2022 Fiscal Year Final Research Report
Elucidation of egg buoyancy acquisition mechanism and its evolutionary biological background in teleosts
| Project/Area Number |
20K15581
|
|---|
| Research Category |
Grant-in-Aid for Early-Career Scientists
|
| Allocation Type | Multi-year Fund |
|---|
| Review Section |
Basic Section 40030:Aquatic bioproduction science-related
|
|---|
| Research Institution | Ehime University |
|---|
Principal Investigator |
Nishimiya Osamu 愛媛大学, 南予水産研究センター, 特定助教 (10824138)
|
|---|
| Project Period (FY) |
2020-04-01 – 2023-03-31
|
| Keywords | スマ / 卵黄形成 / 浮遊性卵 / ビテロジェニン / 2型Vtgシステム / Vtgプロモーター / エストロジェン応答性配列 / 繁殖生理学 |
|---|
| Outline of Final Research Achievements |
The objective of this study was to elucidate the regulatory mechanism of vtg transcription in kawakawa (Euthynnus affinis) and its involvement in the accumulation of vtg subtypes in oocytes.
The hepatic expression levels of three types of vitellogenins (vtgs) in mature female kawakawa were compared. The results revealed that the expression levels of vtgAa and vtgAb were higher than that of vtgC, but no significant difference was observed between the two vtgs. On the other hand, the promoter sequences of vtgAa and vtgAb differed in the number of estrogen-responsive sequences. Therefore, it is possible that both promoters exhibit distinct responsiveness to E2, which may lead to variations in expression levels depending on the stage of ovarian development. This study provides essential knowledge for understanding the regulatory mechanism of vtg transcription in this species.
|
| Free Research Field |
水産
|
| Academic Significance and Societal Importance of the Research Achievements |
魚類の産卵様式は、一般的に系統分類学的に古いグループでは水に沈む「沈性卵」を生む一方、真骨魚では海水中で浮く卵「浮遊性卵」を生むものが登場した。これにより産卵域が広範囲に広がり、現在では多様性・資源量ともに最も繁栄する海産魚類グループが形成されたと推察される。浮遊性卵の形成機構は、2種の Vtgに由来する卵黄タンパク質が卵母細胞内に取り込まれた際の蓄積比率により「軽い卵」、「重い卵」の調節がなされると考えられている。しかし、その蓄積比率の調節機構は明らかになっておらず、また系統進化上この機構を獲得するにあたった経緯は未解明であり、本研究は学術・水産業の両面に有益な基礎的知見を提供するに至った。
|
