黑斑蛙核型、C-带及Ag-NORs 研究

本文采用外周血淋巴细胞培养法制备染色体标本，观察黑斑蛙的染色体标本，研究黑斑蛙的核型，C-带和Ag-NORs。研究结果表明：（1）黑斑蛙淋巴细胞染色体数目为2n=26，其中有5对大染色体和8对小染色体，核型是二型性核型；（2）分别对雌雄个体的中期分裂相进行观察，在第11号染色体长臂中部有明显的次缢痕，但变异核型次缢痕在第8号染色体长臂的中部；（3）在第5号染色体长臂上有一条明显的近端粒C-带；（4）第11号染色体是一对具有银染核仁形成区的同源染色体，且雌雄个体的银染位置相同。

A Study on the Karyotype,C-banding and Ag-NORs in Rana nigromaculata

The chromosome samples of Rana nigromaculata were prepared by peripheral blood lymphocyte cultured in vitro.Karyotype,C-banding and silver-staining nucleolus organizer regions(Ag-NORs) were observed on chromosomes samples.The result showed that:(1) the chromosome number of Rana nigromaculata is 26(2n=26),i.e.,10 large and 16 small chromosomes,the large chromosomes are matched into 5 homologous pairs and small chromosomes are matched into 8 homologous pairs,and further indicates the karyotype of Rana nigromaculata is bi-modal;(2) Metaphases of female and male were observed separately,the chromosome of No.11 has a pronounced secondary constriction in the middle of long arms.But the position of secondary constriction in the aberrant type individuals is in the middle of long arms of the No.8;(3) it has only one obvious C-banding close to the telomere,which is located in the long arms of the No.5;(4) The chromosome No.11 is a pair of homologous chromosomes with Ag-NORs,and the position of Ag-NORs in female and male is identical.