title: Colony-stimulating factor 2 enhances the developmental competence of yak (Poephagus grunniens) preimplantation embryos by modulating the expression of heat shock protein 70 kDa 1A.
abstract: Colony-stimulating factor 2 (CSF2) is known to promote the development and survival of rodents and ruminants preimplantation embryos; however, the effect of CSF2on yak embryos has not been reported. The objective of this study was to investigate the effects of CSF2on the developmental competence of yak embryos cultured in vitro in modified synthetic oviduct fluid (mSOF) medium and on the expression pattern of heat shock protein 70 kDa 1A (HSPA1A). In each experiment, cumulus-oocyte complexes (COCs) were matured in vitro and fertilized with frozen-thawed semen. Zygotes were treated with varying concentrations of CSF2(0, 10, 50, 100 ng/mL) until day 8 after fertilization. Embryo development was calculated as the percentage of oocytes that formed embryos at the 2-cell, 4-cell, 8-cell, 16-cell, morula and blastocyst stages. The total cell numbers (TCN) per blastocyst and their allocation to the inner cell mass (ICM) and trophectoderm (TE) lineages were determined using differential CDX2 staining. The expression of HSPA1A was examined by quantitative real-time PCR (qRT-PCR) and immunochemistry to determine the mRNA and protein levels. The results showed that treatment with 50 ng/mL CSF2significantly (P < 0.05) increased the rate of blastocyst formation (19.01% versus 9.93%) and the TCN per blastocyst (96.94 versus 81.41) compared to the control group. However, no significant differences were observed in the other stages of development. qRT-PCR analysis confirmed that treatment with 50 ng/mL CSF2significantly (P < 0.05) inhibited the expression of HSPA1A mRNA in blastocysts cultured in vitro relative to the control group, but there were no significant differences between the other treatment groups. Immunocytochemical analysis confirmed that HSPA1A protein accumulation was gradually reduced in yak blastocysts cultured in 0, 10, 100 or 50 ng/mL CSF2, however, no significant differences were observed between the 10 and 100 ng/mL treatments (P > 0.05). In conclusion, these findings demonstrate that CSF2inhibits the expression of HSPA1A to facilitate yak blastocyst formation and increase cell numbers.
authors.affiliation: Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, China.
authors.forename: Zexing
authors.initials: Z
authors.lastname: Wen
authors.affiliation: Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, China.
authors.forename: Yangyang
authors.initials: Y
authors.lastname: Pan
authors.affiliation: Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Cui
authors.affiliation: Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, China.
authors.forename: Xiumei
authors.initials: X
authors.lastname: Peng
authors.affiliation: Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Chen
authors.affiliation: Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, China.
authors.forename: Jiangfeng
authors.initials: J
authors.lastname: Fan
authors.affiliation: Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, China.
authors.forename: Guyue
authors.initials: G
authors.lastname: Li
authors.affiliation: Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, China.
authors.forename: Tian
authors.initials: T
authors.lastname: Zhao
authors.affiliation: Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, China.
authors.forename: Shujian
authors.initials: S
authors.lastname: Qin
authors.affiliation: Gansu Province Livestock Embryo Engineering Research Center, College of Veterinary Medicine, Gansu Agricultural University, Lanzhou, China. Electronic address: sjyu@163.com.
authors.forename: Sijiu
authors.initials: S
authors.lastname: Yu
mesh_terms: D000818:Animals; D001755:Blastocyst / Q000737:chemistry / Q000187:drug effects / Q000502:physiology*; D002417:Cattle / Q000196:embryology*; D003470:Culture Media; D004305:Dose-Response Relationship, Drug; D046149:Embryo Culture Techniques / Q000662:veterinary; D047108:Embryonic Development / Q000187:drug effects*; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000008:administration & dosage / Q000494:pharmacology*; D018840:HSP70 Heat-Shock Proteins / Q000032:analysis / Q000235:genetics*; D059471:In Vitro Oocyte Maturation Techniques; D009028:Morula; D012333:RNA, Messenger / Q000032:analysis
chemical_list: D003470:Culture Media; D018840:HSP70 Heat-Shock Proteins; D012333:RNA, Messenger; D016178:Granulocyte-Macrophage Colony-Stimulating Factor
keywords: CSF(2); HSPA1A; IVF; Yak