PRJNA564985
Danaus plexippus Chromosome-scale assembly
Unlike most female-heterogametic (WZ female / ZZ male) animals, moths and butterflies exhibit sex chromosome dosage compensation patterns typically seen only in male-heterogametic species. The monarch butterfly carries a newly-derived Z chromosome segment arising from an autosomal fusion with the ancestral Z. Using a chromosome-scale genome assembly, we show that Z chromosome gene expression is balanced between sexes, but the two segments exhibit distinct modes of compensation. This is the first known case of plurality of sex chromosome dosage compensation mechanisms along a single sex chromosome within a species.