The expression of the allelic gene of murine C3 in fetal and neonatal mice.
A single co-dominant gene locus linked to H-2, tentatively designated C3-1 locus by us, controls allotypic variation of murine complement (C) C3 as previously described. We used this genetically determined variation of murine C3 as a marker in the probe for the synthesis of this C component in fetal and neonatal mice. Phenotypes of murine C3 were determined by a combined use of analytical isoelectric focusing and immunofixation and by antigenic analysis with alloantiserum directed to the gene product of one of the alleles at the C3-1 locus. Fetuses and neonates of inbred mice (BALB/c and NC strains), F1 hybrids, and backcross progeny express the same C3 phenotype as the one observed in adult mice of the corresponding C3 genotype. No evidence for the occurrence of "fetal C3" in fetal mice was obtained. Furthermore, allotypic differences of C3 between mother and fetus or neonates provide evidence that murine C3 is synthesized by fetus or neonate and is not transferred from mother transplacentally nor via colostrum. In summary, mice synthesize C3 according to the allelic structural gene(s) at the C3-1 locus even during their early developmental life.
D000483:Alleles; D000818:Animals; D000831:Animals, Newborn; D003176:Complement C3 / Q000096:biosynthesis / Q000235:genetics*; D005260:Female; D005333:Fetus; D005838:Genotype; D008297:Male; D008431:Maternal-Fetal Exchange; D051379:Mice; D008807:Mice, Inbred BALB C; D010641:Phenotype; D011247:Pregnancy; D011817:Rabbits
D003176:Complement C3