Email updates

Keep up to date with the latest news and content from BMC Evolutionary Biology and BioMed Central.

Open Access Research article

Testes-specific hemoglobins in Drosophila evolved by a combination of sub- and neofunctionalization after gene duplication

Eva Gleixner12, Holger Herlyn3, Stefan Zimmerling1, Thorsten Burmester4 and Thomas Hankeln1*

Author affiliations

1 Institute of Molecular Genetics, University of Mainz, 55099 Mainz, Germany

2 Center for Systems Biology, University of Freiburg, 79104 Freiburg, Germany

3 Institute of Anthropology, University of Mainz, 55099 Mainz, Germany

4 Biocenter Grindel and Zoological Museum, University of Hamburg, 20146 Hamburg, Germany

For all author emails, please log on.

Citation and License

BMC Evolutionary Biology 2012, 12:34  doi:10.1186/1471-2148-12-34

Published: 19 March 2012

Abstract

Background

For a long time the presence of respiratory proteins in most insects has been considered unnecessary. However, in recent years it has become evident that globins belong to the standard repertoire of the insect genome. Like most other insect globins, the glob1 gene of Drosophila melanogaster displays a conserved expression pattern in the tracheae, the fat body and the Malpighian tubules.

Results

Here we show that the recently discovered D. melanogaster globin genes glob2 and glob3 both display an unusual male-specific expression in the reproductive tract during spermatogenesis. Both paralogs are transcribed at equivalent mRNA levels and largely overlap in their cellular expression patterns during spermatogenesis. Phylogenetic analyses showed that glob2 and glob3 reflect a gene duplication event that occurred in the ancestor of the Sophophora subgenus at least 40 million years ago. Therefore, flies of the Drosophila subgenus harbor only one glob2/3-like gene.

Conclusions

Phylogenetic and sequence analyses indicate an evolution of the glob2 and glob3 duplicates by a combination of sub- and neofunctionalization. Considering their restricted, testes-specific expression, an involvement of both globins in alleviating oxidative stress during spermatogenesis is conceivable.