TCTP Promotes Hu Sheep Rumen Epithelial Development before Weaning

Abstract

BackgroundHu Sheep is a world precious breed of sheep. Rumen is the most important digestive organ for ruminant animals. A better understanding of the molecular mechanisms involved in rumen development help us design better strategies to improve the production of sheep. Translationally controlled tumor protein (TCTP) is a highly conserved protein that involves various cellular processes. However, its role in rumen epithelium development remains unknown.ResultsTCTP was expressed in stratum basale, stratum spinosum and stratum granulosum of rumen epithelium. TCTP mRNA expression was extremely high on the day of birth, it then significantly decreased on day 15 and gradually increased until day 45 of age. TCTP protein expression remained in a relative low level from day 0 to day 15 of age, it then significantly increased on day 30 and gradually decreased until day 60. The ratio of Ki67 positive cell in stratum basale cell followed the similar pattern as the expression of TCTP. The papillae length decreased at first 15 days of postnatal life. Thereafter, the papilla undergo a period of growth from 538.1±17.3μm to 2211.1±56.6μm until 60 days of age. The phosphorylation of AKT is the highest on day 15 of age, then decreased until day 45. The ratio of acetate:propionate in rumen fluid decreased from day 30 to day 60 of age. ConclusionsTCTP participates in rumen papillae growth by promoting rumen stratum basale cell proliferation. We suggest that the translation of TCTP mRNA is regulated by AKT phosphorylation and the development of rumen papillae is associated with acetate:propionate ratio.