The genetics of hemoglobin in hybrids—I. A molecular basis for hybrid vigor

Abstract

1. 1. Hemoglobins from various bird and fish hybrids have been studied by starch electrophoresis and by oxygen equilibrium analysis. In most crosses there are no new proteins—i.e. the electriphoretic patterns for hybrids and for mixtures of the parental hemoglobins are identical. 2. 2. In two of the centrarchid fish crosses the F 1's have new “hybrid hemoglobin” that occurs neither in the parents nor in hemoglobin mixtures. Oxygen equilibrium studies indicate that the “hybrid hemoglobin” has much stronger heme-heme interactions, thus resulting in a molecule with superior blood gas transport properties. 3. 3. Data have also been obtained on several F 2 hybrid populations and on a multiple cross. 4. 4. Besides the obvious significance of such studies for the biochemical basis of “hybrid vigor”, this new information on the proteins of hybrid animals is of potential phylogenetic interest, for the hemoglobin electrophoretic patterns of two species of the genus Microptenus can be closely approximated by chain recombination involving hemoglobins of two other species of this genus.