Jia Y, Xie G, Aamodt E
Department of Biochemistry and Molecular Biology, Louisiana State University Medical Center, Shreveport 71130-3932, USA.
Genetics. 1996 Jan;142(1):141-7. doi: 10.1093/genetics/142.1.141.
Mutations in a newly identified gene, pag-3, cause ectopic expression of touch neuron genes meo-7, mec-7lacZ and mec-4lacZ in the lineal sisters of the ALM touch neurons, the BDU neurons. Pag-3 mutants also show a reverse kinker uncoordinated phenotype. The first pag-3 allele was isolated in a screen for mutants with altered immunofluorescence staining patterns. Two additional pag-3 alleles were identified in a noncomplementation screen of 38,000 haploid genomes. All of the pag-3 alleles were recessive to wild type and cause the same phenotypes. Two-factor crosses, deficiency mapping and three-factor crosses located pag-3 to the right arm of the X chromosome between unc-3 and unc-7. Because recessive mutations in pag-3 result in expression of several touch cell specific genes in the BDU neurons, pag-3(+) must directly or indirectly suppress expression of these genes in the BDU neurons. Although pag-3 mutants did not show mec-3lacZ expression in their BDU neurons, expression of mec-7lacZ and mec-4lacZ in the BDU neurons of pag-3 mutants required mec-3(+).
新发现的基因pag - 3发生突变，会导致触觉神经元基因meo - 7、mec - 7lacZ和mec - 4lacZ在ALM触觉神经元的直系姐妹BDU神经元中异位表达。Pag - 3突变体还表现出反向扭结不协调的表型。首个pag - 3等位基因是在对免疫荧光染色模式改变的突变体进行筛选时分离得到的。在对38000个单倍体基因组进行的非互补筛选中又鉴定出另外两个pag - 3等位基因。所有pag - 3等位基因相对于野生型均为隐性，并导致相同的表型。双因子杂交、缺失定位和三因子杂交将pag - 3定位于X染色体右臂上unc - 3和unc - 7之间。由于pag - 3中的隐性突变会导致BDU神经元中几个触觉细胞特异性基因的表达，所以pag - 3(+)必定直接或间接抑制BDU神经元中这些基因的表达。虽然pag - 3突变体在其BDU神经元中未显示出mec - 3lacZ表达，但pag - 3突变体的BDU神经元中mec - 7lacZ和mec - 4lacZ的表达需要mec - 3(+)。
