EXPERIMENTAL PHENOCOPY OF A MINUTE MATERNAL-EFFECT MUTATION ALTERS BLASTODERM DETERMINATION IN EMBRYOS OF DROSOPHILA-MELANOGASTER
EXPERIMENTAL PHENOCOPY OF A MINUTE MATERNAL-EFFECT MUTATION ALTERS BLASTODERM DETERMINATION IN EMBRYOS OF DROSOPHILA-MELANOGASTER
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DOI：
10.1016/0012-1606(89)90231-5
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发表时间：
1989-04-01
影响因子：
2.7
通讯作者：
SCHUBIGER, G
中科院分区：
文献类型：
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作者：
BORING, LF;SINERVO, B;SCHUBIGER, G
第三条染色体微小基因M(3)i55的母源单倍体剂量不足在早期胚胎发生的合胞体核周期期间使蛋白质合成速率降低约30%。Mi55的母源效应还在幼虫的后腹部产生分节缺陷（齿带融合）。此外，来自微小基因母亲的胚胎在胚胎发生的细胞胚盘阶段显示分节基因fushi tarazu（ftz）的异常表达模式。我们开发了一种计算机辅助分析来描述ftz表达的偏差，这表明在幼虫中发生融合的体节原基中出现异常狭窄的ftz条带。出乎意料的是，在未发生异常发育的体节原基中出现异常宽的ftz条带。此外，Mi55使所有ftz条带间区域普遍变窄。我们通过向野生型胚胎注射环己酰亚胺，使其蛋白质合成速率降低到与微小基因胚胎相当的水平，从而模拟了微小基因突变。因此，早期胚胎发生期间蛋白质合成的普遍降低导致后腹部体节原基的异常决定。
Maternal haploinsufficiency for a third chromosome Minute, M(3)i55, lowers rates of protein synthesis by .apprx. 30% during the syncytial nuclear cycles of early embryogenesis. The maternal effect of Mi55 also produces segmentation defects (denticle belt fusions) in the posterior abdomen of larvae. Furthermore, embryos from Minute mothers show abnormal expression patterns of the segmentation gene fushi tarazu (ftz) at the cellular blastoderm stage of embryo-genesis. We developed a computer-aided analysis to describe the deviations in ftz expression which demonstrates that abnormally narrow ftz stripes occur in segment primordia that become fused in the larva. Unexpectedly, an abnormally wide ftz stripe occurs in segment primordia which do not develop abnormally. In addition, Mi55 produces a general narrowing of all ftz- interstripes. We phenocopied the Mintue mutation by injecting wild-type embryos with cycloheximide concentrations which decreased protein synthesis rates to levels comparable with those of Minute embryos. Thus, a general decrease in protein synthesis during early embryogenesis leads to abnormal determination of posterior abdominal segment primordia.