@article {67181,
	title = {A novel family of secreted insect proteins linked to plant gall development.},
	journal = {Current Biology},
	volume = {31},
	year = {2021},
	month = {2021 May 10},
	pages = {1836},
	abstract = {<p>In an elaborate form of inter-species exploitation, many insects hijack plant development to induce novel plant organs called galls that provide the insect with a source of nutrition and a temporary home. Galls result from dramatic reprogramming of plant cell biology driven by insect molecules, but the roles of specific insect molecules in gall development have not yet been determined. Here, we study the aphid Hormaphis cornu, which makes distinctive "cone" galls on leaves of witch hazel Hamamelis virginiana. We found that derived genetic variants in the aphid gene determinant of gall color (dgc) are associated with strong downregulation of dgc transcription in aphid salivary glands, upregulation in galls of seven genes involved in anthocyanin synthesis, and deposition of two red anthocyanins in galls. We hypothesize that aphids inject DGC protein into galls and that this results in differential expression of a small number of plant genes. dgc is a member of a large, diverse family of novel predicted secreted proteins characterized by a pair of widely spaced cysteine-tyrosine-cysteine (CYC) residues, which we named BICYCLE proteins. bicycle genes are most strongly expressed in the salivary glands specifically of galling aphid generations, suggesting that they may regulate many aspects of gall development. bicycle genes have experienced unusually frequent diversifying selection, consistent with their potential role controlling gall development in a molecular arms race between aphids and their host plants.</p>
},
	issn = {1879-0445},
	doi = {10.1016/j.cub.2021.01.104},
	author = {Korgaonkar, Aishwarya and Han, Clair and Lemire, Andrew L and Siwanowicz, Igor and Bennouna, Djawed and Kopec, Rachel E and Andolfatto, Peter and Shigenobu, Shuji and Stern, David L}
}
@article {45724,
	title = {Aphids evolved novel secreted proteins for symbiosis with bacterial endosymbiont.},
	journal = {Proc Biol Sci},
	volume = {280},
	year = {2013},
	month = {2013 Jan 7},
	pages = {20121952},
	abstract = {<p>Aphids evolved novel cells, called bacteriocytes, that differentiate specifically to harbour the obligatory mutualistic endosymbiotic bacteria Buchnera aphidicola. The genome of the host aphid Acyrthosiphon pisum contains many orphan genes that display no similarity with genes found in other sequenced organisms, prompting us to hypothesize that some of these orphan genes are related to lineage-specific traits, such as symbiosis. We conducted deep sequencing of bacteriocytes mRNA followed by whole mount in situ hybridizations of over-represented transcripts encoding aphid-specific orphan proteins. We identified a novel class of genes that encode small proteins with signal peptides, which are often cysteine-rich, that are over-represented in bacteriocytes. These genes are first expressed at a developmental time point coincident with the incorporation of symbionts strictly in the cells that contribute to the bacteriocyte and this bacteriocyte-specific expression is maintained throughout the aphid{\textquoteright}s life. The expression pattern suggests that recently evolved secretion proteins act within bacteriocytes, perhaps to mediate the symbiosis with beneficial bacterial partners, which is reminiscent of the evolution of novel cysteine-rich secreted proteins of leguminous plants that regulate nitrogen-fixing endosymbionts.</p>
},
	keywords = {Amino Acid Sequence, Animals, Aphids, Buchnera, DNA, Complementary, Evolution, Molecular, High-Throughput Nucleotide Sequencing, In Situ Hybridization, Insect Proteins, Protein Sorting Signals, RNA, Messenger, Sequence Alignment, Sequence Analysis, RNA, Symbiosis},
	issn = {1471-2954},
	doi = {10.1098/rspb.2012.1952},
	author = {Shigenobu, Shuji and Stern, David L}
}
