Table 2.

Adult bone phenotypes of knockout mice for RXR and RXR-partners

NR	Mouse model	Cell type	Bone phenotype	Bone mineral density	Bone resorption	Bone formation
RXR	aRxra−/− [64]	Systemic	–	–	–	–
	Rxrb−/− [65]	Systemic	Normal	NA	NA	NA
	Rxrg−/− [66]	Systemic	Normal	NA	NA	NA
	Mx1-Cre/Rxrafl/flbfl/fl [8]	Osteoclast lineage	Increased bone mass	Male ↑ Female →	↓	→
PPAR	Ppara−/− [110]	Systemic	Normal	→	→	→
	PpardSox2-cKO [74]	Systemic (except placenta)	Osteopenia	↓	↑	→
	Pparg+/− [81]	Systemic	Increased bone mass Osteopetrosis	↑	→	↑
	Tie2Cre/Ppargfl/fl [82]	Osteoclast lineage	Increased bone mass	↑	↓	→
LXR	Lxra−/− [60]	Systemic	Increased bone mass	Male → Female ↑	↓	→
	Lxrb−/− [60]	Systemic	Normal	→	↓	↑
	Lxrab−/− [60]	Systemic	Normal	→	→	→
FXR	Fxr−/− [61]	Systemic	Osteopenia	Male ↓ Female →	↑	↓
PXR	Pxr−/− [62]	Systemic	Osteopenia	Male ? Female ↓	↑	↓
CAR	Car−/− [52]	Systemic	Increased bone mass	Male ↑ Female →	→	↑?
Nur77	Nurr77−/− [63]	Systemic	Osteopenia	↓	↑	→
Nurr1	Nurr1+/− [111]	Systemic	Normal	NA	NA	NA
RAR	Rara−/− [75]	Systemic	Normal	→	→	→
	Rarb−/−	Systemic	Normal	NA	NA	NA
	Rarg−/− [75]	Systemic	Osteopenia	↓	↑	?
TR	TRα−/− [112]	Systemic	Osteosclerosis	↑	↓	NA
	TRb−/− [112]	Systemic	Osteoporosis	↓	↑	NA
VDR	VDR−/− [113, 114]	Systemic	Rickets Osteomalacia	↓	→	↑
	Col2Cre+/−VDRfl/fl [83]	Chondrocyte	Increased bone mass	↑	↓	→

Arrows indicate increase, decrease, or no change

NA not assessed

^aEmbryonically lethal