Conservation of CD1 protein expression patterns in the chicken.

The CD1 molecules are cell-surface proteins that bind and present foreign lipids and glycolipids to T cells in a manner similar to the MHC system. While the mammalian CD1 antigen presentation pathway is well characterized, little is known about CD1 in non-mammalian vertebrates. Previous studies have identified two CD1 homologues in the chicken.

Cycles of chromosome instability are associated with a fragile site and are increased by defects in DNA replication and checkpoint controls in yeast.

We report here that a normal budding yeast chromosome (ChrVII) can undergo remarkable cycles of chromosome instability. The events associated with cycles of instability caused a distinctive "sectoring" of colonies on selective agar plates. We found that instability initiated at any of several sites on ChrVII, and was sharply increased by the disruption of DNA replication or by defects in checkpoint controls.