Sex determination mechanisms of plant-parasitic nematodes in Tylenchina

Abstract

Sex determination mechanisms are unexpectedly diverse in organisms and change rapidly during evolution. Among nematodes, molecular sex determination mechanisms have been well characterized in a few species of Caenorhabditis. Caenorhabditis species have an XO male/XX hermaphrodite or female sex determination system, and it is thought that the XX/XO sex determination system is predominant among nematodes. Although XX/XY or environmental sex determination systems have been also suggested for some nematodes, particularly parasitic nematodes, the molecular mechanisms of these systems are still unclear. To understand the sex determination mechanisms of plant-parasitic nematodes in Tylenchina, we have investigated both the initial trigger for sex determination using a genome-wide comparative analysis and the genetic cascade that follows that initial switch in Bursaphelenchus nematodes by using forward genetic screening and genomics. Recently, we have been expanding these studies to the root-knot nematodes. In this seminar, I will discuss the sex determination mechanisms of plant-parasitic nematodes that have been clarified from our studies.