title: Epidermal growth factor improves developmental competence and embryonic quality of singly cultured domestic cat embryos.
abstract: This study examined the influence of EGF on the expression of EGF receptors (EGFR) and developmental competence of embryos cultured individually versus those cultured in groups. Cat oocytes were in vitro matured and fertilized (IVM/IVF), and cleaved embryos were randomly assigned to one of seven culture conditions: one group each in which embryos were subjected to group culture supplemented with or without 5 ng/ml EGF and five groups in which embryos were subjected to single-embryo culture supplemented with EGF (0, 5, 25, 50 or 100 ng/ml). Morulae, blastocysts and hatching blastocysts were assessed at days 5 and 7; post IVF, respectively, and total blastocyst cell numbers were assessed at day 7. Relative mRNA expressions of EGFR of 2-4-cell embryos, 8-16-cell embryos, morulae and blastocysts cultured in groups or singly with or without EGF supplementation were examined. OCT3/4 and Ki67 in blastocysts derived from the group or single-embryo culture systems with or without EGF supplementation were localized. A higher rate of embryos cultured in groups developed to blastocysts than individually incubated cohorts. Although EGF increased blastocyst formation in the single-embryo culture system, EGF did not affect embryo development in group culture. Expression levels of EGFR decreased in morulae and blastocysts cultured with EGF. An increased ratio of Ki67-positive cells to the total number of cells in the blastocyst was observed in singly cultured embryos in the presence of EGF. However, EGF did not affect the expression of OCT3/4. These findings indicate that EGF enhanced developmental competence of cat embryos cultured singly by stimulating cell proliferation and modulating the EGFR expression at various developmental stages.
authors.affiliation: Department of Obstetrics, Gynaecology and Reproduction, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand.
authors.forename: Chommanart
authors.initials: C
authors.lastname: Thongkittidilok
authors.forename: Theerawat
authors.initials: T
authors.lastname: Tharasanit
authors.forename: Nucharin
authors.initials: N
authors.lastname: Songsasen
authors.forename: Thanida
authors.initials: T
authors.lastname: Sananmuang
authors.forename: Sirirak
authors.initials: S
authors.lastname: Buarpung
authors.forename: Mongkol
authors.initials: M
authors.lastname: Techakumphu
mesh_terms: D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D001755:Blastocyst / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D002415:Cats; D004477:Ectogenesis / Q000187:drug effects*; D046149:Embryo Culture Techniques / Q000662:veterinary; D004815:Epidermal Growth Factor / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D066246:ErbB Receptors / Q000819:agonists* / Q000235:genetics / Q000378:metabolism; D005260:Female; D005307:Fertilization in Vitro / Q000662:veterinary; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D006801:Humans; D059471:In Vitro Oocyte Maturation Techniques / Q000662:veterinary; D008024:Ligands; D008297:Male; D009028:Morula / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D009994:Osmolar Concentration; D012333:RNA, Messenger / Q000378:metabolism; D011994:Recombinant Proteins / Q000378:metabolism / Q000494:pharmacology; D013785:Thailand
chemical_list: D015415:Biomarkers; D008024:Ligands; D012333:RNA, Messenger; D011994:Recombinant Proteins; D004815:Epidermal Growth Factor; D066246:ErbB Receptors