Comparative genomic analysis of the human and nematode Caenorhabditis elegans uncovers potential reproductive genes and disease associations in humans.

Reproduction is an important biological process. However, studies of human reproduction at the molecular level are limited due to the difficulty of performing in vivo studies. Hence, a mechanistic understanding of human reproduction remains still poor. Thus, it is important to use an alternative model organism for mechanistic studies of human reproduction. In this study, we used the nematode Caenorhabditis elegans as a model for studying human reproduction and identified 61 human and 535 worm reproductive genes through a combination of comparative genomic and Gene Ontology (GO) analyses. Interestingly, in terms of sex specificity, the number of male-specific genes was greater than the number of female-specific genes. Gene enrichment analysis identified biologically significant processes such as protein localization to cajal bodies/telomeres/nuclear bodies/chromosomes, helicase activity, pyrimidine biosynthesis and determination of adult lifespan. Regarding the analysis of human reproductive diseases among the identified genes, 10 and 12 genes were identified in the human- and C. elegans-based analyses, respectively. In addition, RNAi knockdown of a newly identified F52H2.6/DHCR24 gene increased brood size and ovulation/egg-laying rate in C. elegans. Therefore, gene identification, disease associations and a proof-of-concept experiment using C. elegans will not only provide insights into mechanistic study of human reproduction, but also demonstrate the utility in studying human reproduction.