instagram pinterest linkedin facebook twitter goodreads

Genetic Linkage

Milkweed Bug Genome Revealed

I'll admit that I have long admired the beauty of the large milkweed bug Oncopeltus fasciatus, without knowing anything about it. So I was pleased to read of the recent publication of its genome sequence, an effort undertaken by 83 researchers working as 27 teams in 10 nations. The findings are reported in Genome Biology.

 

Most of the 100+ insect species that have had their genomes sequenced are homometabolous, which means that they develop through several stages of larvae, metamorphose, and then burst from their cocoons looking completely different. (See "The Making of a Mutant" for a scintillating view of fruit fly larvae living in goop in a milk bottle.) Flies, beetles, wasps, and butterflies are among the homometabolous.

 

In contrast, milkweed bugs are hemimetabolous. The species of this group are less well represented among the sequenced, although they are more numerous. The juvenile stages of milkweed bugs are tiny, flightless versions of the adults, called nymphs, that have more orange.

 

The hemimetabolous insects have trademark mouthparts that pierce and suck, and include agricultural pests and vectors of human disease, like the kissing bugs that deliver Trypanosoma cruzi, the cause of Chagas' disease. A more familiar hemimetabolous insect is the bed bug Cimex lectularius.

 

The milkweed bug, so-named because it eats the bitter seeds of the milkweed plant Asclepias syriaca, joins many other insects and their arthropod cousins in having their genetic selves laid bare as part of the i5k project. The international consortium is sequencing the genomes of 5,000 arthropod species.

 

So far partial or complete genomes have been unveiled for, in alphabetical order, ants, aphids, bedbugs, bees, beetles, borers, cockroaches, crabs, crayfish, fleas, flies, lice, locusts, mealybugs, midges, mites, mosquitoes, pillbugs, psyllids, scorpions, shrimp, spiders, stinkbugs, ticks, wasps, weevils, worms, the delightful-sounding snowberry maggot and meadow spittlebug, and a pretty butterfly called a Glanville fritillary.

 

To continue reading, go to DNA Science, my blog at Public Library of Science.

 

Be the first to comment