Jurnal Biodjati 8(1):1–12, May 2023 http://journal.uinsgd.ac.id/index.php/biodjati e-ISSN : 2541-4208 p-ISSN : 2548-1606 Genetic Characteristics of Chloropsis cochinchinensis Gmelin, 1789 Based on The Mitochondrial DNA COI Gene Jarulis* 1 , Apin Saputra 2 , Risky Hadi Wibowo 3 INTRODUCTION The blue-winged leafbird Chloropsis cocinchinensis is an aves group from the fam- ily Chloropseidae with a body length of 17 cm and bright green feathers. In the male group, the colour of the throat and eye rings are black and yellowish, respectively, while in the fe- male group, the eye circles are not yellowish. The presence of blue feathers on the wings and tail distinguish this species of leafbird from others. Spread throughout India, South- Citation Jarulis, Saputra, A. & Wibowo, R. H. (2023). Genetic Characteristics of Chloropsis cochinchinen- sis Gmelin, 1789 Based on The Mitochondrial DNA COI Gene. Jurnal Biodjati, 8(1), 1–12. DOI: 10.15575/biodjati.v8i1.20260 *Corresponding author Abstract. The rate of illegal poaching of blue-winged leafbirds (Chlo- ropsis cochinchinensis) throughout Indonesia, particularly Bengkulu, is quite high. However, only minimal molecular information is avail- able for this species. We performed mtDNA COI gene sequencing to explore genetic characters (conservative site, variable site, parsimo- ny site, and singleton site) of blue-winged leafbirds. Using Qiagen's DNeasy® Blood and Tissue Kit based on the Spin-Column Protocol, total DNA was isolated, and PCR amplifcation methods were per- formed. DNA derived from a PCR reaction was forwarded to PT. First Base Malaysia for sequencing. Using MEGA 10.0 and BIOEDIT, the COI gene nucleotide sequence data were assembled, edited, and ana- lyzed to explore of single nucleotide polymorphism, genetic distance, and phylogeny. The 616 bp COI genes contained 566 conservative sites (C), 50 variation sites (V), 24 information parsimony sites (Pi), and 26 singleton sites (S), as indicated by the results. The greatest nucleotide base composition was cytosine (34.1–34.9%), while the lowest was guanine (15.7–16.2%). The proportion of adenine-thy- mine nucleotide base pairs was greater than that of guanine-cytosine (50.3%). There were 26 barcode-specifc mutation sites, 17 transition substitution mutation sites, and 9 transverse substitution mutation sites. The average genetic distance between C. cochinchinensis indi- viduals was 2.2%, but the average genetic diference between species was 9.0%. All C. cochinchinensis individuals in our sample clustered within the same clade and were distinguished from other species with- in the same genus. The COI gene sequences of C. cochinchinensis that we acquired are novel and can be utilized for molecular identifcation of the species. Keywords: barcode, Chloropseidae, conservation, mitochondrial, phylogeny, poaching 1,2,3 Department of Biology, Faculty of Mathematics and Natural Sciences, Universitas Bengkulu, Indonesia, 38371 e-mail: 1* jarulis@unib.ac.id 2 aprisaputrad@gmail.com 3 riskyhadiwibowo@gmail.com Received: 10 September, 2022 Revise from: 13 September, 2022 Accepted: 19 January, 2023 Copyright © 2023 Jurnal Biodjati This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0/)