Maternal transfer of complement components C3-1, C3-3, C3-4, C4, C5, C7, Bf, and Df to offspring in rainbow trout (Oncorhynchus mykiss).
Defense mechanisms in developing fish are poorly known but before maturation of lymphoid organs and immunocompetence, innate mechanisms are essential. The complement system represents a major part of innate immunity. Our main objective was to map the presence of complement components early in fish development. Rainbow trout eggs, embryos, and hatchlings were assayed for the onset and duration of C3-1, C3-3, C3-4, C4, C5, C7, factor B, and factor D transcription using real-time reverse transcription-polymerase chain reaction. In general, complement transcript levels increased steadily from day 28 postfertilization to hatch, followed by a decrease during yolk-sac resorption. All the complement proteins studied were found in unfertilized eggs. There was no correlation between the transcript and protein levels throughout the study period. Complement proteins appeared in the liver, kidney, and intestine between day 7 and 35 but not until day 77 in the heart. This study is the first to address the ontogeny of several complement components and represents the first evidence that maternal transfer of complement components, other than C3, occurs in teleost fish.
Løvoll
Marie
M
Department of Marine Biotechnology, Norwegian College of Fishery Science, University of Tromsø, Tromsø 9037, Norway.
Kilvik
Terje
T
Boshra
Hani
H
Bøgwald
Jarl
J
Sunyer
J Oriol
JO
Dalmo
Roy A
RA
D000818:Animals; D003176:Complement C3 / Q000378:metabolism; D003181:Complement C4 / Q000378:metabolism; D003182:Complement C5 / Q000378:metabolism; D003184:Complement C7 / Q000378:metabolism; D011415:Complement Factor B / Q000378:metabolism; D011416:Complement Factor D / Q000378:metabolism; D003165:Complement System Proteins / Q000032:analysis / Q000235:genetics / Q000378:metabolism*; D004625:Embryo, Nonmammalian / Q000737:chemistry / Q000276:immunology / Q000378:metabolism; D017686:Oncorhynchus mykiss / Q000196:embryology* / Q000235:genetics / Q000276:immunology*; D010063:Ovum / Q000737:chemistry / Q000276:immunology* / Q000378:metabolism; D012333:RNA, Messenger / Q000032:analysis / Q000378:metabolism; D014018:Tissue Distribution; D014158:Transcription, Genetic
D003176:Complement C3; D003181:Complement C4; D003182:Complement C5; D003184:Complement C7; D012333:RNA, Messenger; D003165:Complement System Proteins; D011416:Complement Factor D; D011415:Complement Factor B