title: High concentrate:forage ratio diet inhibiting omasal epithelium growth is associated with decreased cyclin D1 and CDK4 expression in growing goats.
abstract: The hypothesis that different concentrate : forage ratio diets alter omasal epithelium proliferation of growing goats via cyclins and regulation of the cell cycle was tested. Growing goats were fed with a high concentrate (HC, n = 8) or a low concentrate (LC, n = 8) diet for 42 days. The concentrate : forage ratio was 40:60 in the HC group and 0:100 in the LC group. In the HC group, the relative weight and DNA content of the omasal epithelium were lower, but the protein : DNA ratio was higher. Flow cytometry revealed that HC omasal cell numbers were smaller in S- and G2 /M-phases of the cell cycle and higher in the G0 /G1 -phases and were accompanied by reduced expression of cyclin D1 and CDK4 mRNA and protein. These data are consistent with morphologic observations in the HC that cell density decreased in the stratum spinosum (SS) plus stratum granulosum (SG) and stratum basale, and that cell density was lower in the SS plus SG. Thus, high-concentrate : forage ratio diet retards omasal epithelial growth by slowing the G1 to S phase transition of the cell cycle and is associated with decreased cyclin D1 and CDK4 expression in growing goats.
authors.affiliation: Laboratory of Animal Physiology and Biochemistry, Nanjing Agricultural University, Nanjing, China.
authors.forename: Huaibao
authors.initials: H
authors.lastname: Zhao
authors.forename: Jinye
authors.initials: J
authors.lastname: Lu
authors.forename: Zhinan
authors.initials: Z
authors.lastname: Huang
authors.forename: Lei
authors.initials: L
authors.lastname: Yan
authors.forename: Martens
authors.initials: M
authors.lastname: Holger
authors.forename: Zanming
authors.initials: Z
authors.lastname: Shen
mesh_terms: D000821:Animal Feed / Q000032:analysis*; D000818:Animals; D002453:Cell Cycle; D019938:Cyclin D1 / Q000235:genetics* / Q000378:metabolism*; D051358:Cyclin-Dependent Kinase 4 / Q000235:genetics* / Q000378:metabolism*; D004847:Epithelial Cells / Q000166:cytology*; D004848:Epithelium / Q000254:growth & development; D015870:Gene Expression; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D006041:Goats / Q000235:genetics* / Q000254:growth & development*; D008969:Molecular Sequence Data; D009851:Omasum / Q000166:cytology* / Q000254:growth & development*
chemical_list: D019938:Cyclin D1; D051358:Cyclin-Dependent Kinase 4
keywords: cell cycle; cyclin D1 and cyclin-dependent kinase 4; diets; goat; omasal epithelium proliferation