Loss of BBS proteins causes anosmia in humans and defects in olfactory cilia structure and function in the mouse.
Defects in cilia are associated with several human disorders, including Kartagener syndrome, polycystic kidney disease, nephronophthisis and hydrocephalus. We proposed that the pleiotropic phenotype of Bardet-Biedl syndrome (BBS), which encompasses retinal degeneration, truncal obesity, renal and limb malformations and developmental delay, is due to dysfunction of basal bodies and cilia. Here we show that individuals with BBS have partial or complete anosmia. To test whether this phenotype is caused by ciliary defects of olfactory sensory neurons, we examined mice with deletions of Bbs1 or Bbs4. Loss of function of either BBS protein affected the olfactory, but not the respiratory, epithelium, causing severe reduction of the ciliated border, disorganization of the dendritic microtubule network and trapping of olfactory ciliary proteins in dendrites and cell bodies. Our data indicate that BBS proteins have a role in the microtubule organization of mammalian ciliated cells and that anosmia might be a useful determinant of other pleiotropic disorders with a suspected ciliary involvement.
Howard Hughes Medical Institute and Department of Molecular Biology and Genetics, 533 Broadway Street Building, Johns Hopkins University, 733 N. Broadway, Baltimore, Maryland 21205, USA.
Heather M
HM
Kulaga
Carmen C
CC
Leitch
Erica R
ER
Eichers
Jose L
JL
Badano
Alysa
A
Lesemann
Bethan E
BE
Hoskins
James R
JR
Lupski
Philip L
PL
Beales
Randall R
RR
Reed
Nicholas
N
Katsanis
D000818:Animals; D020788:Bardet-Biedl Syndrome / Q000235:genetics*; D002923:Cilia / Q000648:ultrastructure; D006801:Humans; D051379:Mice; D008869:Microtubule-Associated Proteins; D008870:Microtubules / Q000648:ultrastructure; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D009297:Nasal Mucosa / Q000378:metabolism / Q000648:ultrastructure; D000857:Olfaction Disorders / Q000235:genetics*; D011506:Proteins / Q000235:genetics* / Q000378:metabolism
C464790:Bbs1 protein, human; D008869:Microtubule-Associated Proteins; D011506:Proteins