The genome of the wasp parasitoide Nasonia

Nasonia is a wasps genre parasitoides that comprises four related species (N. vitripennis, N. giraulti, N. longicornis and N. oneida). There are insects of tiny size (2-3 millimeters) that put his eggs in the cold sores of several species of flies.

The Group of Work of the Genome of Nasonia, an international consortium formed by 157 investigators of 13 countries led by John H. Werren, teacher of biology in Universiad de Rochester, and Stephen Richards, of the Center of Sequence of the Human Genome in Baylor College of Medicine, there is secuenciado the genome of three species of this himenóptero (N. vitripennis, N. giraulti and N. longicornis).

Why Nasonia?

The wasps parasitoides are insects which larvae parasitan several phases of the development of other arthropods. The females inject poison and put his eggs on or inside his guest and the larvae develop feeding on him until they kill it. The parasitoides are used usually for the biological control of plagues of insects and it is believed that there are approximately 600.000 species. Nasonia parasite several flies species and it is the second genre of himenópteros whose genome has been secuenciado (the first one was that of the bee). It has a period of development of two weeks and it is very prolific, easy to support in a laboratory and the crossing between species produces a fertile descent. All this turns Nasonia into a model for the study of the evolutionary genetics and of the development. Hence the importance of the sequence of his genome inside the Project Genome of the Insects, which will allow to study in depth the biology of the insects parasitoides and improve his utility for the biological control of plagues of agricultural and medical importance.

Peculiarities of his genome

The sequence of the genome of Nasonia has given place to a series of scientific articles that explore diverse facets of his biology at molecular level.

• The Nasonia genome is organized in five chromosomes with approximately 239,8 million pairs of bases and approximately 17.279 genes, 60 % of which it has counterparts in the human beings, 18 % is a specific of the arthropods, 2,4 % seems to be exclusive of the himenópteros and 12 % does not have homologías egg whites or it is a Nasonia only one.
• It contains a high number of repetitions of ADN and trasposones (sequences of ADN saltarinas capable of answering and of being inserted in a new place of a certain genome).
• The genome codifies all the enzymes necessary for the metilación of the ADN, a genetic modification related to the regulation of the genes in human beings and other vertebrates, although it stays away in insects as Drosophila. It stays for seeing if the metilación in Nasonia has the same regulatory functions as in vertebrates. In the bee, for example, the metilación of the ADN is related to the development of the castes and in Nasonia one believes that it has to do with the determination of the sex.
• Nasonia has the biggest number of genes yellow/mayor royal jelly (genes related to the formation of castes and the sociability) found in any insect. Although his function in Nasonia is not known, they express themselves in different textiles and phases of the development.
• The bacterium endosimbionte Wolbachia and some poxvirus have transferred his genes to the Nasonia genome. The horizontal transference (between not related organisms) of genes can be a mechanism to acquire new genes and functions.
• The carnivorous Nasonia diet has provoked a loss or reorganization of the metabolic routes of some amino acids.
• Nasonia has a finished arsenal of poisonous toxins. In contrast to the poison of the bee, which it causes necrosis and pain, the poisons of the parasitoides are subtler and they induce physiological changes in his guest like the detention of the development, suppression of the immune answer, induction of palsy, cellular death and alteration of the behavior. 79 possible toxins have been identified and close to the half they are not related to the toxins of the poison of other insects. These poisons might be useful for the pest control and the development of medicines.

Functional and Evolutionary Insights from the Genomes of Three Parasitoid Nasonia Species The Nasonia Genome Working Group. 2010. Science 327, pp. 343-348. The Nasonia Genome Working Group (2010). Functional and Evolutionary Insights from the Genomes of Three Parasitoid Nasonia Species Science, 327 (5963), 343-348 DOI: 10.1126/science.1178028 Web Werren Lab of the laboratory of John H. Werren with information about the biology of Nasonia. NasoniaBase Repository of information about the genome of Nasonia.