자연에 존재하는 생명체들은 유기-무기 성분들이 포함된 미세구조로 이루어진 계층학적으로 복잡한유-무기 나노 복합재를 합성한다. 자연에서 진행되는 유기-무기 나노복합재의 생성 및 재생 과정은 생광물화과정으로서 생물학적 환경에서 진행되는 생광물화과정의 연구는 신물질 합성에 대한 단서를 제공할 뿐만 아니라 산업적으로 중요한공정의 개발에 있어 귀중한 지침으로 활용될 수 있다. 연체동물 역시 생광물화과정을 수행하는 다른 생명체들과 마찬가지로 단백질과 다당류로 이루이진 유기매트릭스와 무기물의 상호작용을 통하여 패각을 설계하고 합성한다. 본 고찰에서는 이매패류의 패각 형성 과정 연구를 기반으로 아울러 생광물화과정 연구를 기반으로 한 소재합성과 관련된 생체모방공학 기술을 고찰하였다.
Biological organisms produce organic-inorganic nanocomposite composites that are hierarchically organized in composition and microstructure, containing both inorganic and organic components in complicated mixtures. The process related to the generation and regeneration of organic-inorganic complex in nature is called biomineralization process. Understanding how the process operates in a biological environment is a valuable guide to the synthesis of novel advanced material and developing important industrial processes. Like the mechanism of organisms, mollusks were also synthesized from interaction between organic matrices and minerals and their morphology was designed through biomineralization. In this study, shell formation has been studied as a bio-model and the application of biomimetics based on biomineralization is focused.
Seogundo is a small island adjacent to the southerncoast of Jeju Island and connected to it by a boulder beach at low tide Surveys of this area were conducted from 2001 to 2009 to enumerate the mollusks there and also to examine their diversity, relative abundance, and ecological relationships. Both the boulder beach itself and several large tidepools were studied, including the coarsesand substrate and several species of seaweed and coralline algae found in the tidepools. Of the 121 species obtained or observed, there were 97 gastropods, 16 bivalves, and 8 polyplacophorans. Live specimens were obtained for about half of those species. About one third were found on rocky substrate, with the most common species being Nodilittorina radiata and Nerita japonica in the upper intertidal zone, N. radiata and Littorina brevicula in the middle intertidal, and Turbo (Lunella) coronata coreensis and Acanthopleura japonica in the lower intertidal and shallow subtidal. The seaweeds and coralline algae contained about 40% of all mollusk species. The most common mollusks in two species of brown seaweed were Ittibittum parcum, Musculus nanus, and Euplica scripta. In a species of red seaweed, Komaitrochus pulcher was the most frequent, as in the coralline algae, along with M. nanus. The coarse sand in the tidepools contained about 25% of the species, with the Cerithiidae having the largest number. A sample of beach drift contained 17 species,with Bittium aleutaceum and Rissoina (Phosinella) pura being most common. Most species, about 60%, were found in a variety of habitats, especially the marine flora; few species exhibited any habitat preferences. Biographically, Jeju Island is part of the Warm Temperate Northwest Pacific Province and the East China Sea ecoregion with a strong faunal affinity with southern Japan, eastern China, and northeastern Taiwan. Zonal-geographical groupings reveal that the fauna is mainly subtropical-low boreal, preferring moderately warm water, with a somewhat smaller number of tropical-subtropical species.
The ultrastructure of germ cells during spermatogenesis and some characteristics of sperm morphology in male Mytilus coruscus, which was collected on the coastal waters of Gyeokpo in western Korea, were investigated by transmission electron microscope observations. The morphology of the spermatozoon has a primitive type and is similar to those of other bivalves in that it contains a short midpiece with five mitochondria surrounding the centrioles. The morphologies of the sperm nucleus type and the acrosome shape of this species have an oval and modified cone shape, respectively. In particular, the axial rod is observed between the nucleus and acrosome of the sperm. The spermatozoon is approximately 45-50 μm in length including a sperm nucleus (about 1.46 μm in length), an acrosome (about 3.94 μm in length) and tail flagellum (approximately 40-45 μm). The axoneme of the sperm tail flagellum consists of nine pairs of microtubules at the periphery and a pair at the center. The axoneme of the sperm tail shows a 9+2 structure. Some special charateristics of sperm morphology of this species in the genus Mytilus are (1) acrosomal morphology, (2) the number of mitochondria in the midpiece of the sperm, and (3)the existence of a satellite. The axial rod appears in the acrosome and sperm nucleus as one of the characteristics seen in several species of the subclass Pteriomorphia, unlikely the subclass Heterodonta containing axial filament instead of the axial rod. The number of mitochondria in the midpiece of the sperm of this species in the family Mytilidae are five, as one of common characteristics appeared in most species in the family Mytilidae. Most of Mytilus species contain a satellite body which is attached to the proximal centriole in the middle piece of the sperm, as one of common characteristics of sperm morphology in the family Mytilidae.
Up until now, we have identified 17 exotic species of Mollusca in Korea. These include Achatina (Lissachatina)fulica, Limax flavus, Limax marginatus, Deroceras reticulatum, Hawaiia minuscula, Zonitoides yessoensis,Zonitoides arboreus, Physa acuta, Pomacea canaliculata, Pomacea insularus, Crepidula (Crepidula) onyx, Mytilus galloprovincialis, Limnoperna fortunei kikuchii, Perna viridis, Argopecten irradians irradians, Pinctada fucata, and Pinctada margaritifera. Among them Achatina (Lissachatina) fulica, Pomacea canaliculata, Pomacea insularus,Argopecten irradians irradians, Pinctada fucata, and Pinctada margaritifera were intentionally introduced, whereas remainings were unintentionally introduced into Korean fauna. These foreign species can be divided into three groups on the basis of their habitats: A. fulica, L. flavus, L. marginatus, D. reticulatum, H. minuscula, Z. yessoensis, and Z. arboreus in terrestrial habitat; P. acuta, P. canaliculata, and P. insularus in fresh water; and C. onyx, M. galloprovincialis, L. fortuneikikuchii, P. viridis, A. irradiansirradians, P. fucata, and P. margaritifera in sea water. Taxanomically, 11 species belong to Gastropoda, whereas 6 species are classified to Bivalvia.
The ultrastructures of germ cells and the accessory cells during spermatogenesis and mature sperm ultrastructure in male Gomphina veneriformis, which was collected on the coastal waters of Yangyang, East Sea of Korea, were investigated by transmission electron microscope observations. The morphology of the spermatozoon has a primitive type and is similar to those of other bivalves in that it contains a short midpiece with four mitochondria surrounding the centrioles. Accessory cells are observed to be connected to adjacent germ cells, they contain a large quantity of glycogen particles and lipid droplets in the cytoplasm. Therefore, it is assumed that they are involved in the supplying of the nutrients for germ cell development, while any phenomena associated with phagocytosis of undischarged, residual sperms by lysosomes in the cytoplasm of the accessory cells after spawning was not observed in this study. The morphologies of the sperm nucleus type and the acrosome shape of this species have a cylindrical and modified long cone shape, respectively. In particular, the axial filaments in the lumen of the acrosome, and subacrosomal granular materials are observed in the subacrosomal space between the anterior nuclear fossa and the beginning part of axial filaments in the acrosome. The spermatozoon is approximately 50-55 μm in length including a long sperm nucleus (about 7.80 μm in length), an acrosome (about 1.13 μm in length) and tail flagellum (40-45 μm). The axoneme of the sperm tail flagellum consists of nine pairs of microtubules at the periphery and a pair at the center. The axoneme of the sperm tail shows a 9+2 structure. Some charateristics of sperm morphology of this species in the family Veneridae are (1) acrosomal morphology, (2) the number of mitochondria in the midpiece of the sperm,. The axial filament appears in the acrosome as one of characteristics seen in several species of the family Veneridae in the subclass heterodonta, unlikely the subclass pteriomorphia containing axial rod instead of the axial filament. As some characteristics of the acrosome structures, the peripheral parts of two basal rings show electron opaque part (region), while the apex part of the acrosome shows electron lucent part (region). These charateristics belong to the family Veneridae in the subclass heterodonta, unlikely a characteristic of the subclass pteriomorphia showing all part of the acrosome being composed of electron opaque part (region). Therefore, it is easy to distinguish the families or the subclasses by the acrosome structures. The number of mitochondria in the midpiece of the sperm of this species are four, as one of common characteristics appeared in most species in the family Veneridae.
TBTCl에 36주 동안 노출된 대복, Gomphina veneriformis 소화선의 미세구조적 변화와 지방갈색소의 축적을 관찰한 결과 외막상피층의 경우 점액세포 감소, 섬모 탈락 및 선조연의 부분적인 소실이 관찰되었다. 소화선세관에서는 저농도의 개체들에서 소화선세관 내강에 소화효소의 양이 증가하였지만 농도 의존적으로 소화선세관의 세포들이 입방형 또는 편평형으로 변하여 세포층의 두께가 얇아지며, 부분적으로 파괴가 관찰되었다. 이러한 광학현미경적 증상들을 자현미경으로 관찰한 결과 내장낭 외막 상피세포와 소화선세관을 둘러싸고 있는 근섬유사이에는 다수의 글리코겐 과립들이 관찰되었고, 호염기성 세포들에서는 조면소포체의 파괴와 세포의 괴사로 인하여 핵의 응축 및 핵막의 파괴가 관찰되었다. 이러한 소화선세관 세포들의 변화로 세포층은 고농도로 대조구와 유의적인 차이를 보이며, 두께가 감소하였다 (P < 0.05). Long Ziehl Neelsen 염 결과, 소화선세관의 세포에서 자주색으로 관찰되는 지방갈색소는 대조구와 유의적인 차이를 보이며 증가하였지만 (P < 0.05), 노출이 진행될수록 소화선세관 세포들이 파괴됨에 따라 그 축적도 감소하였다. 따라서 본 연구 결과 TBT는 대복 소화선세관 세포들의 미세구조를 파괴함에 따라서 이들 세포들이 가지는 소화기능을 억제하는 것으로 생각되어지며, 농도 의존적으로 지방갈색소의 축적이 높아지기 때문에 지방 갈색소는 TBT의 오염정도를 파악하기 위한 biomarker로서 충분히 이용 가능한 것으로 생각된다.
The purpose of this study was to investigate the effect of tributyltin (TBT) on histopathological and ultrastructural changes in the digestive gland structure of the equilateral venus, Gomphina veneriformis. Experimental period was 36 weeks. Experimental groups consist of control condition and 3 TBTCl exposure conditions (0.4, 0.6, 0.8 TBTCl μg L-1). Outer envelop of the visceral mass of G. veneriformis exposed to TBTCl was observed disappearance of microvilli and cilia, decrease of mucous cell and partially destruction of epithelium. In the digestive gland showed an increase of number of hemocyte and mucopolysaccaride near the digestive tubule at early time of the exposure. Especially, in 0.8 μg TBTCl L-1 group, collapse of digestive tubule with modification of epithelium was observed. TEM observation revealed the numerous glycogen granules in epithelium of the outer envelop and connective tissue. In the ciliated cell of the primary duct formed the cilia in cytoplasm. Basophilic cell was observed destruction of the rough endoplasmic reticulum and mitochondria. Also, nucleus in the epithelium of the digestive tubule was disappeared heterochromatin and nucleolus, and condense. As the concentration of TBTCl increased,the accumulation of lipofucin increased in the digestive gland, but the collapse of digestive tubule induced a decrease of accumulation of lipofuscin.
A morphological and ultrastructural study on the prostate of a land snail Nesiohelix samarangae was conducted. The prostate of Nesiohelix samarangae is a tubular gland connected with the large hermaphrodite duct. The lining of the prostate tubules possesses two distinct types of epithelial cells, one secretory and the other non-secretory. The secretory cells contained numerous secretory granules in various sizes and electron density. Most of the secretory granules showed light electron density but some of them showed heavy density. The ciliated cells were non-secreting cells situated only toward the lumen of the tubules and appeared as ordinary epithelial lining cells. The ciliated cells of the epithelium extensively interdigitate with each other and their apical surfaces had numerous cilia and microvilli. The bases of the ciliated cells did not reach the basal region of the secretory cells.
우리나라 서해에 분포하는 두족류의 출현양상을 조사하기 위해 2006년부터 2008년까지 계절별로 연 4회 조사하였다. 어구는 북부 연안은 새우조망, 중부 연안은, 닻자망, 남부 연안은 개량안강망, 근해는 저층트롤을 사용하였다. 출현한 두족류는 14종, 총개체수 19,789 개체였다. 서해의 우점종은 귀오징어였다. 북부 해역은 살오징어, 중부 해역은 꼴뚜기류 그리고 남부 해역은 참꼴뚜기가 우점종으로 나타났다.
우리나라 서해에 분포하는 두족류의 출현양상을 조사하기위해 2006년부터 2008년까지 계절별로 연 4회 조사하였다. 어구는 북부 연안은 새우조망, 중부 연안은 , 닻자망 , 남부 연안은 개량안강망, 근해는 저층트롤을 사용하였다. 출현한 두족류는 14종, 총개체수 19,789 개체였다. 서해의 우점종은 귀오징어였다. 북부 해역은 살오징어, 중부 해역은 꼴뚜기류 그리고 남부 해역은 참꼴뚜기가 우점종으로 나타났다.
Density-dependant growth and mortality rate of Manila clam Ruditapes philippinarum reared in net cages was investigated in Gomso Bay, Korea where unusually high mortality of clams has been reported. For the experiment,four groups of clam cages were set up with a density of 2,000 clams/m2 (group A), 1,000 clams/m2 (group B), 500clams/m2 (group C) and 100 clams/m2 (group D). Mortality and growth of clams in each experimental cage was monitored biweekly from May 2001 to September 2001. Highest mortality in group A was observed in late August,while highest mortality of rest groups was observed in early September. In September, the cumulative mortality in group A was 99%, while it was 93.2% in group B, 91.2% in group C and 88% in group D. Shell growth rate of clams in thecages was found to be density dependent; monthly shell length increase was 0.67 mm in group A,1.33 mm in group B, 1.63 mm in group C and 1.71 mm in group D. Our study indicated that clam growth and mortality in the Bay is density dependent and the growth and survival rate is negatively correlated with the density.
제주 항 내에 서식하는 대수리 Thais clavigera를 조직학적 방법을 이용하여 1998년 3월부터 1999년 2월까지 생식소 발달과 생식주기 그리고 imposex 현상에 대해 조사하였다. 조직학적 관찰 결과, 배우자형성은 암,수 모두 10월에 처음 시작 되었고, 성숙한 알들은 주로 5월에서부터 7월 사이에 관찰되었다. 생식소단면적 지수 역시 알이 성숙하는 5월과 7월 사이 급격히 증가하였으며, 8월에 급격히 낮아져, 7월과 8월 사이에 집중적인 산란이 있었던 것으로 사료되었다. 유기주석화합물에 의한 imposex 현상의 진행 정도를 나타내는 RPSI는 월 평균 59.5-173.4%로 다른 지역에 비하여 비교적 높게 나타났으며, 이는 제주 항 내의 유기주석화합물에 의한 것으로 추정되었다.
제주 항 내에 서식하는 대수리 Thais clavigera를 조직학적 방법을 이용하여 1998년 3월부터 1999년 2월까지 생식소발달과 생식주기 그리고 imposex 현상에 대해 조사하였다. 조직학적 관찰 결과, 배우자형성은 암,수 모두 10월에 처음 시작 되었고, 성숙한 알들은 주로 5월에서부터 7월 사이에 관찰되었다. 생식소단면적 지수 역시 알이 성숙하는 5월과 7월 사이 급격히 증가하였으며, 8월에 급격히 낮아져, 7월과 8월 사이에 집중적인 산란이 있었던 것으로 사료되었다. 유기주석화합물에 의한 imposex 현상의 진행 정도를 나타내는 RPSI는월 평균 59.5-173.4%로 다른 지역에 비하여 비교적 높게 나타났으며, 이는 제주 항 내의 유기주석화합물에 의한 것으로추정되었다.
