PCR cloning of a histone H1 gene from Anopheles stephensi mosquito cells: comparison of the protein sequence with histone H1-like, C-terminal extensions on mosquito ribosomal protein S6.
BACKGROUND
In Aedes and Anopheles mosquitoes, ribosomal protein RPS6 has an unusual C-terminal extension that resembles histone H1 proteins. To explore homology between a mosquito H1 histone and the RPS6 tail, we took advantage of the Anopheles gambiae genome database to clone a histone H1 gene from an Anopheles stephensi mosquito cell line.


RESULTS
We designed specific primers based on RPS6 and histone H1 alignments to recover an Anopheles stephensi histone H1 corresponding to a conceptual An. gambiae protein, with 92% identity. Southern blots suggested that Anopheles stephensi histone H1 gene has multiple variants, as is also the case for histone H1 proteins in Chironomid flies.


CONCLUSIONS
Histone H1 proteins from Anopheles stephensi and Anopheles gambiae mosquitoes share 92% identity to each other, but only 50% identity to a Drosophila homolog. In a phylogenetic analysis, Anopheles, Chironomus and Drosophila histone H1 proteins cluster separately from the histone H1-like, C-terminal tails on RPS6 in Aedes and Anopheles mosquitoes. These observations suggest that the resemblance between histone H1 and the C-terminal extensions on mosquito RPS6 has been maintained by convergent evolution.
Zhai
Yongjiao
Y
Department of Entomology, University of Minnesota, 1980 Folwell Ave,, St, Paul, MN, 55108 USA. zhai0004@umn.edu
Fallon
Ann M
AM
D000595:Amino Acid Sequence; D000818:Animals; D000852:Anopheles / Q000378:metabolism*; D001483:Base Sequence; D015139:Blotting, Southern; D003001:Cloning, Molecular / Q000379:methods*; D019295:Computational Biology / Q000379:methods*; D017931:DNA Primers / Q000737:chemistry; D018076:DNA, Complementary / Q000378:metabolism; D004330:Drosophila; D019143:Evolution, Molecular; D006657:Histones / Q000737:chemistry / Q000235:genetics*; D019476:Insect Proteins; D008969:Molecular Sequence Data; D010802:Phylogeny; D010961:Plasmodium; D016133:Polymerase Chain Reaction / Q000379:methods*; D017434:Protein Structure, Tertiary; D038601:Ribosomal Protein S6 / Q000737:chemistry*; D017386:Sequence Homology, Amino Acid
D017931:DNA Primers; D018076:DNA, Complementary; D006657:Histones; D019476:Insect Proteins; D038601:Ribosomal Protein S6