Parental Heat Calls Affect Hypothalamic Gene Expression and DNA Methylation in Embryonic Zebra Finches: Neuroendocrine Mechanisms of Adaptive Growth Trajectories
Start Date
12-4-2024 3:15 PM
Location
CLC Ballroom
Document Type
Presentation
Abstract
Organisms have evolved a variety of mechanisms to compensate for rapid environmental change. A dramatic example has been described for the zebra finch (Taeniopygia castanotis), a songbird native to Australia. Zebra finch parents produce a high-pitched acoustic signal (“heat call”) during bouts of extreme hot weather common to the territory. This sound triggers a developmental change in the eggs they are incubating, so that the offspring become better adapted to heat after hatching. Here, we explore the mechanism of this adaptive developmental reprogramming, hypothesizing that epigenetic changes in the embryonic hypothalamus will follow from heat call exposure. We used Reduced Representation Bisulfite Sequencing (RRBS) in the whole brain to explore DNA methylation changes, and RNA-Sequencing to explore gene expression in the hypothalamus of embryos chronically exposed to heat calls in an incubator. Our results show DNA methylation changes in the glucocorticoid receptor (NR3C1) gene in a novel location in the second exon that was previously not linked to developmental changes due to early life conditions in other taxa. We also found evidence of neuroendocrine and cytoskeletal gene expression changes in the hypothalamus. Finally, heat call exposed embryos also showed DNA methylation changes in neuronal network genes and nuclear receptors involved in transcriptional regulation suggesting a genomic reprogramming of zebra finch embryos undergoing adaptive developmental changes upon chronic exposure to heat calls.
Keywords
Heat Call, Prenatal Communication, Hypothalamus, Zebra Finch, Development Reprogramming, DNA Methylation, Glucocorticoid Receptor
Parental Heat Calls Affect Hypothalamic Gene Expression and DNA Methylation in Embryonic Zebra Finches: Neuroendocrine Mechanisms of Adaptive Growth Trajectories
CLC Ballroom
Organisms have evolved a variety of mechanisms to compensate for rapid environmental change. A dramatic example has been described for the zebra finch (Taeniopygia castanotis), a songbird native to Australia. Zebra finch parents produce a high-pitched acoustic signal (“heat call”) during bouts of extreme hot weather common to the territory. This sound triggers a developmental change in the eggs they are incubating, so that the offspring become better adapted to heat after hatching. Here, we explore the mechanism of this adaptive developmental reprogramming, hypothesizing that epigenetic changes in the embryonic hypothalamus will follow from heat call exposure. We used Reduced Representation Bisulfite Sequencing (RRBS) in the whole brain to explore DNA methylation changes, and RNA-Sequencing to explore gene expression in the hypothalamus of embryos chronically exposed to heat calls in an incubator. Our results show DNA methylation changes in the glucocorticoid receptor (NR3C1) gene in a novel location in the second exon that was previously not linked to developmental changes due to early life conditions in other taxa. We also found evidence of neuroendocrine and cytoskeletal gene expression changes in the hypothalamus. Finally, heat call exposed embryos also showed DNA methylation changes in neuronal network genes and nuclear receptors involved in transcriptional regulation suggesting a genomic reprogramming of zebra finch embryos undergoing adaptive developmental changes upon chronic exposure to heat calls.