M. Murphy et al., Molecular cloning of an Atlantic salmon nucleoside diphosphate kinase cDNAand its pattern of expression during embryogenesis, GENE, 257(1), 2000, pp. 139-148
To gain insight into the process of development in Atlantic salmon (Salmo s
alar), we sought to identify genes that were differentially expressed at ga
strulation. A polymerase chain reaction-based differential screening strate
gy allowed for the isolation of an Atlantic salmon nucleoside diphosphate k
inase cDNA (nm23). Structural characterisation showed a high degree of homo
logy with a large number of previously isolated nucleoside diphosphate kina
ses (NM23s), both prokaryote and eukaryote, though it represents the first
teleost nucleoside diphosphate kinase identified. Highest similarities were
found with the type 1 and type 2 NM23 isoforms of mammals. Phylogenetic an
alysis indicates that the duplication event that gave rise to these isoform
s occurred after the splitting of tetrapods and fish, suggesting that the s
almon NM23 represents a more ancestral isoform. The position of the salmon
sequence on the phylogenetic tree indicates that the salmon genome is expec
ted to have at least three copies of genes from the nm23 gene family. North
ern blot analysis showed a single transcript of approximately 0.7 kb in bot
h embryonic and adult tissues. Examination of the temporal pattern of expre
ssion of salmon nucleoside diphosphate kinase during embryonic development
revealed that this gene is first expressed at the time of gastrulation. Nuc
leoside diphosphate kinases are thought to have a vital role in regulatory
processes such as signal transduction, proliferation and differentiation. T
aken together, these results suggest that nucleoside diphosphate kinases ha
ve an important role to play in early embryogenic development in vertebrate
s. (C) 2000 Elsevier Science B.V. All rights reserved.