The HINT1 and HINTW responsive element(s) in WDR36 proximal promoter region

• Main Authors: Ling-Yi Huang, 黃齡誼
• Other Authors: Shiue, Y.L.
• Format: Others
• Language: en_US
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/00109166517901166248

碩士 === 國立中山大學 === 生物醫學研究所 === 98 === Two hypotheses currently exist regarding to the determining factors for sexual development and differentiation in birds. One is based on the unbalanced sex chromosome, meaning that avian sex determination is dominated by “Z-chromosome dosage”. The other brings up (reconsider this) the key factor of “W chromosome” which is a particular sex chromosome in female birds (ZW). In the previous studies, we constructed a female-subtract-male cDNA library before morphological gonad differentiation. After sequencing and annotation, a total of 279 expression sequence taqs (ESTs) were identified, with potentially higher expression levels in females. By utilizing quantitative RT-PCR, 16 potential ESTs and three marker transcripts (HINT1, FET1 and WDR36), which identified to be involved in sexual development at 3, 5, 7, 9 days post-coitum (dpc) was analyzed in chicken embryos. Results indicated that AGR2, CPT2, DUSP19, HINTW, LOC771368 and EY53070791 had higher expression levels in female than in male embryos at 3 and 5 dpc; FET1 expression level in female embryos gradually increased from 3 to 9 dpc. Moreover, both HINT1 and WDR36 were higher expressed in male than in female embryos across 3 to 9 dpc. However, HINT1 exhibited higher expression levels starting at early stage, whereas WDR36 at later stage. Next, we constructed HINT1-GFP fusion protein and overexpressed this protein in chicken B-cell line (DT40), resulting in upregulation of WDR36 expression. On the contrary, overexpressed HINTW-GFP fusion protein in DT40 cells had decreased WDR36 expression level. Moreover, we designed a small hairpin RNA by utilizing RNA interference technique to knockdown expression of HINTW, which resulted in WDR36 upregulation. Finally, we then estimated the regulation of WDR36 promoter activity through analyzing HINT1-GFP overexpression. Results had shown that HINT1-GFP can improve WDR36 promoter activity. Therefore, we suppose that HINT1 can regulate WDR36 transcription via WDR36 proximal promoter region. Ongoing HINT1 responsive element(s) must be identified to characterize whether HINT1 or HINTW regulates WDR36.