Prolactin is an anterior pituitary hormone involved in various physiological phenomenon including reproduction. The prolactin receptor (PRLR) is detected in diverse tissues such as brain, ovary, placenta and uterus in several mammalian species. A total of 227 pigs [Korean native pigs (KNP) 27; Landrace pigs 29; Korean native pigs x Landrace F1 91; Nanchuckmacdon pigs 80] were used to investigate the allele frequency difference of the prolactin receptor (PRLR) gene among the four pig lines. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) with Alu I restriction enzyme was used to determine the genotypes of PRLR. Frequencies of PRLR alleles among the four different pig lines were not significantly different (Chi-square=3.94, DF=3, P=0.27). A total of 40 Nanchuckmacdon pigs were used to investigate the effect of the prolactin receptor (PRLR) gene on total number of piglets born (TNB), number of piglets of alive (NBA) using general linear model implemented in MINITAB software. For TNB, the AB genotype had higher genotypic value (10.61) than the values of AA (9.83) and BB (10.30). Likewise, the AB genotype had higher genotypic value (8.96) than the values of AA (8.18) and BB (8.90) for NBA. However, these associations of the PRLR gene with TNB and NBA were not statistically significant. In conclusion, it is necessary to increase the sample size for investigating the effect of the PRLR gene on TNB and NBA in pigs.

최근 국내 멧돼지 문제는 농작물 피해 및 도심 출몰로 인하여 사회적으로 심각한 상황에 직면해 있다. 본 연구는 경남 거창군의 멧돼지에 의한 농작물 피해사례를 바탕으로 피해에 영향을 끼치는 환경 요인들에 대하여 파악하고자 2012년 5월부터 10월까지 수행 되었다. 농작물 피해 분석 결과 주로 8월과 9월 사이 피해가 가장 많이 발생하였고, 벼의 빈도가 가장 높았으며 피해 강도는 고구마가 가장 높은 것으로 나타났다. 이는 멧돼지의 농작물 선호성과 특정시기에 대한 가용성과 관련이 있는 것으로 판단된다. 또한 농작물 피해에 경사, 지형기복, 산림과의 거리, 수계로부터의 거리, 도로로부터의 거리, 주거지로부터의 거리의 요인들이 영향을 미치는 것으로 나타났다. 피해 강도에 따른 환경요인의 차이는 나타지 않아 멧돼지는 한번 피해를 끼친 농경지를 지속적으로 방문하여 피해를 누적 시키는 것으로 파악된다. 따라서 멧돼지에 의한 농작물 피해를 저감시키기 위해서는 피해가 발생할 수 있는 곳에 멧돼지가 비선호하는 작물로 대체 재배하며 전기펜스 설치, 엽사와 포획틀을 이용한 멧돼지 개체수 조절이 필요할 것으로 판단된다.

An intensive analysis was conducted of the maternal lineages of the Jeju native pigs (JNPs). A total of 100 mtDNA sequences from Asian wild boars (AWB), European wild boars (EWB), Asian domestic pigs (ADP), European domestic pigs (EDP), and JNPs were used for the phylogeny and network analyses. Two distinct JNP groups were found JNPA and JNPE in the Asian and European cluster. The maternal lineage of JNPE was the closest to that of EWB and a clear haplogroup sharing an identical haplotype (hap16) among 15 individuals of JNPE and 2 individuals of EWB was identified. However, except for hap18, no EDP shared any identical haplotypes with JNPE, suggesting that no obvious maternal contribution of EDP has occurred in JNPE in recent years. The possible existence of an additional and unknown path of maternal lineage from EDP into JNPE could therefore be postulated, in addition to those from AWB and ADP into the JNPA groups. Thus, JNPE appeared to have a pure maternal lineage that had no recent contact with EDP, and both the JNPA groups and JNPE are pure Jeju native pigs.

Alterations affecting the status of robustness and health can bring about physiological changes including hematological parameters in pigs. To identify quantitative trait loci (QTL) associated with 8 hematological phenotypes (one leukocyte trait, six erythrocyte traits, and one platelet trait), we performed a genome-wide association study using the Porcine SNP 60K BeadChip in an intercross population between Landrace and Korean native pigs. A total of 36,740 SNPs from 816 F2 offspring were analysed for each blood related traits after filtering by quality control. Data were analysed genome-wide rapid association using the mixed model and regression (GRAMMAR) approach. A total of 257 significant SNPs (P<1.36x10-6) on SSC3, 6, 8, 13, and 17 were detected for blood related traits in this study. Interestingly, the genomic region between 17.9 and 130 Mb on SSC8 was found to be significantly associated with RBC, MCV, and MCH. Our results include 5 significant SNPs within five candidate genes (KIT, IL15, TXK, ARAP2, and ERG) for hematopoiesis. Further validation of these identified SNPs could give valuable information for understanding the variation of hematological traits in swine.

Previously, we reported a quantitative trait locus (QTL) that affect total teat number (TTN) on pig chromosome 7 (SSC7) in a large F2 intercross population between Landrace and Korean native pigs. The aim of this study was to refine the QTL associated with TTN and to identify positional candidate gene(s) within the refined genomic region. TTN was recorded in 1,105 F2 progeny. All experimental animals were genotyped using 998 informative single nucleotide polymorphism (SNP) markers located on SSC7. A haplotype-based linkage and association analysis using the PHASEBOOK programme was applied to perform high-resolution QTL analysis. Additionally, linear mixed-effect models were used to assess the effect of a positional candidate gene on TTN and other economically important traits [i.e., thoracic vertebrae number (THO), carcass body length (CBL) and weight (CW), back fat thickness (BFT) and intramuscular fat content (IMF) in loin muscles]. Joint linkage and association analysis refined the critical region to a 1.07 Mb region that included a novel positional candidate gene, BRMS1L, that encodes the breast cancer metastasis-suppressor 1-like protein, which could possibly be implicated in normal mammary gland development. Significant association of an SNP marker (g.-1087 G>A) in the 5’-flanking region of BRMS1L with TTN (P=1.10x10-8), THO (P=5.80x10-4), and CBL (P=0.038) was observed. Based on these data, we propose BRMS1L as a positional candidate gene for TTN in pigs. After validation of the association in other independent populations and further functional studies, these results could be useful in optimizing breeding programmes that improve TTN and other economically important traits in swine

In the swine industry, growth related traits are important economic traits directly linked to profitability. Representative growth traits include daily gain, back fat thickness, and carcass weight. This study was conducted to search for positional candidate genes associated with the carcass weight through a genome-wide association study(GWAS) using suggestive levels of statistical thresholds in pigs. As a result of the genome-wide analysis of the associations with carcass weight, the single nucleotide polymorphism(SNP) markers with suggestive significance were identified in 1 SNP marker on chromosome 2(ALGA0015365) and 1 SNP marker on chromosome 4(ALGA0023678). We could select positional 2 candidate genes, located close to the SNP markers with suggestive significance levels. The SNP markers in adjacent to the 2 genes(LOC100519538, LOC100737583) may provide basic data regarding the marker-assisted selection for the carcass weight trait in pigs.

The aim of this study was to identify quantitative trait loci (QTLs) influencing teat number traits in an F2 intercross between Landrace and Korean native pigs (KNP). Three teat number traits (left, right, and total) were measured in 1105 F2 progeny. All experimental animals were genotyped with 173 informative microsatellite markers located throughout the pig genome. We detect that seven chromosomes harbored QTLs for teat number traits: genome regions on SSC1, 3, 7, 8, 10, 11, and 13. Six of fourteen identified QTL reached genome-wide significance. In SSC7, we identified a major QTL affecting total teat number that accounted for 5.6% of the phenotypic variance, which was the highest test statistic (F-ratio = 61.1 under the additive model, nominal P = 1.3×10-14) observed in this study. In this region, QTL for left and right teat number were also detected with genome-wide significance. With exception of the QTL in SSC10, the allele from KNP in all 6 identified QTLs was associated with decreased phenotypic values. In conclusion, our study identified both previously reported and novel QTL affecting teat number traits. These results can play an important role in determining the genetic structure underlying the variation of teat number in pigs.

Using a partial D-loop sequence of mtDNA, a comprehensive molecular evolutionary analysis was performed of the maternal lineages of the Jeju native pigs(JNPs) that presented in Jeju Island. A total of 100 DNA sequences from Asian domestic pigs(ADP), European domestic pigs(EDP), Asian wild boars(AWB), European wild boars(EWB), and JNPs were used for the molecular evolutionary analyses including phylogeny and network analyses. The most fitted model for the phylogenetic analysis was determined using hierarchical likelihood-ratio tests conducted by MrModeltest implemented in the PAUP package. A consensus tree was established from 5,000,000 iterations using the MR BAYS program. Three recognizable JNP groups–one(JNPE) in the European cluster and two(JNPA1 and JNPA2) in the Asian cluster–were detected in the estimated phylogenetic tree and network. The maternal lineage of JNPE was the most adjacent to that of EWB and a clear haplogroup sharing an identical haplotype(hap16) among 15 individuals of JNPE and 2 individuals of EWB was detected.

Growth traits, such as body weight, directly influence productivity and economic efficiency in the swine industry. In this study, we estimate heritability for body weight traits usinginformation from pedigree and genome-wide single nucleotide polymorphism (SNP) chip data. Four body weight phenotypes were measured in 1,105 F2 progeny from an intercross between Landrace and Jeju native black pigs. All experimental animals were subjected to genotypic analysis using PorcineSNP60K BeadChip platform, and 39,992 autosomal SNP markers filtered by quality control criteria were used to construct genomic relationship matrix for heritability estimation. Restricted maximum likelihood estimates of heritability were obtained using both genomic- and pedigree- relationship matrix in a linear mixed model. The heritability estimates using SNP information were smaller (0.36-0.55) than those which were estimated using pedigree information (0.62-0.97). To investigate effect of common environment, such as maternal effect, on heritability estimation, we included maternal effect as an additional random effect term in the linear mixed model analysis. We detected substantial proportions of phenotypic variance components were explained by maternal effect. And the heritability estimates using both pedigree and SNP information were decreased. Therefore, heritability estimates must be interpreted cautiously when there are obvious common environmental variance components.

This study tested the association between genotypes of the single nucleotide polymorphism (SNP) marker, rs81437607 and capric acid (FA_C10_0) compositions in longissimus dorsi muscle in pigs. Eighteen fatty acid (FA) compositions were measured in a total of 974 F2 animals among 1,106 F2 progeny produced between Landrace and Jeju Black Pig (JBP). Among FA compositions tested, we identified a cluster of highly significant SNPs for capric acid compositions on 58 Mb position of Sus scrofa chromosome 12 (SSC12) using genome-wide association study (GWAS) with F2 genotypes from SNP panel analysis. GWAS results showed that the rs81437607 was the highest trait-related SNP marker with capric acid levels. Three genotypes (C/C, C/T and T/T) of rs81437607 marker were found in F2 population by further pyrosequencing. Association analysis results showed the significant differences between rs81437607 genotypes and capric acid compositions (P<0.05). The F2 pigs harboring rs81437607 C/C (0.119±0.002%) and C/T (0.116±0.002%) genotypes showed additively higher levels of capric acid content than those of T/T homozygotes (0.109±0.002%) (P=1.30×10-12). These results suggested that the genetic variations of rs81437607 may be helpful to find causative variants and assist as molecular genetic markers for improving the capric acid contents in longissimus dorsi muscle in pigs.

Amphiregulin (AREG), a glycoprotein that is a member of the epidermal growth factor (EGF) family, is expressed by the porcine conceptus and endometrium. AREG genotypes were determined based on an SNP in the intron 3 of the gene. Contradictory effects of AREG genotypes on reproductive traits in different pig breeds were reported previously. G allele had undesirable effect on reproductive trait in Meishan breed, while it had favorable effects in Polish Landrace and Large White. We determined AREG genotypes of 179 pigs including the Duroc, Landrace, Yorkshire, Korean native pig (KNP), and Meishan breeds. Two new SNPs were identified near the previously reported SNP in the intron 3 of AREG. Frequencies of AREG alleles among the Duroc, Landrace, Yorkshire, and KNP sows were significantly different (p<0.001), indicating association between AREG genotypes and pig breeds. The first parity litter size was significantly affected by the breeds (p=0.014), but not by AREG genotypes (p=0.148). However, there were breed and AREG genotype associated trends in the first parity litter size. The first parity litter size appeared to be higher in Duroc and KNP sows with G allele, while it appeared to be lower in Landrace sows with G allele. Significant variability of AREG alleles among pig breeds, for the first time in Duroc and KNP sows, was identified. AREG genotypes may influence reproductive traits differentially for each breed and thus, AREG genotypes may need to be considered when sows are bred to increase litter size.

혈청 내 존재하는 효소 중 Glutamic pyruvic transaminase(GPT)는 근육이나 간세포의 손상에 대한 임상 화학적 지표로 사용 된다. 본 연구는 Landrace와 한국재래돼지의 F2 교잡 축군(N=1,105)에 대해 Porcine SNP 60K beadchip을 사용하여 유전자형 분석을 실시하고, GPT 형질과의 관련성을 검증하기 위해 Genome-Wide Association Study(GWAS)를 수행하였다. F2 교잡축군의 가계구조를 보정한 GWAS를 수행하기 위하여 혼합모형과 회귀분석을 조합한 GRAMMAR방법을 관련성 분석에 사용 하였다. 유의성 있는 SNP 표지들은 Sus scrofa chromosome(SSC) 6, 7, 그리고 13에서 동정되었다. 이들유의성 있는 SNP marker들에 가장 근접한 염색체상 위치의 유전자를 그 유전자의 기능을 고려하여 SSC7에서 2개의 위치후보유전자(BCL11B, AHNAK2)를 선정하였다. Pyrosequencing법을 통하여 이 들유전자 내에 존재하는 4개 SNP 표지들의 유전자형을 분석하여 GPT 형질간의 관련성 분석에 이용하였다. 관련성 분석결과, BCL11B g.267 T>C에서 nominal P=7.23×10-8 과 AHNAK2 g.1439 C>T에서 nominal P=5.64×10-6, g.1736 C>A에서 nominal P=3.51×10-6의 결과를 얻었다. 이 들 중 가장 유의한 결과를 얻은 BCL11B 유전자의 g.267 T>C SNP 표지는 추가 연구를 통하여 혈청 GPT 변이에 영향을 미치는 위치상 후보 유전자 표지로 사용 되어 질 수 있을 것이라 사료되어진다.

본 연구는 멸종위기종인 한국산 산양(n=3)의 생태 및 행동학적 특징을 밝히기 위하여 2010년 5월부터 2011년 9월까지 설악산국립공원에서 이루어졌다. 구조된 산양은 GPS Collar 발신기를 부착하여 구조된 원서식지에 재 방사 하였으며, 연구기간 동안 수집된 4,752개의 위치 좌표를 이용하여 연간 행동권, 계절별 행동권, 월별 이용 고도를 분석하였다. 연구결과, 설악산 산양의 연간 행동권은 MCP 95% 0.88㎢, MCP 50% 0.27㎢, FK 95% 0.43㎢, FK 50% 0.09㎢로 계절별 행동권은 MCP 95%에서 봄 0.47㎢, 여름 0.45㎢, 가을 0.63㎢, 겨울 0.50㎢로, 가을 행동권이 넓은 것으로 나타났다. 또한 FK 95% 분석을 통해서도 봄 0.23㎢, 여름 0.19㎢, 가을 0.33㎢, 겨울 0.22㎢로 가을철 행동권이 가장 큰 것으로 나타났다. 암·수 연간행동권은 MCP 95% 수준에서 암컷 1.03㎢, 수컷은 0.58㎢로 분석되었다. 월별 이용 고도는 6, 7, 8월이 가장 높았으며 12, 1, 2월에 가장 낮은 고도를 이용했다. 본 연구는 산양의 서식지 관리 정책 및 복원과 보전을 위한 객관적 자료 확보 및 국내에서 수행 중이거나 계획 단계에 있는 야생동물의 성공적인 복원에 기여하고자 수행되었다.

돼지의 체장, 체폭, 체중 등의 연속적인 변이를 가지는 양적형질에 속하는 형질인 성장형질은 양돈업에 있어서 생산성과 수익성에 직결된 중요한 경제 형질이다. 성장형질로는 일당증체량, 등지방두께, 등심단면적 및 도체품질 등이 있으며, 그중에서 등심단면적과 관련이 있는 후보 유전자를 Genome-wide 수준에서 선발하기 위하여 Illumina 사의 Porcine SNP 60K chip을 이용하여 순종 Landrace 집단(수컷 : 50두, 암컷 : 440두)을 분석하였다. Plink program을 이용하여 filtering 과정을 거쳐 최종적으로 31,960개의 SNP marker를 선별하였으며, Genome-wide 임계수준을 bonferroni correction (i.e.1/31957=3.12×10-5)을 이용해서 결정했을 때, SSC16에서 유의성 있는 4개의 SNP marker들을 발견하였다. 이 중 가장 유의성 있는 SNP marker인 DRGA0016148(P=1.38×10-5)와 근접한 후보유전자로 PDE4D를 선정하였고, PDE4D에서 2개(g.9870 T>C, g3976 C>T)의 SNP를 탐색하였다. 본 연구에서는 Genome-wide association study (GWAS)를 이용하여 등심단면적과 관련성이 있는 SNP를 선발하여, 등심단면적과 후보유전자 PDE4D와의 관련성을 규명하고자 연구를 실시하였으나, PDE4D g.9870 T>C 에서는 Hardy-weinberg equilibrium P-value 0.7581로 음의 상관관계를 나타내었으며, PDE4D g.3976 C>T에서는 모두 호모타입이 확인되었다.

일반적으로 돼지는 어떤 종류의 모색을 가지든 피부는 연분홍색을 띄는 것으로 알려져 있으나, 경 남 김해 H 육가공회사로 출하된 개체 중 흑모색에 검은색 피부를 가진 돼지가 발견되었다. 그 원인 을 규명하고자, 모색과 연관되어 있다고 알려진 MC1R, KIT 유전자와 피부색과 연관되어 있다고 알 려진 ASIP 유전자의 특징을 살펴보았다. MC1R의 sequencing 분석 결과, 아미노산 67, 68번째 자 리의 6개 염기 C(CCC CCC)는 Hampshire와 동일한 ED2/ED2 유전자형인 것으로 밝혀졌고, KIT의 경우 qOLA_CNV, Pyro_Splice 및 sequencing 분석한 결과, Duroc의 i/i 유전자형과 같은 유전자형 으로 밝혀졌다. ASIP의 경우 염기서열을 분석한 결과, 모든 종에서 차이가 없는 것으로 확인되었다. 유연관계 분석을 위해 Phase software와 network 분석을 실시한 결과, MC1R은 Hap22와 Hap23 이, KIT는 Hap22, Hap43과 유색종과 유연관계를 형성하는 것으로 확인되었다. 반면에 ASIP는 Hap04, Hap09이 야생멧돼지와 중국재래돼지를 제외한 품종들과의 유연관계를 확인할 수 있었다. 더 나아가 각 품종 간 유사성 분석을 위해 PCA를 실시한 결과, MC1R은 Berkshire, KIT는 Berkshire와 Hampshire가 유사성을 가지는 것으로 밝혀졌고, ASIP는 Berkshire 와 Duroc의 유사 성을 관찰할 수 있었다.