RNA expression analysis of MSL complex components in Drosophila aneuploid embryogenesis

Unbalanced gene dosage of aneuploidy usually results in some detrimental consequences in development, or even in death．The male specific lethal (MSL) complex, which is thought to play a fundamental role in regulating dosage compensation in Drosophila , also has great impact on gene expression in aneuploidy．To explore the molecular mechanism in embryogenesis, gene expression of MSL complex components was compared between normal diploid and autosomal trisomy embryos．TSA-FISH (tyramide signal amplification-fluorescence in situ hybridization) technology was used to detect changes in subcellular localization of transcripts. In early stage of aneuploid embryo development or maternal expression stage when no MSL complex is assembled, most complex component genes already showed differences at the transcript level．Such differences mainly derived from maternal non-haploid gametes．As embryo development proceeds, gene dosage imbalance due to increased chromosome fragmentation produced inverse dosage effect leading to differential expression of the MSL complex components．Consequently, it will continue to affect subsequent development of aneuploid embryos at later stages．