A form of gene conversion (q.v.) rendered evident by identical sister-spore pairs in a fungal octad that exhibits a non-Mendelian ratio. For example, if an ordered octad of ascospores from a cross of + × m = (++) (++) (++) (mm), one chromatid of the m parental chromosome appears to have been converted to +. In half-chromatid conversion, an octad of (++) (++) (+m) (mm) indicates that one chromatid of the m parental chromosome was “half-converted.” See ordered tetrad.
Subjects: Genetics and Genomics.