• 한국발생생물학회지:발생과생식
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• 제17권4호
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• pp.337-343
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• 2013

Post-thawed larval rearing in Pacific oyster Crassostrea gigas was performed to investigate the survival rate with time course in three kinds of larvae cryopreserved. The highest survival rate and larval activity index (LAI) of post-thawed larvae were obtained from the permeation in 0.2 M sucrose and 2.0 M ethylene glycol (EG) at $-1^{\circ}C/min$ in freezing speed showing the survival rates just after thawing of 63.8% in trochophore, 84.1% in D-shaped veliger and 56.3% in early umbo veliger. In post-thawed larval rearing with food supply, the larvae lasted their lives until 24 hours in trochophore, 75 hours in D-shaped veliger and 57 hours in early umbo veliger. The results suggested that each larval stage post-thawed revealed no more further development to subsequent respective stage.

• 한국수산과학회지
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• 제33권6호
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• pp.559-564
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• 2000

진주조개와 참굴의 성숙한 모패를 이용하여 인위적으로 산란유발한 다음 수온별로 난발생 실험을 하였다. 진주조개와 참굴의 난발생은 수온이 높을수록 발생단계별 소요 시간이 짧아지는 경향을 보였으며, 적정 발생수온은 각각 $20{\~}25^{\circ}C$와 $15{\~}25^{\circ}C$였으며, 진주조개에서 초기 D형 유생에 이른 시간은 $20^{\circ}C$와 $25^{\circ}C$에서 각각 41.7, 27.5시간, 참굴에서는 $15^{\circ}C,\;20^{\circ}C,\;25^{\circ}C$에서 각각 35.3, 26.3, 17.6시간이 소요되었다. 수온 ($WT: ^{\circ}C$)과 발생 단계별 소요 시간 (h: hour)의 관계식은 다음과 같다. 진주조개-8 세포기. $$1/h=0.0463WT-0.6945 (r^2=0.9702)$$ 상 실 기. $$1/h=0.0196WT-0.2184 (r^2=0.8118)$$ 담 륜 자: $$1/h=0.0076WT-0.0802 (r^2=0.8756)$$ D형 유생: $$1/h=0.0031WT-0.0380 (r^2=0.9075)$$ 참 굴-8 세포기. $$1/h=0.0210WT-0.1123 (r^2=0.9862)$$ 상 실 기.$$1/h=0.0143WT-0.1077 (r^2=0.9833)$$ 담 륜 자: $$1/h=0.0052WT-0.0218 (r^2=0.9857)$$ D형 유생: $$1/h=0.0029WT-0.0170 (r^2=0.9689)$$ 이들 관계식을 기초로 하여 진주조개와 참굴의 초기 발생에 있어서 난발생이 정지하는 생물학적 영도의 평균값을 구한 결과, 진주조개 $12.3^{\circ}C$, 참굴 $5.7^{\circ}C$로 산정되었다.

• Fisheries and Aquatic Sciences
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• 제8권1호
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• pp.27-33
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• 2005

This is a subsequent study to our previous finding that Pacific oysters, Crassostrea gigas, gained a so-called upper plateau concentration, around 30,000 ng/g dry weight digestive gland for benzo(a)pyrene, showed reproductive behavior but produced their ensuing reproductive outputs damaged. A serial dilution of sediment elutriates from Jinhae Bay, Korea, where pollution was progressive, were exposed to gametes of the Pacific oyster for 0, 5, 10, 20, 30, and 60 min to detail the pollutant effects on very young specimens. There was an apparent critical dilution over which adverse effects are evident. This was $10\%$ of the present sediment elutriate, corresponding to 0.3 ng/g on the basis of total polycyclic aromatic hydrocarbons (PAHs) for the oyster. Within the dilution the embryonic development was not influenced by the duration of exposure to its gamete stage. At higher dilutions over the critical dilution, occurrence of abnormality increased dependent on the pollutant dilution and the duration of exposure. Similar trends were also found in larval mortality. However, overall, the chemical toxicity was more significant to morphogenesis than to survival, suggesting a potential recruitment of the pollutants-induced abnormal larvae in the wild population to threaten the population integrity.

• 한국수산과학회지
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• 제47권6호
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• pp.853-859
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• 2014

The goal of this study was to evaluate the effects of cryoprotectants [dimethyl sulfoxide (DMSO), methanol, polyethylene glycol, and propylene glycol], cryoprotectant concentrations (10% and 20%), equilibration time (3, 10, and 30 min), cooling rate ($3^{\circ}$, $5^{\circ}$, $7^{\circ}$, and $10^{\circ}/min$), and straw size (0.25 and 0.5 mL) for sperm cryopreservation of tetraploid Pacific oysters. There was a significant difference among the four cryoprotectants, with 10% DMSO yielding the highest post-thaw survival and activity index of sperm. A significant relationship was observed between the cryoprotectant and its concentration. The sperm with equilibration times of 30 min yielded higher post-thaw survival and activity indices than those with 3 and 10 min equilibration times. The sperm cooled at a rate of $5^{\circ}/min$ yielded the highest post-thaw survival and activity index, and the results were significantly different from those observed for cooling at $7^{\circ}$ and $10^{\circ}/min$. Post-thaw survival and activity indices of sperm using a 0.25-mL straw were significantly higher than those using a 0.5-mL straw.

• 한국수산과학회지
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• 제48권6호
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• pp.876-882
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• 2015

The aim of this study was to investigate changes in the biochemical characteristics of the Pacific oyster Crassostrea gigas in response to boiling water bath ($85^{\circ}C$, $100^{\circ}C$) and autoclaving ($100^{\circ}C$) heat treatments for 5, 10, 15, and 20 min. The weight loss (7.6-9.5%) of oysters exposed to a $100^{\circ}C$ boiling water bath for 15 min was lower compared to those receiving no treatment. Oysters exposed to the $100^{\circ}C$ boiling water bath for 20 min lost 27.8% of their total weight. The $100^{\circ}C$ autoclaving treatment resulted in weight loss of 13.0-26.1%, with the highest weight loss occurring after 10 min of treatment (26.1%). Heat-treated oysters had significantly higher levels of crude lipid and crude protein relative to untreated oysters (P<0.05). In the heat-treated oysters, total amino acids (including proline and glutamic acid) were increased, but they were decreased by the 20-min $100^{\circ}C$ boiling water bath and autoclaving treatments. The fatty acid composition of oysters was not significantly affected by the water bath heat treatment, but oysters treated with $100^{\circ}C$ autoclaving for 20 min had decreased polyunsaturated fatty acids. Oysters exposed to the water bath heat treatment had significantly increased vitamin A content, but $100^{\circ}C$ autoclaving for 20 min was associated with reduced vitamin A content, as compared to all of the other heat treatments. Therefore, oysters were affected by heat treatment, undergoing metamorphosis and weight loss, but nutrient quality did not change significantly compared to controls, except with the 20-min $100^{\circ}C$ boiling water bath and autoclaving treatments.

• 한국발생생물학회지:발생과생식
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• 제27권3호
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• pp.101-115
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• 2023

Environmental factors impact oyster growth, condition, and gonadal development, which is linked to gamete characteristics observed through histology. The reproductive cycle of bivalves is related to energy storage and utilization. Therefore, in this study, the year-round growth change and gonadal development of oysters were observed using histological analysis, and the biochemical composition changes were confirmed. The oysters used in this study are being nurtured in Gadeok-do, and 40 oysters were randomly sampled monthly from March 2021 to February 2022. Result of histological analysis of gonads, oysters were showed early development from December to February, late development from March and April, mature and ripe from May to July, spawned from August to October, and spent from November to December. Condition index values of oysters decreased in summer and autumn and increased again when entered the spent after spawning. The protein content of oysters was high in May, the maturity period, and the lipid content decreased during the spawning period. In addition, EPA and DHA, the major fatty acids of oysters, were low during the spawning period and high during the maturation period. As a result, this study suggested a close relationship between changes in oyster growth, biochemical composition, and the reproductive cycle.

• 생명과학회지
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• 제27권4호
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• pp.398-407
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• 2017

BTG1 (B-cell translocation gene 1)은 APRO family (anti-proliferative protein family)에 속하며, 이들은 공통의 생물학적 기능은 세포증식을 억제하는 것으로 알려져 있다. 본 연구에서, 굴의 gill cDNA library를 random sequencing을 통한 EST 분석과정에서 BTG1 clone을 확보하였으며, 분자생물학적 특성을 조사하였다. 굴의 BTG1은 182 개의 아미노산으로 구성되며, zebrafish와 57%, human과 56%의 상동성을 나타냈으며, 사람이나 설치류와 달리 ORF (open reading frame) 내에 intron이 존재하지 않았다. Genomic DNA walking을 통해 굴의 BTG1의 predicted promoter를 확인하였으며, 분석결과 AP-1 element와 SRE (serum response element) 부위가 존재하였으며, 5'flanking region에 cAMP response element (CRE) 부위가 확인되었다. 굴의 BTG1의 조직별 유전자발현 수준을 확인하기 위해 real-time PCR을 수행하였으며, 6 개 조직 모두에서 BTG1의 유전자발현이 나타났으며, 그 중에서 heart와 mantle에서 높은 수준의 mRNA 발현을 확인할 수 있었다.

• 한국어병학회지
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• 제14권2호
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• pp.65-70
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• 2001

본 연구는 20일 동안 TBTO 노출에 의한 참굴의 생존율 및 hemolymph 내의 무기성분과 효소활성의 변동을 조사하였다. TBTO 노출에 의한 참굴의 생존율은 실험 20일 동안 $10{\mu}g$/L이하의 농도에서 90%이상을 나타냈다. 그러나 참굴의 생존율은 TBT농도가 증가함에 따라 감소하기 시작하여 실험 10일째 TBT농도 $80{\mu}g$/L이상, 실험 20일째는 $50{\mu}g$/L이상의 농도에서 유의한 감소가 관찰되었고, $100{\mu}g$/L에서는 실험 16일째 전 개체가 사망하였다. 참굴의 hemolymph의 calcium 농도는 10일째 대조구를 포함한 TBTO $5\sim10{\mu}g$/L 농도에서 유사한 값을 나타냈으나 $50{\mu}g$/L 이상의 TBTO 농도에서는 급격히 증가하여 대조구에 비해 유의한 증가가 관찰되었다. 또한 20일째 calcium 농도는 10일째 보다 전반적으로 증가하였으며, 대조구와 비교하여 $20{\mu}g$/L 이상의 농도에서 유의한 증가를 나타냈다. GPT활성은 실험 전 기간을 통해 모든 농도구에서 뚜렷한 변화를 보이지 않았다. 그러나 GOT는 실험 10일째 이상의 $20{\mu}g$/L이상의 농도에서 유의한 증가를 나타냈다.

• 한국패류학회지
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• 제28권3호
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• pp.215-223
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• 2012

한국 서해안 해역에서 2011년 9월부터 2012년 1월까지 수평망식으로 양성한 굴의 산란기 이후 생태 생리학적 변화를 조사하였다. 조사 지역은 충남 태안 연안의 의항, 신두리, 이원의 두 곳을 선정하여 생식소지수, 조직학적 분석, 생식소와 폐각근 내의 RNA/DNA의 양과 비, condition index (CI), 연체부지수 등을 분석하여 건강도를 판정하였다. 연구결과 의항에서 수평망식으로 양식한 굴은 다른 지역의 굴과 생리학적 차이를 보였다. 즉, 폐각근 내 RNA/DNA의 양 및 비가 조사기간 동안 지속적으로 감소하였고 가장 낮은 CI와 연체부지수를 보였다. 이원지역의 St. 1과 2에서 양식한 굴은 산란기 이후 빠른 회복력을 보여 RNN/DNA가 증가하였고, 연체부지수와 CI 또한 10월까지 급격히 증가한 이후 감소하는 것으로 나타났다. 신두리 지역의 굴은 연체부지수와 CI가 10월까지 급격하게 감소하였다. 그러나 이러한 건강도 판정요소와는 다르게 폐각근 내 RNA/DNA 비는 단백질의 증가 양상처럼 10월까지 지속적으로 증가하는 것으로 조사되었다. 특이한 점은 신두리와 이원의 St. 1에서는 12월까지도 부분방출기의 개체가 관찰이 되었다. 모든 결과를 종합하여 볼 때 본 연구에서 사용된 RNA/DNA 양과 비의 변화, 연체부지수, CI 등의 간단한 지표만으로도 양식 굴의 건강상태, 산란 후 회복과정에 관한 정보 취득이 가능하였다. 따라서 이와 같은 자료를 통하여 우량종패 생산을 위한 굴 어미관리가 가능하고, 또한 소비자들이 선호할 수 있는 양질의 굴 생산이 가능할 것으로 판단되므로 향후에도 다년간 연구조사가 필요할 것으로 생각된다.

• 한국패류학회지
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• 제26권4호
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• pp.317-326
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• 2010

The availability of fast and inexpensive sequencing technology has enabled researchers around the world to conduct many genome sequencing and expressed sequence tag (EST) projects of diverse organisms. In recent years, whole genome projects have been undertaken to sequence ten species from the phylum Mollusca. These include Aplysia californica, Lottia gigantea, Crassostrea virginica, Spisula solidissima, Mytilus californianus, Biomphalaria glabrata, Crepidula fornicata, Elysia chlorotica, Lottia scutum and Radix balthica. Additionally, complete mitochondrial genomes of 91 mollusks have been reported. In Korea, EST projects have been conducted in nine mollusk species that include Nesiohelix samarangae, Pisidium (Neopisidium) coreanum, Physa acuta, Incilaria fruhstorferi, Meretrix lusoria, Ruditapes philippinarum, Nordotis gigantea, Crassostrea gigas and Laternula elliptica. Finally, the mitochondrial genome projects from the Pacific Oyster (Crassostrea gigas) and the rock shell (Thais clavigera) have been conducted and reported. However, no systemic mollusk genome project has so far been conducted in Korea. In this report, the current status and research trends in mollusk genome study in Korea will be discussed.