• 한국어류학회지
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• 제33권2호
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• pp.107-116
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• 2021

우리나라에는 잉어목 Cypriniformes 종개과 Nemacheilidae에 속하는 종개속(genus Barbatula) 어류로 종개 B. toni와 대륙종개 B. nuda의 2종이 서식하는 것으로 알려져 있다. 이들은 최근 서식환경의 변화와 자연재해에 의한 인위적 도입 등으로 고유 분포역이 훼손되면서 종의 계통지리학적 경계의 붕괴가 우려되고 있다. 본 연구에서는 미토콘드리아 DNA 유전자의 Cytochrome b 염기서열에 근거한 유전자형 네트워크를 통해 유전적 다양성과, 한반도 주변의 종개속 어류를 포함한 계통 유연 관계 분석을 통해 우리나라 종개속 어류의 분자계통학적 위치를 검토하였다. 그 결과 우리나라 종개와 대륙종개에서 각각 3개와 29개의 유전자형을 획득하였으며, 종개 그룹, 한강 대륙종개 그룹, 동해 대륙종개 그룹의 3개 단계통을 확인하였다. 각 그룹 간 변이사이트는 10~24%로 높은 유전자 변이율을 보였으며, 특히 동해 대륙종개 그룹은 한강 대륙종개 그룹이나 종개 그룹뿐만 아니라 중국, 일본, 러시아, 유럽의 종들과 독립적인 클러스터를 형성하고 있어 종 수준으로 분화했을 가능성을 시사하고 있다.

• 한국어류학회지
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• 제33권3호
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• pp.167-176
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• 2021

본 연구는 왜매치의 초기생활사를 밝히기 위해 충청남도 당진시 서원천에서 성어를 채집하여 인공수정을 통해 수행하였다. 왜매치 암컷의 산란량은 1,225~2,100개(1,662±437개, n=10) 정도였다. 난의 형태는 원형으로 크기는 1.05~1.13(1.08±0.02, n=30) mm였다. 수정란은 수온 22℃에서 부화까지 72~80시간이 소요되었다. 부화 직후의 난황자어는 전장 2.10~2.23 (2.16±0.04, n =10) mm로 입과 항문은 열려 있지 않았고 난황을 가지고 있었다. 부화 후 5일째는 전장 3.29~3.45 (3.36±0.04, n=10) mm로 난황을 모두 흡수하였고 먹이를 섭취하면서 전기자어로 이행하였다. 부화 후 15일째는 전장 4.97~5.30 (5.13±0.12, n=10) mm로 척추 끝부분이 상단으로 휘어지기 시작하면서 중기자어로 이행하였다. 부화 후 25일째는 전장 8.97~9.60 (9.44±0.16, n=10) mm로 꼬리지느러미 말단 끝부분이 45°로 완전히 휘어지면서 후기자어로 이행하였다. 부화 후 35일째는 전장 12.0~13.5 (12.7±0.53, n=10) mm로 각 부위별 지느러미 기조 수(등지느러미 iii 7개, 뒷지느러미 iii 6개, 배지느러미 i 7개)가 정수로 도달하면서 치어기로 이행하였다.

• 한국어류학회지
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• 제33권2호
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• pp.57-63
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• 2021

본 연구는 경북 낙동강에 서식하는 떡붕어의 초기생활사를 관찰하여 근연종과 차이점을 확인하기 위해 분류학적 기초자료를 확보하고자 하였다. 떡붕어 암컷의 산란량은 30,400~44,900개(37,650±7,250개) 정도였다. 난의 형태는 원형으로 크기는 1.24~1.37 mm (1.31±0.04 mm, n=30)였다. 수정란은 수온 21℃에서 부화까지 110시간이 소요되었다. 부화 직후의 난황자어는 전장 4.69~5.65 mm (5.15±0.31 mm, n=10)로 입과 항문은 열려있지 않았고 난황을 가지고 있었다. 부화 후 3일째 전기자어는 전장 6.27~6.70 mm (6.59±0.08 mm, n=10)로 난황 흡수가 완료되면서 먹이를 섭취하였다. 부화 후 10일째 후기자어는 전장 8.71~8.92 mm (8.81±0.07 mm, n=10)로 꼬리지느러미 말단 끝부분이 45°로 휘어졌다. 부화 후 42일째는 전장 15.1~16.8 mm (15.8±0.57 mm, n=10) 각 부위별 지느러미 기조 수(등지느러미 iii17개, 뒷지느러미 iii4개)가 정수로 도달하면서 치어기로 이행하였다.

• 한국어병학회지
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• 제24권3호
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• pp.279-287
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• 2011

Transcriptional response patterns of mud loach (Misgurnus mizolepis; Cypriniformes) hepcidin, a potential ortholog to human hamp1, in response to experimental challenges with non-pathogenic and pathogenic bacterial species were analyzed based on the semi-quantitative reverse transcription-PCR assay. Mud loach hepcidin transcripts were much more preferentially induced by pathogenic bacterial species (Edwardsiella tarda and Vibrio anguillarum) causing apparent pathological symptoms than by non-pathogenic species (Escherichia coli and Bacillus thuringiensis) displaying neither clinical signs nor mortality. However in overall, the induced amounts of hepcidin transcripts were positively related with the number of bacterial cells delivered in both pathogenic and non-pathogenic bacterial species. Inducibility of hepcidin transcripts were variable among three tissues examined (liver, kidney and spleen) in which kidney and spleen were more responsive to the bacterial challenge than liver. Time course expression patterns of hepcidin mRNAs after challenge were different between groups challenged with pathogenic and non-pathogenic species, although the overall pattern of hepcidin expression was in accordance with that generally observed in battery genes appeared during early phase of inflammation. Fish challenged with E. coli (non-pathogenic) showed the significant induction of hepcidin transcripts within 24 hr post injection (hpi) but the level was rapidly declined to the basal level either at 48 or 96 hpi. On the other hand, hepcidin transcript levels in E. tarda (pathogenic)-challenged fish were continuously elevated until 48 hpi, then downregulated at 96 hpi, although the level at 96 hpi was still significantly higher than control level observed in non-challenged fish. This expression pattern was consistent in all the three tissues examined. Taken together, our data indicate that hepcidin is tightly in relation with pathological and/or inflammation status during bacterial challenge, consequently providing useful basis to extend knowledge on the host defensive roles of hepcidin under infectious conditions in bony fish.

• Fisheries and Aquatic Sciences
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• 제14권1호
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• pp.43-54
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• 2011

Gene structure of copper/zinc-superoxide dismutase (Cu/Zn-SOD; sod1) was characterized in Hemibarbus mylodon (Teleostei; Cypriniformes), an endangered freshwater fish species in Korean peninsula. Full-length cDNA of H. mylodon SOD1 consisted of a 796-bp open reading frame sequence encoding 154 amino acids, and the deduced polypeptide sequence shared high sequence homology with other orthologs, particularly with regard to metal-coordinating ligands. Genomic structure of the H. mylodon sod1 gene (hmsod1; 1,911 bp from the ATG start codon to the stop codon) was typical quinquepartite (i.e., five exons interrupted by four introns); the lengths of the exons were similar among species belonging to various taxonomic positions. The molecular phylogeny inferred from sod1 genes in the teleost lineage was in accordance with the conventional taxonomic assumptions. 5'-flanking upstream region of hmsod1, obtained using the genome walking method, contained typical TATA and CAAT boxes. It also showed various transcription factor binding motifs that may be potentially involved in stress/immune response (e.g., sites for activating proteins or nuclear factor kappa B) or metabolism of xenobiotic compounds (e.g., xenobiotic response element; XRE). The hmsod1 transcripts were ubiquitously detected among tissues, with the liver and spleen showing the highest and lowest expression, respectively. An experimental challenge with Edwardsiella tarda revealed significant upregulation of the hmsod1 in kidney (4.3-fold) and spleen (3.1-fold), based on a real-time RT-PCR assay. Information on the molecular characteristics of this key antioxidant enzyme gene could be a useful basis for a biomarker-based assay to understand cellular stresses in this endangered fish species.

• Fisheries and Aquatic Sciences
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• 제12권3호
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• pp.179-184
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• 2009

Hemibarbus mylodon (Cypriniformes) is an endemic freshwater fish species in the Korean peninsula, for which urgent conservation efforts are needed. To understand their stress responses in relation to metal toxicity and thermal elevation, we performed a real-time RT-PCR-based expression assay of hepatic copper/zinc-superoxide dismutase (Cu/Zn-SOD), a key antioxidant enzyme, in response to experimental heavy metal exposure or heat treatment. The transcription of hepatic Cu/Zn-SOD was differentially modulated by acute exposure to Cu, cadmium (Cd), or Zn. Exposure to each metal at $5{\mu}M$ for 24 h revealed that Cu stimulated the mRNA expression of Cu/Zn-SOD to a greater extent than the other two heavy metals. The elevation in Cu/Zn-SOD transcripts in response to Cu exposure was dose-dependent (0.5 to $5{\mu}M$). Time course analysis of Cu/Zn-SOD expression in response to Cd exposure ($5{\mu}M$) revealed a transient pattern up to day 7. Exposure to thermal stress (an increase from 22 to $30^{\circ}C$ at a rate of $1^{\circ}C/h$ followed by $30^{\circ}C$ for 18 h) did not significantly alter SOD transcription, although heat shock protein 90 kDa (HSP90) transcription was positively correlated with an increase in temperature.

• 한국어류학회지
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• 제30권3호
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• pp.161-166
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• 2018

한국 고유종 돌마자 Microphysogobio yaluensis의 후각기관과 서식처 및 생태와의 연관성을 알아보기 위해 실체 현미경과 광학현미경을 이용하여 구조 및 조직학적 특징을 조사하였다. 후각기관은 외부적으로 전비공, 후비공 그리고 비경계판으로 구성되어 있으며, 내부는 22~24개의 후판들과 비선으로 구성되었다. 후판은 감각상피와 비감각상피로 이루어져 있는데, 감각상피는 후감각신경, 지지세포, 기저세포들로 구성되었으며, 비감각상피는 층상상피세포, 비감각섬모세포, 산성과 중성을 갖는 황점액소의 점액세포들로 구성되어 있다. 이러한 후각기관들의 특징들은 돌마자의 높은 후각능력과 의존성 그리고 서식처 환경에 밀접한 관계가 있을 것으로 생각되며 분류학적 연구에도 활용될 수 있을 것으로 생각된다.

• Fisheries and Aquatic Sciences
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• 제18권1호
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• pp.99-107
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• 2015

A natural hybrid of a probable intergeneric mating between the striped shiner Pungtungia herzi and the stone morocco Pseudorasbora parva (Cypriniformes: Cyprinidae) was captured in the Geumho River, a tributary of the Nakdong River basin in Korea. Morphological characters and DNA sequences were analyzed to verify its hybrid state and identify the parentage of its parent species. The hybrid exhibited a phenotypic intermediacy between the two parent species in the number of vertebrae and the mouth shape. Out of 1,488 base pair (bp) positions of the nuclear recombination activating gene 1 gene (rag1), which has a biparental mode of inheritance, 41-bp substitutions were detected between the two parent species, whereas an electropherogram of the hybrid displayed polymorphic double peaks at all of the base positions, along with one additional one, strongly indicating its hybrid state. Meanwhile, sequence comparison of the mitochondrial cytochrome b gene (mt-cyb) (1,140 bp), which has a maternal mode of inheritance, showed only 5-22-bp differences (97.6-99.5% identities) between the hybrid and Pu. herzi, but as many as 158-168-bp differences (85.2-86.1% identities) between the hybrid and Ps. parva, clearly indicating Pu. herzi as the maternal species. Thus, combined analyses of independent data sets (i.e., morphology and nuclear and mitochondrial DNA sequences) offered convincing evidence for the hybrid state of a naturally occurring hybrid resulting from intergeneric mating between a female Pu. herzi and a male Ps. parva.

• Animal Systematics, Evolution and Diversity
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• 제29권1호
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• pp.18-22
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• 2013

A recent study on the mitochondrial genetic variation of the Carassius auratus population in South Korea suggested that there are 3 distinct mitochondrial lineages in the country, and that they are geographically separated between westward rivers and southward rivers, respectively. In this study, the population genetic structure of amplified fragment length polymorphism (AFLP) of Carassius auratus was investigated. The results of analysis of molecular variance (AMOVA) supported the geographic distinction between westward and southward river populations, but only 3.66% of total genetic variance lies among these populations. The panmicticity of the AFLP genetic variation is backed up by the results of the neighbor-joining dendrogram drawn from a linearized pairwise $F_{ST}$ matrix and Bayesian clustering analysis. The discordance of genetic structure between mitochondrial and AFLP genetic variation may come from difference in effective population size between these markers and/or gene flow between westward and southward river populations through river capture events.

• Animal Systematics, Evolution and Diversity
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• 제13권1호
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• pp.21-27
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• 1997

한국 고유종인 새코미꾸리(Cobitis rotundicaudata)의 집단간 유전적 차이에 따른 종 분화 여부를 밝히고자 4개집단을 대상으로mitochondrial DNA(mtDNA)의 RFLP분석을 실시 하였다. C. rotundicaudata mtDNA를 10개의 6-base cutting 제한요소로 처리한 다음 그 절 편 양상을 비교, 분석한 결과 4개 집단 공히 mtDNA의 전체 genome 크기는 약 16.5$\pm$ 0.5Kbp였으며 공통절편수(F)에서 한강 2개 집단(가평, 진부)과 동해안 마읍천 짐단간의 F값 은 0.911로 매우 가까웠으나 낙동강의 산청집단은 타 3개 집단과 F=0.375로 차이가 있었다. 또한 염기치환율(p)에 있어서도 한강 2개 집단 및 마읍천 집단간은 평균 p=0.005로 매우 유 사하였으나, 산청 집단은 타 집단들과 염기치환율에 있어 p=0.059로 종수준의 뚜렷한 차이 를 나타내어서 이들은 각각 별종으로 사료된다.