When a gene called Sex-lethal is expressed, a male-specific exon may be skipped during splicing, leading to the synthesis of a female-specific Sex-lethal protein.

• 当一段称为性别致死（sex-lethal）的基因转录出RNA时，雄果蝇专有的表现子可能在剪接过程中遭切除，最后产生雌果蝇专有的性别致死蛋白；