멍게 배 발생에서 미토콘드리아의 비대칭 분포 조절
Control of asymmetric distribution of mitochondria during ascidian embryogenesis
- 주제(키워드) 도움말 Ascidian , Asymmetric cell division , Mitochondria , Monoclonal antibody , MEK signaling
- 발행기관 강릉원주대학교 일반대학원
- 지도교수 도움말 김길중
- 발행년도 2015
- 학위수여년월 2016. 2
- 학위명 석사
- 학과 및 전공 도움말 일반대학원 해양응용생명공학과
- 실제URI http://www.dcollection.net/handler/kangnung/000000008142
- 본문언어 한국어
초록/요약 도움말
In animal development, the mechanisms by which localized factors and organelles in egg cytoplasm were exactly distributed into each daughter cell are essential for formation of various cell types. Thus, asymmetric cell divisions are one of the significant issues in developmental biology. Although the mechanisms have been thought to be important for the proper embryonic development, our understanding has remained limited. In the present study, distribution of mitochondria-rich cytoplasm was examined in embryos of the ascidian, Halocynthia roretzi, by immunohistochemical staining with a mitochondria-specific monoclonal antibody 101. Results of the immunostaining of mitochondria coincided with those of vital staining with DiOC2(3), which are able to detect mitochondrial distribution in cytoplasm of ascidian embryos. During Halocynthia embryogenesis, ooplasmic mitochondria were mainly segregated into epidermis, muscle, and neural precursor cells. At the 8-cell stage, mitochondria were segregated into the posterior cytoplasm of the B4.1 blastomeres. During the next stages, mitochondria were preferentially distributed into cells of the B-line muscle and the A-line nerve cord precursor compared with each sister cell. In these blastomeres, mitochondria were asymmetrically localized into the marginal regions before each cleavage. The 110-cell stage embryos showed asymmetric distribution of mitochondria in the blastomeres of the vegetal hemisphere. However, mitochondria were divided equally among the blastomeres of the animal hemisphere between the 8-cell and the 110-cell stages. In animal blastomeres, mitochondria were converging on the center of cell, around the nuclei, just before each cell division. When embryos were treated with MEK inhibitor U0126 between the 32-cell and the early 64-cell stages, the resultant 110-cell stage embryos showed symmetric distribution of mitochondria in the blastomeres of the vegetal hemisphere. In these embryos, the B6.2 blastomeres made equal daughter cells in size and symmetric distribution of mitochondria occurred at the next two cell division. However, blocking of Nodal and Notch signaling between the 32-cell and 110-cell stages did not affect cell division pattern and mitochondrial distribution in the cells of the vegetal hemisphere. Therefore, it is likely that MEK signaling is involved in asymmetric distribution of mitochondria in the vegetal blastomeres and unequal cleavage of the B6.2 lineage cells in the ascidian embryo.
more목차 도움말
I. 서론 . 1
II. 재료 및 방법 . 6
1. 실험동물
2. Immunofluorescence staining
3. Inhibition of MEK, Nodal and Notch signaling
III. 결과 8
1. 101 항체의 특이성
2. 멍게 배아의 발생 단계별 미토콘드리아의 분포
3. MEK signaling과 미토콘드리아의 분포
IV. 고찰 22
V. 참고문헌. 24
