High divergence across the whole mitochondrial genome in the "pan-Antarctic" springtail Friesea grisea: evidence for cryptic species?
Collembola are one of the few hexapod groups adapted to live in the harsh environmental conditions of Antarctic terrestrial ecosystems. Diversity is limited to a few species that can be very abundant in coastal deglaciated sites. A remarkable lack of overlap in Collembola species composition is evident between Western and Eastern Antarctica, and Friesea grisea is currently the only species whose distribution is thought to span these two main regions of the continent. However, our analysis of the complete sequences of the mitochondrial genomes from specimens obtained from each of the two regions showed unexpected genetic divergence, well above the average levels observed between populations belonging to the same species, and so indicating that these are actually separate species, despite their lack of distinguishing morphology. Detailed analysis of the two genomes showed the presence of a non-coding region observed between trnS(uga) and nad1. Other features of these mitochondrial genomes, such as base compositional bias, secondary structure features of tRNAs and the presence of regulatory elements in the control region, are described and discussed from an evolutionary standpoint.
Torricelli
Giulia
G
Department of Evolutionary Biology, University of Siena, 53100 Siena, Italy. torricelli5@unisi.it
Carapelli
Antonio
A
Convey
Peter
P
Nardi
Francesco
F
Boore
Jeffrey L
JL
Frati
Francesco
F
D020856:AT Rich Sequence; D000818:Animals; D000864:Antarctic Regions; D001181:Arthropods / Q000235:genetics*; D001483:Base Sequence; D017931:DNA Primers; D004272:DNA, Mitochondrial / Q000235:genetics*; D009690:Nucleic Acid Conformation; D016133:Polymerase Chain Reaction; D012335:RNA, Ribosomal / Q000737:chemistry / Q000235:genetics; D012343:RNA, Transfer / Q000737:chemistry / Q000235:genetics
D017931:DNA Primers; D004272:DNA, Mitochondrial; D012335:RNA, Ribosomal; D012343:RNA, Transfer