Abstract:
Five complete cDNA sequences related to Wnt/β-catenin signal pathway, designated
wnt2,
wnt2
bb,
wnt3
a,
wnt8
a and
ctnnb1, were amplified by RT-PCR and RACE approaches from yellow catfish (
Pelteobagrus fulvidraco). The validated cDNAs encoding
wnt2,
wnt2
bb,
wnt3
a,
wnt8
a and
ctnnb1 were 1 743, 2 133, 1 379, 1 508 and 2 636 bp in length, encoding peptides of 351, 372, 291, 387 and 791 amino acid residues, respectively. The amino acid alignment and phylogenetic analysis revealed that these sequences were relatively conserved among vertebrates, and Wnt/β-catenin genes of
P. fulvidraco were more closely related to those of
Astyanax mexicanus. All Wnt/β-catenin mRNAs were expressed in nine tested tissues (brain, spleen, kidney, gill, heart, muscle, mesenteric fat, liver and ovary), but at variable levels. Effect of waterborne Cu exposure on ovarian mRNA levels of the five genes of
P. fulvidraco were determined. On day 28,
wnt3
a mRNA levels in the ovary significantly decreased with increasing waterborne Cu concentration, but
wnt8
a showed the opposite trend. On day 56, mRNA levels of these five genes from the ovary of
P. fulvidraco showed no significant differences among the three groups. The present study may be helpful to understand the physiological functions of Wnt/β-catenin pathway in fish.