GENETIC SEGREGATION AND DEVELOPMENTAL PHASING OF CHICK FETAL-LEUKEMIC ANTIGEN

The patterns of genetic segregation and developmental phasing of chicken fetal-leukemic antigen (CFA) are reported for the pigeon and duck. Pigeon RBC's lose two CFA determinants with development: CFA 6 between 6-7 days post-hatch and CFA I at 8-9 days following hatching. Duck RBC's undergo rapid phasing of CFA, with several determinants appearing and disappearing within a few days during embryogeny. Acquisition and loss of these determinants correspond with quantitative changes in the agglutinability of embryonic duck RBC's with rabbit antisera specific for CFA.The developmental appearance of CFA determinant 10 on pigeon RBC's was found to undergo genetic segregation in individual pigeons within two breeding populations. CFA 10 is first detected on pigeon RBC's between 33-34 days after hatching and its appearance appears to be under the control of an autosomal recessive gene. No segregation was observed for any CFA determinants in either the mallard or Pekin ducks.CFA 6 and 10 were found to be present as cryptic determinants on adult pigeon (lacking CFA determinant 10 (10-)) RBC's. Treatment with neuraminidase, but not trypsin or protease, exposed both determinants. Possible explanations involving the genetic segregation and developmental phasing of CFA in pigeons and ducks are discussed. © 1979 AMERICAN GENETIC ASSOCIATION.