Geographic patterns of inversion polymorphism in the second chromosome of the cactophilic Drosophila buzzatii from northeastern Argentina

SOTO, I.M.; SOTO, E.M.; CARREIRA, V. P.; HURTADO, J.P.; FANARA, J.J.; HASSON, E.

JOURNAL OF INSECT SCIENCE

UNIV ARIZONA

Año: 2010 vol. 10 p. 1 - 11

1536-2442

The  inversion  polymorphisms  of  the  cactophilic  Drosophila  buzzatti  Patterson  and  Wheeler (Diptera: Drosophilidae) were  studied  in  new  areas  of  its  distribution  in Argentina. A  total  of thirty-eight natural populations, including 29 from previous studies, were analyzed using multiple regression analyses. The results showed that about 23% of total variation was accounted for by a multiple regression model in which only altitude contributed significantly to population variation, despite  the  fact  that  latitude  and  longitude  were  also  included  in  the  model.  Also,  inversion frequencies  exhibited  significant  associations with mean  annual  temperature,  precipitation,  and atmospheric pressure. In addition, expected heterozygosity exhibited a negative association with temperature  and  precipitation  and  a  positive  association with  atmospheric  pressure.  The  close similarity of the patterns detected in this larger dataset to previous reports is an indication of the stability  of  the  clines.  Also,  the  concurrence  of  the  clines  detected  in  Argentina  with  those reported for colonizing populations of Australia suggests the involvement of natural selection as the main mechanism shaping inversion frequencies in D. buzzatii.