Neofunctionalization of a duplicate hatching enzyme gene during the evolution of teleost fishes

2014 Fiscal Year Final Research Report

• Project/Area Number: 24770230
• Research Category: Grant-in-Aid for Young Scientists (B)
• Allocation Type: Multi-year Fund
• Research Field: Evolutionary biology
• Research Institution: Josai University (2013-2014); Sophia University (2012)
• Principal Investigator: SANO Kaori 城西大学, 理学部, 助手 (70612092)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 新規機能獲得遺伝子 / 孵化酵素

Outline of Final Research Achievements

In teleosts, hatching enzyme gene diversification has occurred in the common ancestor of Otocephala and Euteleostei, such that members of these subdivisions possess two types of hatching enzyme genes, belonging to clade I and clade II. Our previous study suggested that the clade I enzyme maintained the ancestral function, while the clade II enzyme gained new function (neofunctionalization). Ｍedaka Oryzias latipes ,belonging to Euteleostei, hatch by cooperative action of clade I and II enzymes, and the substrate specificities of them are completely different. To elucidate the amino acid substitutions important for change of substrate specificity, the recombinant clade I enzyme which was substituted nine of the two hundreds amino acids to clade II enzyme type (clade I mut9) was generated by E. coli expression system. The clade I mut9 changed the substrate specificity to be similar to that of clade II enzyme, and cleaved the peptides designed from clade II enzyme specific cleavage sites.

Free Research Field

機能進化学