Figure 4.—

Genetic and developmental DNA polymorphisms associated with Cbs 1R-4G. DNAs from mass cultures of young B and C3 homozygotes (<30 fissions old) and from B/C3 heterozygotes passaged for at least 500 fissions (panel of terminal assortants; see materials and methods) were PCR amplified using the Tel and Cbs 1R-4G primers. The SB prefix has been omitted from the names of the terminal assortants (1805–1821). The major size difference (compare B and C3 lanes) is determined by the germline-encoded allele difference; the allele assorted to purity is indicated under each lane. The minor, within-allele size variation (e.g., compare assortants 1810–1812) is developmental and results from telomere addition site microheterogeneity associated with chromosome breakage during MAC differentiation (see text).