The Drosophila fertility factor kl-3 is linked to the Y-chromosome of the vector of Chagas’ disease Triatoma infestans (Hemiptera: Reduviidae) and is essential for male fertility

In many insects, the Y chromosome plays a key role in sexual determination and male fertility. The Chagas disease vector has 22 autosomal chromosomes and a pair of XY sex chromosomes. However, the knowledge on the Y chromosome of this species, its genetic content or its biological function, is very poor. Due to repetitive DNA, Y chromosome sequences are poorly assembled in genome projects, hindering structural and functional studies on Y-linked genes. Our group has developed many of the bioinformatic tools to identify Y-linked sequences in assembled genomes. Here, we describe the identification of a γ-dynein heavy chain linked to the Y-chromosome of . This protein is orthologous to the Y-linked gene . In , dyneins of the Y chromosome are known as male fertility factors and their deletion causes male infertility. We performed knockdown of the expression to ascertain its function in . Our results showed that injection of dsKL3 reduced, significantly, the fertility of males (p<0.01). The mean number of eggs laid by the control group was 35.64 eggs/couple while the kl-3 knockdown group was of 11.82 eggs/couple (five couples did not lay any eggs). Differences in eclosion rate was even more significant, with a hatching mean rate of 16.85±10.03 and 1.69±3.58 (p<0.001) for the control and the silenced groups respectively. Our results suggest that maintains its functional role as essential for male fertility in . Hence, it seems that the Y-chromosome of has a key role in male fertility. This is the first report of a orthologue linked to the Y chromosome of an insect species outside the diptera clade. In addition to the first report of a Y-linked gene in with a role for male fertility, this finding is of great relevance for the study of the evolution of Y chromosomes and further studies that could lead to novel approaches in insect control.