Study On Karyotype And Banding Of Gymnodiptychus Dybowskii Kessler

The Gymnodiptychus Dybowskii Kessler belongs to Gyprinidae, Schizothoracinae, Gymnodiptychus Herzestein, and distribute in Yili river, Talimu river, Urumchi river, Manasi river, Chu river, Talasi river, Xier river, Ala lake, Zhaishang lake, and so on. Gymnodiptychus Dybowskii Kessler is the peculiar wild species in Xinjiang, which is very rare. The meat of the fish is very good, has high nutrition. Now, the number of the fish is exiguous, this fish has hugely value of research and artificial raise. The purpose of this research is to study the number of chromosome of the Gymnodiptychus Dybowskii Kessler, and set up its Karyotype. Then describe and analyse the C-banding and G-banding of the chromosome of Gymnodiptychus Dybowskii Kessler. Draw idiograms of Karyotype, C-bands and G-bands. Artificial raise of Gymnodiptychus Dybowskii Kessler is research assignment of cytogenetics, and studies on chromosome is important part of cytogenetics. So the study on Karyotype and bands of this fish have important value to its Artificial raise and breed. New breed's raise and fostering of cross need to identify of every chromosome, and accurate detect of variation and recombination. The technology of C-banding and G-banding is good tools of these detection. Study on C-banding and G-banding deepen the level of chromosome research. Afford enormous advantages to developing of genetic engineering. Although there was no report in this research area in our country or overseas about Gymnodiptychus Dybowskii Kessler, well-rounded technique has been acquire in other fishes. This research improved from those technique, successfully acquire high quality glass flake of chromosome.1. Karyotype analysisThe chromosome specimens of Gymnodiptychus Dybowskii Kessler were obtained from metaphase of head kidney and kidney cell by vivo-injection of PHA and cultivation of Colchicine, low osmosis, hypatoic-air drying technique, and then studied their Giemsa stain. Select 100 metaphase cells from different body which separating well, having good shape, and the number of chromosome is integrity. Observation and statistics of chromosome under the microscope, ascertain the 2n number of chromosome. Come to a conclusion the total number of Gymnodiptychus Dybowskii Kessler's chromosome is 98,the frequency of this number arising is 78%. Measured and analysed the chromosome we can obtain this conclusion:Karyotype formula of Gymnodiptychus Dybowskii Kessler is 2n=98=28m+30sm+12st+28t, NF=156. The m group has a pair of bigger chromosomes ml. sml,sm2,tl and t2 are longer than other chromosomes in the same group. Small chromosomes and sex chromosomes with X/Y heterotypes were not found.2. C-banding analysisProperly lengthen the time of Colchicine action make for chromosome's shortening and overstriking. The chromosome shortened and overstriked to the benefit of showing C-bands.This research used Summer's BSG method showing bands, made some improvement then dispose chromosomes of Gymnodiptychus Dybowskii Kessler. The result is every chromosome has C-bands. Those bands exit in centrome regions, pericentric regions, interstitial regions and terminal regions, all chromosomes'centrome regions show C-band positive result. m2, m10, sm2 and sm(6-8) chromosome's two sides terminal region have positive bands, m1, m3, m4, m14, sm1, sm3, sm9, sm13, st(1-6), t1, t3, t6, t8 and t(10-13) chromosome's one side terminal region have positive band. sm5 has one side telomere band, and there is a interstitial region band at near middle area of long arm. The color of one chromosome's interstitial region band is more dark, has a big width stretch to terminal region of the long arm. sm12 has one telomere band, one chromosome has interstitial region band, the other chromosome's band is not obvious. t3 has interstitial region band but the color is shallow. The showing frequency of Gymnodiptychus Dybowskii Kessler's C-band is high.3. G-banding analysisThe shape and length of chromosome have great influence on the impact of G-band's showing. The time of Colchicine action has prodigious influence on length of chromosome. After explored, most suitable time of Colchicine action for Gymnodiptychus Dybowskii Kessler's chromosome to show G-band is 1.5 hours. This research used trypsin to process chromosomes, and Giemsa stain in order to seeing about the G-banding karyotype of Gymnodiptychus Dybowskii Kessler. All chromosomes have abundant G-bands. The number, position and color degree of G-bands of homologous chromosomes are mostly uniform. Bands in different chromosome has different number, different breadth and different color degree, uniformity of distribution are different, has complicated diversity. No.15 chromosome has most bands, it has 9 bands per chromosome. No.32,35,45 chromosome has least bands, only showing 2 bands. Other chromosomes' number of G-bands are between 9 and 2. The great mass of chromosomes show positive G-band in centrome regions, the number of chromosomes that shows negative bands in centrome regions is few than positive G-bands.