LncRNA gene <i>ANTSR</i> coordinates complementary sex determination in the Argentine ant.

Abstract

Animals have evolved various sex determination systems. Here, we describe a newly found mechanism. A long noncoding RNA (lncRNA) transduces complementary sex determination (CSD) signal in the invasive Argentine ant. In this haplodiploid species, we identified a 5-kilobase hyper-polymorphic region underlying CSD: Heterozygous embryos become females, while homozygous and hemizygous embryos become males. Heterozygosity at the <i>CSD</i> locus correlates with higher expression of <i>ANTSR</i>, a gene that overlaps with the <i>CSD</i> locus and specifies an lncRNA transcript. <i>ANTSR</i> knockdown in <i>CSD</i> heterozygotes leads to male development. Comparative analyses indicated that, in Hymenoptera, <i>ANTSR</i> is an ancient yet rapidly evolving gene. This study reveals an lncRNA involved in genetic sex determination, alongside a previously unknown regulatory mechanism underlying sex determination based on complementarity among noncoding alleles.