Cloning, differential tissue expression of a novel hcApo gene, and its correlation with total carotenoid content in purple and white inner-shell color pearl mussel Hyriopsis cumingii.
As a molecular carrier and storage protein, apolipoprotein (Apo) mediates the intracellular uptake of lipids, proteins, vitamins and carotenoids. In this study, we identified a novel Apo gene, designated hcApo, from the freshwater pearl mussel Hyriopsis cumingii. The complete hcApo cDNA consists of 4104 nucleotides with an open reading frame encoding 1155 amino acid residues. The hcApo protein contains a conserved lipoprotein N-terminal domain (LPD-N) that is a characteristic of the large lipid transfer protein (LLTP) superfamily. The hcApo mRNA is constitutively expressed in a wide range of tissues with the highest expression level in the liver. Moreover, differential expression analysis revealed that the hcApo gene is more highly expressed in the liver, kidney, mantle and gill of purple line mussels compared to white line mussels. In situ hybridization investigations of the precise expression site of hcApo mRNA in the mantle showed that hcApo mRNA is specifically expressed in the outer epithelial cells of the middle fold and the inner epithelial cells of the outer fold of the mantle, as well as throughout the outer epithelium of the outer fold and ventral mantle. Another very important finding is that significantly positive correlation existed between the hcApo gene expression level and the total carotenoid content in purple line mussels. These findings may provide a better understanding of the roles of hcApo in the molecular mechanisms of shell formation and coloring of H. cumingii.
Key Laboratory of Freshwater Fishery Germplasm Resources, Shanghai Ocean University, Ministry of Agriculture, Shanghai 201306, China.
Xilei
X
Li
Key Laboratory of Freshwater Fishery Germplasm Resources, Shanghai Ocean University, Ministry of Agriculture, Shanghai 201306, China.
Zhiyi
Z
Bai
Key Laboratory of Freshwater Fishery Germplasm Resources, Shanghai Ocean University, Ministry of Agriculture, Shanghai 201306, China.
Hongrui
H
Luo
Key Laboratory of Freshwater Fishery Germplasm Resources, Shanghai Ocean University, Ministry of Agriculture, Shanghai 201306, China.
Yue
Y
Liu
Key Laboratory of Freshwater Fishery Germplasm Resources, Shanghai Ocean University, Ministry of Agriculture, Shanghai 201306, China.
Guiling
G
Wang
Key Laboratory of Freshwater Fishery Germplasm Resources, Shanghai Ocean University, Ministry of Agriculture, Shanghai 201306, China; E-Institute of Shanghai Universities, Shanghai Ocean University, Shanghai 201306, China; Shanghai Engineering Research Center of Aquaculture, Shanghai Ocean University, Shanghai 201306, China. Electronic address: jlli2009@126.com.
Jiale
J
Li
D000595:Amino Acid Sequence; D000818:Animals; D001053:Apolipoproteins / Q000235:genetics* / Q000378:metabolism*; D001483:Base Sequence; D002338:Carotenoids / Q000378:metabolism*; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D015870:Gene Expression; D008969:Molecular Sequence Data; D010802:Phylogeny; D010858:Pigmentation / Q000235:genetics / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D014018:Tissue Distribution; D049876:Unionidae / Q000235:genetics* / Q000378:metabolism*
D001053:Apolipoproteins; D018076:DNA, Complementary; D012333:RNA, Messenger; D002338:Carotenoids
Apolipoprotein; Carotenoids; Gene expression; Hyriopsis cumingii; Inner-shell color