Genetic Population Structure in the Antarctic Benthos: Insights from the Widespread Amphipod, Orchomenella frankliniReportar como inadecuado




Genetic Population Structure in the Antarctic Benthos: Insights from the Widespread Amphipod, Orchomenella franklini - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Currently there is very limited understanding of genetic population structure in the Antarctic benthos. We conducted one of the first studies of microsatellite variation in an Antarctic benthic invertebrate, using the ubiquitous amphipod Orchomenella franklini Walker, 1903. Seven microsatellite loci were used to assess genetic structure on three spatial scales: sites 100 s of metres, locations 1–10 kilometres and regions 1000 s of kilometres sampled in East Antarctica at Casey and Davis stations. Considerable genetic diversity was revealed, which varied between the two regions and also between polluted and unpolluted sites. Genetic differentiation among all populations was highly significant FST = 0.086, RST = 0.139, p<0.001 consistent with the brooding mode of development in O. franklini. Hierarchical AMOVA revealed that the majority of the genetic subdivision occurred across the largest geographical scale, with Nem≈1 suggesting insufficient gene flow to prevent independent evolution of the two regions, i.e., Casey and Davis are effectively isolated. Isolation by distance was detected at smaller scales and indicates that gene flow in O. franklini occurs primarily through stepping-stone dispersal. Three of the microsatellite loci showed signs of selection, providing evidence that localised adaptation may occur within the Antarctic benthos. These results provide insights into processes of speciation in Antarctic brooders, and will help inform the design of spatial management initiatives recently endorsed for the Antarctic benthos.



Autor: Helena Phoenix Baird , Karen Joy Miller, Jonathan Sean Stark

Fuente: http://plos.srce.hr/



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