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江豚分带核型的研究

张锡然, 陈宜峰, 周开亚   

  1. 南京师范大学生物系
  • 出版日期:2006-07-29 发布日期:2007-09-13

BANDED KARYOTYPES OF THE FINLESS PORPOISE,NEOPHOCAENA PHOCAENIDES,FROM THE YANGTZE RIVER

ZHANG Xiran, CHEN Yifeng, ZHOU Kaiya   

  • Online:2006-07-29 Published:2007-09-13

摘要: 本文首次报道了一头雌性江豚的分带核型(C-带,G-带及银染色)。结果表明,江琢异染色质主要分布于染色体的两臂上,其中最大的中间异染色质位于No.7q的近心区,其他中间异染色质分布于No.6q,No.15q,No.16q,No.17q和No.18q上,除此,No.8p,No.9p,No.10p,No.13p,No.15p和No.16p呈现端异染色质。G- 分带,使每条染色体得到较好的鉴别与配对,并且C-带深染的部位恰是G-带浅染的部位,但并非所有浅染G-带都同深染C-带一一对应。银染观察发现,阳性结果仅出现于一对小的近中着丝粒染色体的短臂上(No.14p)。文章还结合文献,对江豚的核型特点及其保守性进行了分析讨论。

关键词: 江豚, 核型, C-带, G-带, 核仁形成区

Abstract: The present paper is the first report of banded karyotypes of the finless porpoise,neophocaena phocaenoides.The karyotypes of a female finless porpoise taken from the Yangtze River near Nanjing were studied in a fibroblast cell culture initiated from kidney by C-,G- and Ag-staining methods.The finless porpoise has a diploid number of 2n =44.Its karyotype consists of four groups(A-D)andone pair of sex chromosomes.The distribution of C-bands in the karyotype was found mainly in interstitial and terminal chromosome positions,whereas the centromeric C-bands(X and no.20) are very
faintly stained.The G-banding pattern of the finless porpoise performed in this study
is of great help for indentifying and pairing all chromosomes of the karyotype.A comparison between the G-and C-banded karyotypes reveals that the C-bands are all matched by very faintly stained G-bands;but there are no converse matches.The Ag-stained karyotypes of the finless porpoise only has oneNOR site,which is in the short arm of pair no.14.In addition,the regular changes of the NOR size in mitosis have also been observed.

Key words: Neophocaena phocaenoides, Karyotype, C-bands, G-bands, NORS