WEKO3
アイテム
ヒラメ栽培漁業における親魚の遺伝的管理に関する研究
https://fra.repo.nii.ac.jp/records/2010809
https://fra.repo.nii.ac.jp/records/201080983193783-405e-406a-8a05-8610ce1ff67c
| 名前 / ファイル | ライセンス | アクション |
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fra_k_11_31.pdf (2.1 MB)
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| Item type | 紀要論文 / Departmental Bulletin Paper(1) | |||||||||||
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| 公開日 | 2024-10-02 | |||||||||||
| タイトル | ||||||||||||
| タイトル | ヒラメ栽培漁業における親魚の遺伝的管理に関する研究 | |||||||||||
| 言語 | ja | |||||||||||
| タイトル | ||||||||||||
| タイトル | Studies on genetic management of hatchery broodstock in relation to the stock enhancement of Japanese flounder Paralichthys olivaceus | |||||||||||
| 言語 | en | |||||||||||
| 言語 | ||||||||||||
| 言語 | jpn | |||||||||||
| キーワード | ||||||||||||
| 言語 | en | |||||||||||
| 主題Scheme | Other | |||||||||||
| 主題 | Japanese flounder; Genetic markers; Population genetics; Conservation genetics; Stock enhancement | |||||||||||
| 資源タイプ | ||||||||||||
| 資源タイプ識別子 | http://purl.org/coar/resource_type/c_6501 | |||||||||||
| 資源タイプ | departmental bulletin paper | |||||||||||
| アクセス権 | ||||||||||||
| アクセス権 | open access | |||||||||||
| アクセス権URI | http://purl.org/coar/access_right/c_abf2 | |||||||||||
| 著者 |
關野, 正志
× 關野, 正志
WEKO
526
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| 抄録 | ||||||||||||
| 内容記述タイプ | Abstract | |||||||||||
| 内容記述 | From the viewpoint of genetic conservation, this study presents application of molecular genetic markers to the population genetics studies of Japanese flounder Paralichthys olivaceus in order to propose several broodstock management options related to the stock enhancement. A (CA)n-microsatellite enriched library of Japanese flounder was constructed using an efficient method to isolate microsatellite DNA regions, from which 16 PCR primer pairs to amplify microsatellites with a high amplification effectiveness were developed. Genetic variability of these loci varied depending on the locus, and all but one of the 16 loci conformed to Hardy-Weinberg's equilibrium (HWE). Mendelian inheritability of these loci was verified in five experimental families of Japanese flounder excepting one instance. The locus at which the significant HWE departure was observed had unstable and unreproducible PCR amplification of a particular allele in one family. These results suggest that 15 out of the 16 microsatellites are viable for further applications to the wide range of the Japanese flounder population genetics studies. Genetic variability and structure maintained in wild Japanese flounder populations (seven populations) were assessed by using 11 microsatellites coupled with the nucleotide sequences of mitochondrial DNA (mtDNA) control region to outline the genetic stock management units. The 11 microsatellites examined showed considerable polymorphisms in all populations, and the section of mtDNA sequences examined was highly variable. Assessment of the genetic structure based on the 11 microsatellites revealed that 11 population pairs in 21 possible pairwise comparisons yielded significant genetic heterogeneities in terms of allele frequency distributions and/or pairwise FST values, and an overall FST value provided evidence of the genetic structuring among the seven populations, although these inter-populational genetic heterogeneities were not necessarily supported by the results of mtDNA sequencing analysis. According to the population relationships estimated from the phylogenetic trees based on the genetic distances (DA and DST) and the results of several hierarchical AMOVA analyses, which were calculated on the basis of the microsatellite data, the seven populations were possibly assigned into three groups consistent with the oceanogeographic positions of the populations. Although the level of the genetic differentiation between the groups was weak, the genetic management of wild flounder should be applied along with the group definitions so as to preserve the currently detectable genetic stock units. Level of genetic variability maintained in currently available hatchery strains was compared with that of wild populations. Three Japanese flounder hatchery strains were screened by means of microsatellite and mtDNA sequencing analysis, and both the number of microsatellite alleles and mtDNA haplotypes, and mtDNA haplotype diversity showed marked reductions in the hatchery strains relative to the comparable three wild populations. Pedigree structure of a hatchery strain was detailed in order to illustrate a skewed contribution of broodstock parents to the next generation, which may possibly cause a reduced effective population size, by using microsatellite profiling technique. The pedigrees of offspring including 113 individuals of larvae sampled within 24 hours after hatching, 216 individuals of one-month-old, and 407 individuals of four-month-old were unambiguously identified. The contribution of candidate broodstock parents (18 individuals) to the next generation was highly skewed as one male of the six males used monopolized the contribution to the offspring pool, and a half of the females (6 of 12 females) did not produce any offspring. The contribution of one family to the released fish, which were culled for larger size in total length, was significantly higher, while those of other two families were lower, suggesting that culling operations for particular traits might cause a large family size variance of released fish through selection in favor of a few family lineages. Culling operations for particular traits thus should be avoided as much as possible to minimize the risk of unexpected pedigree structure to be a possible cause of the reduced effective size. Possible way to retard loss of genetic variations in closed and non-pedigreed captive populations of Japanese flounder was explored by using a microsatellite-based kinship estimator (rxy statistic). The difference of pairwise rxy values among and between full-sib, half-sib, and unrelated categories in a hatchery strain was highly significant, suggesting that the rxy statistic would have a high utility to discriminate kinships. Minimal kinship (mk) selection approach based on the rxy statistic, which is a breeding strategy to minimize loss of genetic variability in captive populations, turned out to be effective in retention of both allelic diversity and gene diversity; this strategy however did not necessarily select unrelated fish as parents to create the next generation. It should thus be necessary to preclude the mating between highly related individuals in the selected fish by using the rxy statistic as a kinship indicator so as to minimize the risk of inbreeding. From the results presented above, the present author discusses here several hatchery management options for further practical hatchery operations to minimize the genetic impact of stocking practice to the wild Japanese flounder populations. | |||||||||||
| 言語 | en | |||||||||||
| 抄録 | ||||||||||||
| 内容記述タイプ | Abstract | |||||||||||
| 内容記述 | 近年の生物多様性の保全に対する関心の高まりとともに，種内に維持されている遺伝的多様性の重要性が認識されるようになってきた。遺伝的多様性の損失は，種が潜在的に持っている再生産力，環境変動への適応性，疾病に対する抵抗力等の低下を導くおそれがある。栽培漁業における種苗生産では，少数の天然魚または継代飼育個体を親魚として用いることが多いため，一般的に種苗の遺伝的多様性は低下している。遺伝学的観点から見た栽培漁業の問題点として，人工種苗の大量放流により，天然魚群の遺伝的多様性が低下し，天然魚が潜在的に持つ生産力が減少すること，また育種素材としての遺伝子資源の損失を招くリスクがあることが挙げられる。ヒラメ Paralichthys olivaceusは，重要な増養殖対象種となっており，全国の沿岸域で栽培漁業が展開されている。これまでのヒラメ人工種苗生産では，遺伝的多様性の保全に対する関心は高いとは言えず，疾病・斃死防除による効率的大量生産に焦点が当てられてきた。今後の種苗生産では，量的な到達目標を設定するだけでなく，種苗の遺伝的多様性を高く保ち，天然資源への遺伝的影響を最小限にするという，遺伝的な質の向上を目指していく必要がある。本研究では，ヒラメのDNAマーカーを開発し，それを用いて，天然魚と放流種苗の保有する遺伝的多様性・特徴を把握した上で，人工種苗の遺伝的多様性の損失を軽減しうる種苗生産法について考察した。本論文は全 7 章で構成される。第 1 章で研究の背景と目的について述べ，第 2 章では，ヒラメのマイクロサテライトDNA 座を単離し，DNAマーカーとしての利用性・妥当性を検証した。第 3 章では，マイクロサテライトDNA解析とミトコンドリアDNA調節領域シーケンス解析により，天然ヒラメ集団の持つ遺伝的多様性を見積もるとともに，その遺伝的集団管理単位を把握するため，地域間の遺伝的異質性を調べた。第 4 章で，実際のヒラメ人工種苗と天然魚集団の遺伝的多様性を比較し，第5章では，マイクロサテライトDNAマーカーをヒラメ人工種苗の親子判別技術に応用して，本手法の人工種苗の遺伝的多様性モニタリングにおける有効性を実証した。第6章では，マイクロサテライトDNAマーカーを用いて人工種苗の血縁関係の推定を試み，それを指標とした遺伝的多様性の損失を軽減するための種苗生産法について考察した。第7章では，今後のヒラメ種苗生産のあり方について言及した。 | |||||||||||
| 言語 | ja | |||||||||||
| 書誌情報 |
ja : 水産総合研究センター研究報告 en : Bulletin of Fisheries Research Agency 巻 11, p. 31-91, ページ数 61, 発行日 2004-03 |
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| 出版者 | ||||||||||||
| 出版者 | 水産総合研究センター | |||||||||||
| 言語 | ja | |||||||||||
| ISSN | ||||||||||||
| 収録物識別子タイプ | PISSN | |||||||||||
| 収録物識別子 | 1346-9894 | |||||||||||
| 書誌レコードID | ||||||||||||
| 収録物識別子タイプ | NCID | |||||||||||
| 収録物識別子 | AA11589591 | |||||||||||
| 情報源 | ||||||||||||
| 識別子タイプ | Local | |||||||||||
| 関連識別子 | fra_k_11_31 | |||||||||||
| 関連サイト | ||||||||||||
| 識別子タイプ | URI | |||||||||||
| 関連識別子 | https://agriknowledge.affrc.go.jp/RN/2010692581 | |||||||||||
| 関連名称 | 日本農学文献記事索引（AgriKnowledge） | |||||||||||
| 著者版フラグ | ||||||||||||
| 出版タイプ | VoR | |||||||||||
| 出版タイプResource | http://purl.org/coar/version/c_970fb48d4fbd8a85 | |||||||||||
