = 2.47 ${\pm}$ 1.47). Our findings suggest that these polymorphisms in ADFP might be important genetic factors involved in carcass quality in beef cattle.

• Asian-Australasian Journal of Animal Sciences
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• v.32 no.11
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• pp.1664-1672
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• 2019

Objective: This study aimed to measure genetic diversity and to determine the relationships among fourteen goose breeds. Methods: Microsatellite markers were isolated from the genomic DNA of geese based on previous literature. The DNA segments, including short tandem repeats, were tested for their diversity among fourteen populations of geese. The diversity was tested on both breeds and loci level and by mean of unweighted pair group method with arithmetic mean and structure program, phylogenetic tree and population structure were tested. Results: A total of 108 distinct alleles (1%) were observed across the fourteen breeds, with 36 out of the 108 alleles (33.2%) being unique to only one breed. Genetic parameters were measured per the 14 breeds and the 9 loci. Medium to high heterozygosity was reported with high effective numbers of alleles (Ne). Polymorphic information contents (PIC) of the screened loci was found to be highly polymorphic for eleven breeds; while 3 breeds were reported moderately polymorphic. Breeding coefficient ($F_{IS}$) ranged from -0.033 to 0.358, and the pair wise genetic differentiation ($F_{ST}$) ranged from 0.01 to 0.36 across the fourteen breeds; for the 9 loci observed and expected heterozygosity, and Ne were same as the breeds parameters, PIC of the screened loci reported 6 loci highly polymorphic and 3 loci to be medium polymorphic, and $F_{IS}$ ranged from -0.113 to 0.368. In addition, genetic distance estimate revealed a close genetic distance between Canada goose and Hortobagy goose breeds by 0.04, and the highest distance was between Taihu goose and Graylag goose (anser anser) breed by 0.54. Conclusion: Cluster analyses were made, and they revealed that goose breeds had hybridized frequently, resulting in a loss of genetic distinctiveness for some breeds.

• Animal cells and systems
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• v.1 no.2
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• pp.247-257
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• 1997

Genetic and morphological variations of Korean Hynobius leechii were surveyed. Starch gel electrophoresis was used to study genetic variation at 23 loci. H. leechii is genetically divided into three groups, each of which is named as Form-A, Form-B, and Form-C. These forms are clearly separated with 4-5 fixed or nearly fixed allelic differences. At a sympatry near Jangseong, Jollanam-do, a significant deviation from random mating between Form-A and Form-B was observed. Therefore, they are considered as two distinct taxi of specific rank. Form-A is widely distributed in the inland of Korea, whereas Form-B is distributed in the islands or near the coastal regions of Western and Southern Korea. Form-B had, in addition, a significant morphological difference from Form-A. On the other hand, Form-C was restricted to an area near Kori atomic power plant, Kyongsangnam-do, and the genetic similarities between this form and Form-A and Form-B were 0.742 and 0.736, respectively. Moreover, Form-C had a unique color pattern, short body and small coccyx. Thus, it seems reasonable to assign this form as another new species.

• Fisheries and Aquatic Sciences
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• v.15 no.2
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• pp.151-155
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• 2012

We used nine microsatellite DNA markers to estimate genetic variation among wild and cultured populations of the sea squirt Halocynthia roretzi. The loci were polymorphic, with 6-32 alleles, and allelic richness ranged from 6.0 to 26.1 in each population. The wild and the cultured populations had similar mean heterozygosities ($H_O$ and $H_E$), allele numbers, and allelic richness. One cultured population with softness syndrome had a lower mean in the observed heterozygosity ($H_O$ = 0.57) and higher mean inbreeding coefficient ($F_{IS}$ = 0.261) than any other populations. This suggests that the loss of genetic variation in the diseased population might be due to increased inbreeding. A neighbor-joining tree and pairwise population estimates of $F_{ST}$ showed moderate genetic differentiation between the wild and the cultured populations. Additionally, the softness syndrome population was genetically divergent from wild populations, but it was genetically close to the cultured populations.

• Animal Systematics, Evolution and Diversity
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• v.13 no.1
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• pp.9-20
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• 1997

한국산 송사리 (Oryzias)속의 송사리 (O. latipes)와 대륙송사리(O. sinensis)의 집단 내 유전적 변이 및 종간 유연관계를 밝히고자 남한의 16개집단과 일본산 송사리(O. latipes) 1개 집단 등 총 17개 집단에 대한 isozyme 분석을 실시하였다. Isozyme 분석 결과 17개의 효소 및 비효소단백질에서 총 32개의 유전자를 검출한 결과, 전체 유전자중 Est-1과 Est-3 는 종 특유의 유전적 표식인자(genetic marker)였다. 송사리집단 중 진도집단의 유전적 변이 가 가장 낮았으며(Ho=0.011, He=0.043), 대륙송사리 서천집단의 유전적 변이가 가장 높았 다.(Ho=0.114, He=0.124). 한국산 송사리 11개 집단의 평균 유전적 변이 정도는 P=12.7%, Ho=0.029, He=0.042, 대륙송사리 5개 집단의 평균 유전적 변이정도는 P=26.3%, Ho=0.082, He=0.097로 각각 나타나 대륙송사리집단의 유전적 변이 정도가 송사리집단에 비해 약 2.5배 정도 높았고 일본산 송사리의 유전적 변이 정도는 P=15.6%, Ho=0.073, He=0.068로 나타났 다. 한국산 송사리와 일본산 송사리와의 유연관계는 S=0.761(D=0.243)로 나타나 유전적으로 뚜렷한 별개의 분류군으로 생각되며, 대륙송사리와 송사리간의 종간 유전적 근연치는 S=0.648(D=0.389)로 일반적인 척추동물의 종간 유전적 분화 수준을 나타냈다.