Today, we release a few improvements to a pioneering genome, Tribolium castaneum (Herbst) 1797.
The red flour beetle (RFB), is a member of the Order Coleoptera, aka beetles, one of the most diverse group of organisms on earth (~400,000 species). Within Coleoptera, the RFB is a member of the family Tenebrionidae, which itself is exceptionally diverse with ~20,000 species. Tenebrionidae are colloquially referred to as tenebs or darkling beetles by Coleopterists and can be found almost everywhere. Some can be omnivorous as larvae and adults but others are specialized on eating fungus for their development (mycetobionts/fungivores).
The RFB has become a stored product pest, originally believed to be native to SE Asia. Now it can now be found worldwide as a result of it hitching rides in product such as (you guessed it) flour.
Many tenebrionids are found in arid environments but other members of this family are diverse in tropical regions. One of their larval adaptations for surviving in exceptionally dry environments is the modification of the Malpighian tubules (rough insect equivalent of your kidneys) into what is termed a cryptonephridium, where they can not only draw out water from their excrement but also absorb atmospheric water trapped in their hindgut.
Many but not all tenebrionid adults have abdominal glands that produce noxious quinones as defensive chemicals, (RFB specifically produces p-benzoquinones with aliphatic hydrocarbons). If you live in North America and have picked up one of these, you will know what we are talking about. As a result of this noxious defensive which is physiologically expensive to produce, some tenebs have a convergent appearance falsely advertising “Don’t eat me I taste bad!”, mimicking the distasteful species.
The RFB was the first beetle to have its genome sequenced and has been the genetic workhorse of Coleoptera. This was done back in 2008 by the Tribolium Genome Sequencing Consortium. Subsequent improvements include Kim et al., 2010 and Herndon et al., 2020. This latter version, available on NCBI here, is used as a starting point for the Hi-C based upgrade. The sample for Hi-C library preparation was obtained from Carolina Biological.
Blog post by Matthew Van Dam
Herndon, N., Shelton, J., Gerischer, L.et al.Enhanced genome assembly and a new official gene set forTribolium castaneum.BMC Genomics21,47 (2020). https://doi.org/10.1186/s12864-019-6394-6
Richards S, Gibbs RA, Weinstock GM, Brown SJ, Denell R, Beeman RW, et al. (April 2008). "The genome of the model beetle and pest Tribolium castaneum". Nature. 452 (7190): 949–55. Bibcode:2008Natur.452..949R. doi:10.1038/nature06784. PMID 18362917
Shimeld, Lisa Anne, "A cytogenetic examination of eight species of Tribolium (Coleoptera: Tenebrionidae)" (1989). Theses Digitization Project. 534. https://scholarworks.lib.csusb.edu/etd-project/534