• 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.

• Proceedings of the Korean Aquaculture Society Conference
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• 2003.10a
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• pp.41-41
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• 2003

Transgenic triploid hybrid between fast-growingtransgenic mud loach (Misgurnus mizolepis) males and cyprinid loach (M. anguillicaudatus) females were generated and their performance on growth, feed conversion ability and reproduction were evaluated. Although the growth accelerations of diploid and triploid transgenic hybrids were not as much as those of original transgenic mud loaches, they still represented persistent growth stimulation ranging 11 to 28 fold when compared to their non-transgenic counterparts, with significantly improved feed conversion efficiency up to 2-fold (compared to non-transgenic hybrid) and 1.5-fold (compared to non-transgenic mud loach) in maximum. The gonad development of diploid hybrids was fertile in histological views regardless of transgenic genotypes but the extent of developmentin hybrid fish were less than mud loach diploids at the same age. On the other hands, very stringent sterility was obtained in both sexes of the triploid hybrid transgenics: ovary and testis from transgenic triploid hybrids were significantly depressed and any notable sign for maturation to ovum or spermatids was not detected. No viable embryo was obtained in a fertilization trial using the suspension prepared from the minced testes of transgenic triploid hybrids. This study may indicate the potential usefulness of triploid hybridization as a mean for reproductive containment of transgenic mud loach.

• 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 Breeding Science
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• v.42 no.1
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• pp.100-108
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• 2010

This study was carried out to confirm the chromosome constitution and homoeologous recombination of progenies derived from various cross combination using tetraploid OA interspecific hybrid originated from mitotic chromosome doubling. Based on the chromosome analysis of progenies crossed reciprocally, there were only triploid progenies when crossed with diploid Asiatics as male or female parent. While only tetraploid progenies were produced when crossed tetraploid Asiatics or tetraploid OA hybrid with tetraploid OA hybrid, respectively. However, two types of progenies, that is, diploid and triploid plants, were produced from cross combinations between diploid Oriental hybrid and tetraploid OA hybrid. From the GISH analysis of OA hybrid, it was confirmed that diploid $F_1$ OA hybrid was consisted of 24 chromosomes (12 Oriental and 12 Asiatics) showing authentic OA hybrid. On the other hand, it was notified that triploid plants (3x=36) were consisted of 24 Asiatics lily chromosomes and 12 Oriental lily chromosomes by analysis of backcross progenies derived from either $A{\times}OA$ or $OA{\times}A$ crosses. In cross between tetraploid OA and OA, all the progenies were tetraploid with equal number of chromosomes without any homoeologous recombination, i.e. each 24 chromosomes of Oriental and Asiatics. In 2x-4x ($O{\times}OA$) cross combination, some progenies had 2x=24 chromosomes originated from only Oriental hybrid, and other progenies had 3x=36 chromosomes derived from 24 chromosomes of Oriental hybrid and 12 chromosomes of Asiatic hybrid. Only tetraploid Asiatics chromosomes without any Oriental one were produced in all the progenies from 4x-4x ($AA{\times}OA$) cross combination.

• Korean Journal of Ichthyology
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• v.2 no.2
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• pp.203-210
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• 1990

The cobitid hybrid complex of C. sinensis and C. longicorpus occurs commonly in the upper streams of the Nakdong River, Korea where it is sympatric with the bisexual species, C. sinensis and C. longicorpus.The specimens of hybrid complex which are all females accounted for approximately 40% of all cobitid fish observed. These cobitid complex having the unique cloudy specks on body sides appeared to be morphologically intermediate between C. sinesis and C. longicorpusus. The chromosomes of hybrid complex were composed of both diploid form of 49 and triploid form of 73. This forms are tentatively presumed to be a unisexual complex originating from hybrid between C. sinensis and C. longcorpus.

• Journal of Plant Biotechnology
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• v.2 no.2
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• pp.109-113
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• 2000

Somatic hybrids were produced by electrofusion between embryogenic callus protoplasts of 'Syougun' mandarin and leaf protoplasts of grapefruit. Hybridity of the two plants was confirmed by leaf morphological characteristics and random amplified polymorphic DNA (RAPD) analysis. The cpDNA analysis using PCR-RFLP could not distinguish those of both parents. These plants showed normal growth and had chromosome number of 27. These unexpected triploid somatic hybrids might be derived from fused cells between diaploid protoplast of embryogenic calli and diploid protoplast of leaf, because polysomaty, a mixture of haploid cells and diploid cells was observed in the lactose medium-pretreated embryogenic calli of 'Syougun' by flow cytomehy analysis.

• Korean Journal of Ichthyology
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• v.7 no.1
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• pp.71-78
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• 1995

Cobitis sinensis - longicorpus complex were commonly found in the upper stream of the Nakdong River in Korea and consisted of mostly with diploid and triploid karyotype forms. Among them, the triploid females of C. sinensis - longicorpus were artificially crossed with diploid males from C. sinensis and diploid males from C. longicorpus, respectively. The progenies from each cross produced the diploid individuals that possessed the paternal characters in their karyotypes and their body color patterns. Based on this results, we can assume that the triploid females, C. sinensis - longicorpus have a peculiar reproductive mode eliminating an uneven genome by the primary meiotic division and then producing a haploid ovum by secondary meiosis.

• Development and Reproduction
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• v.21 no.2
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• pp.181-191
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• 2017

A comparison of the growth, hematological values, fatty acids, and gonadal and growth hormonal changes of river puffer, Takifugu obscurus, tiger puffer, T. rubripes, their hybrids (river puffer ${\times}$ tiger puffer) and hybrid triploids was performed during 3 months of their early growth period. Several features were observed during these 3 months: hybrids showed the highest levels of specific growth rate, 1.48%; hybrid triploids showed the smallest change in viscera fat (P<0.05), but GSI was not significantly different among groups (P>0.05). Considering hematological parameters, hybrid triploids had increased mean corpuscular volume and mean corpuscular hemoglobin (P<0.05), but other parameters were not significantly different between groups (P>0.05). With respect to fatty acids, puffer fish, hybrids and hybrid triploids contained fatty acids such as SFAs, MUFAs, n-3 PUFAs and n-6 PUFAs. There were significantly different amounts of total fatty acids between groups (P<0.05), however, rates of changes in fatty acids did not differ significantly between groups (P>0.05). Gonadal hormone (estradiol and testosterone) changes in the river puffer and tiger puffer were significantly higher than that observed in hybrids and hybrid triploids. The hybrids and tiger puffers had higher amounts of growth hormone (thyroid stimulating hormone and thyroxine) than the hybrid triploids and river puffers (P<0.05).

• Korean Journal of Microbiology
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• v.29 no.1
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• pp.8-15
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• 1991

Interspecific hybrids between the ASpergillus spp., A. awamori, A. usamii and A. oryzae, were obtained by nuclear transfer technique. Nuclei isolated from an auxotrophic mutant strain were transferred into the protoplasts of a recipient strain of different species. The frequency of interspecific hybrid formation by nuclear transfer was $2*10^{-5}$ $-7*10^{-4}$ In contrast, no interspecific hybrid was isolated by protoplast fusion. Among the hybrids tested, 10 strains showed increased activity of some or all components of cellulases, xylanases and amylase up to more than two times. Isozyme pattern of the hybrids were analyzed by polyacrylamide gel electrophoresis and isoelectric focusing followed by activity staining, which showed that some of the hybrids have isozyme patterns unidentical to either of the two parents. By measuring the DNA contents and the sizes ofthe conidia, the karyotypes of the hybrids were estimated to be aneuploid near to haploid, diploid or triploid. It was concluded that the unclear transfer technique is much more efficient in the formation of interspecific hybrids than protoplast fusion and is very useful for the improvement of Aspergillus strains.

• Journal of Aquaculture
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• v.10 no.1
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• pp.39-47
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• 1997

Induction of hybrid and allotriploid between female rainbow trout, oncorhynchus mykiss and male cherry salmon, O. masou were performed. Triploid rate in allotriploid was 92% and the survival rates of allotriploid exceeded that of their hybrid counterparts. Karyological studies revealed that the hybrid had exactly the same intermediate diploid karyotypers as that of two parental species, while allotriploid had two sets of the maternal haploid complement and one set of the paternal haploid complement. Hybrid revealed an intermediate size in celluar and nuclear size of erythrocyte, while allotriploid revealed larger cellular and nuclear size of erythrocytes than hybrid. The number of nucleolar organizer regions of hybrid were 1 or 2, while those of allotriploids were 1, 2 or 3. These results proved that allotriploidization can lead to increase cytogenetical characters compared to counterpart hybridization.