title: Successful cryopreservation of whole sheep ovary by using DMSO-free cryoprotectant.
abstract: OBJECTIVE
  The study aims to assess the protective effects of dimethyl sulfoxide (DMSO)-free solution based on trehalose on the cryopreservation of a whole sheep ovary and evaluate its use as an efficient cryoprotectant.
  
  
  METHODS
  Twenty-one ovaries collected from 6- to 8-month-old non-pregnant female sheep were randomly distributed into three groups, namely, a fresh group, a DMSO-free group, and a DMSO group. The morphology, cell apoptosis (by hematoxylin and eosin (HE) staining and terminal deoxynucleotidyltransferase-mediated dUTP nick-end labeling (TUNEL) assay), and mRNA transcript of Bcl-2-associated X protein (BAX) and cold inducible RNA-binding protein (CIRP) (by real-time PCR) of the thawed sheep ovaries and fresh controls were tested to establish a criterion for appraising the results of the cryopreservation.
  
  
  RESULTS
  (i) The histological assessment indicated that the structure of the DMSO-free ovaries remained largely intact and comparable to those of the fresh control groups; whereas, significant damage was observed in the ovaries of the DMSO group (P < 0.05). (ii) The TUNEL assay and mRNA transcript of the BAX assessment showed that the apoptosis parameter in the fresh group was the lowest among all the groups (P < 0.05), and the parameter in the DMSO-free group was significantly lower than that in the DMSO group (P < 0.05). (iii) The level of the CIRP transcripts increased the most in the DMSO-free group followed by the DMSO group and the fresh control group (P < 0.05).
  
  
  CONCLUSIONS
  These results indicate that a DMSO-free cryoprotectant solution, especially a trehalose cryoprotectant, is an efficient cryoprotectant and has a beneficial effect on the cryopreservation of whole sheep ovaries.
authors.affiliation: Center for Reproduction and Genetics, Suzhou Hospital Affiliated to Nanjing Medical University, 26 Daoqian Street, Suzhou, Jiangsu, 215002, China, hellododo@126.com.
authors.forename: Tianqi
authors.initials: T
authors.lastname: Du
authors.forename: Lan
authors.initials: L
authors.lastname: Chao
authors.forename: Shuqin
authors.initials: S
authors.lastname: Zhao
authors.forename: Linglong
authors.initials: L
authors.lastname: Chi
authors.forename: Dong
authors.initials: D
authors.lastname: Li
authors.forename: Yanjun
authors.initials: Y
authors.lastname: Shen
authors.forename: Qing
authors.initials: Q
authors.lastname: Shi
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Deng
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000737:chemistry / Q000494:pharmacology*; D004121:Dimethyl Sulfoxide; D005260:Female; D010053:Ovary / Q000187:drug effects / Q000473:pathology / Q000502:physiology*; D010477:Perfusion / Q000295:instrumentation / Q000379:methods; D016601:RNA-Binding Proteins / Q000235:genetics; D012756:Sheep; D014199:Trehalose / Q000494:pharmacology; D051028:bcl-2-Associated X Protein / Q000235:genetics
chemical_list: D003451:Cryoprotective Agents; D016601:RNA-Binding Proteins; D051028:bcl-2-Associated X Protein; D014199:Trehalose; D004121:Dimethyl Sulfoxide