title: The polymorphism of lysozyme gene in Zhikong scallop (Chlamys farreri) and its association with susceptibility/resistance to Listonella anguillarum.
abstract: Lysozyme functions as a crucial biodefence effector against the infection of bacterial pathogens in innate immunity. The nucleotide sequence polymorphisms in promoter region of a nuclear goose type lysozyme gene from Zhikong scallop Chlamys farreri (designated as CFLysG) were investigated to explore their association with susceptibility/resistance to Listonella anguillarum infection. Eight sites of single nucleotide polymorphisms (SNPs) and two sites of insert-deletion (ins-del) polymorphisms were identified in the promoter region of CFLysG. Two of them, -753 TATCTCGATCAGG ins-del polymorphism and -391 A-G SNP were selected to analyze their distribution in the susceptible and resistant stocks, which were identified according to the survival time after L. anguillarum challenge. Using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), two genotypes were found at each site, which were ins/del and ins/ins at locus -753, and A/A and A/G at locus -391, respectively. The -753 ins/del genotype was more prevalent in the resistant stock than that in the susceptible stock, 30% vs 16.67% in frequency, but there was no significant difference in the frequency distribution between these two stocks (P=0.15). In contrast, the frequency of -391A/G genotype in the resistant stock was significantly higher (30%) than that in the susceptible stock (7.14%) (P=0.007), indicating a significant association with the resistance of Zhikong scallop to L. anguillarum. To confirm the presumption, another independent challenge experiment was performed, in which the cumulative mortality of scallops with -391 A/A genotype (96.8%) was significantly higher than those with -391 A/G genotype (64.5%) (P=0.001), which further validate the association between -391 A/G genotype and the resistance of Zhikong scallop to L. anguillarum. These results suggested that the -391 A/G could be a potential marker applied in future selection of Zhikong scallop with enhanced resistance to L. anguillarum.
authors.affiliation: Institute of Oceanology, Chinese Academy of Sciences, 7 Nanhai Rd., Qingdao 266071, China.
authors.forename: Ling
authors.initials: L
authors.lastname: Li
authors.forename: Jianmin
authors.initials: J
authors.lastname: Zhao
authors.forename: Lingling
authors.initials: L
authors.lastname: Wang
authors.forename: Limei
authors.initials: L
authors.lastname: Qiu
authors.forename: Huan
authors.initials: H
authors.lastname: Zhang
authors.forename: Chaohua
authors.initials: C
authors.lastname: Dong
authors.forename: Ming
authors.initials: M
authors.lastname: Cong
authors.forename: Linsheng
authors.initials: L
authors.lastname: Song
mesh_terms: D000818:Animals; D001483:Base Sequence; D005838:Genotype; D053526:Listonella / Q000502:physiology*; D009113:Muramidase / Q000235:genetics*; D049897:Pectinidae / Q000201:enzymology / Q000235:genetics / Q000382:microbiology; D010641:Phenotype; D011110:Polymorphism, Genetic; D011401:Promoter Regions, Genetic / Q000235:genetics; D016415:Sequence Alignment
chemical_list: D009113:Muramidase