TY - JOUR
T1 - Diversity of stonefly hexamerins and implication for the evolution of insect storage proteins
AU - Hagner-Holler, Silke
AU - Pick, Christian
AU - Girgenrath, Stefan
AU - Marden, James H.
AU - Burmester, Thorsten
N1 - Funding Information:
We thank Klaus Enting and Rainer Rupprecht (Mainz) for P. marginata specimens, and Falko Roeding and Robert Schöpflin for the help with the implementation of the r8s program. This work has been supported by grants of the Deutsche Forschungsgemeinschaft (Bu956/5; Bu956/9) and by NSF grant IBN-9722196. The nucleotide sequences reported in this paper have been submitted to the EMBL/GenBank™ Databases under the accession nos. AM690365 to AM690371 , EF620538 , EF617597 and EF617598 .
PY - 2007/10
Y1 - 2007/10
N2 - Hexamerins are large storage proteins of insects in the 500 kDa range that evolved from the copper-containing hemocyanins. Hexamerins have been found at high concentration in the hemolymph of many insect taxa, but have remained unstudied in relatively basal taxa. To obtain more detailed insight about early hexamerin evolution, we have studied hexamerins in stoneflies (Plecoptera). Stoneflies are also the only insects for which a functional hemocyanin is known to co-occur with hexamerins in the hemolymph. Here, we identified hexamerins in five plecopteran species and obtained partial cDNA sequences from Perla marginata (Perlidae), Nemoura sp. (Nemouridae), Taeniopteryx burksi (Taeniopterygidae), Allocapnia vivipara (Capniidae), and Diamphipnopsis samali (Diamphipnoidae). At least four distinct hexamerins are present in P. marginata. The full-length cDNA of one hexamerin subunit was obtained (PmaHex1) that measures 2475 bp and translates into a native polypeptide of 702 amino acids. Phylogenetic analyses showed that the plecopteran hexamerins are monophyletic and positioned at the base of the insect hexamerin tree, probably diverging about 360 million years ago. Within the Plecoptera, distinct hexamerin types evolved before the divergence of the families. Mapping amino acid compositions onto the phylogenetic tree shows that the accumulation of aromatic amino acids (and thus the evolution of "arylphorins") commenced soon after the hexamerins diverged from hemocyanins, but also indicates that hexamerins with distinct amino acid compositions reflect secondary losses of aromatic amino acids.
AB - Hexamerins are large storage proteins of insects in the 500 kDa range that evolved from the copper-containing hemocyanins. Hexamerins have been found at high concentration in the hemolymph of many insect taxa, but have remained unstudied in relatively basal taxa. To obtain more detailed insight about early hexamerin evolution, we have studied hexamerins in stoneflies (Plecoptera). Stoneflies are also the only insects for which a functional hemocyanin is known to co-occur with hexamerins in the hemolymph. Here, we identified hexamerins in five plecopteran species and obtained partial cDNA sequences from Perla marginata (Perlidae), Nemoura sp. (Nemouridae), Taeniopteryx burksi (Taeniopterygidae), Allocapnia vivipara (Capniidae), and Diamphipnopsis samali (Diamphipnoidae). At least four distinct hexamerins are present in P. marginata. The full-length cDNA of one hexamerin subunit was obtained (PmaHex1) that measures 2475 bp and translates into a native polypeptide of 702 amino acids. Phylogenetic analyses showed that the plecopteran hexamerins are monophyletic and positioned at the base of the insect hexamerin tree, probably diverging about 360 million years ago. Within the Plecoptera, distinct hexamerin types evolved before the divergence of the families. Mapping amino acid compositions onto the phylogenetic tree shows that the accumulation of aromatic amino acids (and thus the evolution of "arylphorins") commenced soon after the hexamerins diverged from hemocyanins, but also indicates that hexamerins with distinct amino acid compositions reflect secondary losses of aromatic amino acids.
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U2 - 10.1016/j.ibmb.2007.06.001
DO - 10.1016/j.ibmb.2007.06.001
M3 - Article
C2 - 17785194
AN - SCOPUS:34548270367
SN - 0965-1748
VL - 37
SP - 1064
EP - 1074
JO - Insect Biochemistry and Molecular Biology
JF - Insect Biochemistry and Molecular Biology
IS - 10
ER -