Inter-Research > DAO > v133 > n3 > p253-261  
DAO
Diseases of Aquatic Organisms

via Mailchimp

DAO 133:253-261 (2019)  -  DOI: https://doi.org/10.3354/dao03349

MHC Class IIB gene polymorphisms associated with resistance/susceptibility to Streptococcus agalactiae in Nile tilapia Oreochromis niloticus

Feng-Ying Gao1,2, Dong Zhang1,2,3, Mai-Xin Lu1,2,*, Jian-Meng Cao1,2, Zhi-Gang Liu1,2, Xiao-Li Ke1,2, Miao Wang1,2, De-Feng Zhang1,2

1Pearl River Fisheries Research Institute, Chinese Academy of Fishery Science, Guangzhou 510380, PR China
2Key Laboratory of Tropical & Subtropical Fishery Resource Application & Cultivation, Ministry of Agriculture, Guangzhou 510380, PR China
3National Demonstration Center for Experimental Fisheries Science Education, Shanghai Ocean University, Shanghai 201306, PR China
*Corresponding author:

ABSTRACT: Genetic variation in the major histocompatibility complex (MHC) Class IIB was tested in Nile tilapia Oreochromis niloticus, and the association between the MHC IIB alleles and disease resistance were also studied. F3 fry offspring (n = 1200) from 12 full-sib families were challenged with Streptococcus agalactiae, which caused significantly different mortalities in different Nile tilapia families (11.00-81.10%). Twenty fry (F1) from each of the 12 families were selected to study the polymorphisms of the MHC Class IIB gene using PCR followed by cloning and sequencing methods. The results showed that the size of the amplified fragment was 770-797 bp. Thirty-seven sequences from 240 individuals revealed 22 different alleles, which belonged to 9 major allele types. Up to 63.58% of nucleotide positions were variable, while the proportion of the amino acid variable positions was up to 68.73%. According to the survival rate of offspring (F3) from 12 full-sib families, we deduced that the alleles Orni-DAB*0107, Orni-DAB*0201 and Orni-DAB*0302 were highly associated with resistance to S. agalactiae, while the allele Orni-DAB*0701 was associated with susceptibility to S. agalactiae. In addition, our previous study found that the allele Orni-DAB*0201 was more frequently distributed in the disease-resistant groups. Therefore, the allele Orni-DAB*0201 could be used as an S. agalactiae resistance-related MHC marker in molecular marker-assisted selective breeding programs for S. agalactiae-resistant Nile tilapia.


KEY WORDS: Nile tilapia · MHC Class IIB · Streptococcus agalactiae · Disease resistance


Full text in pdf format 
Cite this article as: Gao FY, Zhang D, Lu MX, Cao JM and others (2019) MHC Class IIB gene polymorphisms associated with resistance/susceptibility to Streptococcus agalactiae in Nile tilapia Oreochromis niloticus. Dis Aquat Org 133:253-261. https://doi.org/10.3354/dao03349

Export citation
Mail this link - Contents Mailing Lists - RSS
Facebook - - linkedIn