Early embryos of inviable hybrids between female masu salmon Oncorhynchus masou masou and male rainbow trout Oncorhynchus mykiss at 9, 12, 15 and 20 days after fertilization were examined for protein expression profiles. A total of 44 proteins, mostly down-regulated products of house-keeping genes and those involved in nucleic acid metabolism or chromatin replication, were identified in hybrid embryos by mass spectrometry analysis and protein database searching. The identified down-regulated proteins may be responsible for the inviability in the hybrids.
© 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.