• Journal of Marine Life Science
• /
• v.5 no.1
• /
• pp.17-24
• /
• 2020

We have identified a heat shock protein 70 gene from freshwater snail, Semisulcospira coreana. The freshwater snail HSP70 gene encode a polypeptide of 639 amino acids. Based on bioinformatic sequence characterization, HSP70 gene possessed three classical signature motifs and other conserved residues essential for their functionality. The phylogenetic analysis showed that S. coreana HSP70 had closet relationship with that of golden apple snails, Pomacea canaliculata. The HSP70 mRNA level was significantly up-regulated in response to thermal and salinity challenges. These results are in agreement with the results of other species, indicating that S. coreana HSP70 used be a potential molecular marker in response to external stressors and the regulatory process related to the HSP70 transcriptional response can be highly conserved among species.

• Fisheries and Aquatic Sciences
• /
• v.14 no.4
• /
• pp.411-416
• /
• 2011

We investigated the nutritional status of the melania snail (Semisulcospira gottschei) using RNA/DNA ratios to evaluate the effect of feeding conditions (artificial versus natural) on the reaction times of the snails in a time course following starvation. In the short experiments (48 h), the RNA/DNA ratios of the artificial feeding groups were significantly higher than those of the natural groups. While two RNA/DNA ratio peaks were observed in the artificial food group during daytime, the natural food group showed a higher ratio at night. Under starvation conditions, the RNA content decreased whereas the DNA content was constant. The RNA/DNA ratios of the freshwater snail in both groups dramatically decreased after starvation and remained constant until the end of the experiment. We verified that the RNA/DNA ratio serves as an index of nutritional condition with respect to the effect of dietary differences. These results are important for understanding optimized aquaculture rearing conditions for this important commercial freshwater snail.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.42 no.5
• /
• pp.434-441
• /
• 2009

This study was conducted to compare the biological activities of 7 melania snails from the family Pleuroceridae (Semisulcospira coreana, Koreanomelania nodifila, Semisulcospira forticosta, Koreoleptoxis globus ovalis, Semisulcospira libertina, Semisulcospira tegulata and Semisulcospira gottschei) in Korea. Among the 7 species, S. coreana, Korean. nodifila, S. forticosta and S. gottschei showed over 80% cytotoxicities on three cancer cell lines (SNU-1, A549 and Hep 3B) compared to the non-treatment, whereas S. libertina and S. tegulata showed almost no growth inhibition activities on the same cancer cell lines. In relation to ACE inhibition activity, only S. coreana, Korean. nodifila, and S. forticosta showed over 60% ACE inhibition activities, whereas other melania snails exhibited inhibition activities of lower than 25%. DPPH radical scavenging activities were also determined, and used to categories melania snails into three groups based on Duncan's multiple range test at P<0.05. The amount of TNF-${\alpha}$ produced by in vitro mouse peritoneal macrophage was determined according to bioactivity on L-929 cells. Three melania snails, S. coreana, Korean. nodifila and S. gottschei, exhibited 95.2%, 89.7% and 93.7% cell death(%) on L-929 cells, respectively. Glucose-6-phosphate dehydrogenase inhibitory activity was also obtained in the extract of S. coreana (31.9%) and Korean. nodifila (28.1%), showing that these extracts can be used as supplemental dietary health foods. In conclusion, we believe that the extracts of melania snails should be given due consideration in functional health food development.

• The Korean Journal of Malacology
• /
• v.2 no.1
• /
• pp.13-25
• /
• 1986

One of the most medically important snail species of Korea is Semisulcospira spp., a member of the freshwater prosobranch family pleuroceridae. The parasites that these snails transmit to humans are mainly Paragonimus westermani and Metagonimus yokogawoi. On the other hand, Semisulcospira snails are edible as a foodstuff in Korea. The present study was first aimed to detect out residual pesticides in the snails collected at the endemic and non-endemic areas of paragonimiasis in Korea and to make relationship to the detectability of larval trematodes shed from the snails. In addition, water specimens from the habitats where the snails were collected were sampled and analysed to elucidate environmental conditions of the habitats. This malaco-ecological survey was done at 7 endemic and 3 non-endemic areas of paragonimiasis for about more than 2 years, May, 1984 through October, 1986. All the water smaples both from the endemic and non-endemic areas of paragonimiasis showed normal ranges of the criteria of upper freshwater streams, with lower B.O.D. (0.4~2.0 ppm) and higher D.O. values (9.5~11.0 ppm) than those in the large river systems Infection rate of digenetic trematodes in total snails collected was 6.7%, but no Paragonimus cercaria was detected out at all even in the endemic areas of paragonimiasis. The ecological factors affecting Paragonimus larvae in the snails were also discussed. A total of 9 chlorinated hydrocarbon pesticieds was targeted to detect out from the tissues of snails. Out of 9 pesticides, aldrin, beta-BHC, p, p-DDT, dieldrin, DDE, lindane, heptachlor and heptachlor epoxide were eluted from the snails. The highest levels of the pesticides were mostly detected out in the snails collected from the Donghae-Chun area of Haman and the Kangwha area of Kyongki-Do, where the lowest infection rates of trematode cercariae (0~0.5%) were revealed. The possibilities that the residual pesticides in the freshwater animals including Semisulcospira snails might be transferable to humans were also discussed.

• The Korean Journal of Malacology
• /
• v.25 no.2
• /
• pp.145-151
• /
• 2009

The ultrastructural changes in germ cells during oogenesis of the melania snail, Semisulcospira libertina libertina have been investigated by light and electron microscopy. The ovary is located on the surface of the hepatopancreas in the spiral posterior region. The ovary exhibited greenish color in the gonadal mature season. The ovary was composed of a number of oogenic follicles. Oogenesis was divided into five stages with histological features: (1) oogonia, (2) previtellogenic, (3) initial vitellogenic, (4) active vitellogenic, and (5) mature stages. Oogonia were oval in shape, $4-6\;{\mu}m$ in diameter, and had a large nucleus. Previtellogenic oocytes were about $20\;{\mu}m$ in diameter and the cytoplasm reacted with hematoxylin in H-E satin. Initial vitellogenic stage, oocytes were $60-80\;{\mu}m$ in diameter, and small yolk granules of low electron density are scattered in the cytoplasm. Oocytes in the initial vitellogenic stage were connected with ovarian follicle by egg stalk. Active vitellogenic oocyte were $100-120\;{\mu}m$ in diameter. Electron density, size and quantity of yolk granules that are distributed in the cytoplasm have increased from the previous stage. Result of TEM observations, the oocyte contains well-developed Golgi complex, endoplasmic reticula and tubular mitochondria in the cytoplasm. Cytoplasm of mature oocyte was filled with proteinaceous yolk globules of high electron density. In this stage, the length of microvilli in the egg envelope was approximately $1.1\;{\mu}m$.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.31 no.3
• /
• pp.516-520
• /
• 2002

This study was designed to investigate the hepatoprotective effects of Semisulcospira libertina and garlic on the acute hepatotoxicity induced by carbon tetrachloride (CCl$_4$) of rats. Male Sprague-Dawley rats weighing 200∼220g were pretreated with dehydrated powder of Semisulcospira libertina (2.1 g/kg, po; SL) and dehydrated powder mixture of Semisulcospira libertina and garlic (3g/kg, 7:3 ratio, po; SG) once daily for 3 consecutive days, and then given a single dose of CCl$_4$(1g/kg in 5ml/kg corn oil, po) and liver function was determined 24 hrs later. Liver damage was assessed by quantitating activities of serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), sorbitol dehydrogenase (SDH) and alkaline phosphatase (ALP) as well as by histopathological examination. Pretreatments with SL and SG significantly decleased CCl$_4$-elevated ALT (48% and 61% respectively), AST (32% and 47%) and SDH (51% and 76%), but had no effect on ALP. SL and SG had revealed hepatoprotective effects against CCl$_4$-induced histopathological changes such as severe necrosis, inflammatory cell infiltration and congestion in the central gene of hepatic lobule. These findings demonstrate that SL and SG may haute the hepatoprotective effect on CCl$_4$-induced liver damage.

• Proceedings of the Korean Aquaculture Society Conference
• /
• 2002.08a
• /
• pp.214-215
• /
• 2002

• Proceedings of the Korean Aquaculture Society Conference
• /
• 2002.08a
• /
• pp.215-217
• /
• 2002

• The Korean Journal of Malacology
• /
• v.2 no.1
• /
• pp.30-34
• /
• 1986

Genetic variations of Semisulcospjra gottschei in Korea were investigated by means of starch gel-electrophoresis. The results are as follows; 1) Eight loci of ${\alpha}$-Gpd, Mdh-2, Pept-1, Pgm-2, Gp-1, Gp-2, Gp-3 and Gp-4 were monomorphic, and 8 loci of Mpi, Mdh-1, Pgi, Got, Pept-2, Pept-3, Pgm-1 and Sdh showed genetic variations. 2) Means of allele per locus ($\bar{A}$) and polymorphism (P) were revealed 0.64 and 0.44, respectively. The value of heterozygosity ($H_G$) showed a little more than heterozygosity $H_D$. ($H_D$=0.09, $H_G$=0.13) 3) Genetic variation appears to be due to loci of Got, Pept, Pgi, and Sdh, all of which of the $H_D$ values are high.

• Parasites, Hosts and Diseases
• /
• v.37 no.1
• /
• pp.5-11
• /
• 1999

Three species of the families Viviparidae and Pleuroceridae, the first intermediate host of paragonimiasis, metagonimiasis and echinostomiasis were studied cytologically. The observed diploid chromosome number was as follows: Semisulcospira libertina 36, S. dolichostoma 34, and Viviparus rivularis 64. The mitotic chromosome complement of S. libertina has nine metacentric pairs and nine submetacentric pairs, and S. dolichostoma has three metacentric pairs and 14 submetacentric pairs of chromosomes. Viviparus rivularis showed two metacentric pairs and 30 submetacentric pairs of chromosomes.