Affenzeller, Susanne

[["dc.bibliographiccitation.artnumber","e0223552"],["dc.bibliographiccitation.issue","10"],["dc.bibliographiccitation.journal","PLoS One"],["dc.bibliographiccitation.volume","14"],["dc.contributor.author","Affenzeller, Susanne"],["dc.contributor.author","Frauendorf, Holm"],["dc.contributor.author","Licha, Tobias"],["dc.contributor.author","Jackson, Daniel J."],["dc.contributor.author","Wolkenstein, Klaus"],["dc.date.accessioned","2020-08-04T08:32:28Z"],["dc.date.available","2020-08-04T08:32:28Z"],["dc.date.issued","2019"],["dc.description.abstract","Eumelanin and pheomelanin are well known and common pigments found in nature. However, their complex polymer structure and high thermostability complicate their direct chemical identification. A widely used analytical method is indirect determination using HPLC with UV detection of both types of melanin by their most abundant oxidation products: pyrrole-2,3-dicarboxylic acid (PDCA), pyrrole-2,3,5-tricarboxylic acid (PTCA), thiazole-4,5-dicarboxylic acid (TDCA), and thiazole-2,4,5-tricarboxylic acid (TTCA). An increasing interest in pigmentation in biological research led us to develop a highly sensitive and selective method to identify and quantify these melanin markers in diverse biological samples with complex matrices. By introducing solid-phase extraction (SPE, reversed-phase) following alkaline oxidation we could significantly decrease background signals while maintaining recoveries greater than 70%. Our HPLC-UV-MS method allows for confident peak identification via exact mass information in corresponding UV signals used for quantitation. In addition to synthetic melanin and Sepia officinalis ink as reference compounds eumelanin markers were detected in brown human hair and a brown bivalve shell (Mytilus edulis). Brown feathers from the common chicken (Gallus g. domesticus) yielded all four eumelanin and pheomelanin markers. The present method can be easily adapted for a wide range of future studies on biological samples with unknown melanin content."],["dc.identifier.doi","10.1371/journal.pone.0223552"],["dc.identifier.pmid","31622353"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/16606"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/67513"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.relation.issn","1932-6203"],["dc.relation.orgunit","Abteilung Geobiologie"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.title","Quantitation of eumelanin and pheomelanin markers in diverse biological samples by HPLC-UV-MS following solid-phase extraction"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","e0201396"],["dc.bibliographiccitation.issue","8"],["dc.bibliographiccitation.journal","PLOS ONE"],["dc.bibliographiccitation.volume","13"],["dc.contributor.author","Affenzeller, Susanne"],["dc.contributor.author","Cerveau, Nicolas"],["dc.contributor.author","Jackson, Daniel John"],["dc.date.accessioned","2019-07-09T11:46:04Z"],["dc.date.available","2019-07-09T11:46:04Z"],["dc.date.issued","2018"],["dc.description.abstract","Identifying and understanding mechanisms that generate phenotypic diversity is a fundamental goal of evolutionary biology. With a diversity of pigmented shell morphotypes governed by Mendelian patterns of inheritance, the common grove snail Cepaea nemoralis (Linnaeus, 1758) has been a model for evolutionary biologists and population geneticists for decades. However, the genetic mechanisms by which C. nemoralis generates this pigmented shell diversity remain unknown. An important first step in investigating this pigmentation pattern is to establish a set of validated reference genes for differential gene expression assays. Here we have evaluated eleven candidate genes for reverse transcription quantitative polymerase chain reaction (qPCR) in C. nemoralis. Five of these were housekeeping genes traditionally employed as qPCR reference genes in other species, while six alternative genes were selected de novo from C. nemoralis transcriptome data based on the stability of their expression levels. We tested all eleven candidates for expression stability in four sub-adult tissues of C. nemoralis: pigmented mantle, unpigmented mantle, head and foot. We find that two commonly employed housekeeping genes (alpha tubulin, glyceraldehyde 3-phosphate dehydrogenase) are unsuitable for use as qPCR reference genes in C. nemoralis. The traditional housekeeping gene UBIquitin on the other hand performed very well. Additionally, an RNAdirected DNA polymerase (RNAP), a Potassium Channel Protein (KCHP) and a Prenylated Rab acceptor protein 1 (PRAP), identified de novo from transcriptomic data, were the most stably expressed genes in different tissue combinations. We also tested expression stability over two seasons and found that, although other genes are more stable within a single season, beta actin (BACT) and elongation factor 1 alpha (EF1α) were the most reliable reference genes across seasons."],["dc.identifier.doi","10.1371/journal.pone.0201396"],["dc.identifier.pmid","30157182"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/15393"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/15688"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/59376"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.subject.ddc","550"],["dc.title","Identification and validation of reference genes for qPCR in the terrestrial gastropod Cepaea nemoralis"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.firstpage","47"],["dc.bibliographiccitation.issue","1"],["dc.bibliographiccitation.journal","Frontiers in Zoology"],["dc.bibliographiccitation.volume","16"],["dc.contributor.author","Affenzeller, Susanne"],["dc.contributor.author","Wolkenstein, Klaus"],["dc.contributor.author","Frauendorf, Holm"],["dc.contributor.author","Jackson, Daniel J."],["dc.date.accessioned","2020-08-04T07:39:30Z"],["dc.date.available","2020-08-04T07:39:30Z"],["dc.date.issued","2019"],["dc.description.abstract","The geometric patterns that adorn the shells of many phylogenetically disparate molluscan species are comprised of pigments that span the visible spectrum. Although early chemical studies implicated melanin as a commonly employed pigment, surprisingly little evidence generated with more recent and sensitive techniques exists to support these observations."],["dc.identifier.doi","10.1186/s12983-019-0346-5"],["dc.identifier.pmid","31889966"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/17046"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/67512"],["dc.language.iso","en"],["dc.notes.intern","Merged from goescholar"],["dc.relation.issn","1742-9994"],["dc.rights","CC BY 4.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0/"],["dc.title","Eumelanin and pheomelanin pigmentation in mollusc shells may be less common than expected: insights from mass spectrometry"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]