HOXA 13 REGULATION OF GENITOURINARY DEVELOPMENT

描述（改编自应用程序） 转录因子Hoxa 13的无义突变导致严重的 泌尿生殖系统（GU）畸形。在人类中，失去Hoxa 13 功能引起家族性手足生殖器综合征（HFGS）， 尿道下裂前列腺、子宫、苗勒管、阴道膀胱、输尿管。和 直肠缺陷在小鼠中，这些发育途径是保守的， Hoxa 13的靶向破坏导致细胞的畸形或发育不全， 前列腺、子宫、尿道、输尿管、苗勒管、阴道、直肠和 膀胱这些结构的发展最有趣的是， 它们中的许多是由未分化的间充质的浓缩形成的。最近， 我证明了Hoxa 13调节肢体中的间充质凝聚， 通过控制指导细胞间粘附的基因来控制脐血管系统（UV）， 凋亡和身份。因为HFGS中受影响的许多结构 来源于间充质凝聚。我假设遗传途径 受HAP 13调节，介导肢体和UV发育， 正常发展的区域。 为了验证这一假设，使用具有框内GFP报告基因的Hoxa 13突变小鼠， 将用于Hoxa 13 GFP等位基因产生强烈的Hoxa 13特异性信号 在受影响的GU地区。该信号促进了 通过荧光激活细胞分选（FACS）的同质细胞群体 表达Hoxa 13的解剖组织。通过FACS纯化的间充质细胞 将对来自突变体和对照胚胎的受影响区域的 体外检测基因表达、细胞粘附、凋亡和 可以解释特定畸形的扩散。这些FACS 富集细胞还将用作基于RNA和cDNA的基因资源 发现方法来鉴定由Hoxa 13调控的其他基因， 在GU发展中发挥作用。一旦确定， 将使用小鼠/仓鼠辐射测定Hoxa 13特异性靶基因 杂交DNA板。任何一种基因的图谱位置和胚胎表达模式 新发现的基因将提供给研究界， 提供了一个资源，以确定未知的遗传成分参与良性 前列腺增生、恶性肿瘤和GU畸形。上位性 Hoxa 13和羟睾酮之间的关系将使用 结合体外筛选的Hoxa 13 GFP报告细胞系， 识别激活Hoxa 13的基因。这种独特的实验设计使得 从细胞和组织的角度研究GU的发展， 失去了Hoxa 13的功能从这个角度来看，洞察基因 并获得正常GU发育所需的细胞机制。

DESCRIPTION (adapted from the application) Nonsense mutations in the transcription factor Hoxa 13 result in severe malformations of the genitourinary (GU) region. In humans, loss of Hoxa 13 function causes familial hand-foot-genital syndrome (HFGS), resulting in hypospadia. prostate, uterine, Mullerian duct, vaginal bladder, ureter. and rectal defects. In mice, these developmental pathways are conserved, as targeted disruption of' Hoxa 13 results in malformation or agenesis of the prostate, uterus, urethra, ureter, MuIlerian ducts, vagina, rectum, and bladder. What is intriguing about the development of these structures is that many of them form from condensations of undifferentiated mesenchyme. Recently, I demonstrated that Hoxa 13 regulates mesenchymal condensation in the limb and umbilical vasculature (UV) by controlling genes that-direct cell-cell adhesion, apoptosis, and identity. Because many of the structures affected in HFGS are derived from mesenchymal condensations. I hypothesize that the genetic pathways regulated by Hoxal13, to mediate limb and UV development also function to direct normal development of the GU region. To test this hypothesis, a Hoxa 13 mutant mouse with an in-frame GFP reporter will be used. The Hoxa 13 GFP allele produces a strong, Hoxa 13-specific signal in the affected GU regions. This signal facilitates the enrichment of homogeneous populations of cells by fluorescence-activated cell sorting (FACS) from dissected tissues expressing Hoxa 13. Mesenchyme cells purified by FACS from the affected regions of mutant and control embryos will be characterized in vitro for changes in gene expression, cell adhesion, apoptosis, and proliferation that could account for specific malformations. These FACS enriched cells will also be used as a resource for RNA-and cDNA-based gene discovery methodologies to identify additional genes regulated by Hoxa 13 that play a role in GU development. Once identified, the chromosomal localization of Hoxa 13 specific target genes will be determined using mouse/hamster radiation hybrid DNA panels. The map positions and embryonic expression patterns of any newly identified genes will be made available to the research community, providing a resource to identify unknown genetic components involved in benign prostate hyperplasias, malignancies, and GU malformations. The epistatic relationship between Hoxa 13, and dhydroxytestosterone will be determined using a Hoxa 13 GFP reporter cell line in conjunction with in vitro screen, to identify genes that activate Hoxa 13. This unique experimental design allows study of GU development from the, perspective of the cells and tissues most affected by loss of Hoxa 13 function. From this perspective, insight genetic and cellular mechanisms required for normal GU development will be gained.