• Fisheries and Aquatic Sciences
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• v.22 no.9
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• pp.19.1-19.10
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• 2019

We investigated the insulin-like growth factor 1 (IGF-1)/AKT signaling pathway involved in muscle formation, growth, and movement in the adductor muscle of triploid Pacific oyster, Crassostrea gigas. Large and small triploid oysters (LTs and STs) cultured under identical conditions were screened, and the signaling pathways of individuals with superior growth were compared and analyzed. mRNA and protein expression levels of actin, troponin, tropomyosin, and myosin, proteins important in muscle formation, were higher in LTs compared with STs. Expression levels of IGF-1, IGF binding protein (IGFBP), and IGFBP complex acid-labile subunit were also higher in LTs compared with STs. Phosphorylation of the IGF receptor as well as that of AKT was high in LTs. In addition, the expression of phosphomammalian target of rapamycin and phospho-glycogen synthase kinase $3{\beta}$ was increased and the expression of Forkhead box O3 was decreased in LTs. Therefore, we suggested that the IGF-1/AKT signaling pathway affects the formation, growth, and movement of the adductor muscle in triploid oysters.

• Development and Reproduction
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• v.26 no.4
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• pp.165-174
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• 2022

Three proteins [myosin heavy chain (MHC), filamin-C fragment (FIL-C), and actin 2 (ACT2)] were identified in adductor muscle from diploid and triploid Pacific oysters (Crassostrea gigas) and the relationship between the condition index (CI) and mRNA expression of these genes was investigated, together with the mRNA expression of molluscan insulin-related peptide (MIP), C. gigas insulin receptor-related receptor (CIR), and insulin-like growth factor binding protein complex acid labile subunit (IGFBP-ALS). Monthly changes in the CI were similar to the changes in the tissue weight rate in both groups. ACT2 and MHC mRNA expression was statistically higher in the triploid than the diploid, while FIL-C mRNA expression was significantly higher in the diploid (p<0.05). The MIP, CIR, and IGFBP-ALS mRNA expression of the diploid oysters were all significantly higher in July than in other months (p<0.05). The MIP, CIR, and IGFBP-ALS mRNA expression in the triploid oysters was high in July, but there were no significant differences (p>0.05). Changes in the expression levels of the genes investigated in this study could be used as intrinsic indicators of the annual growth, maturity, and spawning period of cultured diploid and triploid C. gigas in Tongyeong, Korea.

• Journal of Aquaculture
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• v.10 no.2
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• pp.123-131
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• 1997

Growth of triploid abalone, Haliotis discus hannai induced by cody (3$^{\circ}C$) shock and its feed efficiency were investigated from larva to adult for 51 months. After 51 months from triploidy induction, the triploid abalones have outgrown to diploid abalones in shell length and total weight. Triploid abalones with inhibition of extrusion of first polar body (3n-1pb) were outgrown to diploid abalones, however, triploid abalones with inhibition of extrusion of second polar body (3n-2pb) were not significantly different from diploid controls in shell length and total weight through the whole rearing period (P<0.05), because of their heterozygosity differences. Daily feeding rates and feed conversion rates decreased with the growth of abalones and both rates had no differnce between two experimental groups. After 51 months from inducing triploid, conditin index of triploid abalone (64.1%) was higher than that of diploid control (59.4%) (P<0.05). Survival rate was 63.0% in triploid group (3n-1pb 62.0%, 3n-2pb 64.0%) and 62.0% in diploid group during the experimental period.

• Development and Reproduction
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• v.4 no.1
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• pp.19-28
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• 2000

Diploid and triploid hybrid between female mud loach Misgurnus mizolepis and male cyprinid loach, M. andguillicaudatus were produced, using artificial propagation. The influence of hybridization and triploidization on characteristics of the some tissues of retina optic tectum and trunk kidney in loach was determined histologically. Diploid hybrid have almost size similarities in nucleus and the cell size of some tissues to both parents. In the triploid hybrid the nucleus and／or the cell size in erythrocyte, horizontal cell in inner nuclear layer of retina ganglion cell in ganglion cell layer of retina, neuronal cell in granular layer of optic tectum, and secondary proximal tubule cell of trunk kidney, are much larger than those of the corresponding cells in the diploid hybrid individuals. However, triploid hybrid showed fewer number of cells in outer nuclear layer in retina and nuclei in secondary proximal tubule of trunk kidney than in diploid hybrid. Results of this study suggest that some characteristics in the triploid hybrid exhibiting larger cell and nucleus size with fewer number of cell than diploid hybrid can be useful criteria for the distinction between diploid hybrid and triploid hybrid, and the ploidy level in loach.

• Fisheries and Aquatic Sciences
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• v.20 no.11
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• pp.29.1-29.7
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• 2017

The objective of this study was to determine a simple and reliable ploidy identification protocol for the rainbow trout (RT), Oncorhynchus mykiss, in the field condition. To evaluate the ploidy level and compare different detection protocols, triploid RT and gynogenesis were induced by UV irradiation and/or heat shock. The hatching rate at day 30 was 85.2% and the survival rate at day 90 was 69.4% (fingerling). The sex ratio of female RT was 93.75% in the gynogenesis group, illustrating that the UV irradiation inactivated the sperm DNA. The hatching rate and survival rate were 82.0 and 74.7%, respectively, in the triploid-induced group. The triploid induction rate by heat shock procedure was 73.9%. Cytogenetic protocols for ploidy identification such as chromosome counting, erythrocyte nuclear size comparison, and analysis of nucleolar organizing regions (NORs) by silver staining were compared. Silver nitrate staining showed the greatest success rate (22/23 and 32/32 for the triploid-induced group and gynogenesis group, respectively), followed by erythrocyte nuclear size comparison (16/23 and 19/32 for the triploid-induced group and gynogenesis group, respectively) and, lastly, chromosome preparation (2/23 and 6/32 for the triploid-induced group and gynogenesis group, respectively) with the lowest success rate. Based on our findings, silver staining for RT ploidy identification is speculated to be highly applicable in a wide range of research conditions, due to its cost-effectiveness and simplicity compared to other numerous ploidy detection protocols.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.6
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• pp.903-909
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• 2022

Triploid fish have attracted the attention of fish farmers owing to of their larger cell size compared to that of diploid fish and their ability to utilize the energy required for sexual maturation for growth instead. However, the effect of increased growth in triploid fish has shown varying results. Therefore, this study aimed to compare growth between diploid and triploid starry flounders and diploid and triploid hybrid juveniles (starry flounder, Platichthys stellatus ♀×stone flounder, Kareius bicoloratus ♂) based on breeding water temperature to investigate the effect of increased growth in triploid fishes. The experiment was performed by categorizing the water temperature as high temperature (EXP. 1, 14.5-23.5℃) and low temperature (EXP. 2, 6.4-13.3℃) based on the optimal water temperature for starry flounder breeding. In EXP. 1, the growth of starry flounder triploids and hybrid triploids was significantly higher than that of diploids. However, in EXP. 2 the weight gain and specific growth rate of the starry flounder triploid were higher, and the growth of starry flounder was higher than that of the hybrids.

• Korean Journal of Veterinary Research
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• v.30 no.3
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• pp.317-331
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• 1990

Chromosomes of gonadal tissues from Fasciola spp, Eurytrema pancreaticum and Calicophoron calicophorum occurred Korean cattle were egamined using modified air-drying method. To compare their phenotype with three different genotypes among Fasciola spp, the adult and egg si2e were measured since they have been known as important taxonomical characters. The results obtained were as followed; Cattle liver fluke, Fasciola spp were classified into three types based on their chromosomal complements such as individual with 2o chromosome(diploid), 30 chromosome(triploid) and 20/30 mosaic constitution(mixoploid). The propotions of appearance of three types were 40.00%, 54.29% and 5.71%, respectively. The frequency of three types in type I which was regarded as F gigantica were 58.82% for diploid, 35.29% for triploid and 5.88% for mixoploid, but in type II which was regarded as F hepatica were 72.2% for triploid, 22.22% for diploid and 5.56% for mixoploid. Egg length of triploid forms was significantly larger than that of diploid forms and egg size of mixoploid forms was similiar to that of triploid forms. Worm size of triploid forms was larger than that of diploid forms and was more similar to that of mixoploid forms, but the statistical data were not significant. Diploid chromosome consisted of one pair of metacentric chromosome(m), four pairs of submetacentric chromosomes(sm), five pairs of subtelocentric chromosomes(st), while triploid chromosome consisted of one pair of metacentric chromosome, seven pairs of submetacen.tric chromosomes, one pair of subtelocentric chromosome and telocentric chromosome(t), respectively. In mixoploid chromosome, constitution of the chromosomes of diploid or triploid cell was consistent with that of diploid or triploid. Chromosomes of gonadal tissues from pancreatic fluke, Eurytrema pancreaticum consisted of 13 pairs of homologs(2n=26, n=13). The mitotic and meiotic divisions were observed frequently. In the mitotic metaphase, Karyotype consisted of five pairs of metacentric chromosomes, four pairs of submetacentric chromosomes, three pairs of subtelocentric chromosomes and one pair of telocentric chromosome. Chromosomes of gonadal tissues from stomach fluke, Calicvphoron calicophorum consisted of 9 pairs of homologs(2n=18, n=9). The meiotic divisions was frequently observed, but mitotic divisions was rare. In the mitotic metaphase, Karyotype consisted of two pairs of metacentric chromosomes, three pairs of submetacentric chromosomes and four pairs of subtelocentric chromosomes. Karyotype of Calicophoron calicophorum differed from that of Japanese C calicophorum which was similar to that of Paramphistomum cervi of Korean cattle. Though that of Calicophoron calicophorum of Korean cattle was similar to that of Paramphistomum explanatum of Korean cattle, that have been recognized to be a different species of fluke.

• The Korean Journal of Malacology
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• v.29 no.2
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• pp.105-111
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• 2013

The gonadal development of triploid and diploid Pacific abalones, Haliotis discus hannai was histologically investigated in spawning season. Diploid abalones had matured oocytes and spermatozoa, but most triploid had spermatocytes or developing oocytes that was slightly retarded in gonadal development compared to diploid abalones. In spawning experiment of triploid and diploid abalones, spawning rates of diploid male and female were 100%, but those of triploid female was 50% and male was 25% respectively. Investigation of spawned abalone eggs and spermatozoa revealed that length of diploid sperms head were 17.47 ${\mu}m$, breadth of head were 10.31 ${\mu}m$, length of spermatozoa were 130.72 ${\mu}m$, but those of triploid spermatozoa were 11.83 ${\mu}m$, 7.89 ${\mu}m$ and 103.36 ${\mu}m$ respectively. Triploid spermatozoa were significantly small to diploid spermatozoa (p < 0.05). The eggs of diploid and triploid were not different in size. The cross experiment between oocytes produced by triploids and spermatozoa by diploids ($3n{\times}2n$ cross) revealed that no fertilization were occurred, and $2n{\times}3n$ cross also revealed same result.

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.735-740
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• 2019

The aim of this study was to conduct a comparative analysis of the diploid and induced triploid cell cycles in marine medaka, Oryzias dancena, tissues. The mean fraction of cells in the G₁, S, and G₂+M phases was 85.5%, 7.6%, and 6.9%, respectively, in the tail fin tissues of diploid fish and 91.2%, 3.6%, and 5.2%, respectively, in those of induced triploid fish. The mean fraction of cells in the G₁, S, and G₂+M phases were 78.4%, 10.6%, and 11.0%, respectively, in the liver tissues of diploid fish; 86.2%, 5.9%, and 7.9%, respectively, in those of induced triploid; 79.3%, 9.4%, and 11.3%, respectively, in the gill tissues of diploid fish; and 85.7%, 5.4%, and 8.9%, respectively, in the induced triploid fish. The differences among the tissues were statistically significant within both the diploid and induced triploid fish (p<0.05). Mitosis was more active in each tissue of the diploid fish than in the corresponding tissues of the induced triploid fish and mitosis was more active in the liver and gill tissues than in the tail fin tissues in both the diploid and induced triploid marine medaka.

• The Korean Journal of Malacology
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• v.30 no.4
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• pp.443-447
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• 2014

Triploids have several potential advantages over diploids in aquaculture, drawing an elevated commercial reaction into the realistic application of the techniques despite we are still in the early stage of triploid industry for the Pacific oysters Crassostrea gigas. We traced the growth performance of the triploid C. gigas for over a year from hatchery spats, which was created by manipulations of chemicals (Cytochalasin B, CB or 6-Dimethylaminopurine, 6-DMAP). The growth was clearly marked by an initial longer dormancy and following a great magnitude of heterogeneity. The dormancy was almost 9 to 10-month long or even longer and was considered as a downside of the creation. The heterogeneity was magnified by appearance of extraordinarily growing oysters in part during summer season, which could be a representative upside of the triploids. Overall, however, the results were not as positive as were expected. The longer dormancy and following heterogeneity observed in our practice could be marked as an additional negative sign of the chemical use. The present study, thus, might be highly indicative in the introduction of biological cross between tetraploid and diploid to produce natural triploid embryos.