Molecular cloning of ten distinct hypervariable regions from the cellulose synthase gene superfamily in aspen trees
Molecular cloning of ten distinct hypervariable regions from the cellulose synthase gene superfamily in aspen trees
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DOI：
10.1093/treephys/24.5.543
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发表时间：
2004-05-01
期刊：
影响因子：
4
通讯作者：
Joshi, CP
中科院分区：
文献类型：
--
作者：
Liang, X;Joshi, CP
最近的分子遗传学数据表明，在拟南芥和其他草本植物中，纤维素合成酶（CesA）基因编码催化纤维素生物合成（CESAs）的酶属于一个大的基因家族。人们对来自森林树木的CesA基因知之甚少。为了从树种中分离新的CesA基因，需要有鉴别性且容易获得的同源DNA探针。CesA基因的高变区（HVRII）代表高度分化的DNA序列，可用于检测CesA基因之间的结构、表达和功能关系。我们利用逆转录聚合酶链反应（RT-PCR）技术，从白杨（Populus tremuloides Michx.）的8种CesA基因和2种CesA样D （CslD）基因中鉴定出HVRII区域。将这些白杨CESA/CSLD HVRII区域与实验室现有的8个CESA/CSLD全长cdna预测的蛋白进行比较，并与最近发布的毛杨CESA/CSLD同源物的搜索结果进行比较。& A.格雷。结果表明，该方法可用于杨树基因组中CesA/CslD基因成员的鉴定。对来自不同植物物种的56个HVRII结构域的系统发育分析表明，植物中至少存在6个不同的CESAs类别，这支持了之前将HVRII区域重新命名为class-specific regions （CSR）的建议。这种CSR克隆方法可以应用于其他作物植物和树种，特别是软木，由于这些基因组的大尺寸，在不久的将来不太可能获得完整的基因组序列。
Recent molecular genetic data suggest that cellulose synthase (CesA) genes coding for the enzymes that catalyze cellulose biosynthesis (CESAs) in Arabidopsis and other herbaceous plants belong to a large gene family. Much less is known about CesA genes from forest trees. To isolate new CesA genes from tree species, discriminative but easily obtainable homologous DNA probes are required. Hypervariable regions (HVRII) of CesA genes represent highly divergent DNA sequences that can be used to examine structural, expressional and functional relationships among CesA genes. We used a reverse transcriptase-polymerase chain reaction (RT-PCR)-based technique to identify HVRII regions from eight types of CesA genes and two types of CesA-like D (CslD) genes in quaking aspen (Populus tremuloides Michx.). Comparison of these aspen CESA/CSLD HVRII regions with the predicted proteins from eight full-length CesA/CslD cDNAs available in our laboratory and with searches for aspen CesA/CslD homologs in the recently released Populus trichocarpa Torr. & A. Gray. genome confirmed the utility of this approach in identifying several CesA/CslD gene members from the Populus genome. Phylogenetic analysis of 56 HVRII domains from a variety of plant species suggested that at least six distinct classes of CESAs exist in plants, supporting a previous proposal for renaming HVRII regions as class-specific regions (CSR). This method of CSR cloning could be applied to other crop plants and tree species, especially softwoods, for which the whole genome sequence is unlikely to become available in the near future because of the large size of these genomes.