The effect of ethanol concentration on the morphological and molecular preservation of insects for biodiversity studies

2021
journal article
article
35
dc.abstract.enTraditionally, insects collected for scientific purposes have been dried and pinned, or preserved in 70% ethanol. Both methods preserve taxonomically informative exoskeletal structures well but are suboptimal for preserving DNA for molecular biology. Highly concentrated ethanol (95-100%), preferred as a DNA preservative, has generally been assumed to make specimens brittle and prone to breaking. However, systematic studies on the correlation between ethanol concentration and specimen preservation are lacking. Here, we tested how preservative ethanol concentration in combination with different sample handling regimes affect the integrity of seven insect species representing four orders, and differing substantially in the level of sclerotization. After preservation and treatments (various levels of disturbance), we counted the number of appendages (legs, wings, antennae, or heads) that each specimen had lost. Additionally, we assessed the preservation ofDNAafter long-term storage by comparing the ratio of PCR amplicon copy numbers to an added artificial standard. We found that high ethanol concentrations indeed induce brittleness in insects. However, the magnitude and nature of the effect varied strikingly among species. In general, ethanol concentrations at or above 90% made the insects more brittle, but for species with robust, thicker exoskeletons, this did not translate to an increased loss of appendages. Neither freezing the samples nor drying the insects after immersion in ethanol had a negative effect on the retention of appendages. However, the morphology of the insects was severely damaged if they were allowed to dry. We also found thatDNApreserves less well at lower ethanol concentrations when stored at room temperature for an extended period. However, the magnitude of the effect varies among species; the concentrations at which the number of COI amplicon copies relative to the standard was significantly decreased compared to 95% ethanol ranged from 90% to as low as 50%. While higher ethanol concentrations positively affect long-term DNA preservation, there is a clear trade-off between preserving insects for morphological examination and genetic analysis. The optimal ethanol concentration for the latter is detrimental for the former, and vice versa. These trade-offs need to be considered in large insect biodiversity surveys and other projects aiming to combine molecular work with traditional morphology-based characterization of collected specimens.pl
dc.affiliationWydział Biologii : Instytut Nauk o Środowiskupl
dc.contributor.authorMarquina, Danielpl
dc.contributor.authorBuczek, Mateusz - 108307 pl
dc.contributor.authorRonquist, Fredrikpl
dc.contributor.authorŁukasik, Piotr - 398824 pl
dc.date.accessioned2021-03-17T09:59:07Z
dc.date.available2021-03-17T09:59:07Z
dc.date.issued2021pl
dc.date.openaccess0
dc.description.accesstimew momencie opublikowania
dc.description.versionostateczna wersja wydawcy
dc.description.volume9pl
dc.identifier.articleide10799pl
dc.identifier.doi10.7717/peerj.10799pl
dc.identifier.eissn2167-8359pl
dc.identifier.projectROD UJ / OPpl
dc.identifier.urihttps://ruj.uj.edu.pl/xmlui/handle/item/267617
dc.languageengpl
dc.language.containerengpl
dc.pbn.affiliationDziedzina nauk ścisłych i przyrodniczych : nauki biologicznepl
dc.rightsUdzielam licencji. Uznanie autorstwa 4.0 Międzynarodowa*
dc.rights.licenceCC-BY
dc.rights.urihttp://creativecommons.org/licenses/by/4.0/legalcode.pl*
dc.share.typeotwarte czasopismo
dc.subject.eninsectspl
dc.subject.enethanolpl
dc.subject.enDNA preservationpl
dc.subject.enmorphologypl
dc.subject.encollectionpl
dc.subject.enbiodiversitypl
dc.subject.enecologypl
dc.subject.enentomologypl
dc.subject.enmolecular biologypl
dc.subject.entaxonomypl
dc.subtypeArticlepl
dc.titleThe effect of ethanol concentration on the morphological and molecular preservation of insects for biodiversity studiespl
dc.title.journalPeerJpl
dc.typeJournalArticlepl
dspace.entity.typePublication
dc.abstract.enpl
Traditionally, insects collected for scientific purposes have been dried and pinned, or preserved in 70% ethanol. Both methods preserve taxonomically informative exoskeletal structures well but are suboptimal for preserving DNA for molecular biology. Highly concentrated ethanol (95-100%), preferred as a DNA preservative, has generally been assumed to make specimens brittle and prone to breaking. However, systematic studies on the correlation between ethanol concentration and specimen preservation are lacking. Here, we tested how preservative ethanol concentration in combination with different sample handling regimes affect the integrity of seven insect species representing four orders, and differing substantially in the level of sclerotization. After preservation and treatments (various levels of disturbance), we counted the number of appendages (legs, wings, antennae, or heads) that each specimen had lost. Additionally, we assessed the preservation ofDNAafter long-term storage by comparing the ratio of PCR amplicon copy numbers to an added artificial standard. We found that high ethanol concentrations indeed induce brittleness in insects. However, the magnitude and nature of the effect varied strikingly among species. In general, ethanol concentrations at or above 90% made the insects more brittle, but for species with robust, thicker exoskeletons, this did not translate to an increased loss of appendages. Neither freezing the samples nor drying the insects after immersion in ethanol had a negative effect on the retention of appendages. However, the morphology of the insects was severely damaged if they were allowed to dry. We also found thatDNApreserves less well at lower ethanol concentrations when stored at room temperature for an extended period. However, the magnitude of the effect varies among species; the concentrations at which the number of COI amplicon copies relative to the standard was significantly decreased compared to 95% ethanol ranged from 90% to as low as 50%. While higher ethanol concentrations positively affect long-term DNA preservation, there is a clear trade-off between preserving insects for morphological examination and genetic analysis. The optimal ethanol concentration for the latter is detrimental for the former, and vice versa. These trade-offs need to be considered in large insect biodiversity surveys and other projects aiming to combine molecular work with traditional morphology-based characterization of collected specimens.
dc.affiliationpl
Wydział Biologii : Instytut Nauk o Środowisku
dc.contributor.authorpl
Marquina, Daniel
dc.contributor.authorpl
Buczek, Mateusz - 108307
dc.contributor.authorpl
Ronquist, Fredrik
dc.contributor.authorpl
Łukasik, Piotr - 398824
dc.date.accessioned
2021-03-17T09:59:07Z
dc.date.available
2021-03-17T09:59:07Z
dc.date.issuedpl
2021
dc.date.openaccess
0
dc.description.accesstime
w momencie opublikowania
dc.description.version
ostateczna wersja wydawcy
dc.description.volumepl
9
dc.identifier.articleidpl
e10799
dc.identifier.doipl
10.7717/peerj.10799
dc.identifier.eissnpl
2167-8359
dc.identifier.projectpl
ROD UJ / OP
dc.identifier.uri
https://ruj.uj.edu.pl/xmlui/handle/item/267617
dc.languagepl
eng
dc.language.containerpl
eng
dc.pbn.affiliationpl
Dziedzina nauk ścisłych i przyrodniczych : nauki biologiczne
dc.rights*
Udzielam licencji. Uznanie autorstwa 4.0 Międzynarodowa
dc.rights.licence
CC-BY
dc.rights.uri*
http://creativecommons.org/licenses/by/4.0/legalcode.pl
dc.share.type
otwarte czasopismo
dc.subject.enpl
insects
dc.subject.enpl
ethanol
dc.subject.enpl
DNA preservation
dc.subject.enpl
morphology
dc.subject.enpl
collection
dc.subject.enpl
biodiversity
dc.subject.enpl
ecology
dc.subject.enpl
entomology
dc.subject.enpl
molecular biology
dc.subject.enpl
taxonomy
dc.subtypepl
Article
dc.titlepl
The effect of ethanol concentration on the morphological and molecular preservation of insects for biodiversity studies
dc.title.journalpl
PeerJ
dc.typepl
JournalArticle
dspace.entity.type
Publication
Affiliations

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