Facilitation of the Bovine Epigenome in the Limbic System: An Atlas of the Bovine Brain

Economically important traits are often complex in nature and regulated by the central nervous system. Understanding the anatomical organization of the bovine brain can foster research in traits such as docility, feed efficiency, fertility, growth rate, and differential susceptibility to Bovine Spongiform Encephalopathy. Because there can be large variation in brain structures between species, a major limitation to research of the bovine brain is the lack of a complete Bos taurus brain atlas. To catalog the anatomy of the bovine brain at high resolution, the brain of a Holstein steer was fixed through perfusion in the maxillary artery with paraformaldehyde perfusion fixative and extracted from the skull for immersion fixation. The brain was sectioned into 60 micrometer coronal sections and every sixth section was stained with thionine or Weil-myelin at NeuroScience Associates (Knoxville, TN). High resolution images were captured of the block face of the brain as it was being sectioned and after histological staining. These images were assembled into a 3D reconstruction for visualization and labeling of major areas of the brain. While this atlas will facilitate future research in brain regulation of many areas of bovine behavior and physiology, our immediate interest is to accurately dissect functionally distinct regions of the limbic system for whole genome bisulfite sequencing of cattle with extreme measures of docility.