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BioMed Research International
Volume 2016, Article ID 5808575, 9 pages
Research Article

Establishment and Characterization of a Telomerase-Immortalized Sheep Trophoblast Cell Line

1College of Veterinary Medicine, Inner Mongolia Agricultural University, Hohhot 010018, China
2Key Laboratory of Clinical Diagnosis and Treatment Technology in Animal Disease, Ministry of Agriculture, Hohhot 010018, China

Received 12 September 2015; Revised 16 December 2015; Accepted 13 January 2016

Academic Editor: Louiza Belkacemi

Copyright © 2016 Yufei Zhang et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The primary sheep trophoblast cells (STCs) have a finite lifespan in culture. This feature limits the scope for long-term in vitro studies with STCs. This study was an attempt to establish and characterize a telomerase-immortalized sheep trophoblast cell line. STCs were isolated and purified by using Percoll and specific immunoaffinity purification, respectively. The purified STCs were transfected with a plasmid carrying sequences of human telomerase reverse transcriptase (hTERT) to create immortalized sheep trophoblast cell line (hTERT-STCs). hTERT-STCs showed a stable expression of hTERT gene, serially passaged for a year, and showed active proliferation without signs of senescence. Cytokeratin 7 (CK-7), secreted human chorionic gonadotrophin subunit β (CG-β), placental lactogen (PL), and endogenous jaagsiekte sheep retrovirus (enJSRV) envelope genes were expressed in hTERT-STCs. Transwell cell invasion assay indicated that hTERT-STCs still possessed the same invasive characteristics as normal primary sheep trophoblast cells. hTERT-STCs could not grow in soft agar and did not develop into tumors in nude mice. In this study, we established a strain of immortalized sheep trophoblast cell line which could be gainfully employed in the future as an experimental model to study trophoblast cells with secretory function, invasive features, and probable biological function of enJSRV envelope genes.