title: Cumulus cell-conditioned medium supports embryonic stem cell differentiation to germ cell-like cells.
abstract: Cumulus cells provide cellular interactions and growth factors required for oogenesis. In vitro studies of oogenesis are limited primarily because of the paucity of their source, first trimester fetal gonads, and the small number of germ lineage precursor cells present within these tissues. In order to understand this obscure but vitally important process, the present study was designed to direct differentiation of embryonic stem (ES) cells into germ lineage cells. For this purpose, buffalo ES cells were differentiated, as embryoid bodies (EBs) and monolayer adherent cultures, in the presence of different concentrations of cumulus-conditioned medium (CCM; 10%, 20% and 40%) for different periods of culture (4, 8 and 14 days) to identify the optimum differentiation-inducing concentration and time. Quantitative polymerase chain reaction analysis revealed that 20%-40% CCM induced the highest expression of primordial germ cell-specific (deleted in Azoospermia- like (Dazl), dead (Asp-Glu-Ala-Asp) box polypeptide 4 (Vasa also known as DDX4) and promyelocytic leukemia zinc finger protein (Plzf)); meiotic (synaptonemal complex protein 3 (Sycp3), mutl homolog I (Mlh1), transition protein 1/2 (Tnp1/2) and protamine 2 (Prm2); spermatocyte-specific boule-like RNA binding protein (Boule) and tektin 1 (Tekt1)) and oocyte-specific growth differentiation factor 9 (Gdf9) and zona pellucida 2 /3 (Zp2/3)) genes over 8-14 days in culture. Immunocytochemical analysis revealed expression of primordial germ cell (c-KIT, DAZL and VASA), meiotic (SYCP3, MLH1 and PROTAMINE 1), spermatocyte (ACROSIN and HAPRIN) and oocyte (GDF9 and ZP4) markers in both EBs and monolayer differentiation cultures. Western blotting revealed germ lineage-specific protein expression in Day 14 EBs. The significantly lower (P<0.05) concentration of 5-methyl-2-deoxycytidine in differentiated EBs compared to undifferentiated EBs suggests that methylation erasure may have occurred. Oocyte-like structures obtained in monolayer differentiation stained positive for ZONA PELLUCIDA protein 4 and progressed through various embryo-like developmental stages in extended cultures.
authors.affiliation: Embryo Biotechnology Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal 132001, India.
authors.forename: Syed Mohmad
authors.initials: SM
authors.lastname: Shah
authors.affiliation: Embryo Biotechnology Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal 132001, India.
authors.forename: Neha
authors.initials: N
authors.lastname: Saini
authors.affiliation: Embryo Biotechnology Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal 132001, India.
authors.forename: Syma
authors.initials: S
authors.lastname: Ashraf
authors.affiliation: Embryo Biotechnology Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal 132001, India.
authors.forename: Manoj Kumar
authors.initials: MK
authors.lastname: Singh
authors.affiliation: Embryo Biotechnology Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal 132001, India.
authors.forename: Radhey Sham
authors.initials: RS
authors.lastname: Manik
authors.affiliation: Embryo Biotechnology Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal 132001, India.
authors.forename: Suresh Kumar
authors.initials: SK
authors.lastname: Singla
authors.affiliation: Embryo Biotechnology Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal 132001, India.
authors.forename: Prabhat
authors.initials: P
authors.lastname: Palta
authors.affiliation: Embryo Biotechnology Laboratory, Animal Biotechnology Centre, National Dairy Research Institute, Karnal 132001, India.
authors.forename: Manmohan Singh
authors.initials: MS
authors.lastname: Chauhan
mesh_terms: D000818:Animals; D002020:Buffaloes; D018929:Cell Culture Techniques; D002454:Cell Differentiation / Q000502:physiology*; D017077:Culture Media, Conditioned; D054885:Cumulus Cells / Q000166:cytology* / Q000378:metabolism; D053487:DEAD-box RNA Helicases / Q000378:metabolism; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000378:metabolism; D005260:Female
chemical_list: D017077:Culture Media, Conditioned; D053487:DEAD-box RNA Helicases