멍게의 수압수용체세포 형성에서 FGF와 MEK 신호의 역할

Role of FGF and MEK Signaling in Formation of the Hydrostatic Pressure Receptor Cells during Ascidian Embryogenesis

  • 서형주 (강릉원주대학교 해양생명공학부) ;
  • 김길중 (강릉원주대학교 해양생명공학부)
  • Seo, Hyeong-Joo (Faculty of Marine Bioscience and Technology, Gangneung-Wonju National University) ;
  • Kim, Gil-Jung (Faculty of Marine Bioscience and Technology, Gangneung-Wonju National University)
  • 발행 : 2009.12.31

초록

멍게 유생의 뇌포에는 2개의 감각색소세포인 평형기와 안점 이외에 또 다른 감각세포로 추정되는 수압수용체세포가 존재한다. 수압수용체세포 형성에 관해서는 현재까지 거의 알려진 것이 없다. 본 연구에서는 수압수용체세포 형성에서 FGF 신호전달 과정의 관련성을 조사했다. 수정란에 Hr-FGF9/16/20 antisense MO를 미세주입했을 때, 발생한 유생에서 수압수용체세포 특이적 Hpr-1 항원의 발현이 검출되지 않았다. 32세포기부터 FGF 수용체 억제제 SU5402 및 MEK 억제제 U0126을 처리한 배아도 수압수용체세포를 갖지 못한 유생으로 발생했다. 다음으로 수압수용체세포 형성에 FGF 신호전달 과정이 관련되는 시기를 자세히 조사했다. 수압수용체세포 형성에는 FGF 수용체 활성이 16세포기부터 64세포기까지 필요하다는 것이 시사되었다. U0126은 8세포기부터 후기 낭배기까지 Hpr-1 항원 발현을 억제했다. Hpr-1 항원 발현은 신경판기 직전부터 U0126의 영향을 받지 않았다. 따라서, 멍게에서 수압수용체세포 형성은 1차 신경유도기부터 후기 낭배기까지 FGF 신호전달 과정을 필요로 한다는 것이 밝혀졌다.

In most larvae of ascidian, two sensory pigment cells, otolith and ocellus, lie in their brain vesicle. They also have a third type of sensory cells: hydrostatic pressure receptor (Hpr) cells. The Hpr cells were presumed to be hydrostatic pressure-detection cells, but their precise functions is still disputed. In this study, we investigated whether an FGF signaling is involved in formation of Hpr cells. When fertilized eggs were injected with Hr-FGF9/16/20 antisense MO, the resulting larvae showed severe abnormalities with no expression of the Hpr cell-specific Hpr-1 antigen. Similar results were obtained using an FGF receptor inhibitor, SU5402, and an MEK inhibitor, U0126. Embryos treated with SU5402 or U0126 during the 32-cell and hatching stages did not express the Hpr-1 antigen. To elucidate the temporal requirement for the FGF signaling in formation of Hpr cells, embryos were treated with SU5402 for 2 h, or U0126 for 20 min during various embryonic stages. Larvae treated with SU5402 from the 16-cell stage to the 64-cell stage did not express the Hpr-1 antigen, whereas those treated at the early gastrula stage expressed the Hpr-1 antigen. When U0126 treatment was carried out at various stages between the 8-cell and late gastrula stages, larvae scarcely formed the Hpr cells. They showed expression of the Hpr-1 antigen when embryos were placed in U0126 just before the neural plate stage. These results suggest that FGF9/16/20 signaling is involved in formation of Hpr cells from the primary neural induction stage to the late gastrula stage.

키워드

참고문헌

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