Deletion that removes the 5' half of the common region exons of mod(mdg4).
The lethal phenotype of mod(mdg4)142Δ29 is fully complemented by mod(mdg4)Z3-3401, but mod(mdg4)142Δ29 fails to complement mod(mdg4)Z3-3401 with respect to X-Y chromosome nondisjunction in male meiosis - transheterozygotes show a high level of X-Y nondisjunction (46%).
The lethal phenotype of mod(mdg4)142Δ29 is fully complemented by mod(mdg4)Z3-5578 and mod(mdg4)Z3-3298, and mod(mdg4)142Δ29 partially or fully complements these alleles with respect to X-Y chromosome nondisjunction in male meiosis - the transheterozygotes show only a low level of X-Y nondisjunction (frequency is indicated in parentheses after each allele); mod(mdg4)Z3-5578 (1.54%) and mod(mdg4)Z3-3298 (1.83%).