tailieunhanh - Báo cáo khoa học: The hemoglobin genes of Drosophila

We recently reported the unprecedented occurrence of a hemoglobin gene (glob1) in the fruitfly Drosophila melanogaster. Here we investigate the structure and evolution of the glob1gene in otherDrosophilaspecies. We cloned and sequencedglob1genes and cDNA fromD. pseudoobscuraand D. virilis, and identified the glob1gene sequences ofD. simulans, D. yak-uba, D. erecta, D. ananassae, D. mojavensisandD. grimshawiin the data-bases. | iFEBS Journal The hemoglobin genes of Drosophila Thorsten Burmester1 Joachim Storf1 Anne Hasenjager2 Sabine Klawitter2 and Thomas Hankeln2 1 Institute of Zoology University of Mainz Germany 2 Institute of Molecular Genetics University of Mainz Germany Keywords Gene duplication globin insects oxygen phylogeny Correspondence T. Burmester Institute of Zoology University of Mainz D-55099 Mainz Germany Fax 49 6131 39 24652 Tel 49 6131 39 24477 E-mail burmeste@ Note The nucleotide sequences reported in this paper have been submitted to the GeriBariklM EMBL databases with the accession numbers AM086021 D. virilis glob1 gene AM086022 D. virilis glob1 cDNA AM086023 D. pseudoobscura glob1 cDNA and AM086024 D. melanogaster glob2 cDNA . Received 13 October 2005 revised 18 November 2005 accepted 23 November 2005 We recently reported the unprecedented occurrence of a hemoglobin gene glob1 in the fruitfly Drosophila melanogaster. Here we investigate the structure and evolution of the globl gene in other Drosophila species. We cloned and sequenced globl genes and cDNA from D. pseudoobscura and D. virilis and identified the globl gene sequences of D. simulans D. yakuba D. erecta D. ananassae D. mojavensis and D. grimshawi in the databases. Gene structure introns in helix positions and gene synteny and sequence of glob1 are highly conserved with high ds dn ratios indicating strong purifying selection. The data suggest an important role of the glob1 protein in Drosophila which may be the control of oxygen flow from the tracheal system. Furthermore we identified two additional globin genes glob2 and glob3 in the Drosophilidae. Although the sequences are highly derived the amino acids required for heme- and oxygen-binding are conserved. In contrast to other known insect globin the glob2 and glob3 genes harbour both globin-typical introns at positions and . Both genes are conserved in various drosophilid species but only expression of glob2 could be .