• 한국양식학회지
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• 제12권3호
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• pp.185-191
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• 1999

A genetic analysis for survival in fry and juvenile stages of masu salmon was described. Data from two year-classes of masu salmon were analyzed to estimate the heritability for survival during the fresh water-rearing period. The overall survival for each year-class during 8 months of freshwater rearing were 17.8 and 11.6%, respectively. Whirling disease virus (WDV) was the main cause of death in all year-classes. Survival data obtained for offspring of 42 sires and 60 dams of masu salmon (two year classes of data) was analyzed. Average survival rates in the observation period ranged 2-87% for 1994; 0-98% for 1995, repectively. In both year-classes, heritabilities for survival derived from the sire components of variance were low(0.13-0.18), except one. Heritabilities derived from the dam components of variance ranged 0.14-0.61, including non-additive genetic and /or common enviromental effects. Correlations between survival in two long-term periods were all positive and medium to high in magnitude(0.345-0.918). Correlations between survival in non-succeeding periods were, in general, low and insignificant. Correlation between long-term survival and growth rate was found in masu salmon. The corresponding correlation in masu salmon was not significantly different from zero. Correlations between sire survival and body weight, length and condition factor of slaughter were not significant, but varied.

• 한국어병학회지
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• 제6권2호
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• pp.87-92
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• 1993

1. 1990년 2월 강원도 삼척군에 소재한 송어양식장에서 전염성 조혈기 괴사증 증상으로 산천어 자치어가 대량폐사하였다. 2. 폐사한 산천어 치어로부터 세포배양법에 의해 전염성 조혈기 괴사증 바이러스가 분리되었다. 3. 분리된 바이러스는 구조단백의 크기와 항원성에 있어 미국에서 분리된 RB-76 바이러스주(electro-pherotype 1)와 유사하였다.

• Fisheries and Aquatic Sciences
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• 제2권2호
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• pp.176-181
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• 1999

The variations of gene expression and pituitary contents of GTH subunits during the ovarian development of masu salmon, Oncorhynchus masou, were investigated. The pituitary GTHs contents was measured by radioimmunoassays (RIAs) using purified GTH subunits and their antibodies. Pituitary contents of GTH $I\beta$ gradually increased from April through August, and reached the maximum in October. On the other hand, pituitary contents of GTH $II\beta$ remained low until August, but they rapidly increased in October. Total RNAs were prepared from pooled pituitaries and the GTH subunits mRNA in pituitaries was quantified by Northern blot hybridization using masu salmon cDNA probes for each GTH subunit. GTH $I\beta$ mRNA level increased with the progression of ovarian maturity. However, GTH $II\beta$ mRNA was detected only at a more advanced stage, and were extremly high at ovulation. A high levels for GTH a mRNA was detected only at ovulation stage. The synchronous increase in pituitary contents and mRNA levels suggested that ovarian maturity in masu salmon was regulated by both GTH I and GTH II.

• 한국양식학회지
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• 제17권1호
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• pp.62-68
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• 2004

A cDNA encoding the masu salmon, Oncorhynchus masou, estrogen receptor $\alpha$ (msER$\alpha$) was cloned from the pituitary gland by polymerase chain reaction (PCR). This cDNA contains an open reading frame encoding 513 amino acid residues, and the calculated molecular weight of this protein is about 56,430 Dalton. The amino acid sequences of the DNA binding and ligand binding domains of msER$\alpha$ showed high homology to those of other fish species (84-100%). Reverse transcription PCR analysis showed that the mRNA level of msER$\alpha$ in the pituitary was slightly higher in estradiol-17$\beta$(E2) injected masu salmon than that of control fish. To test the biological activity of msER$\alpha$, the cDNA was ligated to a mammalian expression vector and transfected into a gonadotrope-derived cell line, L$\beta$T2, with a reporter plasmid including estrogen responsive element. Expression of the reporter protein, luciferase, was E2 and msER$\alpha$-dependent. The masu salmon ER$\alpha$ is structurally conserved among teleost species and functions as a transcriptional activator in the pituitary cells.

• 한국어류학회지
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• 제12권2호
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• pp.118-123
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• 2000

성어기 시마연어의 성장 관련 형질에 대한 유전율 및 표현형 상관과 유전 상관의 추정을 실시하였다. 유전 인자는 전장, 체중 그리고 두장에 관하여 시마연어의 19개월령 및 23개월령에서 추정을 실시하였다. 유전율은 1995년 19개월령에서는 각각의 성장 형질에서 0.22로 추정되었으며, 1996년 23개 월령에서는 0.19~0.36으로 추정되었다. 성장 형질들간의 표현형 상관 및 유전 상관은 각각 0.85~0.98, 0.67~1. 26으로 높게 나타났다. 시마연어의 성장을 향상시키기 위해서는 가족 선발 혹은 가족 선발내의 개체 선발을 가미한 조합 선발이 유효할 것으로 판단된다.

• 한국수산과학회지
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• 제34권4호
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• pp.419-421
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• 2001

Heritability estimations of masu salmon smelt at underyearing of age were described. Masu salmon was taken from aquaculture station of Mori in Japan. After fertilization, the offsprings in each family were reared in separate egg trays and fingerling tanks. The percentage of fish in each tank which smoltified at 11-month old was recorded, and environmental and genetic factors influencing the percentage smoltification were also studied. Percentage of smoltification was not significantly affected by the number of fish held in a tank, or fish density (correlation coefficient 0.10). However, there was a high correlation ($0.821\~0.565$) between smelt percentage and growth related traits of fish in a family. Heritability estimated from total data was $0.47\pm0.13$, when effects of tanks were ignored.

• 한국어병학회지
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• 제25권2호
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• pp.117-121
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• 2012

The pathogenicity of viral hemorrhagic septicemia virus (VHSV) from olive flounder Paralichthys olivaceus was investigated with masu salmon Oncorhynchus masou fry. The cumulative mortality of fish challenged with FYeosu05 isolate at $10^{6.5}$ $TCID_{50}$/fish was 60%. No mortality was observed in fish challenged with the isolates at $10^{5.5}$ $TCID_{50}$/fish and in mock-challenged fish. The affected fish showed darkening of the body, expanded abdomen, pale gills and enlarged spleen. VHSV from $10^{6.3}$ to $10^{7.8}$ $TCID_{50}$/g-tissue was re-isolated from the dead fish. These results suggest that the VHSV from olive flounder is pathogenic to masu salmon fry, although with low virulence.

• 한국양식학회지
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• 제13권1호
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• pp.13-19
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• 2000

A genetic analysis of reproductive characters of masu salmon at three year classes was described. the reproductive performance of masu salmon spawning at 2 years of age was analyzed using data number fertility hatchability and growth traits to the juvenile stage. The phenotypic correlations among the traits were also estimated. it was determined that egg volume was the principle deter-minant of egg number and that the relationship of number to size was negative. It is recommended that selection for egg size be included in all selection programs and egg number be ignored in any welection program designed to increase body size. Phenotypic correlations between body size of parents and egg traits as well as between body size of offspring and egg traits were not significantly positive or negative magnitude at three year classes.

• 한국수산과학회지
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• 제41권1호
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• pp.1-6
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• 2008

The changes in osmolality and the gene expression profiles of prolactin (PRL) and growth hormone (GH) with rapid changes in salinity were compared in the eel (Anguilla japonica), crucian carp (Carassius carassius), and masu salmon (Oncorhynchus masou). Fish stocked in freshwater (FW) were abruptly transferred to experimental tanks containing FW, 50% seawater (50% SW), or 100% SW (SW). Blood samples and pituitary glands were collected 2 and 24 hrs after the exposure. No mortality was observed in SW eel (n=6), whereas all of the crucian carp (n=6) and two masu salmon (n=6) exposed to SW died after land 24 hrs, respectively. The PRL mRNA levels of the eel and masu salmon decreased in 50% SW and SW compared to those of the fish kept in FW after 24 hrs, whereas the PRL levels of crucian carp were higher in 50% SW than in FW. Unlike the PRL mRNA levels, the GH mRNA levels of the eel did not differ significantly among three different salinities, while the GH mRNA levels of crucian carp and masu salmon increased significantly in 50% SW and SW after 24 hrs. The serum osmolalities increased marginally in the eel and masu salmon in 50% SW at 24 hrs (19% and 9%, respectively), whereas those of crucian carp increased abruptly in 50% SW (50% increase). These results suggest that the synthesis of PRL and GH is important in relation to the osmoregulatory system with environmental changes in salinity.

• 한국수산과학회지
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• 제31권2호
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• pp.278-287
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• 1998

담수산 어류에 관한 비교 생화학적 연구의 일환으로서, 우리나라 특산의 냉수성 담수 어류인 천연산 열목어와 천연산 및 양식산 산천어의 표피 carotenoids를 TLC, column chromatography 및 HPLC로 분리하고 $NaBH_4$에 의한 환원반응, $I_2$에 의한 이성화반응 및 uv-visible spect-rophotometer로 동정하여 비교, 검토한 결과는 다음과 같다. 열목어 표피의 총 carotenoids 함량은 천연산이 $3.72\;mg\%$으로서 연어과의 다른 어종에 비해 함량이 높았으며 carotenoids 조성은 zeaxanthin $36.9\%$, $\beta-carotene\;14.7\%$로서 주성분을 이루고, 그 외 triol $7.8\%$, isocryptoxan-thin $7.3\%$, 4-hydroxy echinenone $5.7\%$, lutein $4.7\%$, salmoxanthin $4.5\%$ 및 astaxathin $2.2\%$의 순으로 나타났으며, canthaxanthin, tunaxanthin A, tunaxanthin B, tunaxanthin C, $\beta-cryptoxanthin$ 및 $\alpha-cryptoxanthin$이 미량성분으로 함유되어있다. 산천어 표피의 총 carotenoids 함량은 천연산 $0.82\;mg\%$인데 비하여 양식산은 $0.66\;mg\%$ 로서 천연산이 양식산에 비해 함량이 높았다. carotenoid 조성은 천연산에서 zeaxanthin $20.7\%$, isocryptoxanthin $17.0\%\;\beta-carotene$이 $15.8\%$로서 주성분을 이루고, 그 외 $\beta-cryptoxanthin\;6.7\%$, triol $6.2\%$, 4-hydroxy echinenone $6.1\%$, salmoxanthin $6.1\%$, canthaxanthin $5.9\%$, Butein $5.8\%$, $\alpha-cryptoxanthin\;4.9\%$ 및 astaxanthin $1.0\%$의 순으로 함유하며, 양식 산에 는 isocryptoxanthin $19.7\%$, $\beta-carotene\;18.0\%$, Beaxanthin $10.3\%$이 주성분을 이루며, 그 외 $\beta-cryptoxanthin\;8.9\%$, $\alpha-cryptoxanthin\;8.5\%$, lutein $8.0\%$, canthaxanthin $7.6\%$, triol $5.1\%$ 및 astaxanthin $2.0\%$의 순으로 함유하였다. 한편 천연산 산천어에는 zeaxanthin, salmoxanrhin 및 4-hydroxy echinenone의 함량이 높은 반면 양식산 산천어에는 $\alpha$-cryptoxanthin의 함량이 높아 서로 다른 경향을 보여 상이하였다. 양식산 산천어에는 천연산 산천어와는 달리, 연어과 특유의 carotenoid인 4-hydroxy echinenone과 salmoxanthin이 검출되지 않았고 또한 천연산 및 양식산 산천어는 천연산 열목어와는 달리 tunaxanthin A, tunaxanthin B 및 tunaxanthin C가 존재하지 않았다.