BIODIVERSITAS ISSN: 1412-033X Volume 22, Number 2, February 2021 E-ISSN: 2085-4722 Pages: 1063-1068 DOI: 10.13057/biodiv/d220263 Short Communication: Molecular study on mt-DNA COX2 gene of Sumatran elephant (Elephas maximus sumatranus) DENY SETYO WIBOWO 1 , RINI WIDAYANTI 2 , MACHMUD ASVAN 3 , PRISTA DWI RESTANTI 4 , HERY WIJAYANTO 1,♥ 1 Department of Anatomy, Faculty of Veterinary Medicine, Universitas Gadjah Mada. Jl. Fauna No. 2, Karangmalang, Depok, Sleman 55281, Yogyakarta, Indonesia. Tel.: +62-274-6492088, Fax.: +62-274-560861,  email: herykh@ugm.ac.id 2 Department of Biochemistry, Faculty of Veterinary Medicine, Universitas Gadjah Mada. Jl. Fauna No. 2, Karangmalang, Depok, Sleman 55281, Yogyakarta, Indonesia 3 Gembira Loka Zoo. Jl. Kebun Raya No. 2, Rejowinangun, Yogyakarta City 55171, Yogyakarta, Indonesia 4 Jawa Timur Conservation Institute. Jl. Kartika No. 2, Kota Wisata, Batu 65314, East Java, Indonesia Manuscript received: 22 September 2020. Revision accepted: 27 January 2021. Abstract. Wibowo DS, Widiyanti R, Asvan M, Restanti PD, Wijayanto H. 2021. Short Communication: Molecular study on mt-DNA COX2 gene of Sumatran elephant (Elephas maximus sumatranus). Biodiversitas 22: 1063-1068. Sumatran elephant is the only subspecies of Asian elephants that receives a critically endangered status from the International Union for Conservation and Nature Resources (IUCN). Identifying the genetic marker of Sumatran elephants is, therefore, important for their conservation. This study aimed to identify the Sumatran elephant based on specific mitochondrial DNA markers of the Cytochrome c oxidase subunit II (COX2) gene. It is an exploratory research considering the limited data and research about the genetic, especially the COX2 of Sumatran elephant (Elephas maximus sumatranus). Forward and reverse sequencing of PCR products was conducted using the primary COX2 from Sumatran elephant samples. The results of the subsequent gene sequencing were aligned with the sequences of other Asian elephants from Genbank using Clustal W software and analyzed using the MEGA program version 6.06. The analysis of genetic distance based on COX2 constituent nucleotides calculated with Kimura’s two-parameter method showed that the genetic distance between Elephas maximus sumatranus and Elephas maximus outside of Sumatra was 0.25%. The phylogenetic trees analyzed using the maximum-likelihood based on nucleotide sequences showed a high homogeneity. The ratio of Elephas maximus sumatranus with Elephas maximus shows levels of nucleotide mutations which are nine nucleotides and four nucleotides. These results indicated that the COX2 gene could not identify the individual species of Sumatran elephant because of the high intraspecies homogeneity, but it detected the interspecies divergence clustered in Asian elephant clade. Keywords: COX2 gene, Elephas maximus sumatranus, genetic diversity, mitochondrial DNA, Sumatran elephant Abbreviations: COX2: Cytochrome c oxidase subunit II; IUCN: Internasional Union for Conservation and Nature Resources; HTI: Hutan Tanaman Industri/Industrial Forest Plantations; mt-DNA: Mitochondrial DNA; ND3: NADH dehydrogenase 3; EDTA: Ethylenediaminetetraacetic acid; TBE: Tris/Borate/EDTA; PCR: Polymerase Chain Reaction INTRODUCTION Indonesia is the richest country for mammal species diversity, which amounts to 701 species. One of the largest mammals that have lived in Indonesia since ancient times is the elephants. The habitat of Asian elephants in Indonesia now spreads in two islands, Sumatra and Borneo, but their population continues to decline due to hunting or land clearing (Sulandari and Zein 2012). Sumatran elephants are the only subspecies of Asian elephant on the red list of the International Union for Conservation and Nature Resources (IUCN). The status of Sumatran elephants is very endangered because 70 percent of them live outside the conservation areas, such as HTI areas (Industrial Forest Plantations), forests around oil palm plantations, even coal mining (Ministry of Forestry 2007). In the second decade of the 21st century, the existence of Asian elephants was increasingly threatened. Out of 13 countries populated by elephants, five (Bangladesh, Bhutan, China, Nepal, and Vietnam) have under 200 wild elephants on average (Islam et al. 2011; Jigme 2011; Zhang 2011; Pradhan et al. 2011; Ly 2011). Meanwhile, Cambodia and Laos have less than 1,000 wild elephants (Maltby and Bourchier 2011). In Sumatra, Indonesia, elephants have been labeled Critically Endangered (red list) (Fernando and Pastorini 2011). Azmi and Gunaryadi (2011) stated that the populations of Asian elephants in Sumatra ranged from 2400 to 2800, occupying 456,167 km 2 inhabited by 47,728,472 humans. The elephant population spreads across 44 locations in seven provinces of Sumatra, namely Nangroe Aceh Darussalam, North Sumatra, Riau, Jambi, Bengkulu, South Sumatra, and Lampung (Ministry of Forestry 2007). There are an estimated 2,040 elephants in Kalimantan that mostly inhabit the Central Forest area (Alfred et al. 2010). Identifying the genetic marker of Sumatran elephants is essential for their conservation. The unavailability of comprehensive morphological data and genetic markers as