Recovery of environmental human DNA by insects.
We tested the hypotheses that foraging insects can acquire human DNA from the environment and that insect-delivered human DNA is of sufficient quantity and quality to permit standard forensic analyses. Houseflies, German cockroaches, and camel crickets were exposed to dusty surfaces and then assayed for human mitochondrial and nuclear loci by conventional and qPCR, and multiplex STR amplification. Over two experiments, 100% of insect groups and 94% of dust controls tested positive for human DNA. Of 177 individuals, 33-67% tested positive and 13 yielded quantifiable human DNA (mean = 0.022 ± 0.006 ng; mean dust control = 2.448 ± 0.960 ng); four had at least one positive allele call for one or more locus; eight others showed multiple peaks at some loci. Results imply that application to routine forensic casework is limited given current detection methodology yet demonstrate the potential use of insects as environmental samplers for human DNA.
Kester
Karen M
KM
Department of Biology, Virginia Commonwealth University, 1000 W. Cary Street, Richmond, VA 23284-2012, USA. kmkester@vcu.edu
Toothman
Mary H
MH
Brown
Bonnie L
BL
Street
W Scott
WS
Cruz
Tracey D
TD
D000818:Animals; D003058:Cockroaches; D004247:DNA / Q000032:analysis* / Q000302:isolation & purification; D017931:DNA Primers; D004175:Diptera; D004391:Dust; D005247:Feeding Behavior; D053803:Forensic Genetics; D006135:Gryllidae; D006801:Humans; D016133:Polymerase Chain Reaction; D013499:Surface Properties; D020080:Tandem Repeat Sequences
D017931:DNA Primers; D004391:Dust; D004247:DNA