Kiyosue T, Shiota H, Higashi K, Kamada H, Shinozaki K
Laboratory of Plant Molecular Biology, The Institute of Physical and Chemical Research (RIKEN), 3-1-1 Koyadai, Tsukuba, Ibaraki 305, Japan.
Biochim Biophys Acta. 1998 May 29;1398(1):42-6. doi: 10.1016/s0167-4781(98)00052-9.
A cDNA clone, designated DcDB1, was isolated from a cDNA library prepared from embryogenic cell clusters of carrot (Daucus carota L.) and characterized. The cDNA (1416 bp) encoded for a protein of 392 amino acid residues that contained a conserved chromo domain. The chromo domain is a 37 aa region found in both the Polycomo gene product, which is a repressor of homeotic genes, and a heterochromatin protein 1 of Drosophila. This domain is postulated to function in the binding of proteins to chromatin. Genomic blot hybridization experiments suggested that the number of DcCB1 genes in the carrot genome is low. The level of DcCB1 mRNAs was high in somatic embryos at globular and heart-shaped stages but low in torpedo-shaped somatic embryos. The level of DcCB1 transcripts decreased during the formation of seeds. The existence of both homeo and chromo box genes in plants suggests that regulatory mechanisms of developmental genes in plants may resemble those in Drosophila.
从胡萝卜（Daucus carota L.）胚性细胞团构建的cDNA文库中分离并鉴定了一个名为DcDB1的cDNA克隆。该cDNA（1416 bp）编码一个含392个氨基酸残基的蛋白质，其中包含一个保守的染色质结构域。染色质结构域是一个由37个氨基酸组成的区域，在同源异形基因的阻遏物Polycomo基因产物和果蝇的异染色质蛋白1中均有发现。推测该结构域在蛋白质与染色质的结合中发挥作用。基因组印迹杂交实验表明，胡萝卜基因组中DcCB1基因的数量较少。DcCB1 mRNA在球形期和心形期的体细胞胚中水平较高，但在鱼雷形体细胞胚中水平较低。在种子形成过程中，DcCB1转录本水平下降。植物中同时存在同源异形盒基因和染色质盒基因，这表明植物发育基因的调控机制可能与果蝇中的相似。
