Bacillus DNA in fossil bees: an ancient symbiosis?
Level 5 - mechanism / opinion, no new human data
Level 5 by design analogy (in vitro bench research on fossil specimen tissue; no human data)
PubMed 8031102 · doi:10.1128/aem.60.6.2164-2167.1994
What was done
DNA was extracted from abdominal tissue of four extinct stingless bees (Proplebeia dominicana) preserved in Dominican amber. The authors performed PCR amplification of a 546-bp fragment of the 16S rRNA gene from Bacillus spp., sequenced the products, performed basic local alignment search tool (BLAST) searches against nonredundant nucleic acid databases, and conducted phylogenetic inference analysis using the maximum-likelihood method.
What was found
A 546-bp 16S rRNA fragment was amplified from the four fossil specimens. Database searches yielded the highest scores with 16S rRNA sequences from Bacillus spp. Phylogenetic analysis placed the four sequences in close relationship with Bacillus pumilus, B. firmus, B. subtilis, and B. circulans, four extant species known to colonize the abdominal tissue of stingless bees. No numerical similarity percentages, confidence intervals, or statistical test statistics were reported in the abstract.
Why it matters
This study provides molecular evidence suggesting that Bacillus-bee associations observed in extant stingless bees may have already existed in extinct Proplebeia dominicana preserved in Dominican amber.
Limits
The sample size is minimal (n = 4 bees). The abstract reports no negative extraction or PCR controls, independent replication, or ancient DNA damage profiling, leaving open the possibility of environmental or laboratory contamination.
Cited by
- supports Microbiologist Raúl Cano isolated viable Bacillus endospores dating 25 to 40 million years old from ancient bees preserved in amber.