Related Experiment Videos
Zebra finch estrogen receptor cDNA: cloning and mRNA expression
E C Jacobs1, A P Arnold, A T Campagnoni
1Program in Neuroscience, UCLA, Los Angeles, CA 90095, USA.
The Journal of Steroid Biochemistry and Molecular Biology
|October 1, 1996
Summary
Estrogen receptors (ER) are crucial for zebra finch song, but their brain distribution was unclear. This study found ER primarily in the hypothalamus and preoptic area, not in song control regions, clarifying their role.
Area of Science:
- Neuroendocrinology
- Molecular Biology
- Avian Neuroscience
Background:
- Estrogen masculinizes zebra finch song neural circuits and activates singing in adults.
- Previous studies show conflicting patterns of estrogen receptor (ER) expression in song control regions.
- Understanding ER distribution is key to deciphering estrogen's role in vocal behavior.
Purpose of the Study:
- To isolate and characterize the zebra finch estrogen receptor (ER) cDNA.
- To determine the distribution of ER mRNA in the zebra finch brain.
- To clarify the role of ER in song control by examining its localization.
Main Methods:
- Isolated ER cDNA from zebra finch hypothalamic-preoptic area.
- Performed Northern blot analysis to detect ER mRNA transcripts.
- Used in situ hybridization histochemistry to localize ER mRNA in brain tissue.
Main Results:
- Isolated a 2792 bp ER cDNA, with the deduced protein being highly homologous to other vertebrates.
- Northern blot revealed three ER mRNA transcripts with differential expression in ovary, oviduct, and telencephalon.
- In situ hybridization showed strong ER mRNA labeling in the hypothalamus and preoptic area, but not in song control nuclei (HVC, RA, MAN, Area X).
Conclusions:
- The study successfully isolated and characterized zebra finch ER cDNA.
- ER mRNA is expressed in specific brain regions, notably the hypothalamus and preoptic area.
- The absence of ER in key song control nuclei suggests indirect mechanisms for estrogen's effects on zebra finch song.