Characterization of the isoforms of type IIb sodium-dependent phosphate cotransporter (Slc34a2) in yellow catfish, Pelteobagrus fulvidraco, and their vitamin D3-regulated expression under low-phosphate conditions.
In this study, two isoforms slc34a2 genes (type IIb sodium-dependent phosphate cotransporter), slc34a2a2 and slc34a2b, were cloned from intestine and kidney of yellow catfish (Pelteobagrus fulvidraco), with rapid amplification of cDNA ends. The structure differences and the regulation effects of dietary VD3under low phosphorus were compared among three isoforms of slc34a2 in yellow catfish. The predicted Slc34a2a2 and Slc34a2b proteins match 65 % and 53.8 % sequence identity, with Slc34a2a1, respectively. The membrane-spanning domains were different among these three isoforms. Intestinal Slc34a2a1 and Slc34a2a2 proteins had eight and eleven transmembrane domains, while renal Slc34a2b protein had nine. The tissue distribution study showed that same as slc34a2a1, slc34a2a2 mRNA was mainly distributed in intestine and slc34a2b mRNA in kidney. The effect of vitamin D3(VD3) level on slc34a2 subfamily expression under low-phosphate conditions, induced by the addition of 0 (VD0), 324 (VD1), 1243 (VD2), 3621 (VD3), 8040 (VD4), or 22700 (VD5) IU VD3/kg feed, was assessed by qPCR. The dose-responsive expression of intestinal slc34a2a2 and high expression of intestinal slc34a2a2 in VD5 together with peak expression of kidney slc34a2b in VD3 coincided with the accumulation of body phosphate content. These data suggested that appropriate level of dietary VD3up-regulated slc34a2a1, slc34a2a2, and slc34a2b mRNA levels, which increased phosphate retention. In conclusion, the current study provided another possible approach to improve dietary phosphate utilization by adding appropriate level of VD3to a low-phosphate diet to regulate intestinal and renal slc34a2 gene expression and thus minimize the excretion of phosphorus in yellow catfish.
The College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China.|Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, People's Republic of China.|Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan, 430070, People's Republic of China.
Pei
P
Chen
East China Sea Fisheries Research Institute, Chinese Academy of Fishery Science, Shanghai, 200090, People's Republic of China.
Yanqing
Y
Huang
Department of Aquaculture, Faculty of Fisheries, Atatürk University, 25240, Erzurum, Turkey.
Abdulkadir
A
Bayir
The College of Fisheries, Huazhong Agricultural University, Wuhan, 430070, People's Republic of China. cfwang@mail.hzau.edu.cn.|Freshwater Aquaculture Collaborative Innovation Center of Hubei Province, Wuhan, 430070, People's Republic of China. cfwang@mail.hzau.edu.cn.|Key Laboratory of Freshwater Animal Breeding, Ministry of Agriculture, Wuhan, 430070, People's Republic of China. cfwang@mail.hzau.edu.cn.
Chunfang
C
Wang
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002397:Catfishes / Q000235:genetics*; D002762:Cholecalciferol / Q000494:pharmacology*; D018076:DNA, Complementary / Q000235:genetics; D029941:Fish Proteins / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects; D007413:Intestinal Mucosa / Q000378:metabolism; D007668:Kidney / Q000378:metabolism; D010710:Phosphates / Q000378:metabolism; D010802:Phylogeny; D020033:Protein Isoforms / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism; D050614:Sodium-Phosphate Cotransporter Proteins, Type IIb / Q000235:genetics*
D018076:DNA, Complementary; D029941:Fish Proteins; D010710:Phosphates; D020033:Protein Isoforms; D012333:RNA, Messenger; D050614:Sodium-Phosphate Cotransporter Proteins, Type IIb; D002762:Cholecalciferol
Gene expression; Isoforms of slc34a2; Low-phosphate diet; Molecular characterization; Vitamin D3