DNA barcodes effectively identify the morphologically similar Common Opossum (Didelphis marsupialis) and Virginia Opossum (Didelphis virginiana) from areas of sympatry in Mexico

Abstract

Two morphologically similar species of opossum from the genus Didelphis-Didelphis virginiana and Didelphis marsupialis-cooccur sympatrically in Mexico. High intraspecific variation complicates their morphological discrimination, under both field and museum conditions. This study aims to evaluate the utility and reliability of using DNA barcodes (short standardized genome fragments used for DNA-based identification) to distinguish these two species. Sequences of the cytochrome c oxidase subunit I (Cox1) mitochondrial gene were obtained from 12 D. marsupialis and 29 D. virginiana individuals and were compared using the neighbor-joining (NJ) algorithm with Kimura's two-parameter (K2P) model of nucleotide substitution. Average K2P distances were 1.56% within D. virginiana and 1.65% in D. marsupialis. Interspecific distances between D. virginiana and D. marsupialis varied from 7.8 to 9.3% and their barcode sequences formed distinct non-overlapping clusters on NJ trees. All sympatric specimens of both species were effectively discriminated, confirming the utility of Cox1 barcoding as a tool for taxonomic identification of these morphologically similar taxa.

Helminths of three species of opossums (Mammalia, Didelphidae) from Mexico

“… Didelphis virginiana inhabits almost all of Mexico, except for the central Plateau and Baja California peninsula. Philander opossum occurs from south Tamaulipas State along the Gulf of Mexico coast and Chiapas State ( Arcangeli-Álvarez 2010 , Cervantes et al 2010 ). The main objective of this work is to present new records of helminth species parasitizing these 3 species of opossums in Mexico and to compare the finding to previous records.…”

Molecular data reveal a new species of Rhopalias Stiles & Hassall, 1898 (Digenea, Echinostomatidae) in the Common opossum, Didelphis marsupialis L. (Mammalia, Didelphidae) in the Yucatán Peninsula, Mexico

“…A few additional records were more recently provided by Acosta-Virgen et al (2015). Interestingly, in the region of Los Tuxtlas, Veracruz, where the three species of opossums are found in sympatry (see Cervantes et al 2010), the four species of Rhopalias have been recorded. In our study, even though we sampled five individuals of D.marsupialis , one of D.virginiana and two of P.opossum from the same locality, we only collected specimens of R.coronatus and R.macracanthus .…”

Diversidad genética y abundancia relativa de Didelphis marsupialis y Didelphis virginiana en Chiapas, México

“…Estudios filogenéticos con marsupiales sugieren poca diferenciación entre las especies, por ejemplo, Jansa y Voss (2000) en un estudio con marsupiales de América mostraron que la divergencia entre especies del género Didelphis oscila entre 0.95 y 1.3% con el gen IRBP; y de 5.7 a 12.6% con el citocromo b. Cervantes et al (2010) encontraron una diferenciación genética de 7.8 a 9.3% entre D. marsupialis y D. virginiana con el citocromo c oxidasa subunidad I (Cox1). La diferenciación observada entre D. marsupialis y D. virginiana en este estudio también puede considerarse baja (13.4%), en tanto que los microsatélites tienen tasas de mutación mayores que el citocromo b, el gen IRBP y el Cox1 (Rentaría, 2007).…”