Study On The Advanced Method Of Preparing Pachytene Bivalents High Resolution Multiple Bands Of Zebrafish (Danio Rerio) And The Evolution Of The Chromosome

Zebrafish (Danio rerio) is one of the most important model species for developmental biology study in vertebrate. Based on the study on advanced method of preparing pachytene bivalents high resolution multiple bands. Meanwhile, using the No. 17 human chromosome-specific DNA as probes, chromosome painting was performed on zebrafish. And three genes were mapped to zebrafish chromosomes conducted by using technology of the physical assignment-fiuorescene in situ hybridazation (FISH).The pachytene bivalents with high-resolution multiple G bands of zebrafish were obtained after the treatment with alkaline hypotonic solution and high concentration of chloroform fixative solution. When analyzing six chromosomes from different metaphase figures, the characteristic and the number of bands were well matched. For the first time, we discuss and summarize the preparation procedure of the zebrafish bivalents methodology, in order to systematize this technique and get the repeatedly patterns and stable result.In addition, with the treatment of restriction endonuclease Alu I directed in situ nick translation, we firstly successfully obtained well-resolved restrictive endonuclease banding of zebraiish's bivalents, which we consider as G-band-like patterns. The aging of the slides is also important, let them dry at room temperature for one week. The results were analyzed and discussed in this paper.The application of this method in cytogenetics research of zebrafish and other fish is expected. Construction of the steady technique system of preparingthe pachytene bivalents with high resolution multiple bands of zebrafish and ideogram is the basement to found it's stable and accurate framwork for its physical map.The genomes of zebrafish and human were studied by means of chromosome painting. The No. 17 human chromosome-specific DNA probes were painted to zebrafish chromosomes and 3 conserved syntenies were found. Localized at the longer arm of chromosome 12(sm4),at the position of 35.9?0.87; at the shorter arm of chromosome 17(sm8),at the position of 40.5 ?0. 78;at the longer arm of chromosome 22(sml2), at the position of 34.3 + 0.33.Three genes were successfully localized on its host chromosome by means of fluorescence in situ hybridization (FISH). The GH gene of zebrafish was localized at the longer arm of chromosome 12(sm4), at the position of 35.5 + 0.77; PDEG gene at the shorter arm of chromosome 17(sm8), at the position of 40.1 ?.01; GFAP gene at the longer arm of chromosome 12(sm4),at the position of 30.3 + 0. 98 . The results confirmed that there are conserved syntenies among the human No. 17 chromosome, pig No. 12 chromosome, and theNo.12 No.l7 No.22 chromosome of zebrafish; at the same time, it also provide the foundation of the conservation of the chromosome evolution. Based on the results of our experiments and those of other people, we have advanced an idea named "chromatin blocks shifting and putting together" about the evolution of chromosome for the first time.