A new cell population regulating cell fate and morphogenesis in the mouse testis

调节小鼠睾丸细胞命运和形态发生的新细胞群

• 批准号: 7894432
• 负责人: Tony J. DeFalco
• 金额: $ 5.38万
• 依托单位: DUKE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-05-01 至 2012-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7894432
• 关键词: Address; Adult; Androgens; Cell Adhesion; Cell Adhesion Molecules; Cell Communication; Cell Differentiation process; Cell Separation; Cells; Data; Development; Disease; Drosophila genus; Embryo; Exhibits; Extracellular Matrix; Extracellular Matrix Proteins; Family; Female; Fertility; Fetal Development; Fetus; Fluorescence-Activated Cell Sorting; Gene Family; Genes; Genetic Techniques; Germ Cells; Goals; Gonadal structure; Homologous Gene; Image; In Situ Hybridization; Infertility; Life; Mammals; Mediating; Methods; Molecular; Morphogenesis; Mus; Neurosecretory Systems; Organogenesis; Orthologous Gene; Pattern; Play; Population; Primordium; Process; Property; Regulation; Role; Seminiferous tubule structure; Shapes; Signal Transduction; Somatic Cell; Sorting - Cell Movement; Stem cells; Sterility; Structure; Testing; Testis; Transgenic Mice; Vascularization; base; cell fate specification; cell type; fetal; immunocytochemistry; in vivo; insight; interstitial; interstitial cell; leydig interstitial cell; male; member; mutant; notch protein; novel; progenitor; reproductive; sertoli cell; sex; sperm cell; trafficking; transcription factor

DESCRIPTION (provided by applicant): Our goal is to understand the mechanisms of cell fate specification and cellular reorganization that transform the fetal gonad into a functional testis. The first step of testis organogenesis is the commitment of approximately half of the somatic cells in the gonad primordium to the Sertoli cell fate. Sertoli cells surround germ cells and undergo the process of de novo cord formation. This basic process of cell sorting defines two compartments of the testis: the testis cords and the interstitium. The testis cords will become the seminiferous tubules, where sperm are produced in adult life, whereas the androgen-producing Leydig cells and other less well-characterized populations differentiate in the interstitium. Although the process of cord formation is essential for masculinization of the fetus and fertility of the adult, it is not well understood. It has been viewed as a Sertoli-cell-driven process; however, several lines of evidence suggest that interstitial cells play a critical role in shaping the process of testis cord formation. One gene that is essential for cell sorting during gonad morphogenesis in Drosophila is traffic jam (tj). tj encodes a member of the Maf transcription factor family, and promotes organogenesis of the Drosophila gonad via the regulation of cell adhesion molecules (CAMs). The mammalian ortholog of tj, MafB, is expressed in an uncharacterized population of progenitor cells that sort out from Sertoli cells at the beginning of fetal testis formation and give rise to the interstitium of the testis. MafB expression is closely associated with the vasculature, and later becomes restricted to fetal Leydig cells. We hypothesize that MafB plays a role in specification of the cell types of the interstitium and in the formation of testis cords, likely acting through control of CAMs or extracellular matrix (ECM) proteins. We have recently shown that Notch signaling is required for regulation of the progenitor population in the interstitium and for Leydig cell differentiation. In Specific Aim 1, we will investigate the hypothesis that Notch signaling is involved in the specification of MafB-expressing cells, using in vivo and ex vivo Notch gain- and Ibss-of-function analysis via immunocytochemistry, in situ hybridization, and quantitative PCR. In Specific Aim 2, we propose to elucidate the role of MafB-expressing cells during testis morphogenesis, employing PCR, microarray techniques, and genetic methods to determine which CAMs are regulated by MafB. In both aims, we will utilize several transgenic mouse lines for live imaging and fluorescence-activated cell sorting to study testis morphogenesis at the cellular level. This study of cell fate specification and cell-cell interactions will contribute to our basic understanding of organogenesis and provide insight into the developmental basis for infertility and reproductive disorders.

描述（由申请人提供）：我们的目标是了解细胞命运特化和细胞重组的机制，将胎儿性腺转化为功能性睾丸。睾丸器官发生的第一步是性腺原基中大约一半的体细胞向支持细胞命运的承诺。支持细胞围绕生殖细胞并经历从头索形成的过程。细胞分选的基本过程定义了睾丸的两个区室：睾丸索和间质。睾丸索将成为生精小管，成年时在其中产生精子，而产生雄激素的莱迪希细胞和其他特征不太明确的细胞群在间质中分化。尽管脐带的形成过程对于胎儿的男性化和成人的生育能力是必不可少的，但人们对它的了解还不多。它被认为是支持细胞驱动的过程;然而，一些证据表明，间质细胞在睾丸索形成过程中起着关键作用。在果蝇的性腺形态发生过程中，一个对细胞分选至关重要的基因是交通堵塞（tj）。tj编码Maf转录因子家族的一个成员，并通过调节细胞粘附分子（CAM）促进果蝇性腺的器官发生。tj的哺乳动物直系同源物MafB在未表征的祖细胞群中表达，所述祖细胞群在胎儿睾丸形成开始时从支持细胞中分选出来并产生睾丸的睾丸结节。MafB的表达与血管系统密切相关，后来仅限于胎儿Leydig细胞。我们推测MafB在睾丸细胞类型的特化和睾丸索的形成中起作用，可能通过控制CAM或细胞外基质（ECM）蛋白起作用。我们最近已经表明，Notch信号是必需的调节祖细胞群体在睾丸和Leydig细胞分化。在特定目标1中，我们将通过免疫细胞化学、原位杂交和定量PCR，使用体内和离体Notch功能获得和Ibss功能分析，研究Notch信号传导参与MafB表达细胞特化的假设。在具体目标2中，我们建议阐明MafB表达细胞在睾丸形态发生过程中的作用，采用PCR，微阵列技术和遗传学方法来确定哪些CAM受MafB调控。在这两个目标中，我们将利用几个转基因小鼠品系的活成像和荧光激活细胞分选研究睾丸形态发生在细胞水平上。这项研究的细胞命运规范和细胞间的相互作用将有助于我们的器官发生的基本理解，并提供深入了解不孕不育和生殖疾病的发展基础。