표제지
목차
Abstract 13
Ⅰ. 서론 15
Ⅱ. 양식산 참조기의 번식생리학적 특성 21
1. 서론 21
2. 재료 및 방법 23
2.1. 실험어 및 사육조건 23
2.2. 생식소 조직학적 분석 26
2.3. 혈중 성호르몬 농도 측정 27
2.4. 생식선자극호르몬(GtHs) 유전자 탐색 및 발현량 분석 28
2.5. 통계처리 31
3. 결과 32
3.1. 실내 사육환경 및 생식소숙도지수(GSI) 변화 32
3.2. 생식소의 조직학적 관찰 35
3.3. 혈중 성호르몬 농도 변화 40
3.4. 생식선자극호르몬(GtHs) 유전자 탐색 및 발현량 43
3.5. 실내 사육조건에서의 산란 특성 48
4. 고찰 50
Ⅲ. 환경 조절에 의한 조기 산란 유도 54
1. 서론 54
2. 재료 및 방법 56
2.1. 실험어 및 환경조건 56
2.2. 광주기가 성성숙 유도에 미치는 영향 57
2.3. 수온이 성성숙 유도에 미치는 영향 59
2.4. 광주기와 수온 복합조절이 성성숙 유도에 미치는 영향 61
2.5. 환경 조절에 의한 성성숙과 조기 산란 유도 63
2.6. 혈중 성호르몬 농도 및 생식소 발달 분석 65
2.7. 통계처리 65
3. 결과 66
3.1. 광주기가 성성숙 유도에 미치는 영향 66
3.2. 수온이 성성숙 유도에 미치는 영향 74
3.3. 광주기와 수온 복합조절이 성성숙 유도에 미치는 영향 82
3.4. 환경 조절에 의한 성성숙과 조기 산란 유도 90
4. 고찰 92
4.1. 광주기가 참조기의 성성숙 유도에 미치는 영향 92
4.2. 수온이 참조기의 성성숙 유도에 미치는 영향 93
4.3. 광주기와 수온 복합조절이 성성숙 유도에 미치는 영향 95
4.4. 환경 조절에 의한 성성숙과 조기 산란 유도 96
Ⅳ. 양식산 참조기의 성 분화 98
1. 서론 98
2. 재료 및 방법 100
2.1. 참조기 인공종자의 성 분화 시기 조사 100
2.2. 수온이 참조기의 성비에 미치는 영향 104
3. 결과 105
3.1. 참조기의 생식소 성 분화 시기 105
3.2. 수온이 참조기의 성비에 미치는 영향 107
4. 고찰 109
Ⅴ. 종합 결론 112
Ⅵ. 참고문헌 115
Table 1. Aquaculture production of Small yellow croaker, Larimichthys polyactis. 20
Table 2. Quantitative reverse transcription-PCR (qPCR) assay primers used in this study. 30
Table 3. Summarized information on the results of Next Generation Sequencing (NGS) of pituitary gland. 44
Table 4. Genbank accession number of the sexual maturation-related genes from the pituitary gland of Larimichthys polyactis. 44
Table 5. Manipulation of environment factors for artificial seed production of small yellow coraker, Larimichthys polyactis. 64
Table 6. Effects of water temperature on the sex ratio of small yellow croaker, Larimichthys polyactis. 108
Figure 1. The yearly catch of Small yellow croaker, Larimichthys polyactis, in Korean waters. 19
Figure 2. Egg collection cage (a) and collected eggs (b) of the small yellow croaker, Larimichthys polyactis. 25
Figure 3. Changes in water temperature and photoperiod during a year at Jeju, Republic of Korea. The gray rectangle indicates the spawning period. 33
Figure 4. Bimonthly changes in gonadosomatic index (GSI) (black bar, male; white bar, female) of cultured yellow croaker, Larimichthys polyactis.... 34
Figure 5. Histological observation of the ovaries of a cultured female small yellow croaker, Larimichthys polyactis. (a) Feb., (b) Apr., (c) Jun., (d) Aug., (e) Oct., (f) Dec. Scale bars=100 um. N, nucleus; Nu, nucleolus; Od, oil droplet; Pn,... 36
Figure 6. Bimonthly changes in oocyte diameter in the ovaries of cultured female small yellow croaker, Larimichthys polyactis. (a) Feb., (b) Apr., (c)... 37
Figure 7. Histological observation of the testes of cultured male small yellow croaker, Larimichthys polyactis. (a) Feb., (b) Apr., (c) Jun., (d) Aug., (e) Oct., (f) Dec. Scale bars=20 um. Sc, spermatocytes; Sg, spermatogonia; St, spermatids; Sz,... 39
Figure 8. Bimonthly changes in steroid hormone levels (white plot, T; black plot, E₂) in cultured female yellow croaker, Larimichthys polyactis. Different... 41
Figure 9. Bimonthly changes in steroid hormone levels (white plot, T; black plot, 11-KT) in cultured male yellow croaker, Larimichthys polyactis. Different... 42
Figure 10. Relative gene expression levels of GPα, FSHβ and LHβ from the pituitary gland of cultured female small yellow croaker, Larimichthys... 46
Figure 11. Relative gene expression levels of GPα, FSHβ and LHβ from the pituitary gland of cultured male small yellow croaker, Larimichthys... 47
Figure 12. Amount of eggs spawned during natural spawning of cultured small yellow croaker, Larimichthys polyactis, in 2018. 49
Figure 13. The photoperiod of each experimental group during the experimental period. The black bar indicates the adjustment period (7 days).... 58
Figure 14. Water temperature of each experimental group during the experimental period. The black bar indicates the adjustment period (7 days).... 60
Figure 15. Water temperature and photoperiod of each experimental group during the experimental period. The black bar indicates the adjustment... 62
Figure 16. Effect of various photoperiods on the gonadosomatic index (GSI) of cultured male small yellow croaker, Larimichthys polyactis. The data are... 67
Figure 17. Effect of various photoperiods on the gonadosomatic index (GSI) of cultured female small yellow croaker, Larimichthys polyactis. The data are... 69
Figure 18. Changes in sex steroid hormone levels (T, 11-KT) of cultured male small yellow croaker, Larimichthys polyactis, under various... 71
Figure 19. Changes in sex steroid hormone levels (T, E₂) of cultured female small yellow croaker, Larimichthys polyactis, under various... 73
Figure 20. Effect of various water temperatures on GSI of cultured male small yellow croaker, Larimichthys polyactis. The data are presented as... 75
Figure 21. Effect of various water temperatures on GSI of cultured female small yellow croaker, Larimichthys polyactis. The data are presented as... 77
Figure 22. Changes in sex steroid hormone levels (T, 11-KT) of cultured male small yellow croaker, Larimichthys polyactis, at various water... 79
Figure 23. Changes in sex steroid hormone levels (T, E₂) of cultured female small yellow croaker, Larimichthys polyactis, at various water... 81
Figure 24. Effect of water temperature and photoperiod on GSI of cultured male small yellow croaker, Larimichthys polyactis. The data are presented as... 83
Figure 25. Effect of water temperature and photoperiod on GSI of cultured female small yellow croaker, Larimichthys polyactis. The data are presented... 85
Figure 26. Changes in sex steroid hormone levels (T, 11-KT) of cultured male small yellow croaker, Larimichthys polyactis, during the experimental... 87
Figure 27. Changes in sex steroid hormone levels (T, E₂) of cultured female small yellow croaker, Larimichthys polyactis, during the experimental... 89
Figure 28. Volume of spawning eggs by induction of early spawning on Feb to Mar. 91
Figure 29. The aquaculture method of larval small yellow croaker, Larimichthys polyactis. DAH, days after hatcing. 102
Figure 30. Early gonadogenesis and sex differentiation of cultured small yellow croaker, Larimichthys polyactis. (a) 20 day after hatching (DAH) (X40), (b) 30 DAH (X400), (c) 40 DAH (X400), (d) 50 DAH (X200), (e) 60 DAH (X100), and (f) 70 DAH... 106