A novel species-specific satellite DNA family in the invasive root-knot nematode Meloidogyne mayaguensis and its potential use for diagnostics

The root-knot nematode (RKN) Meloidogyne mayaguensis is considered as one of the most damaging RKN species because of its extremely wide host range. Recent surveys have shown the rapid spread of this parasite in agro-ecosytems, often making crop cultivation not viable in the heavily infested areas. Here, we report the identification, molecular cloning, genomic organisation and sequence analysis of a new satellite DNA (satDNA) family from M. mayaguensis (named pMmPet). It is comprised of two groups of A+T rich, tandemly repeated units of 174 and 180 bp, respectively. Using these sequences as targets, hybridisation and PCR experiments performed on a wide collection of 44 populations belonging to 15 RKN species showed that the pMmPet family could only be detected in the 16 M. mayaguensis populations tested. In addition, because of their repetitive nature, positive detection of pMmPet sequences was achieved in single individual nematodes. Therefore, the repeated sequence described here possesses features that make it an excellent candidate for use as a specific and extremely sensitive tool for the accurate detection and identification of this invasive pest on a routine basis. Clearly, monitoring the occurrence and spread of M. mayaguensis at the domestic and international levels are needed to avoid wholesale loss of agricultural resources in the infested regions.