Study on the mechanism of antibody transport to avian egg yolks by PLA2R receptor and its application to produce eggs rich in IgY

2023 Fiscal Year Final Research Report

• Project/Area Number: 20H03128
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Basic Section 42010:Animal production science-related
• Research Institution: Nagoya University
• Principal Investigator: Murai Atsushi 名古屋大学, 生命農学研究科, 教授 (10313975)
• Co-Investigator(Kenkyū-buntansha): 水島 秀成 北海道大学, 理学研究院, 助教 (20515382)
• Project Period (FY): 2020-04-01 – 2023-03-31
• Keywords: 畜産学 / 栄養生理学 / ニワトリ / 卵 / IgY / 抗体 / 母子免疫

Outline of Final Research Achievements

Avian IgY antibodies are accumulated in egg yolks to protect against infection, and they are essential for strengthening the immune function of the next generation of chicks. In this study, we aimed to examine that PLA2R is the receptor responsible for IgY transport to the egg yolk. By investigating localization of PLA2R expression in the ovary, we found that PLA2R is expressed in the terminal capillaries of the theca cell layer of the ovarian follicle. Binding analysis of IgY mutants to PLA2R showed that the mutant with high transport efficiency (G365A) had strong binding activity to PLA2R, while the mutants with low transport efficiency (G365D, N408A) had weak binding activity to PLA2R. As an exception, the Y363A mutant, which is not transported to the egg yolk, was found to have a significantly strong binding affinity to PLA2R and was difficult to dissociate. Therefore, it was found that PLA2R is the key receptor that regulates IgY transport to the egg yolk.

Free Research Field

栄養生理学

Academic Significance and Societal Importance of the Research Achievements

PLA2Rが鳥類の母子免疫を制御する鍵受容体であることが明らかにされたことで、母子免疫という多くの生物種が保有する事象の仕組みの一端が明らかとなった。そして、FcRY/IgY相互作用を制御することで、鳥類の卵黄中のIgY量を増やし、鳥類の新生ヒナの免疫力を高めるための新しい戦略を提供できる可能性を秘める。遺伝子改変されたFcRY/IgY相互作用によって引き起こされる免疫異常も慎重に考慮した上で、今後の研究戦略を練る必要があろう。