Bbs2-null mice have neurosensory deficits, a defect in social dominance, and retinopathy associated with mislocalization of rhodopsin.
Bardet-Biedl syndrome (BBS) is a heterogeneous, pleiotropic human disorder characterized by obesity, retinopathy, polydactyly, renal and cardiac malformations, learning disabilities, hypogenitalism, and an increased incidence of diabetes and hypertension. No information is available regarding the specific function of BBS2. We show that mice lacking Bbs2 gene expression have major components of the human phenotype, including obesity and retinopathy. In addition, these mice have phenotypes associated with cilia dysfunction, including retinopathy, renal cysts, male infertility, and a deficit in olfaction. With the exception of male infertility, these phenotypes are not caused by a complete absence of cilia. We demonstrate that BBS2 retinopathy involves normal retina development followed by apoptotic death of photoreceptors, the primary ciliated cells of the retina. Photoreceptor cell death is preceded by mislocalization of rhodopsin, indicating a defect in transport. We also demonstrate that Bbs2(-/-) mice and a second BBS mouse model, Bbs4(-/-), have a defect in social function. The evaluation of Bbs2(-/-) mice indicates additional phenotypes that should be evaluated in human patients, including deficits in social interaction and infertility.
Nishimura
Darryl Y
DY
Department of Pediatrics, Division of Medical Genetics, University of Iowa, Iowa City, IA 52242, USA.
Fath
Melissa
M
Mullins
Robert F
RF
Searby
Charles
C
Andrews
Michael
M
Davis
Roger
R
Andorf
Jeaneen L
JL
Mykytyn
Kirk
K
Swiderski
Ruth E
RE
Yang
Baoli
B
Carmi
Rivka
R
Stone
Edwin M
EM
Sheffield
Val C
VC
D000818:Animals; D017209:Apoptosis; D020788:Bardet-Biedl Syndrome / Q000235:genetics* / Q000378:metabolism* / Q000473:pathology; D002923:Cilia / Q000473:pathology; D004195:Disease Models, Animal; D018390:Gene Targeting; D006801:Humans; D052177:Kidney Diseases, Cystic / Q000235:genetics / Q000473:pathology; D008297:Male; D051379:Mice; D018345:Mice, Knockout; D009765:Obesity / Q000235:genetics / Q000378:metabolism; D010641:Phenotype; D020419:Photoreceptor Cells, Vertebrate / Q000473:pathology; D012174:Retinitis Pigmentosa / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D012243:Rhodopsin / Q000378:metabolism*; D012678:Sensation Disorders / Q000235:genetics / Q000503:physiopathology; D012930:Social Dominance; D013091:Spermatogenesis / Q000235:genetics / Q000502:physiology
D012243:Rhodopsin