Localization of an abundant myeloid-related sequence

Differential screening of a CML-derived cDNA library was used to isolate a cDNA clone representing an abundant mRNA in leukocytes of chronic phase, chronic myelogenous leukemia (CML) patients. This myeloid-related sequence (mrs) comprises approximately 2% of the chronic phase, CML mRNA. Hybridization of the radiolabeled cDNA to the cellular RNAs of intact, morphologically distinguishable, primary hematopoietic cells indicates that the primary cells producing mrs RNA are eosinophils (Eo), basophils (Baso), promyelocytes (Pro) and myelocytes (Mye). In the neutrophilic series, the abundance of mrs RNA decreases as the cells mature. The mrs RNA potentially encodes a 93 amino acid protein that has not been previously described. It has been localized to chromosome 8, region 8q21.1-23.