학술논문
Genetic diversity of Oecomys (Rodentia, Sigmodontinae) from the Tapajos River basin and the role of rivers as barriers for the genus in the region
Original investigation
Original investigation
Document Type
Academic Journal
Author
Source
Mammalian Biology. July 2019, Vol. 97 Issue 1, p41, 9 p.
Subject
Language
English
ISSN
1616-5047
Abstract
Introduction Knowledge about species richness of arboreal rice rats, genus Oecomys, has increased considerably in recent years through the use of chromosomal and molecular analyses, revealing new species and greater [...]
The genus Oecomys is one of the most speciose within the subfamily Sigmodontinae, with most species found in the Amazon region. Recent studies have shown that the diversity, recognition of specific boundaries and geographical distribution is still imprecise for the genus. Herein, we investigate the genetic diversity of Oecomys in the Tapajos River basin and determine whether its rivers (Tapajos, Teles Pires, and Juruena) act as barriers for some species or populations in this genus based on phylogenetic analyzes with the mitochondrial marker cytochrome b (cytb) and the nuclear marker intron 7 p-fibrinogen, and on populational analysis with cytb. The phylogenetic relationships showed the presence of seven species in the region, namely O. bicolor, Oecomys aff. catherinae, O. catherinae, O. cleberi, O. paricola, O. roberti, and O. tapajinus. The geographic distributions of O. bicolor and O. cleberi seem to be shaped by the Tapajos and Teles Pires Rivers, with the former species occurring on the right bank and the latter species on the left bank of both rivers. Moreover, O. cleberi was the only Oecomys species to be recorded on the left bank of the Tapajos River. Our results also indicate that gene flow occurs between O. cleberi populations from the west Juruena and Tapajos Rivers and is absent between opposite banks of the Juruena River. The isolation by distance was discarded for this species. No evidence of gene flow was found for O. bicolor populations, and the isolation by distance was positive for this species. The spatial distribution of specimens and haplotypes of O. paricola indicates that the Teles Pires River does not act as a barrier for this species. Finally, Fs test significant results for O. cleberi and O. paricola showed that species population expansion cannot be discarded for these species. Keywords: Phylogeny Geographic distribution Gene flow Teles Pires River Juruena River
The genus Oecomys is one of the most speciose within the subfamily Sigmodontinae, with most species found in the Amazon region. Recent studies have shown that the diversity, recognition of specific boundaries and geographical distribution is still imprecise for the genus. Herein, we investigate the genetic diversity of Oecomys in the Tapajos River basin and determine whether its rivers (Tapajos, Teles Pires, and Juruena) act as barriers for some species or populations in this genus based on phylogenetic analyzes with the mitochondrial marker cytochrome b (cytb) and the nuclear marker intron 7 p-fibrinogen, and on populational analysis with cytb. The phylogenetic relationships showed the presence of seven species in the region, namely O. bicolor, Oecomys aff. catherinae, O. catherinae, O. cleberi, O. paricola, O. roberti, and O. tapajinus. The geographic distributions of O. bicolor and O. cleberi seem to be shaped by the Tapajos and Teles Pires Rivers, with the former species occurring on the right bank and the latter species on the left bank of both rivers. Moreover, O. cleberi was the only Oecomys species to be recorded on the left bank of the Tapajos River. Our results also indicate that gene flow occurs between O. cleberi populations from the west Juruena and Tapajos Rivers and is absent between opposite banks of the Juruena River. The isolation by distance was discarded for this species. No evidence of gene flow was found for O. bicolor populations, and the isolation by distance was positive for this species. The spatial distribution of specimens and haplotypes of O. paricola indicates that the Teles Pires River does not act as a barrier for this species. Finally, Fs test significant results for O. cleberi and O. paricola showed that species population expansion cannot be discarded for these species. Keywords: Phylogeny Geographic distribution Gene flow Teles Pires River Juruena River