摘要
果蠅發育過程當中，EGFR訊號傳遞的過程是受到精確的調控。母果蠅卵巢是由許多的卵室所組合而成，卵室內的卵母細胞與濾泡細胞之間的交互作用決定其前後與背腹極性，進而決定未來胚胎的體軸，EGFR訊號傳遞路徑在此極性決定過程中扮演極為重要的角色。Kekkon-1為EGFR訊號傳遞路徑的標的基因，同時作為負性調控因子以調控EGFR活性，然而對於EGFR訊號傳遞路徑如何調控kekkon-1基因表現的詳細機制尚未被清楚的了解。為了尋找參與調控kekkon-1表現的分子，我們必須先找出負責調控kekkon-1表現的DNA序列。在我們實驗分析結果中，發現到kekkon-1上游3.2kb的區域就足以使kekkon-1表現在正常的位置。接著我們把這3.2kb DNA片段分為三個部份: F1、F2、F3，發現F3片段就足以使kekkon-1表現，此實驗結果可以得知負責調控kekkon-1表現的DNA序列應位在F3片段中。之後我們再把F3分成更小部份來分析，從此一系列的實驗，我們把負責調控kekkon-1表現的DNA序列縮小到更窄的範圍。
並列摘要
Epidermal growth factor receptor (EGFR) signaling is precisely regulated in space and time during Drosophila development. In the Drosophila ovary, both the anterior-posterior and dorsal-ventral axes of the egg chamber are established by cellular interations between germline cells and somatic follicle cells, and EGFR signaling is involved in the processes. Kekkon-1 (kek1), an EGFR targeted gene, acts in a negative feedback loop to regulate the activity of the EGF receptor, yet the detailed mechanisms of how EGFR signaling regulates the expression of kek1 during oogenesis remain unclear. To screen molecules required for kek1 expression, we need to identify the minimal kek1 enhancer. Here, we analyzed the kek1 locus, finding that 3.2kb region upstream of the kek1 transcriptional start is sufficient for kek1 expression, which is observed in the posterior follicle cells at early stages and in a triangle of dorsal-anterior follicle cells at stage 10B. We then dissect the 3.2kb region into three fragments: F1, F2, and F3, finding that only the F3 fragment (879 nucleotides) could provide the similar kek1 expression. The result suggests that the kek1 regulatory elements might be located in the F3 fragment. Later, further deletion analyses narrow the kek1 regulatory elements down.
並列關鍵字
無資料參考文獻
Boulet, A. M., and Scott, M. P. (1988). Control elements of the P2 promoter of the Antennapedia gene. Genes Dev 2, 1600-1614.
Brunner, D., Ducker, K., Oellers, N., Hafen, E., Scholz, H., and Klambt, C. (1994). The ETS domain protein pointed-P2 is a target of MAP kinase in the sevenless signal transduction pathway. Nature 370, 386-389.
French, R. L., Cosand, K. A., and Berg, C. A. (2003). The Drosophila female sterile mutation twin peaks is a novel allele of tramtrack and reveals a requirement for Ttk69 in epithelial morphogenesis. Dev Biol 253, 18-35.
Ghiglione, C., Carraway, K. L., 3rd, Amundadottir, L. T., Boswell, R. E., Perrimon, N., and Duffy, J. B. (1999). The transmembrane molecule kekkon 1 acts in a feedback loop to negatively regulate the activity of the Drosophila EGF receptor during oogenesis. Cell 96, 847-856.
Golembo, M., Yarnitzky, T., Volk, T., and Shilo, B. Z. (1999). Vein expression is induced by the EGF receptor pathway to provide a positive feedback loop in patterning the Drosophila embryonic ventral ectoderm. Genes Dev 13, 158-162.