The Genetic and Molecular Basis of Sex Determination in Ceratopteris

角蕨性别决定的遗传和分子基础

• 批准号: 9723154
• 负责人: Jo Ann Banks
• 金额: $ 56.44万
• 依托单位: Purdue Research Foundation
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-09-01 至 2001-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9723154&HistoricalAwards=false
• 关键词: Genetic; Molecular; Basis; Sex; Determination

9723154 Banks Technical section Gametophytes of the fern Ceratopteris richardii are sexually dimorphic, either hermaphroditic or male. The determinant of sex in this and other ferns is antheridiogen, a gibberellin-like pheromone that is secreted by the hermaphroditic gametophytes and which promotes male development of other sexually undetermined gametophytes. The plant hormone abscisic acid blocks the antheridiogen response. Several key regulatory genes involved in sex determination have been identified by generating and characterizing mutations that alter the normal sex of the gametophyte. A genetic analysis of these mutants defines a regulatory network of at least eight interacting genes that are involved in determining sex type. Among these are two major sex-determining genes, TRA-1 and FEM-1, whose activities are required to promote the differentiation of female and male traits, respectively. Each gene also negatively regulates the expression of the other such that the sex of the gametophyte ultimately depends on which gene is expressed first. Antheridiogen activates a signal transduction pathway defined by the HER genes which affects the sex of the gametophyte by regulating the activity of TRA-1.This model of sex determination will be tested by continuing the genetic and morphological analysis of new and existing sex-determining mutants. One such gene, a Ceratopteris homolog of KNOTTED-1 is likely to also be involved in meristem development in the hermaphrodite and a target of repression by antheridiogen during male development. Several genes that are up-regulated in response to exposure to exogenous antheridiogen have also been isolated and the functions of these genes will be determined. A final objective is to develop an Agrobacterium-mediated transformation system in the fern. If successful, the Ac/Ds transposable elements of maize will be introduced and their ability to transpose in the fern will be tested. If they are mobile, mutants induced by transposon tagging will be sought . Non-technical section How sex is determined in plants is an important developmental question whose answer may ultimately have practical applications in agriculture and plant breeding. The proposed studies will provide a basic understanding of the genes involved in sex determination and the signaling pathway for known pheromonal and hormonal cues. ***

小行星9723154 技术部分Ceratopteris richardii的配子体是两性的或雄性的。这种蕨类植物和其他蕨类植物的性别决定因素是雄激素，一种类似赤霉素的信息素，由两性配子体分泌，促进其他性别未定的配子体的雄性发育。植物激素脱落酸阻断雄激素反应。通过产生和表征改变配子体正常性别的突变，已经确定了几个参与性别决定的关键调控基因。对这些突变体的遗传分析定义了至少8个参与决定性别类型的相互作用基因的调控网络。其中有两个主要的性别决定基因，TRA-1和FEM-1，其活性分别是促进雌性和雄性性状分化所必需的。每个基因也负调控另一个基因的表达，使得配子体的性别最终取决于哪个基因首先表达。雄激素原激活HER基因的信号转导通路，通过调节TRA-1的活性来影响配子体的性别。一个这样的基因，一个水蕨同源物的KNOTTED-1可能也参与了分生组织的发展，在雌雄同体和男性发育过程中的一个目标的抑制由antheridiogen。几个基因的表达上调，在暴露于外源性精子原也已被分离，这些基因的功能将被确定。最终目标是开发农杆菌介导的蕨类植物转化系统。如果成功的话，将引入玉米的Ac/Ds转座因子，并测试它们在蕨类植物中转座的能力。如果它们是移动的，将寻找通过转座子标记诱导的突变体。 植物的性别是如何决定的是一个重要的发展问题，其答案最终可能在农业和植物育种中有实际应用。拟议的研究将提供一个基本的了解基因参与性别决定和信号通路的已知信息素和激素的线索。 ***