Background and Aim: Indonesian cuscuses are now becoming scarce because of the reduction of habitat and poaching. Further, molecular characterization of Indonesian cuscuses is still very lacking. This study aimed to determine genetic markers and phylogenetic relationships of Indonesian cuscuses based on 16S rRNA gene sequences.

Materials and Methods: This study used 21 cuscuses caught from two provinces and 16 islands: 13 from Maluku and eight from Papua. Cuscus samples were taken by biopsy following ethics guidelines for animals. The genome isolation was done using gSYNC DNA Mini Kit (Geneaid Biotech Ltd., Taiwan). The 16S rRNA gene was amplified by primers (16SKUSAF and 16SKUSAR), and the polymerase chain reaction product obtained was 1875 base pair (bp). The analysis of genetic characterization and the phylogenetic relationship was performed using MEGA version X software (https://www. megasoftware.net/).

Results: 16S rRNA gene sequencing attained 1598 bp for all samples. Based on the 16S rRNA nucleotide sequences, cuscuses from Papua and Maluku belong to the genus Phalanger and Spilocuscus. Phalanger spp. and Spilocuscus spp. from Papua can be distinguished from Phalanger and Spilocuscus from Maluku, except Spilocuscus from Ternate has a very close relationship with cuscus from Sentani, Papua.

Conclusion: Indonesian cuscuses were derived into two clades based on 16S rRNA gene sequence, one group to genus Phalanger and another group to Spilocuscus.

Keywords: Indonesian cuscuses, Maluku, Papua, Phalanger, phylogeny, Spilocuscus.