Genome Size Reversely Correlates With Host Plant Range in Helicoverpa Species

In 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 per...

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Autores principales: Zhang, Shen, Gu, Shaohua, Ni, Xinzhi, Li, Xianchun
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6363812/
https://www.ncbi.nlm.nih.gov/pubmed/30761014
http://dx.doi.org/10.3389/fphys.2019.00029
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author Zhang, Shen
Gu, Shaohua
Ni, Xinzhi
Li, Xianchun
author_facet Zhang, Shen
Gu, Shaohua
Ni, Xinzhi
Li, Xianchun
author_sort Zhang, Shen
collection PubMed
description In 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.
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spelling pubmed-63638122019-02-13 Genome Size Reversely Correlates With Host Plant Range in Helicoverpa Species Zhang, Shen Gu, Shaohua Ni, Xinzhi Li, Xianchun Front Physiol Physiology In 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. Frontiers Media S.A. 2019-01-30 /pmc/articles/PMC6363812/ /pubmed/30761014 http://dx.doi.org/10.3389/fphys.2019.00029 Text en Copyright © 2019 Zhang, Gu, Ni and Li. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Physiology
Zhang, Shen
Gu, Shaohua
Ni, Xinzhi
Li, Xianchun
Genome Size Reversely Correlates With Host Plant Range in Helicoverpa Species
title Genome Size Reversely Correlates With Host Plant Range in Helicoverpa Species
title_full Genome Size Reversely Correlates With Host Plant Range in Helicoverpa Species
title_fullStr Genome Size Reversely Correlates With Host Plant Range in Helicoverpa Species
title_full_unstemmed Genome Size Reversely Correlates With Host Plant Range in Helicoverpa Species
title_short Genome Size Reversely Correlates With Host Plant Range in Helicoverpa Species
title_sort genome size reversely correlates with host plant range in helicoverpa species
topic Physiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6363812/
https://www.ncbi.nlm.nih.gov/pubmed/30761014
http://dx.doi.org/10.3389/fphys.2019.00029
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