Lineage‐specific evolution of zona pellucida genes in fish. Issue 3 (21st February 2022)

• Record Type: Journal Article
• Authors: Sano, Kaori; Shimada, Sho; Mibu, Hideki; Taguchi, Mizuki; Ohsawa, Takasumi; Kawaguchi, Mari; Yasumasu, Shigeki
• Is Part Of: Journal of experimental zoology. Volume 338:Issue 3(2022)
• Page Start: 181
• Page End: 191
• Publication Date: 2022-02-21
• Subjects: change in synthesis organ -- egg envelope -- teleost evolution -- zona pellucida; Developmental biology -- Periodicals; Evolution (Biology) -- Periodicals; Molecular evolution -- Periodicals; Zoology -- Periodicals; Evolution, Molecular -- Periodicals; Developmental Biology -- Periodicals; Zoology -- Periodicals; 591
• DOI: 10.1002/jez.b.23122
• Languages: English
• ISSNs: 1552-5007

Abstract

Abstract: The zona pellucida (ZP) protein constitutes the egg envelope, which surrounds the vertebrate embryo. We performed a comprehensive study on the molecular evolution of ZP genes in Teleostei by cloning and analyzing the expression of ZP genes in fish of Anguilliformes in Elopomorpha, Osteoglossiformes in Osteoglossomorpha, and Clupeiformes in Otocephala to cover unsurveyed fish groups in Teleostei. The present results confirmed findings from our previous reports that the principal organ of ZP gene expression changed from ovary to liver in the common ancestors of Clupeocephala. Even fish species that synthesize egg envelopes in the liver carry the ovary‐expressed ZP proteins as minor egg envelope components that were produced by gene duplication during the early stage of Teleostei evolution. The amino acid repeat sequences located at the N‐terminal region of ZP proteins are known to be the substrates of transglutaminase responsible for egg envelope hardening and hatching. A repeat sequence was found in zona pellucida Cs of phylogenetically early diverged fish. After changing the synthesis organ, its role is inherited by the N‐terminal Pro‐Gln‐Xaa repeat sequence in liver‐expressed zona pellucida B genes of Clupeocephala. These results suggest that teleost ZP genes have independently evolved to maintain fish‐specific functions, such as egg envelope hardening and egg envelope digestion, at hatching. Abstract : Summary of the types and expression localization of ZP genes in teleosts Species added in the present study are underlined. The ZP gene, which is known as a major component of the egg envelope, and other genes are separately shown. Highlights: During teleostei evolution, several ZP‐gene duplication events have led to changes in the synthesis site of the egg envelope and fish‐specific evolution, which is closely related to the formation of the egg envelope and its hardening and hatching.