REV Gene Family and Meristem Initiation

0131492 Clark拟南芥属的所有地上胚后发育都是通过茎和花分生组织器官的起始发生的。因此，芽和花分生组织的起始是随后图案形成和细胞分化的基本先决条件。 REVOLUTA（REV）基因在侧枝和花分生组织的起始中的作用最近被描述。 遗传和分子分析表明，REV的行为在侧分生组织起始的过程中的早期，是必需的，至少间接地，为重新激活已知的分生组织调节，如CLV基因座，WUS和STM，在横向位置。 REV编码III型HD-zip蛋白，含有推定的DNA结合同源结构域、可能参与二聚化的亮氨酸拉链结构域和START固醇/脂质结合结构域。 其他分析表明，REV也是正常血管器官发育所必需的。 REV是拟南芥中一个由5个基因组成的基因家族的成员，它在维管组织、器官和侧分生组织中早期表达。 rev突变体表型的可变表达性和其他基因家族成员的功能丧失等位基因的表型的缺乏表明，这些基因可能表现出功能冗余。 事实上，其他基因家族成员已被牵连在器官发育/极性和血管发育，通过分析获得的功能等位基因。 功能冗余在植物基因组中可能非常普遍，植物基因组中的基因复制水平明显高于动物基因组。 然而，很少有人知道的性质的功能规范之间的整个基因家族，已经演变成多个发展的角色。 因此，REV基因家族是一个很好的系统，以确定不同的基因家族成员之间的关系和潜在的重叠的作用，每个在植物development.This建议试图使用REV基因家族的功能相关的基因家族的特点，以及推进侧分生组织的发展的理解。 每个家庭成员的功能丧失等位基因已经确定，遗传分析将确定每个基因对哪个发育过程有贡献。 将评估每个基因的mRNA表达模式，以及每个基因编码的蛋白质的功能等效性。 将对潜在下游目标进行表征。 这项工作将提供一个关键的全面了解的关系，也许起源，一个功能相关的基因家族。 这对其它植物发育系统中冗余基因的作用具有重要意义。 此外，侧分生组织起始的关键调节因子的作用将被表征。

0131492Clark All above ground post-embryonic development in Arabidopsis occurs through the initiation of organs at shoot and flower meristems. Thus, the initiation of shoot and flower meristems is a fundamental prerequisite for subsequent pattern formation and cell differentiation. The role of the REVOLUTA (REV) gene in the initiation of lateral shoot and flower meristems has recently been described. Genetic and molecular analysis suggested that REV acts early in the process of lateral meristem initiation, and is required, at least indirectly, for the reactivation of known meristem regulators, such as the CLV loci, WUS and STM, at lateral positions. REV encodes a type III HD-zip protein, containing a putative DNA-binding homeodomain, a leucine zipper domain likely involved in dimerization, and a START sterol/lipid binding domain. Other analysis has revealed that REV is also required for normal vascular organ development. Consistent with these developmental roles, REV is expressed early in vascular tissue, organs and lateral meristems.REV is a member of a closely related gene family consisting of five genes in Arabidopsis. The variable expressivity of rev mutant phenotypes and the lack of phenotypes for loss-of-function alleles of other gene family members suggest that these genes may exhibit functional redundancy. Indeed, other gene family members have been implicated in organ development/polarity and vascular development through the analysis of gain-of-function alleles. Functional redundancy is likely to be very common among plant genomes, where the level of gene duplication is significantly higher than among animal genomes. However, little is known about the nature of functional specification among an entire gene family that has evolved multiple developmental roles. The REV gene family thus makes an excellent system in which to determine the relationships between the various gene family members and the potentially overlapping roles that each plays in plant development.This proposal seeks to use the REV gene family to characterize a functionally interrelated gene family, as well as advance understanding of lateral meristem development. Loss-of-function alleles have been identified for each family members and genetic analysis will determine to which development processes each gene contributes. The mRNA expression patterns of each gene will be assessed, as well as the functional equivalence of the proteins encoded by each gene. Potential downstream targets will be characterized. This work will provide a critical comprehensive understanding of the relationships, and perhaps origins, of a functionally interrelated gene family. This will be of significance to other plant developmental systems in which the action of redundant genes are important. Furthermore, the roles of key regulators of lateral meristem initiation will be characterized.