Revista Chilena de Historia Natural 82 (2): 265-275, 2009
RESEARCH ARTICLE
Range expansion of Oligoryzomys longicaudatus (Rodentia, Sigmodontinae) in
Patagonian Chile, and first record of Hantavirus in the region
SEBASTIÁN BELMAR-LUCERO, PAULA GODOY, MARCELA FERRÉS, PABLO VIAL & R. EDUARDO
At present, 20 species of Oligoryzomys (Rodentia, Sigmodontinae) are
recognized in the Neotropical region, most of them distinguished by their karyotypes, which fluctuates between 46-70 chromosomes.
Two species are currently recognized in Chile, Oligoryzomys longicaudatus (Bennet, 1832; “colilargo” or the long-tailed
pygmy rice rat; 2n = 56), which ranges from 27° to approximately 51° S, and O. magellanicus (Bennet, 1836; Magellanic
pygmy rice rat; 2n = 54), south of 51° S in the Patagonian region of Chile and Argentina. As part of an ongoing research on the
southern Patagonia of Chile, we report the results of small mammal samplings in six localities. We karyotyped 28 specimens and we
also sequenced the hypervariable mtDNA region I in 22 individuals, aligning these sequences with an under development phylogeny of
O. longicaudatus. We also evaluated the serology and viral charge in all captured specimens to detect the presence of
antibodies to Andes virus (ANDV) through Strip Immunoblot Assay (SIA), and of viral genome by RT-PCR. The results consistently
showed that the karyotype of southern Patagonia specimens was 2n = 56, equal to that of O. longicaudatus, and that
individuals from this area do not differentiate phylogenetically from those of the northern range of distribution. In addition, the serology
showed the presence of antibodies IgG anti-ANDV and of viral genome in heart, kidney, spleen, and lungs of a single specimen of
Oligoryzomys from the locality of Fuerte Bulnes in the Magallanes region. We conclude that all specimens trapped south
of 51° S correspond to Oligoryzomys longicaudatus, thus expanding the distribution of this specieì from 51° to at least 55°
S. The results also extended the disîribution of the Andes strain of Hantavirus to southernmost Patagonia.
“colilargo”, Hantavirus,
Oligoryzomys longicaudatus, O. magellanicus, Patagonia
