A Null Mutation in Basigin, an Immunoglobulin Superfamily Member, Indicates Its Important Roles in Peri-implantation Development and Spermatogenesis

Abstract

Basigin is a highly glycosylated transmembrane protein with two immunoglobulin-like domains. We generated mutant mice lacking the basigin gene (Bsg) by gene targeting. Bsg (-/-) embryos developed normally during preimplantation stages. However, the majority of Bsg (-/-) embryos died around the time of implantation. At this time, basigin mRNA was strongly expressed in the trophectoderm, embryo proper, and uterine endometrium of Bsg (+/+) mice. These results suggest that basigin is involved in intercellular recognition during implantation. Embryos which survived the critical period yielded Bsg (-/-) mutant mice. Half of the mutant mice died before 1 month after birth, due to interstitial pneumonia. The surviving adult mutant mice were small and sterile. Spermatogenesis was arrested in the mutant mice. Most of the spermatocytes in the Bsg (-/-) mouse were arrested and degenerated at the metaphase of the first meiosis, and only a small number differentiated to step 1 spermatids. In the female mutants, the ovaries and genital tract were morphologically normal, and the defect was probably in the capability of implantation of the uterus. In conclusion, basigin is an important cell-surface molecule involved in early embryogenesis and reproduction.

Homo‐oligomer formation by basigin, an immunoglobulin superfamily member, via its N‐terminal immunoglobulin domain

“…In addition, the adult mutant mice are small and sterile [21]. Spermatogenesis is arrested at the metaphase of the first meiosis, which is consistent with the Bsg expression pattern in the germ cells in wild-type testes [21]. In the female mutants, the ovaries and genital tracts are morphologically normal, and the defects are probably in the capability of implantation of the uterus and the maturation of oocytes [21,24].…”

“…Adult null mutants exhibit lowered sensitivity to irritating odors [22] and deficits in spatial learning and memory [23]. In addition, the adult mutant mice are small and sterile [21]. Spermatogenesis is arrested at the metaphase of the first meiosis, which is consistent with the Bsg expression pattern in the germ cells in wild-type testes [21].…”

“…The mouse testis is the organ where Bsg has a vital function, as revealed by a study on Bsg knock-out mice [21]. Thus, we first examined whether or not Bsg expressed in the mouse testis forms homo-oligomers.…”

“…Pivotal roles of Bsg in development have been revealed by a series of studies of Bsg knock-out mice. Many Bsg null mutant embryos are lost around the time of implantation [21]. Adult null mutants exhibit lowered sensitivity to irritating odors [22] and deficits in spatial learning and memory [23].…”

Basigin/CD147 Promotes Renal Fibrosis after Unilateral Ureteral Obstruction

“…30 We previously generated Bsg-deficient mice (Bsg Ϫ/Ϫ ) and reported several abnormalities, including male and female sterility, progressive retinal degeneration, increased cell proliferation on mixed lymphocyte culture, decreased memory function, and abnormal sensory function. [31][32][33] Most recently, we also found that Bsg is an E-selectin ligand and is involved in renal ischemia/reperfusion injury. 34 In this study, we focused on Bsg functions in renal fibrosis induced by unilateral ureteral obstruction (UUO).…”