Genetic divergence and demography of pudu deer (Pudu puda) in five provinces of southern Chile, analyzed through latitudinal and longitudinal ranges

Abstract

Pudu deer (Pudu puda) is endemic to the temperate rainforests of Chile. Genetic studies at different geographic scales for this species are required to better determine the genetic divergence within and among populations and their demography across the distribution range. These data can provide unique insights into the species or population status for conservation plans and decision-makers. We analyzed the mtDNA control region (CR) and cytochrome b (Cyt b) sequences of pudu deer in five provinces of southern Chile located at different latitudinal locations (Cautín, Valdivia, Osorno, Llanquihue and Chiloé Island) and three geographic areas within the studied provinces, representative of different longitudinal sites (Andes range, Central Valley and Coastal Range), to understand their genetic divergence and demography. The haplotype (H) and nucleotide (Π) diversities of CR and Cyt b ranged from 0.64286 to 0.98333 and from 0.00575 to 0.01022, respectively. CR diversity was significantly different among provinces, with Valdivia showing higher values than Llanquihue and Chiloé Island (H = 0.98333 vs. 0.64286–0.92727, P < 0.05). Cyt b variation also showed significant differences among provinces, particularly, among Cautín and Llanquihue (H = 1.000 vs. 0.222, P < 0.05). Genetic structuring among provinces was relatively high, as indicated by the FST index (FST = 0.41905). Clustering analysis indicated the presence of a distinctive cluster for Chiloé Island individuals. Fu’s FS and Tajima’s D based on CR revealed significant, negative deviations from equilibrium for Chiloé Island (D = -1.65898), Valdivia (Fs = -7.75335) and Llanquihue (Fs = -3.93267), suggesting population expansion in these provinces. Analysis at the longitudinal range showed significant differences among areas based on Π (P < 0.05), with the Andes range and Central Valley showing higher diversity than the Coastal Range. Neither population structuring (FST = 0.01360, P > 0.05) nor distinctive clusters in the longitudinal range were observed. Fu’s Fs and Tajima’s D were negative and significant for the Coastal Range based on CR (Fs = -6.64752, P < 0.001) and Cyt b (D = -1.74110, P < 0.05), suggesting the existence of population expansion. Our results suggest that pudu deer in the analyzed provinces is a genetically structured species, which could be associated with reduced panmixia among populations. The genetic divergence pattern and the population expansion recorded are likely to be associated with past processes of recolonization after Pleistocene glaciation events.