title: Putative "stemness" gene jam-B is not required for maintenance of stem cell state in embryonic, neural, or hematopoietic stem cells.
abstract: Many genes have been identified that are specifically expressed in multiple types of stem cells in their undifferentiated state. It is generally assumed that at least some of these putative "stemness" genes are involved in maintaining properties that are common to all stem cells. We compared gene expression profiles between undifferentiated and differentiated embryonic stem cells (ESCs) using DNA microarrays. We identified several genes with much greater signal in undifferentiated ESCs than in their differentiated derivatives, among them the putative stemness gene encoding junctional adhesion molecule B (Jam-B gene). However, in spite of the specific expression in undifferentiated ESCs, Jam-B mutant ESCs had normal morphology and pluripotency. Furthermore, Jam-B homozygous mutant mice are fertile and have no overt developmental defects. Moreover, we found that neural and hematopoietic stem cells recovered from Jam-B mutant mice are not impaired in their ability to self-renew and differentiate. These results demonstrate that Jam-B is dispensable for normal mouse development and stem cell identity in embryonic, neural, and hematopoietic stem cells.
authors.affiliation: Division of Developmental Biology, Research Center for Genomic Medicine, Saitama Medical University, 1397-1 Yamane, Hidaka, Saitama 350-1241, Japan.
authors.forename: Takehisa
authors.initials: T
authors.lastname: Sakaguchi
authors.forename: Masazumi
authors.initials: M
authors.lastname: Nishimoto
authors.forename: Satoru
authors.initials: S
authors.lastname: Miyagi
authors.forename: Atsushi
authors.initials: A
authors.lastname: Iwama
authors.forename: Yohei
authors.initials: Y
authors.lastname: Morita
authors.forename: Naoki
authors.initials: N
authors.lastname: Iwamori
authors.forename: Hiromitsu
authors.initials: H
authors.lastname: Nakauchi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kiyonari
authors.forename: Masami
authors.initials: M
authors.lastname: Muramatsu
authors.forename: Akihiko
authors.initials: A
authors.lastname: Okuda
mesh_terms: D000818:Animals; D015815:Cell Adhesion Molecules / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D002478:Cells, Cultured; D003433:Crosses, Genetic; D004622:Embryo, Mammalian / Q000166:cytology*; D005260:Female; D005786:Gene Expression Regulation; D018390:Gene Targeting; D006412:Hematopoietic Stem Cells / Q000166:cytology*; D006579:Heterozygote; D007136:Immunoglobulins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D008297:Male; D008565:Membrane Proteins / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D046228:Microarray Analysis; D039902:Multipotent Stem Cells / Q000166:cytology; D009154:Mutation / Q000235:genetics; D009417:Nerve Tissue / Q000166:cytology*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D013737:Testis / Q000166:cytology; D062765:Junctional Adhesion Molecule B
chemical_list: D015815:Cell Adhesion Molecules; D007136:Immunoglobulins; D008565:Membrane Proteins; D012333:RNA, Messenger; C498781:Jam2 protein, mouse; D062765:Junctional Adhesion Molecule B