Site-specific and developmental expression of pannexin1 in the mouse nervous system.
Until recently, members of the connexin gene family were believed to comprise the sole molecular component forming gap junction channels in vertebrates. The recent discovery of the pannexin gene family has challenged this view, as these genes may encode for a putative second class of gap junction proteins in vertebrates. The expression of pannexin genes overlaps with those cellular networks known to exhibit a high degree of gap junctional coupling. We investigated the spatio-temporal mRNA distribution of one member of this gene family, pannexin1 (Panx1), in the brain and retina of mice using quantitative real-time polymerase chain reaction and a combination of in situ hybridization and immunohistochemistry for cellular resolution. Our results demonstrate a widespread expression of Panx1 in the brain, retina and other non-neuronal tissues. In the cortex, cerebellum and eye, Panx1 is expressed at early embryonic time points and peaks around embryonic day 18 followed by a decline towards adulthood. Most notably, Panx1 is detectable in neurons of many brain nuclei, which are known to be coupled by gap junctions as well as in previously unrecognized areas. Abundant expression was found in the adult hippocampal and neocortical pyramidal cells and interneurons, neurons of the reticular thalamus, the inferior olive, magnocellular hypothalamic neurons, midbrain and brain stem motoneurons, Purkinje cells and the retina.
Ray
Arundhati
A
Department of Neuroanatomy and Molecular Brain Research, Faculty of Medicine, Ruhr University, Bochum, Germany.
Zoidl
Georg
G
Weickert
Svenja
S
Wahle
Petra
P
Dermietzel
Rolf
R
D000818:Animals; D000831:Animals, Newborn; D015152:Blotting, Northern / Q000379:methods; D017630:Connexins; D004622:Embryo, Mammalian; D005260:Female; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D017403:In Situ Hybridization / Q000379:methods; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D009420:Nervous System / Q000196:embryology / Q000254:growth & development / Q000378:metabolism*; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods
D017630:Connexins; D009419:Nerve Tissue Proteins; C503631:Panx1 protein, mouse; D012333:RNA, Messenger