title: Neofunctionalization of zona pellucida proteins enhances freeze-prevention in the eggs of Antarctic notothenioids.
abstract: The mechanisms by which the eggs of the Antarctic notothenioid fishes avoid freezing are not fully understood. Zona pellucida proteins (ZPs) are constituents of the chorion which forms a protective matrix surrounding the egg. Here we report occurrence of freezing temperature-related gene expansion and acquisition of unusual ice melting-promoting (IMP) activity in a family of Antarctic notothenioid ZPs (AnnotoZPs). Members of AnnotoZPs are shown to bind with ice and non-colligatively depress the melting point of a solution in a range of 0.26 to 0.65 °C at a moderate concentration. Eggs of zebrafishes expressing an AnnotoZP transgene show improved melting point depression and enhanced survival in freezing conditions. Mutational analyses in a representative AnnotoZP indicate the ZP domain and patches of acidic residues are essential structures for the IMP activity. AnnotoZPs, therefore, represent a group of macromolecules that prevent freezing by a unique ZP-ice interaction mechanism distinct from the known antifreeze proteins.
authors.affiliation: Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.|Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Lixue
authors.initials: L
authors.lastname: Cao
authors.affiliation: Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Qiao
authors.initials: Q
authors.lastname: Huang
authors.affiliation: Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Zhichao
authors.initials: Z
authors.lastname: Wu
authors.affiliation: School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Dong-Dong
authors.initials: DD
authors.lastname: Cao
authors.affiliation: Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Zhanling
authors.initials: Z
authors.lastname: Ma
authors.affiliation: Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Qianghua
authors.initials: Q
authors.lastname: Xu
authors.affiliation: Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Hu
authors.affiliation: Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Yanxia
authors.initials: Y
authors.lastname: Fu
authors.affiliation: Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Shen
authors.affiliation: Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Jiulin
authors.initials: J
authors.lastname: Chan
authors.affiliation: School of Life Sciences, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Cong-Zhao
authors.initials: CZ
authors.lastname: Zhou
authors.affiliation: Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Wanying
authors.initials: W
authors.lastname: Zhai
authors.affiliation: Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources, Ministry of Education, College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China.
authors.forename: Liangbiao
authors.initials: L
authors.lastname: Chen
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D000864:Antarctic Regions; D021301:Antifreeze Proteins / Q000502:physiology*; D003080:Cold Temperature; D004252:DNA Mutational Analysis; D020224:Expressed Sequence Tags; D005615:Freezing; D016678:Genome; D008958:Models, Molecular; D009865:Oocytes / Q000502:physiology*; D010802:Phylogeny; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000378:metabolism; D013696:Temperature; D019076:Transgenes; D015027:Zebrafish / Q000235:genetics / Q000502:physiology*; D015044:Zona Pellucida / Q000502:physiology*
chemical_list: D021301:Antifreeze Proteins; D011994:Recombinant Proteins