Fig. 2

Morphology of the abdominal segments of the dCTCF mutants. (A) Scheme of BX-C (presented as a sequence coordinate line). The Ubx, Abd-A, and Abd-B transcripts are marked by horizontal black arrows. The boundary positions are indicated by vertical black bars with dotted lines. The mapped dCTCF-binding sites in the boundaries are indicated by red circles. (B) Morphology of the abdominal segments of the dCTCF mutants. Male (top) and female (bottom) abdominal cuticles are shown for lines expressing wt and mutant variants of dCTCF. The filled red arrowheads show morphological features indicative of transformations associated with increased or ectopic Abd-B expression. The empty red arrowheads indicate signs of transformations associated with decreased Abd-B expression relative to that in wt. The double-sided arrows indicate the size of the A7 tergite and female genitalia. Circular arrows indicate rotation of the male genitalia. Fertility was determined by the ability of males or females to produce offspring when crossed with males or females from the same line or y¹w¹¹¹⁸ line. “Fertile” means that the CTCF mutants produce offspring when crossed with each other. “Low fertile” means that the CTCF mutants cannot produce offspring when crossed with each other, but produce offspring when crossed with CTCF⁺ flies (y¹w¹¹¹⁸). “Sterile” means that the CTCF mutants cannot produce offspring when crossed with CTCF⁺ flies (y¹w¹¹¹⁸)