Avian ecological epigenetics: pitfalls and promises

Abstract

Epigenetic mechanisms can alter gene expression without a change in the nucleotide sequence and are increasingly recognized as important mechanisms that can generate phenotypic diversity. Most of our current knowledge regarding the origin and role of epigenetic variation comes from research on plants or mammals, often in controlled rearing conditions. Epigenetic research on birds in their natural habitats is still in its infancy, but is needed to answer questions regarding the origin of epigenetic marks and their role in phenotypic variation and evolution. Here we review the potential for studying epigenetic variation in natural bird systems. We aim to provide insights into (1) the origin of epigenetic variation, (2) the relationship between epigenetic variation and trait variation, and (3) the possible role of epigenetic variation in adaptation to changing environments. As there is currently little research on epigenetics in wild birds, we examine how findings on other taxa such as plants and mammals relate to birds. We also examine some of the pros and cons of the most commonly used methods to study patterns of DNA methylation in birds, and suggest some topics we believe need to be addressed to develop the field of wild avian epigenetics further. Zusammenfassung Anwendung von Epigenetik an freilebenden VögelnEpigenetische Mechanismen sind in der Lage die Aktivität eines Gens zu beeinflussen ohne die DNA-Sequenz zu veränderen und werden zunehmend als wichtige Mechanismen erkannt um phänotypische Diversität generieren zu können. Der größte Teil unseres derzeitigen Wissens über den Ursprung und die Rolle epigenetischer Variationen stammt aus der Erforschung von Pflanzen oder Säugetieren, oft unter kontrollierten Aufzuchtbedingungen. Die epigenetische Forschung an Vögeln in ihren natürlichen Lebensräumen steckt noch in den Kinderschuhen, ist jedoch erforderlich, um Fragen zur Herkunft der epigenetischen Merkmale und ihrer Rolle bei der Variation und Evolution des Phänotyps zu beantworten. Hier untersuchen wir das Potenzial zur Untersuchung der epigenetischen Variation in natürlichen Vogelsystemen. Wir möchten Einblicke geben in Communicated by M. Wink.

Epigenetics of Animal Personality: DNA Methylation Cannot Explain the Heritability of Exploratory Behavior in a Songbird

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Epigenetic mediation of the onset of reproduction in a songbird

“…The strength of this approach is that we are able to examine how DNA methylation within an individual varies with the reproductive state. More informative tissues such as gonads, hypothalamus, or liver cannot be sampled repeatedly 39 and do not allow a direct correlation with the reproductive state as some females would be sampled before egg laying. The biological relevance of red blood cells as informative tissue with respect to the seasonal onset of reproduction, however, remains unclear.…”

epiGBS2: an improved protocol and automated snakemake workflow for highly multiplexed reduced representation bisulfite sequencing

“…Here, we present an update of the epiGBS laboratory and computational analysis protocols. Compared to the original epiGBS method, the updated protocols in epiGBS2, as presented here, decrease costs and time investment and increase user-friendliness and reproducibility, also allowing for an effective use of epiGBS in a wider range of species, including vertebrates such as birds 11 .…”