title: [Mesenchymal stem cells do not differentiate into "quasi-sperm"].
abstract: OBJECTIVE
  To determine whether the surviving mesenchymal stem cells (MSCs) in the testis after transplantation can differentiate into quasi-sperm.
  
  
  METHODS
  (1) Making an animal model with sterilized testes. Forty 4-week old white male BASB/C mice were used to establish an animal model with sterilized testes and divided randomly into an experimental and a control group. (2) Cell preparation. The MSCs from 10 gray male 129-mice were isolated, cultured and purified by Percoll density gradient centrifugation combined with the adherent method. When the MSCs grew to an adequate number, they were made into a cell suspension with NS at a concentration of 1 million cells/ml. (3) Xenogeneic transplantation of the MSCs into the testis. The MSC suspension was blindly injected into the testes of the mice in the experimental group and NS into the testes of the controls. (4) Post-transplantation observation. Forty white female BASB/C mice were adopted, each put into a box with a male mouse from the experimental group or the control group, and then observed for pregnancy.
  
  
  RESULTS
  In the experimental group, 8 cases of pregnancy (40%) were observed at 31-46 d (38.5 d on average), the offspring all white. In the control group, only 1 case of pregnancy (5%) was seen at 45 d, the offspring all white, too. It was suggested that the MSCs of the 129-mice failed to differentiate into functional quasi-sperm and pass their genes to their offspring, as would expectedly have been presented by a mixture of black and white. The pregnancy rates of the two groups were significantly different (P < 0.05), which indicated that MSCs could promote the healing of the testis damage.
  
  
  CONCLUSIONS
  MSCs cannot differentiate into quasi-sperm after heterogeneity transplantation into the testis, but can promote the healing of the testis damage.
authors.affiliation: Reproductive Medical Center, Second People's Hospital of Guangzhou, Guangzhou, Guangdong 510150, China.
authors.forename: Feng-hua
authors.initials: FH
authors.lastname: Liu
authors.forename: Dong-zi
authors.initials: DZ
authors.lastname: Yang
authors.forename: Yi-feng
authors.initials: YF
authors.lastname: Wang
authors.forename: Xiao-ping
authors.initials: XP
authors.lastname: Liang
authors.forename: Wen-ming
authors.initials: WM
authors.lastname: Peng
authors.forename: Chang-an
authors.initials: CA
authors.lastname: Cao
authors.forename: Xi-gu
authors.initials: XG
authors.lastname: Chen
authors.forename: Zhong-min
authors.initials: ZM
authors.lastname: Guo
mesh_terms: D000818:Animals; D002454:Cell Differentiation; D004195:Disease Models, Animal; D005260:Female; D007248:Infertility, Male / Q000209:etiology*; D008297:Male; D045164:Mesenchymal Stem Cell Transplantation; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D051379:Mice; D008807:Mice, Inbred BALB C; D011247:Pregnancy; D011897:Random Allocation; D013737:Testis / Q000637:transplantation*; D014184:Transplantation, Homologous