CORRELATIONS BETWEEN CHROMOSOME SEGMENTS AND FITNESS INDROSOPHILA MELANOGASTER. IV. FECUNDITY, VIABILITY AND THE THIRD CHROMOSOME

Abstract

Unmarked segments within the 3rd chromosomes of 3 different D. melanogaster lines were assessed for their effects on egg production and egg viability. By making a series of crosses among original and derived recombinant lines, it was possible to estimate parameters representing additive, dominance (for egg production) and interaction effects of the segments. Each segment influences both traits, except to extents which are dependent on the genetic background provided by an adjacent segment. There is no clear pattern with respect to the segments'' joint effects on the 2 characters. Unlike previous studies involving the X chromosome, the majority of the derived recombinant lines were superior in fitness to their original lines. The agricultural implications of this result with respect to the manipulation of chromosomal segments to achieve higher yields are discussed.