EXTREME POPULATION STRUCTURING IN THE THREATENED GHOST BAT, MACRODERMA-GIGAS - EVIDENCE FROM MITOCHONDRIAL-DNA

The ghost bat, Macroderma gigas, has undergone a major range contracti on and is currently restricted around a few, highly disjunct maternity sites. The amount and distribution of mitochondrial DNA (mtDNA) varia tion within extant populations has been used to assess levels of curre nt and historical maternal gene flow between these populations. An app roximately 330 base pair fragment spanning a hypervariable area of the mtDNA control region was amplified and sequenced by using 22 individu als from four current ghost bat populations. The mean sequence diversi ty of 4.5 % between populations was six times higher than that within populations (0.68 %), and alleles within populations were monophyletic . Restriction enzyme analysis of amplified products from an additional 100 individuals revealed fixed allelic differences in the distributio n of control region genotypes between the four populations. It is sugg ested that this extreme genetic subdivision is a consequence of long-t erm female philopatry. For the purposes of management each population should be treated as an independent entity. The depth of the genetic s tructuring suggests that the isolation of extant populations preceded the historical range contraction.