GENETIC INTERACTIONS COORDINATING PIEBALD SPOTTING

协调花斑斑点的遗传相互作用

• 批准号: 6290285
• 负责人: William J Pavan
• 金额: --
• 依托单位: NATIONAL HUMAN GENOME RESEARCH INSTITUTE
• 依托单位国家: 美国
• 资助国家: 美国
• 起止时间: 至
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/6290285
• 关键词: complementary DNA; developmental genetics; gene expression; gene interaction; gene mutation; genetic mapping; genetic strain; laboratory mouse; messenger RNA; neural plate /tube; northern blottings; nucleic acid sequence; pigmentation; receptor expression

The black and white spotting pattern observed in piebald (s) mice results from abnormal neural crest development due to a mutation in endothelin receptor B (EDNRB). The severity and distribution of the pigment patterns are vastly different in two inbred strains carrying the s mutation (Mayers/s and C3H s/s). We hypothesized that additional genes may be responsible for coordinating the differences in patterning observed. Quantitative genetic analysis of backcross progeny from these two strains identified four genetic modifiers located on Chromosomes 2, 5, 8 and 10. The modifier on Chromosome 10 increases the dorsal spotting 2-fold more than ventral spotting (19.7% vs 9.1%, p < 0.0001), suggesting this modifier has spatial or temporal affects on pigment patterning. Analysis of mapping data implicates Steel (mast cell growth factor) as a candidate gene for this locus. Sequence comparison of cDNA isolates did not indicate any differences in the coding region, however differences in the level of steady state mRNA in adult tissues was observed by Northern blot analyses. Comparison of the genomic structure of the Steel gene demonstrated 12/12 restriction enzymes showing differences in the size of DNA fragments, however no differences were observed in two un-linked genes, EDNRB and endothelin 3. These results suggest the increased dorsal spotting observed in the Mayer strain of s mice is due to a mutation that alters the Steel expression pattern.We have tested this hypothesis by using crosses between the Mayer strain and Steel null mice. Consistent with our hypothesis, the Mayer allele at Steel cannot complement a Steel null mutation and results in increased dorsal spotting. Future studies using embryonic reconstitution experiments and expression pattern studies will also be explored to determine the molecular alterations and interactions at each modifier locus. - biotechnology research, cancer research, digestive diseases, gene mapping(non-human), neuroscience, pediatric research,

在花斑小鼠中观察到的黑色和白色斑点图案是由内皮素受体B（EDNRB）突变引起的异常神经嵴发育引起的。色素模式的严重程度和分布在两个携带s突变的近交系（Mayer/s和C3 H s/s）中有很大不同。我们假设，额外的基因可能负责协调观察到的模式的差异。从这两个菌株的回交后代的定量遗传分析确定了四个遗传修饰位于染色体2，5，8和10。10号染色体上的修饰子使背侧斑点比腹侧斑点增加2倍（19.7%对9.1%，p < 0.0001），表明该修饰子对色素图案具有空间或时间影响。映射数据的分析暗示钢（肥大细胞生长因子）作为该位点的候选基因。cDNA分离物的序列比较没有表明编码区的任何差异，但是通过北方印迹分析观察到成体组织中稳态mRNA水平的差异。Steel基因的基因组结构的比较表明，12/12限制性内切酶显示DNA片段大小的差异，但在两个未连锁的基因EDNRB和内皮素3中没有观察到差异。这些结果表明，在Mayer品系小鼠中观察到的背部斑点增加是由于改变Steel表达模式的突变所致。我们通过Mayer品系小鼠和Steel缺失小鼠之间的杂交来验证这一假设。与我们的假设一致，Steel的Mayer等位基因不能补充Steel无效突变，并导致背部斑点增加。未来的研究使用胚胎重建实验和表达模式的研究也将探讨，以确定在每个修饰基因座的分子改变和相互作用。- 生物技术研究，癌症研究，消化系统疾病，基因图谱（非人类），神经科学，儿科研究，