Technau G M, Campos-Ortega J A
Proc Natl Acad Sci U S A. 1987 Jul;84(13):4500-4. doi: 10.1073/pnas.84.13.4500.
In embryos of Drosophila melanogaster the development of a pluripotent cell in the neurogenic ectoderm as a member of either a neural or an epidermal lineage depends on its interactions with neighboring cells. Certain genes, designated neurogenic, participate in this process in that there is a deficiency of epidermal histotypes in mutant embryos lacking neurogenic gene functions. To test the cell autonomy of expression of the neurogenic phenotype, individual cells were transplanted from the neurogenic ectoderm of mutant donor embryos into wild-type host embryos. Cells transplanted from donors homozygous for any of several mutant alleles of the neurogenic genes amx, N, bib, mam, neu, and Dl were found to give rise to clones exhibiting a distribution of neural and epidermal histotypes similar to that of the wild type. By contrast, cells transplanted from donors homozygous for loss of the neurogenic E(spl) gene gave rise exclusively to clones of neural histotypes. Thus, only the expression of E(spl) is autonomous, with that of all of the other tested neurogenic genes being nonautonomous. These results are consistent with the inference that the nonautonomous genes provide a source and the autonomous gene provides a receptor of a hypothetical intercellular regulatory signal that is necessary for cell commitment to an epidermal rather than neural fate.
在黑腹果蝇胚胎中，神经外胚层中多能细胞发育为神经谱系或表皮谱系的一员，这取决于其与相邻细胞的相互作用。某些被称为神经源性的基因参与了这一过程，因为在缺乏神经源性基因功能的突变胚胎中，表皮组织类型存在缺陷。为了测试神经源性表型表达的细胞自主性，将单个细胞从突变供体胚胎的神经外胚层移植到野生型宿主胚胎中。发现从神经源性基因amx、N、bib、mam、neu和Dl的几个突变等位基因纯合的供体移植的细胞产生的克隆表现出与野生型相似的神经和表皮组织类型分布。相比之下，从神经源性E(spl)基因缺失的纯合供体移植的细胞仅产生神经组织类型的克隆。因此，只有E(spl)的表达是自主的，而所有其他测试的神经源性基因的表达是非自主的。这些结果与以下推断一致：非自主基因提供一种来源，而自主基因提供一种假设的细胞间调节信号的受体，这种信号对于细胞确定为表皮而非神经命运是必需的。
