Evolution of Sexually Dimorphic Germ Cells in Volvox carteri

团藻两性生殖细胞的进化

• 批准号: 7630574
• 负责人: JAMES UMEN
• 金额: $ 34.87万
• 依托单位: SALK INSTITUTE FOR BIOLOGICAL STUDIES
• 依托单位国家: 美国
• 财政年份: 2006
• 资助国家: 美国
• 起止时间: 2006-06-27 至 2011-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7630574
• 关键词: Algae; Alleles; Animals; Architecture; Behavior; Biological Models; Biology; Cells; Chlamydomonas; Chlamydomonas reinhardtii; Development; Distant; Ectopic Expression; Eukaryota; Evolution; Explosion; Female; Gender; Gene Expression; Genes; Genetic; Genetic Polymorphism; Genome; Genomics; Germ; Germ Cells; Goals; Green Algae; Homologous Gene; Human; Label; Lead; Life; Link; Malignant Neoplasms; Mating Types; Molecular Genetics; Morphology; Mutation; Oligonucleotides; Organism; Partner in relationship; Pathway interactions; Pattern; Physiology; Plants; Positioning Attribute; Production; Protein Isoforms; Proteins; RNA Interference; Relative (related person); Reproduction; Reproductive Health; Retinoblastoma; Role; Sex Chromosomes; Sexual Development; Somatic Cell; Stem cells; Testing; Time; Tumor Suppressor Proteins; Vascular Plant; Volvox; Walking; Women' s Role; Work; asexual; dimorphism; egg; life history; male; molecular marker; neuronal cell body; novel; programs; reproductive; research study; retinoblastoma tumor suppressor; scaffold; sex; sex determination; sexual dimorphism; sperm cell; trait

DESCRIPTION (provided by applicant): SUMMARY. The long-term goal of this work is to understand the molecular genetic mechanisms that underlie developmental complexity. Multicellularity has evolved multiple times in the history of life and has led to an explosion of eukaryotic diversity, including novel reproductive strategies. Sexual dimorphism and multicellularity have coevolved in several lineages, but the mechanisms that led to their co-evolution in animals and plants lie in the distant past and are unknown. Volvox carteri is a multicellular green alga that shares recent common ancestry with its closest unicellular relative, Chlamydomonas reinhardtii. From a single-celled Chlamydomonas ancestor V. carteri has evolved many metazoan-like features including complete germ-soma separation and sexually dimorphic development. During sexual differentiation V. carteri females produce eggs and males produce sperm, a trait that is controlled by a mating type (mt) locus with two alleles, mtf (female) and mtm (male). The genomic region that encodes V. carteri mt has been identified and partially characterized, leading to the following Aims: (i) Clone and sequence both alleles of mt; (ii) Use annotation and transcriptional profiling to identify key regulators of sex determination; (iii) Characterize the genes that are responsible for sexually dimorphic development including vMATS, a mt-linked retinoblastoma (RB) tumor suppressor homolog that is highly polymorphic between V. carteri males and females; (iv) Directly test the role of female and male vMATS isoforms and other potential sex determining genes in regulating sexual differentiation by using ectopic expression and genetic inactivation experiments. The discovery of the V. carteri mating locus provides an unprecedented opportunity to dissect the molecular genetic changes that underlie the evolution of sexual dimorphism and to understand how sex chromosomes evolve to influence developmental programming. RELEVANCE. Germ cells are critical for human reproductive health and are also associated with some forms of human cancer, but their biology is poorly understood. The work proposed here is expected to reveal the underlying genetic architecture that leads to the production of eggs and sperm in a simple model system, and has already uncovered a potentially conserved link between a human tumor suppressor and germ cell formation.

描述（由申请人提供）：摘要。这项工作的长期目标是了解发育复杂性背后的分子遗传机制。多细胞性在生命史上已经进化了多次，并导致了真核生物多样性的爆炸性增长，包括新的繁殖策略。两性二态性和多细胞性在多个谱系中共同进化，但导致它们在动物和植物中共同进化的机制却存在于遥远的过去并且未知。团藻是一种多细胞绿藻，与其最近的单细胞近亲莱茵衣藻有着共同的祖先。从单细胞衣藻祖先 V. carteri 进化出许多类似后生动物的特征，包括完全的生殖体分离和性二态性发育。在性别分化过程中，V. carteri 雌性产生卵子，雄性产生精子，这一性状由具有两个等位基因 mtf（雌性）和 mtm（雄性）的交配型 (mt) 基因座控制。编码卡特里弧菌 mt 的基因组区域已被鉴定并部分表征，从而实现以下目标： (i) 对 mt 的两个等位基因进行克隆和测序； (ii) 使用注释和转录分析来确定性别决定的关键调节因子； (iii) 表征负责两性二态性发育的基因，包括 vMATS，一种 mt 连锁视网膜母细胞瘤 (RB) 肿瘤抑制同源物，在 V. carteri 雄性和雌性之间具有高度多态性； (iv)通过异位表达和基因失活实验直接测试雌性和雄性vMATS亚型以及其他潜在的性别决定基因在调节性分化中的作用。 V. carteri交配位点的发现提供了前所未有的机会来剖析两性二态性进化背后的分子遗传变化，并了解性染色体如何进化以影响发育编程。关联。生殖细胞对人类生殖健康至关重要，也与某些形式的人类癌症有关，但人们对它们的生物学知之甚少。这里提出的工作预计将揭示导致在简单模型系统中产生卵子和精子的潜在遗传结构，并且已经揭示了人类肿瘤抑制因子和生殖细胞形成之间的潜在保守联系。