Microdissection and Painting of the W Chromosome in Ginkgo biloba Showed Different Labelling Patterns

銀杏W染色體顯微分離及螢光原位雜交分析顯示性染色體不同雜交帶型

蘭添穎(T. Y. Lan) ； 陳瑞陽(R. Y. Chen) ； 李秀蘭(X. L. Li) ； 董鳳平(F. P. Dong) ； 齊玉琛(Y. C. Qi) ； 宋文芹(W. Q. Song)

《Botanical Studies》 49卷1期 (2008/01) Pp. 33-37

摘要

以雌性銀杏(Ginkgo biloba)根尖細胞為材料，採用玻璃針分離法，通過顯微操作器成功地分離出銀杏W染色體。將分離得到的W染色體去蛋白、Sau3A酶切，進行LA-PCR擴增。以DIG-dUTP標記的銀杏基因組DNA為探針進行Southern雜交，結果表明顯微分離出的染色體擴增片段與銀杏基因組DNA同源，從而證明W染色體DNA確實已被成功擴增。以W染色體第2輪PCR產物為探針，在適當條件下對銀杏雌雄中期細胞進行螢光原位雜交，發現螢光信號較密集分佈於W染色體，Z染色體長臂末端1/2的區域的信號強度則比其他部位弱，同時螢光信號也出現在其他染色體的著絲粒及端粒等區域。該結果表明，銀杏的W和Z染色體的序列結果存在差異，特別是在長臂末端1/2區域處。這個區域可能是一個雌性特異區域，是在性染色體進化過程中逐漸形成的。

關鍵字

顯微分離 ； 染色體繪圖 ； 螢光原位雜交 ； 銀杏 ； 性染色體

並列摘要

The chromosome 1 with bigger satellite, supposed to be the W chromosome, was microdissected from the metaphase spreads of female ginkgo root-tip cells with a fine glass needle controlled by a micromanipulator. The dissected chromosome was amplified in vitro by the Sau3A linker adaptor mediated PCR (LA-PCR) technique. Southern hybridization analysis indicated that DNA from the single W chromosome was successfully amplified. FISH analyses with the PCR products have been performed in the metaphase spreads of female and male ginkgo. FISH signals were observed along the entire W chromosome, while along about 1/2 length at the end of the long arm of the Z chromosome, the intensity of signals was lower than at other segments. This suggested that the chromosome 1 of ginkgo might harbor different DNA sequence structures at the 1/2 length end of the long arm, and this region on the W chromosome might be a female-specific region which formed during evolution of the sex chromosomes.

並列關鍵字

Chromosome painting ； FISH ； Ginkgo biloba ； Microdissection ； Sex chromosome