棉花纤维特异表达基因Gh F1的分离及鉴定

Isolation and Identification of Specifically Expressed Gene GhF1 in Cotton Fiber Cells

采用mRNA荧光差异显示结合cDNA末端快速扩增技术,克隆了一个棉纤维特异表达基因的全长cDNA,命名为GhF1,该cDNA全长622 bp,含有一个编码66个氨基酸蛋白的开放阅读框。Southern杂交分析表明该基因在陆地棉(Gossypium hirsutumL.)中含有两个拷贝。Northern杂交分析表明该基因在棉花纤维细胞特异表达,在纤维发育过程中,GhF1转录产物的累积主要发生在纤维细胞发育的早期阶段。尽管未发现该基因与已知基因有任何同源性,但其分布的组织特异性和表达的发育阶段性暗示该基因在纤维伸长中起作用。

Fluorescence differential display （FDD） technique was use to identify genes that are specifically or preferentially expressed in cotton fiber cells. A full-length cDNA of differential display cDNA fragments was cloned with rapid amplification of the cDNA ends. The cDNA contains an open reading frame of 622 bp encoding a protein of 66 amino acids. 3＇-UTR of the cDNA is 85 bp and 5＇-UTR is 389 bp. The gene was designated GhF1. Southern blot analysis showed that the gene had two copies in upland cotton genomic. PCR analysis using sequence of the cDNA as primer and genomic DNA as template showed the gene had no intron in cotton genomic. Northern blot analysis using the fulllength cDNA as probe was performed to investigate the expressed level of GhF1 in various organ and in the developing cotton fiber cells. The results showed that the gene was specifically expressed in fiber cells and its transcripts were abundant at the primary cell wall elongation stage and the expressed level decreased with the fiber cell development, inferring that GhF1 may play a role in polar elongation of cotton fiber cells. Sequence comparison to GenBank indicats GhF1 is a new gene and its function is unknown.