GENETIC INTERACTIONS COORDINATING PIEBALD SPOTTING

协调花斑斑点的遗传相互作用

• 批准号: 6108971
• 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/6108971
• 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.

观察到的黑色和白色斑点图案， 花斑小鼠由异常神经嵴发育引起 由于内皮素受体B（EDNRB）突变。严重程度 和分布的色素模式有很大的不同， 携带s突变的近交系（Mayer/s和C3H s/s）。我们 假设额外的基因可能负责 协调所观察到的图案的差异。定量 这两个品系回交后代的遗传分析 鉴定了位于染色体2、5、8上的四种遗传修饰剂 和10. 10号染色体上的修饰符增加了背侧 斑点比腹侧斑点多2倍（19.7%对9.1%，p <0.05）。 0.0001），表明该修饰符对 颜料图案测绘数据分析表明，钢（桅杆 细胞生长因子）作为该基因座的候选基因。序列 cDNA分离物的比较没有表明在 编码区，但在稳态水平的差异 用北方印迹法分析成虫组织中的mRNA。 Steel基因的基因组结构比较 12/12的限制性内切酶显示， DNA片段的大小，但没有观察到差异 两个非连锁基因EDNRB和内皮素3。这些结果 表明在Mayer品系中观察到的背部斑点增加 是由于一个突变，改变了钢表达 模式。我们已经测试了这一假设，通过使用交叉之间的 Mayer品系和Steel无效小鼠。与我们的假设一致， Steel的Mayer等位基因不能与Steel无效突变互补 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 还将探索研究以确定分子改变， 和每个修饰基因座的相互作用。