title: Divergence of RNA localization between rat and mouse neurons reveals the potential for rapid brain evolution.
abstract: BACKGROUND
  Neurons display a highly polarized architecture. Their ability to modify their features under intracellular and extracellular stimuli, known as synaptic plasticity, is a key component of the neurochemical basis of learning and memory. A key feature of synaptic plasticity involves the delivery of mRNAs to distinct sub-cellular domains where they are locally translated. Regulatory coordination of these spatio-temporal events is critical for synaptogenesis and synaptic plasticity as defects in these processes can lead to neurological diseases. In this work, using microdissected dendrites from primary cultures of hippocampal neurons of two mouse strains (C57BL/6 and Balb/c) and one rat strain (Sprague-Dawley), we investigate via microarrays, subcellular localization of mRNAs in dendrites of neurons to assay the evolutionary differences in subcellular dendritic transcripts localization.
  
  
  RESULTS
  Our microarray analysis highlighted significantly greater evolutionary diversification of RNA localization in the dendritic transcriptomes (81% gene identity difference among the top 5% highly expressed genes) compared to the transcriptomes of 11 different central nervous system (CNS) and non-CNS tissues (average of 44% gene identity difference among the top 5% highly expressed genes). Differentially localized genes include many genes involved in CNS function.
  
  
  CONCLUSIONS
  Species differences in sub-cellular localization may reflect non-functional neutral drift. However, the functional categories of mRNA showing differential localization suggest that at least part of the divergence may reflect activity-dependent functional differences of neurons, mediated by species-specific RNA subcellular localization mechanisms.
authors.forename: Chantal
authors.initials: C
authors.lastname: Francis
authors.forename: Shreedhar
authors.initials: S
authors.lastname: Natarajan
authors.forename: Miler T
authors.initials: MT
authors.lastname: Lee
authors.forename: Mugdha
authors.initials: M
authors.lastname: Khaladkar
authors.forename: Peter T
authors.initials: PT
authors.lastname: Buckley
authors.forename: Jai-Yoon
authors.initials: JY
authors.lastname: Sul
authors.affiliation: Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA. Eberwine@mail.med.upenn.edu.
authors.forename: James
authors.initials: J
authors.lastname: Eberwine
authors.forename: Junhyong
authors.initials: J
authors.lastname: Kim
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D000818:Animals; D005075:Biological Evolution; D003712:Dendrites / Q000378:metabolism; D007150:Immunohistochemistry; D017404:In Situ Hybridization, Fluorescence; D051379:Mice; D008807:Mice, Inbred BALB C; D008810:Mice, Inbred C57BL; D058977:Molecular Sequence Annotation; D009473:Neuronal Plasticity / Q000235:genetics; D009474:Neurons / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D059467:Transcriptome
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D009687:Nuclear Proteins; D012333:RNA, Messenger