• 한국발생생물학회지:발생과생식
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• 제8권1호
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• pp.43-47
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• 2004

낙동강 하구역에서 1년 동안 채집한 붉은줄참새우, Palaemon macrodatylus를 대상으로 안병에 분포하는 신경성 분비세포의 형태적 특징 및 계절별 분비 활성 변화를 살펴보았다. 안병의 신경계는 신경세포층(lamina ganglionaris), 외수(medulla externs), 내수(medulla interns) 및 종수(medulla terminalis)로 구성되어 있다. 그리고 안병에서 관찰되는 신경성 분비세포는 A, B, C, D세포 등으로 구분되었고 이들의 형태학적 특징은 다음과 같다. A세포의 직경은 약 10 $mu extrm{m}$전후로 주로 외수에 세포군을 이루어 분포하고 있으며, B세포의 직경은 6 $\mu\textrm{m}$전후로 가장 작은 세포이고 핵질이 세포질에 비해 크다. 그리고 C세포의 직경은 15∼20 $\mu\textrm{m}$로 둥근핵을 가지며 내수와 종수에서 B세포와 세포군을 이루어 분포하고 있으며, D세포의 직경은 약20∼30 $\mu\textrm{m}$로서 관찰되는 세포중 가장 크며 타원형의 형태를 보이고 있다. 이들 신경성 분비세포의 계절별 분비 활성 변화를 살펴본 결과,3-4월의 개체에서 A, B및 C세포는 활성화되기 시작하여 6∼7월에는 대부분의 개체에서 활성적인 신경성 분비세포를 가진 것으로 나타났다 그러나 8월 이후 대부분의 개체에서 비활성적인 신경성 분비세포를 가지는 것으로 관찰되었다.

• Fisheries and Aquatic Sciences
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• 제1권2호
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• pp.269-275
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• 1998

Spider crabs, Libinia emarginata, were eyestalk-ablated unilaterally and bilaterally to manipulate endogenous methyl farnesoate (MF) to increase during the embryogenesis. Endogenous MF were measured weekly over the embryogenesis of the crab, using HPLC with the aids of GC/MS and MS database (CAS 010485-70-8) for the identification of the hormone. Initial MF titers both in the hemolymph and embryos of intact control were at bottom levels and the hormone concentrations kept unchanged (p<0.05), reflecting physiological unnecessaries of the hormone in the embryogenesis. Eyestalk ablation significantly stimulated the crabs to increase endogenous MF in both tissues (p<0.0l). In the response of the embryos to the increased MF, no growth stimulations were observed, at least, in the first part of embryogenesis. The increased mortalities and immature sheddings of embryos resulted from the crabs under the influence of elevated MF in both tissues, instead, suggesting that the elevated MF against the crab's requirement blocked the normal developmental process of the crab embryos. These data can give crustacean endocrinologists some insights to understand the effects of the hormone on the crustacean reproduction studied previously in which JH analogs ambiguously affected the crustacean reproduction depending on the reproductive stages. The data also can give shrimp aquaculturists some implication of a possible generation of unfavorable shrimp seeds attributed to elevated egg MF originated from their eyestalk-ablated mother shrimp.

• BMB Reports
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• 제39권4호
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• pp.371-376
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• 2006

Crustacean hyperglycemic hormone (CHH) plays a major role in controlling glucose level in the haemolymph and also triggers important events during molting and reproductive cycles. In Penaeus monodon, three types of CHH, namely Pem-CHH1, Pem-CHH2 and Pem-CHH3, have been previously characterized. In this study, mouse polyclonal antibody was raised against recombinant Pem-CHH1 that was expressed in Escherichia coli. The anti-Pem-CHH1 antibody recognized all three types of Pem-CHHs but did not cross-react with either related hormone, molt-inhibiting hormone of P. monodon, or unrelated human growth hormone. The hyperglycemic activity in the extract from the eyestalk neural tissues was significantly depleted after incubating with anti-Pem-CHH antibody. Direct injection of the antibody into shrimp caused about 30-50% reduction in the haemolymph glucose level. The result demonstrates the ability of anti-Pem-CHH1 antibody to deplete the activity of CHH in vivo, and thus provides a possibility of using anti-Pem-CHH1 antibody to inhibit the hormone activity as a strategy to modulate growth and reproduction in this species.

• Ocean and Polar Research
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• 제31권3호
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• pp.257-264
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• 2009

Seventeen females of the mud crab Scylla serrata, from the State of Kosrae, Micronesia, were transported to the Fisheries Resources Research Institute, Gyeongsangnam-do, in oxygen-filled plastic bags. After acclimatization to a $30^{\circ}C$ holding temperature, nine females were selected for seed production trials. Spawning was hastened using eyestalk ablations; however, this may not be required in commercialscale mud crab seed production. Primary spawning produced an average of 2.4 million hatched larvae, whereas secondary spawning produced 0.4 million. About 10 days elapsed between spawning and hatching and 30 days between hatching and crablet. Mass mortalities up to 90% were observed between stages zoea 1 and zoea 2 in every trial. The highest survival rate from zoea 1 to crablet was estimated at 0.25%. Most commercial shrimp hatcheries in Korea are equipped with almost all necessary facilities and could be converted easily to mud crab hatcheries, able to run three to four times per year using hatchery technologies developed for blue crabs and Chinese mitten crabs.

• 한국수산과학회지
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• 제26권1호
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• pp.76-90
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• 1993

징거미새우의 생식소 성숙 제어에 대한 광주성발달과 안병 X-organ과의 관계를 밝히기 위하여 1) 생식소 성숙 제어에 미치는 수온과 광주기의 영향, 2)생식소 성숙에 대한 안병 절제 효과, 3) 안병에 있는 외수 X-organ (MEX-organ)조직의 활성에 대한 계절적인 변화 등을 조사하였다. 전난황형성기(12월${\sim}$다음해 3월)와 난황형성기(4월${\sim}$5월)에 있어서, 생식소 성숙은 주로 수온에 영향을 받으며, 광주조건(12L/12D, 15L/9D)에 관계없이 수온상승에 의하여 GSI가 증가하고 생식소도 성숙하였다. 반면, 산란기(6월${\sim}8$월)에 있어서, 생식소 성숙은 주로 광주조건에 영향을 받으며, 15L/9D와 같은 장일 조건에서는 생식소 성숙이 지속되고 높은 GSI값을 나타내는 반면, 12L/12D와 같이 단일화된 조건에서는 난소내에 있는 대부분의 난황형성기 난모세포들은 퇴화${\cdot}$흡수되어 휴지기 상태의 난모세포로 되었고, GSI는 감소되었다. 휴지기(9월${\sim}11$월)에 있어서, 수온($16^{\circ}C,\;22^{\circ}C,\;28^{\circ}C$)과 광주조건(12L/12D, 15L/9D)을 조합한 모든 실험구에서는 재성숙이 일어나지 않았다. 생식소 성숙에 대한 안병 절제 효과는 전난황형성기와 산란기때 보다 휴지기 때가 더 강하게 나타났다. 안병 MEX-organ에서 직경이 $20{\mu}m$이상인 신경분비세포 수는 생식주기에 따라 변동을 보였으며, 휴지기 때 그 수는 $77{\pm}12$로 증가하였고, 난황형성기때는 $55{\pm}7$로 감소하였다. 그러나 Bellonci 조직의 크기(volume)는 휴지기 때에 비해서 난환형성기때 증가하는 경향을 보였다.

• Fisheries and Aquatic Sciences
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• 제16권4호
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• pp.267-272
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• 2013

Chicken-type lysozyme (c-lysozyme) is present in shrimp and is active against some bacteria. To further understand the regulation of c-lysozyme in the fleshy shrimp Fenneropenaeus chinensis, we determined the tissue-specific gene expression of c-lysozyme and the time-course of mRNA expression in response to Vibrio anguillarum and lipopolysaccharide (LPS) injection by quantitative reverse real-time polymerase chain reaction. The results showed that c-lysozyme was expressed in all tissues tested, including gill, eyestalk, eye, hemocytes, hepatopancreas, intestine, heart, and pleopod. It was most highly expressed in the intestine followed by the eyestalk, gill, hemocytes and hepatopancreas. The mRNA expression level began to decline in a short time after V. anguillarum challenge and was then upregulated by two fold or more at 24 h post injection (hpi) compared to that at 0 h. Expression was suppressed shortly after LPS injection and began to increase with higher levels of 5.8-, 5.2- and 8.4-fold at 24, 48, and 72 hpi, respectively. Higher expression was sustained and showed a gradual increasing trend until the end of the experiment (72 hpi). These results increase our understanding of the regulation of defense mechanisms and facilitate an evaluation of the effects of probiotics or immunostimulants in shrimp culture.

• Fisheries and Aquatic Sciences
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• 제17권1호
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• pp.115-121
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• 2014

Eyestalk ablation (ESA) is commonly used in aquaculture to stimulate ovarian maturation in crustaceans, and methyl farnesoate (MF) affects crustacean molting and reproduction. To investigate the physiological effects of ESA and MF treatments on the shrimp Litopenaeus vannamei, we compared the effects of single eyestalk removal and MF injections. The ESA group had the lowest survival rate (50%), and individuals in the $0.1{\mu}g$ and $1.0{\mu}g$ MF-treated groups had survival rates of 80 and 73.3%, respectively. Conversely, molting numbers were highest in the ESA group, and similar to those of the 1.0-${\mu}g$ MF group. To investigate shrimp growth, we measured body weight during the experimental period and found that individuals in the ESA and $1.0{\mu}g$ MF groups showed significant increases in body weight. Furthermore, to investigate the effects of ESA and MF treatments on gonadal maturation, the gonad somatic index (GSI) was calculated after the experiment. All treated groups (ESA and MF) had higher GSI values than the control group, but the ESA and $1.0{\mu}g$ MF groups were not significantly different. Using histological ovary analysis, we determined that all treated groups showed indications of the previtellogenic stage, unlike the control group (immature stage). These results suggest that the high-MF-concentration treatment produced effects similar to those of ESA with respect to molting number, growth, and ovarian maturation.

• BMB Reports
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• 제35권5호
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• pp.476-481
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• 2002

The CHH/MIH/GIH peptide family of black tiger prawn (Paneaus monodon) is important in shrimp reproduction and growth enhancement. In this study, the cDNA that encodes the complete peptide that is related to the CHH/MIH/GIH family (so-called, Pem-CMG) in the eyestalk of P. monodon was successfully expressed in a methylotrophic yeast Pichia pastoris under the control of an alcohol oxidase promoter. In order to obtain the secreted Pem-CMG, a secretion signal of either the Saccharomyces cerevisiae $\alpha$-factor or Pem-CMG was employed. The results demonstrated that ${\alpha}Pem$-CMG, either with (${\alpha}2EACMG$) or without (${\alpha}CMG$) the Glu-Ala repeats, was secreted into the medium, while Pem-CMG with its own secretion signal failed to be secreted. The total protein amount that was secreted from the transformant that contained either ${\alpha}2EACMG$ or ${\alpha}CMG$ was approximately 60 mg/l and 150 mg/l, respectively. The N-terminus of the Pem-CMG peptide of both ${\alpha}2EACMG$ and ${\alpha}CMG$ was correctly processed. This produced the mature Pem-CMG peptide.