Japan.J.Ichthyol. 魚 類 学 雑 誌 40(1):65-75,1993 40(1):65-75,1993

Electrophoretic Studies of Diploid, Triploid, and Tetraploid Forms of the Japanese Silver Crucian , auratus langsdorfii

Yasushi Shimizu,1,2 Takashi Oshiro1 and Mitsuru Sakaizumi2,31

Department of Aquatic Biosciences, Tokyo University of Fisheries, 4-5-7 Konan, Minato-ku, Tokyo 108, 2Department of Experimental Science, The Tokyo Metropolitan Institute of Medical Science, 3-18-22 Honkomagome, Bunkyo-ku, Tokyo 113, Japan 3Present address: Department of Biology, College of General Education, Niigata University, 2-8050 Ikarashi, Niigata 950-21, Japan

(Received October 29, 1992; in revisedform February 8, 1993; accepted March 22, 1993)

Abstract The diploid-polyploid complex in the Japanese silver crucian carp (ginbuna), Carassius auratus langsdorfii, includes a diploid bisexual form, a triploid gynogenetic form and a tetraploid gynogenetic form. However, the origin of the polyploids remains to be clarified. Flow cytometric and electrophoretic analyses of Japanese crucian carp demonstrated that all the individuals with a two-banded pattern for an AMY-2 gene were polyploid, and 90% of the polyploids gave such a two-banded pattern. One of the two bands was not found in diploid subspecies in Japan but was present in both Korean crucian carp and . The diploid subspecies, kinbuna (C.auratus subsp.), which is distributed along the Pacific coast of eastern Japan, generated a diagnostic band of phosphoglucomutase. This band was also found in the polyploid "ginbuna" from the same region, but was observed in neither triploids nor diploids from other regions. The region-specific distribution of patterns of muscle lactic dehydrogenases indicated that the crucian carp examined in the present study could be divided into three groups, which originated, respectively, from the Pacific coast of eastern Japan, the Sea of Japan coast of eastern Japan, and western Japan. These results suggest a possible polyphyletic origin of polyploid forms of "ginbuna" via multiple hybridizations.

Polyploid species are rare amongst vertebrates but distribution of these in the fresh waters of Japan have been reported in fish, amphibians and reptiles. and the efforts of Japanese ichthyologists. Naka- In fish, a triploid form in natural populations is mura (1984) recognised five subspecies: kinbuna known in six genera of teleosts, namely, Poeciliopsis, (C.auratus subsp.); ginbuna (C.a. langsdorfii); Poecilia, Carassius, Phoxinus, Rutilus, and Cobitis nagabuna (C.a. buergeri); (C.a. grand- (Vrijenhoek et al., 1989). A tetraploid form has also oculis); and gengorobuna (C.a. cuvieri). The sub- been observed in Cobitis and Carassius. species were distinguished by their coloration and Ginbuna, the Japanese silver crucian carp, is some meristic characteristics, such as dorsal fin-ray widely distributed in Japan (Okada and Nakamura, and gill-raker numbers. Differences in these charac- 1948; Kobayasi, 1982; Onozato et al., 1983). There teristics are not always clear, however, especially in are three forms of ginbuna; a bisexual diploid form the first three subspecies mentioned. Polyploidy with 100 chromosomes; a unisexual (all-female) trip- found in "ginbuna" seems to render the classification loid form with 156 chromosomes; and a unisexual more complicated, and triploid specimens with mor- tetraploid (all-female) form with 206 chromosomes. phology intermediate between kinbuna and ginbuna Both unisexual forms reproduce by gynogenesis have been found (Kobayasi, 1982). The diploid (Kobayasi et al., 1970, 1977; Kobayasi, 1971; Koba- chromosome number of Japanese crucian carp (2n= yasi and Ochi, 1972). 100) is considered to be of tetraploid origin, render- The classification and evolution of Japanese cru- ing electrophoretic and chromosomal analyses more cian carp remain to be clarified in spite of the wide complicated and difficult.

―65― Y.Shimizu, T.Oshiro & M.Sakaizumi

Fig. 1. Location of sites at which subspecies of Carassius auratus were collected. Numbers are explained in the text.

In order to solve these problems, it is necessary to Materials and Methods examine both diploid and polyploid individuals of Japanese crucian . Electrophoretic data availa- Fish ble to date are limited and direct comparisons be- tween electromorphs and ploidy for each individual Fish from wild populations of ginbuna and kin- have not previously been reported (Amano et al., buna were collected in 1989 at 26 sites in Japan and 1971; Taniguchi and Ishiwatari, 1972; Taniguchi and two in Korea (Fig. 1). Collection sites are enu- Sakata, 1977; Liu et al., 1980). merated below. The number of electrophoretically This report describes the largely consistent two- examined specimens from each site is given in paren- banded pattern of a specific amylase and the absence theses. of one of the two bands in Japanese bisexual C. 1=Uwano, Kamikita, Aomori (2); 2=Gamo, auratus subspecies, and notes that polyploid "gin- Sendai, Miyagi (9); 3=Obama, Souma, Fukushima buna" differ regionally from a genetic perspective. (10); 4=Kawawada, Mito, Ibaraki (11); 5=Fuchi- These observations support the putative hybrid gami, Akikawa, Tokyo (17); 6=Fukkoshi, Noshiro, origin of polyploid "ginbuna" through multiple hy- Akita (7): 7=Hirasawa, Yuwa, Akita (21); 8= bridizations with different combinations of genomes Detomachi, Honjo, Akita (1); 9=Miyajuku, Asahi, derived from ancestral forms. Yamagata (12); 10=Nishi-ootsuka, Kawanishi,

―66― Electrophoresis of Japanese Crucian Carp

A

B

C Fig. 2. Electrophoretic patterns of enzymes from subspecies of Carassius auratus. A) Amylases: lane 1, Yukuhashi-3 (3n); lane 2, Yukuhashi-4 (3n); lane 3, Yukuhashi-5 (2n); lane 4, Taragi-1 (2n); lane 5, Sasebo-1 (3n); lane 6, Sasebo-2 (3n); lane 7, Sasebo-3 (3n); lane 8, Uto-1 (2n); lane 9, Uto-2 (2n); lane 10, Shima-1 (3n); lane 11, Shima-2 (3n); lane 12, Shima-3 (3n). B) Phosphoglucomutases: lane 1, Sendai-5 (3n); lane 2, Sendai-4 (4n); lane 3, Sendai-3 (2n); lane 4, Tanabe-3 (2n); lane 5, Yanaizu-7 (2n). C) Muscle lactate dehydrogenases: lane 1, Asahi-5 (2n); lane 2, Asahi-6 (2n); lane 3, Mihama-3 (2n); lane 4, Mihama-4 (2n); lane 5, Mito-3 (2n). Direction of electrophoresis was from top to bottom in each case.

―67― Y.Shimizu, T.Oshiro & M.Sakaizumi

Table 1. Ploidy and electromorphs of each specimen

―68― Electrophoresis of Japanese Crucian Carp

Table 1. Continued

1 Others; 2chimeric tetraploid; 3five of 47 polyploid individuals (10.6%) lacked the AB bands but possessed the A phenotype of AMY-2.

Yamagata (7); 11=Osada, Inawashiro, Fukushima Flow cytometry (8); 12=Zenkoji, Nishikawa, Niigata (3); 13=Saba, Yanaizu, Gifu (13); 14=Irie, Maibara, Shiga (8); For the preparation of erythrocyte samples, the 15=Ooto, Kinomoto, Shiga (6); 16=Sakajiri, caudal fin was cut from the fish with a disposable Mihama, Fukui (11); 17=Kehi, Toyooka, Hyogo surgical blade and the tail dipped into a solution of (4); 18= Inaricho, Tanabe, Wakayama (3); 19= 10mM EDTA, 1% (w/v) gelatin and 5mM veronal Gudo, Nakamura, Kochi (1); 20=Usuno, Madama, buffer (pH 7.4). After two washes with the same Ooita (1); 21=Minato, Shiida, Fukuoka (1); 22= buffer, a small aliquot of a suspension of erythrocytes Imai, Yukuhashi, Fukuoka (5); 23=Kofuji, Shima, was put into 1ml of propidium iodide staining solu- Fukuoka (4); 24=Sakioka, Sasebo, Nagasaki (3); 25 tion, which was composed of 50ƒÊg/ml propidium =Nagahama , Uto, Kumamoto (2); 26=Taragi, iodide, 0.1% sodium citrate, and 0.2% (v/v) Non- Taragi, Kumamoto (1); 27=Shinpyong, Chollabuk- idet P-40. After incubation for 30min at 4•Ž, the do, Korea (4); 28=Sudong, Kyonsangnam-do, cells were monitored for fluorescence with an EPICS Korea. CS flow cytometer (Coulter Electronics, Hialeah, Gengorobuna, C.a. cuvieri, were taken from FL). 10,000 cells were counted per sample. stocks at the Tokyo University of Fisheries. Goldfish Erythrocytes of Oryzias latipes, from the stock at (wakin) were purchased from a fish dealer. The Tokyo Metropolitan Institute of Medical Sci-

―69― Y. Shimizu, T. Oshiro & M. Sakaizumi

ence, were used as controls. Histograms showed Electrophoresis and staining discrete peaks for O. latipes, and diploid, triploid,

and tetraploid cells in the case of the crucian carp. The liver, intestines, and skeletal muscle of each

The relative DNA content was determined by calcu- individual were dissected out and homogenized with

lating the ratio of mean fluorescence of crucian carp 10mM Tris-HCl (pH7.0). Each homogenate was

cells to that of cells of O. latipes. centrifuged at 15,000•~g for 10min and the resultant

supernatant used for electrophoretic analysis. Super-

oxide dismutase (SOD) from liver, lactic dehydroge-

Table 2. Electromorphs of specimens whose ploidy nases (LDH) from muscle, and amylases (AMY) was not determined from intestines were analysed on native, discontinu- ous, vertical polyacrylamide slab gels in the buffer

system of Davis (1964). Each gel sheet of 140•~100

1mm3 was composed of a 12% acrylamide •~ plus

0.125% bisacrylamide separation gel and a 3% ac-

rylamide plus 0.8% bisacrylamide stacking gel. Phos-

phoglucomutases (PGMs) from liver were separ- ated by electrophoresis on horizontal agarose gels.

Each gel sheet of 140•~180•~1mm3 was composed of

0.9% agarose and 2% polyvinylpyrrolidone (K-90;

Nacarai Tesque, Kyoto, Japan). The buffer system

for analysis of PGMs consisted of 135mM tris-

hydroxymethylaminomethane (Tris) and 43mM

citric acid (pH7.0) for the electrode buffer, and 9

mM Tris and 3mM citric acid (pH7.0) for the gel.

Potentials of 400V were applied for two hours at

4•Ž for acrylamide gel electrophoresis For agarose

gel electrophoresis a potential of 300V was applied for 1.5 hours. Staining procedures were those de-

scribed by Shaw and Prasad (1970) and Sakaizumi et

al. (1992).

Results

Flow cytometric analyses of erythrocytes from 119

wild-caught specimens demonstrated that they in-

cluded 71 diploids, 46 triploids, one tetraploid, and

one hypodiploid. The tetraploid showed chimerism

with two small, broad peaks at 2n and 5n, in addition

to a 4n peak that included 75% of all cells. All six

goldfish were determined to be diploid. Electrophoretic patterns were examined for four

different proteins. The phenotypic patterns of these

enzymes showed polymorphism. Most of the speci-

mens gave a single band for SOD. The C phenotype

with a single, rapidly migrating band was observed in

the case of C. a. cuvieri exclusively. Three individu-

als from Noshiro and two from Yuwa had a three-

banded phenotype AB. Other specimens had the B

1 Others; 2a single individual from Japan with the B pheno- phenotype. type of AMY-2. The AMY band that migrated most slowly toward

―70― Electrophoresis of Japanese Crucian Carp the anode, AMY-1, was monomorphic. The rapidly be classified into at least three types, as shown in migrating AMY-2 occurred as two bands (Fig. 2A). Figure 2C. All specimens from western Japan were All of the Japanese diploid specimens, including C. a. type 2, irrespective of ploidy. By contrast, type 1 was cuvieri possessed only the A band (A phenotype). By predominant in fish from the Sea of Japan coast of contrast, all of the Korean specimens and the gold- eastern Japan, irrespective of ploidy. Type 3 was sh possessed only the B band (B phenotype). Offi 47 observed in the majority of diploids and in some Japanese polyploids, 42 specimens (89.4%) had a triploids from the Pacific coast of eastern Japan. The pattern with both the A and B bands (AB pheno- polymorphic patterns were very complicated and type). Specimens with the AB phenotype were have not yet been interpreted. always polyploid. Five triploid specimens with the A On the basis of the geographic distribution of phenotype were all from eastern Japan. A single electrophoretic patterns of PGM and LDH, the re- individual from Mihama possessed the B phenotype, sults were summarized as shown in Table 3. Fish but the DNA content of the specimen was not ex- from the Pacific coast of eastern Japan, which had a amined (Table 2). high frequency of the B band of PGM, were com- PGM gave multiple banding patterns. For con- posed of diploid kinbuna and polyploid "ginbuna." venience, the bands were designated in alphabetical Along the coast of the Sea of Japan, diploid and order, starting from that with the slowest mobility triploid ginbuna, which had the type 1 LDH pattern, (Fig. 2B). The diploid specimens from Akikawa, were distributed. Diploid and triploid ginbuna, that Sendai and Mito possessed the B band. This band had the type 2 LDH pattern and PGM patterns was also detected frequently in the analyses of poly- lacking the B band were distributed in western ploids from the Pacific coast of eastern Japan (15 out Japan. of 20 specimens) and three triploids from the Sea of Japan coast of eastern Japan, but it was not observed in specimens from western Japan or Korea. The B Discussion band was not detected in C. a. cuvieri. The polymorphic patterns of muscle LDH could The gynogenetic form of ginbuna is known to exist

Table 3. Geographic variation of ploidy and electrophoretic characteristics

1 Not determined.

―71― Y. Shimizu, T. Oshiro & M. Sakaizumi

alongside the usual bisexual form of this subspecies. was found exclusively in polyploid (3n and 4n) indi-

The two forms are morphologically indistinguisha- viduals. The B band was not found in any Japanese ble, suggesting that gynogenesis in ginbuna is not of diploids but was present in Korean crucian carp and hybrid origin, although such an origin is typical of goldfish, the latter being considered to be derived other gynogenetic vertebrates. Initial evidence, how- from a Chinese subspecies, C. a. auratus (Ojima and ever, in favor of a hybrid origin of the gynogenetic Takai, 1979). All gynogenetic offspring of triploid form of ginbuna is provided by the peculiar distribu- ginbuna with the AB phenotype had the same pheno- tion of chromosomes in the first meiotic metaphase type as their mothers (data not shown). These results suggest that the polyploid form of "ginbuna" (Cherfas, 1966, 1981; Yamashita and Nagahama, 1989). This observation may reflect genetic non- has a hybrid origin. If such is the case, one candidate uniformity of the genomes that constitute the trip- as a parent seems to be a Continental subspecies of C. loid set of chromosomes. Further evidence comes auratus. It should be noted that triploids with the A from the C-banding patterns of chromosomes in six phenotype were detected in eastern Japan. Zhang et subspecies of Japanese and Chinese crucian carp al. (1992a) reported that one of the PGM bands

(Ueda and Ojima, 1978; Ojima et al., 1979; Ojima observed in the mother was lost in her gynogenetic and Takai, 1979). Ginbuna with triploid chromo- offspring at fairly high frequency. It is probable that somes from Lake Biwa carry a pair of markers triploids with the A phenotype lost the B band owing

characterized by conspicuous C-bands on the short to crossing-over or by deletion after establishment of

arms of the second largest submetacentrics. In kin- the triploid form in eastern Japan. An exceptional

buna (C. auratus subsp.) and Chinese crucian carp individual from Mihama, which had the B phenotype and was therefore assumed to be triploid, seemed to (C. a. auratus), two such markers occur in the female, whereas there is only one in the male. These have lost the A band after polyploidization.

results suggest possible heterogeneity of the genomes The B band of PGM was observed in most of the

that constitute the triploid set of chromosomes. Yet specimens from the Pacific coast of eastern Japan,

more evidence comes from interspecific hybridi- regardless of their ploidy, and in some polyploids

zation experiments. Triploid hybrids were found from the Sea of Japan coast. Since all the diploids

among the offspring from backcrosses of F1 females from Akikawa, which had the B band, could be identified as kinbuna on the basis of gill-raker num- (•~C. a. cuvieri) with males of the common carp or C. a. cuvieri (Ojima et al., 1975; bers (31-34), this band can be regarded as a diagnos-

Zhang et al., 1992b). Kobayasi (1985) succeeded in tic characteristic of kinbuna. Thus, it is highly

obtaining triploid females among the F2 progeny of a probable that the B band generated by polyploids in

cross between a female diploid ginbuna and a male eastern Japan is derived from kinbuna, which has a

goldfish (C. a. auratus). Furthermore, he obtained a diploid chromosome number. By contrast, neither fertile tetraploid female, which reproduced gynogen- triploids nor diploids from western Japan possessed

etically, from a cross between an F1 female (C. a. this band, suggesting a different origin of polyploids

cuvieri female•~C. a. gibelio male) and an F1 male of in eastern and western Japan.

the reciprocal cross. Production of allotriploid While all the western specimens gave the type 2

medaka by interspecific hybridization between Ory- pattern of muscle LDH regardless of ploidy, eastern

zias latipes and O. curvinotus was achieved by Saka- sh exhibited polymorphism. In particular, mostfi fish

izumi et al. (1992) and Kurita et al. (1992). from the Sea of Japan coast of eastern Japan gave the

In the present study, specimens were classified into type 1 pattern, which was not found in other regions.

diploids, triploids or tetraploids by flow cytometry These results indicated that the population on the

and subsequently subjected to individual elec- Sea of Japan coast of eastern Japan is distinct from

trophoretic analyses. Examination of various pro- those in other regions. The type 3 pattern can be

tein and enzyme polymorphisms resulted in diagnos- regarded as another diagnostic marker for kinbuna.

tic polymorphisms in association with ploidy or geo- Considering all these results, the specimens ex-

graphic regions, being recognized for three enzyme amined in this study can be classified into eight systems. groups (Table 4). Gengorobuna (C. a. cuvieri), with

The two-banded pattern (AB) of AMY-2 could be a diploid chromosome number, are distinct from all other groups, both morphologically and elec- generated by hybrids between subspecies with bands AMY-2-A and AMY-2-B, respectively. This pattern trophoretically. Korean crucian carp, although their

―72― Electrophoresis of Japanese Crucian Carp

ploidy was not determined, are electrophoretically Japanese polyploid "ginbuna." It is probable that different from Japanese crucian carp. Kinbuna (C. tetraploids arose from the rare incorporation of the auratus subsp.) can be considered a true subspecies, sperm of diploid species into a triploid egg, since the with the diagnostic characteristics shown in Table 4. tetraploid from Sendai had electrophoretic charac- "Ginbuna ," however, is composed of at least five teristics similar to those of triploids from the same different forms from a genetic perspective: polyploid- location. Unidirectional acceptance of scales trans- Pacific; diploid-and polyploid-Sea of Japan; and planted from triploids to tetraploids (Onozato et al., diploid-and triploid-western Japan. Since it is prob- 1983) gives some supports to this suggestion. able that the polyploids are of hybrid origin, those An analysis of restriction endonucleases of mito- from different regions appearing to have arisen poly- chondrial DNA has demonstrated that kinbuna and phyletically through multiple hybridizations, it is eastern "ginbuna" have similar haplotypes, which are considered inappropriate to include all five groups in distinct from that of western ginbuna (Okazaki et the single taxon, C. a. langsdorfii. It should be al., unpublished data). This supports the hypothesis emphasized that "ginbuna," which are distributed regarding the origin of polyploids and is relevant to alongside kinbuna, may have a genome (s) derived the classification problem mentioned above. More- from the latter. over, it is well known that diploid, triploid, and tetra- It is possible that the triploid forms from western ploid forms are distributed in Hokkaido (Kobayasi, Japan and the Sea of Japan coast of eastern Japan 1982; Onozato et al., 1983). Fish from this area are have two different genomes which may be derived particularly important for elucidation of the origin from diploid ginbuna with AMY-2-A and an un- of polyploids in Japan and for studies of the relation- known subspecies with AMY-2-B. The triploid form ship between Japanese "ginbuna" and the Russian from the Pacific coast of eastern Japan seems to have silver crucian carp, C. a. gibelio. Direct comparisons two distinct genomes that may be derived from kin- between ploidy, electrophoretic characteristics of the buna and an unknown subspecies. Examination of nuclear genome, and analysis of mtDNA, which the C-bands of the eastern triploids may provide allow identification of the maternal form, in the information useful to such a discussion because kin- crucian carp from Japan and adjacent Continental buna also have metacentrics with large C-bands. areas will provide a more complete picture of the It should be noted that tetraploids have never been relationship between the different forms of the "gin- found in western Japan (Kobayasi, 1982). This is buna complex" and its origin, and will enable a further evidence in favor of the multiple origin of the revision of the nomenclature of that complex.

Table 4. Diagnostic characteristics and distribution of Japanese and Korean forms of Carassius auratus

1 Band-B positive; 2band-B negative; 3not examined.

―73― Y. Shimizu, T. Oshiro & M. Sakaizumi

Acknowledgments sinensis-curvinotus-celebensis. Nippon Suisan Gakkaishi, 58: 2311-2314. (In Japanese with English abstract.) Liu, S.-M., K. Sezaki, K. Hashimoto and M. Nakamura. We are grateful to Dr. Sang-Rin Jeon, Sang 1980. Distribution of polyploids of "ginbuna" Carassius Myung Women's University, Seoul, for his kind help auratus langsdorfii in Japan. Bull. Japan. Soc. Sci. Fish., in the collection of the specimens. The assistance in 48: 413-418. the collection of the specimens provided by Dr. Nakamura, M. 1984. Key to the freshwater of Japan, Satoshi Hamaguchi, Niigata University, Niigata, and fully illustrated in color. Hokuryukan, Tokyo. 262 pp., Dr. Choji Taya, The Tokyo Metropolitan Institute of 175+VIII pls. (In Japanese.) Medical Science, Tokyo, is also greatly appreciated. Ojima, Y., M. Hayashi and K. Ueno. 1975. Triploidy appeared in the backcross offspring from funa-carp cross- ing. Proc. Japan Acad., 51B: 702-706. Literature Cited Ojima, Y., and A. Takai. 1979. Further cytogenetical studies on the origin of the goldfish. Proc. Japan Acad., Amano, H., K. Hashimoto and F. Matsuura. 1971. Starch 55B: 346-350.

gel electrophoresis of hemoglobin of "funa." Bull. Japan. Ojima, Y., T. Ueda and T. Narikawa. 1979. A cytogenetic Soc. Sci. Fish., 37: 48-54. assessment of the origin of the goldfish. Proc. Japan Cherfas, N.B. 1966. Natural triploidy in females of the Acad., 55B: 58-63.

unisexual form of the goldfish (C. auratus gibelio Okada, Y., and N. Nakamura. 1948. Studies on the races of Bloch.). Genetika (Moscow), 2: 16-24. (In Russian Carassius auratus (L.) in Japan. 1. Carassius auratus (L.)

with English summary.) in Jo-numa, a small lake in Gumma Prefecture. Nippon Cherfas, N.B. 1981. Gynogenesis in fishes. Pages 255-273 Suisan Gakkaishi, 13: 279-284. (In Japanese with Eng- in V.S. Kirpichnikov, ed. Genetic bases of fish selection. lish abstract.)

Springer-Verlag, Berlin. Onozato, H., M. Torisawa and M. Kusama. 1983. Distri- Davis, D.A. 1964. Disc electrophoresis-II. Method and bution of the gynogenetic polyploid crucian carp, Caras-

application to human serum proteins. Ann. NY Acad. sius auratus in Hokkaido, Japan. Japan. J. Ichthyol., 30: Sci., 121: 404-427. 184-190. (In Japanese with English abstract.)

Kobayasi, H. 1971. A cytological study on gynogenesis of Sakaizumi, M., Y. Shimizu and S. Hamaguchi. 1992. Elec- the triploid ginbuna (Carassius auratus langsdorfii). trophoretic studies of meiotic segregation in inter-and Zool. Mag., 80: 316-322. (In Japanese with English intraspecific hybrids among East Asian species of the abstract.) genus Oryzias (Pisces: Oryziatidae). J. Exp. Zool., 264: Kobayasi, H. 1982. The distribution of polyploid funa 85-92.

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17: 75-81. (In Japanese.) crucian carp-I. Cellulose-acetate electrophoretic pat- Kobayasi, H. and H. Ochi. 1972. Chromosome studies of tern. Japan. J. Ichthyol., 19: 217-222.

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―74― Electrophoresis of Japanese Crucian Carp

Zhang, F., T. Oshiro and F. Takashima. 1992a. Chromo- と比 較 した.AMY-2の バ ン ドパ ター ンに 関 して2倍 体 は ギ ンブ

some synapsis and recombination during meiotic division ナ,キ ンブナ,ゲ ンゴ ロ ウ ブナ と もA型 で あ った の に対 し,AB 型 の個 体 はす べ て3倍 体 で,3倍 体 の 約90%(西 日本 で は す べ て in gynogenetic triploid ginbuna, Carassius auratus langs- の 個 体)がAB型 を示 した.一 方,韓 国 産 フナ はB型 で あ った. dorfii. Japan. J. Ichthyol., 39: 151-155. キ ン ブナ に特 徴 的 なPGMのBバ ン ドが,東 日本 の太 平 洋 側 産 Zhang, F., T. Oshiro and F. Takashima. 1992b. Fertility of の3倍 体 の75%と 日本 海 側 の3倍 体 の 一部 で観 察 され た.ま た, triploid backcross progeny, (gengorobuna Carassius au- 東 日本 の 日本 海 側 に は倍 数 性 を問 わ ず この地 域 に特 異 的 なLDH ratus cuvieri ♀ ×carp Cyprinus carpio ♂) F1♀ ×carp or の パ ター ンが認 め られ た.こ れ らの結 果 は,倍 数 性 ギ ン ブナ が雑 engorobuna ♂. Japan. J. Ichthyol., 39: 229-233. 種 起 源 で あ り,し か も多 系 統 的 で あ る と す る仮 説 を 支持 す る も の と考 え られ る.

電 気 泳 動 パ タ ー ン か ら み た 倍 数 性 ギ ン ブ ナ の 特 性 (清 水 ・尾 城:〒108港 区 港 南4-5-7東 京 水 産 大 学 資 源

清 水 泰 ・尾 城 隆 ・ 酒 泉 満 育 成 学 科;酒 泉:〒113文 京 区 本 駒 込3-18-22東 京 都 臨 床 医 学 総 合 研 究 所 実 験 動 物 研 究 部 門.現 住 所:〒950- 21新 潟 市 五 十 嵐2の 町8050新 潟 大 学 教 養 部 生 物 学 教 日 本 各 地 で 採 集 し た ギ ン ブ ナ に つ い て,そ の 倍 数 性 と ア イ ソ ザ イ ム パ タ ー ン を 調 べ,キ ン ブ ナ,ゲ ン ゴ ロ ウ ブ ナ,韓 国 産 フ ナ 室)

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