| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1995: ¥300,000 (Direct Cost: ¥300,000)
Fiscal Year 1994: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1993: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Research Abstract |
Matsui (1990) reported two types of Rana tagoi to be present in Nishitama district in Tokyo. Rana tagoi Okada distributed widely in Japan, and readily obtainable from Henbori in Hinohara Mura, and Rana sakuraii Matsui et Matsui, in the forests of Kanto and Kinki districts, and obtainable from the Bonbori reiver in Musashitsukaichi Machi. R.sakuraii is a new species in consideration of its differences with R.tagoi morphologically and ecologically. Nishioka (1993) had indicated that R.sakuraii is a subspecies based on mating data for R.tagoi and R.sakuraii. Karyotypes of R.tagoi from Henbori and R.sakuraii from Musashiitsukaichi Machi in Nishitama district in Tokyo were analyzed by conventional staining, C-banding and late replication (LR)-banding on 20 frogs, ten frogs of each type, consisting of 5 females and 5 males. Chromosome numbers were 2n=26 in all cases. Thirteen pairs of chromosomes (Nos.1-13) were arranged in order of relative length (RL) which was express as percentage of gen
… More
ome length. The 26 chromosomes either contained five (Nos.1-5) pairs of large chromosomes and or eitht (Nos.6-13) pairs of small chromosomes. Chromosome 10 had a secondary constriction with the long arm. Twelve pairs other than chromosome pair 8 showed the same sex features in all frogs. For chromosome pair 8, sex-specific changes were noted in all cases. All frogs had chromosome pair No.8, the XY type sex chromosomes. In R.sakuraii, the X chromosome was metacentric and whose numerical value of the centromere position (NVC) was from 45.2<plus-minus>0.17 and 48.3<plus-minus>0.61. The Y chromosome was submetacentric and NVC was 27.2<plus-minus>0.73. In R.tagoi, the X chromosome was submetacentric with NVC from 27.4([SY.+-.[)0.71 and 29.1<plus-minus>0.72. The Y chromosome was submetacentric with the NVC of 36.1<plus-minus>0.84. C-banding analysis indicated that, in R.sakuraii, neither X nor Y chromosomes C-band except for centromere, while in R.tagoi the X chromosomepossessed a C-band with a long arm and the Y chromosome to have no C-band possessing both a long and short arm. LR-banding analysis demonstrated the X and Y chromosomes to possess a LR-band with a short arm and two LR-bands each with a long arm, respectively and the banding for one frog species and subspecies to be essentially same. One frog species and the subspecies each had an XY-type chromosome. Molecular biological analysis is being conducted on the gene with the Y chromosome as the testis determinant but reliable data have yet to be obtained as to whether the sex chromosome is actually related to sex differentiation or determination. This point must be resolved by additio Less
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