Genome Size Reversely Correlates With Host Plant Range in Helicoverpa Species
AffiliationUniv Arizona, Dept Entomol
Univ Arizona, BIO5 Inst
MetadataShow full item record
PublisherFRONTIERS MEDIA SA
CitationZhang S, Gu S, Ni X and Li X (2019) Genome Size Reversely Correlates With Host Plant Range in Helicoverpa Species. Front. Physiol. 10:29. doi: 10.3389/fphys.2019.00029
JournalFRONTIERS IN PHYSIOLOGY
Rights© 2019 Zhang, Gu, Ni and Li. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY).
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at firstname.lastname@example.org.
AbstractIn organisms with very low percentages of transposable elements (TEs), genome size may positively or negatively correlate with host range, depending on whether host adaptation or host modification is the main route to host generalism. To test if this holds true for insect herbivores with greater percentages of TEs, we conducted flow cytometry to measure the endopolyploidy levels and C-values of the host modification (salivary gland and mandibular gland in head), host adaptation (midgut), and host use-independent tissues (male gonad, hemolymph, and Malpighian tubules) of the generalist Helicoverpa armigera and the head of its older specialist sister H. assulta. Larval salivary gland displayed a consecutive chain of endopolyploidy particles from 8Cx to higher than 32Cx and larval head and midgut had endopolyploidy nuclei clusters of 16Cx and 32Cx, whereas larval male gonad, hemolymph, and Malpighian tubules possessed no endopolyploidy nuclei of higher than 8Cx. The estimated genome size of the Solanaceae plant specialist H. assulta is 430 Mb, significantly larger than that of its older generalist sister Heliothis virescens (408 Mb) and those of its two generalist descendants H. armigera (394 Mb) and H. zea (363 Mb). These data not only reveal a negative correlation between host plant range and genome size in this terminal lineage, but also imply that Helicoverpa species appear to depend more on host modification than on host adaptation to achieve polyphagy.
NoteOpen access journal
VersionFinal published version
SponsorsUSDA National Institute of Food and Agriculture [ARZT-1360890-H31-164, ARZT-1370400-R31-168]; National Natural Science Foundation of China [31772164, 31401737, 31171874]; Beijing talents fund [2015000021223ZK29]