Abstract：
How complex morphological patterns form is an intriguing question in developmental biology. However, the mechanisms that generate complex patterns remain largely unknown. Here, we sought to identify the genetic mechanisms that regulate the tan (t) gene in a multi-spotted pigmentation pattern on the abdomen and wings of Drosophila guttifera. Previously, we showed that yellow (y) gene expression completely prefigures the abdominal and wing pigment patterns of this species. In the current study, we demonstrate that the t gene is co-expressed with the y gene in nearly identical patterns, both transcripts foreshadowing the adult abdominal and wing melanin spot patterns. We identified cis-regulatory modules (CRMs) of t, one of which drives reporter expression in six longitudinal rows of spots on the developing pupal abdomen, while the second CRM activates the reporter gene in a spotted wing pattern. Comparing the abdominal spot CRMs of y and t, we found a similar composition of putative transcription factor binding sites that are thought to regulate the complex expression patterns of both terminal pigmentation genes y and t. In contrast, the y and t wing spots appear to be regulated by distinct upstream factors. Our results suggest that the D. guttifera abdominal and wing melanin spot patterns have been established through the co-regulation of y and t, shedding light on how complex morphological traits may be regulated through the parallel coordination of downstream target genes.
摘要：
复杂的形态模式如何形成是发育生物学中一个有趣的问题。然而,产生复杂模式的机制在很大程度上仍然未知。这里,我们试图确定在果蝇腹部和翅膀上多点色素沉着模式中调节tan（t）基因的遗传机制。以前,我们表明，黄色（y）基因表达完全预示了该物种的腹部和机翼色素模式。在目前的研究中,我们证明t基因与y基因以几乎相同的模式共表达，两个转录本都预示着成人腹部和翼黑色素斑点的模式。我们确定了t的顺式监管模块(CRM)，其中之一在发育中的p腹部上的六排纵向斑点中驱动记者表达，而第二个CRM以斑点机翼模式激活报告基因。比较y和t的腹点CRM，我们发现了一个类似的组成推定转录因子结合位点，被认为是调节两个终末色素沉着基因y和t的复杂表达模式。y和t翼点似乎受不同的上游因素调节。我们的结果表明，通过共同调节y和t，阐明如何通过下游靶基因的平行协调来调节复杂的形态性状。
