PMID- 22632112 OWN - NLM STAT- MEDLINE DCOM- 20121203 LR - 20211021 IS - 1477-7827 (Electronic) IS - 1477-7827 (Linking) VI - 10 DP - 2012 May 25 TI - Bovine trophoblastic cell differentiation and binucleation involves enhanced endogenous retrovirus element expression. PG - 41 LID - 10.1186/1477-7827-10-41 [doi] AB - BACKGROUND: Endogenous retrovirus (ERV) envelope (env) genes are involved in the differentiation of trophoblastic cells in humans and mice. However, there is limited information about their roles in ruminant trophoblastic cells. Thus, we attempted to explore the possible roles of ERV elements in the binucleation of bovine trophoblastic cells using in vitro bovine trophoblastic (BT) cell lines. METHODS: In this study, blastocysts and elongated embryos were obtained from Japanese Black cows, and endometrial and fetal membrane tissues were collected from day 17 to 37 of gestation. The gene expression levels of four ERV elements, bERVE (bovine endogenous retrovirus envelope element-like transcript) -A, bERVE-B, BERV (bovine endogenous retrovirus) -K1 env, and BERV-K2 env, were analyzed in the fetal and endometrial tissue and cultured BT cell lines using quantitative RT-PCR. On-Matrigel gel and on-collagen gel culturing were used to induce binucleate cell (BNC) formation in the BT cell lines. How the culture conditions affected the expression of BNC-specific genes and ERV elements was examined by quantitative RT-PCR and immunocytochemistry. RESULTS: bERVE-A, bERVE-B, BERV-K1 env, and BERV-K2 env were expressed in almost all BT cell lines; however, only bERVE-A and BERV-K1 env were detected in trophoblastic tissues during the peri-implantation period. In the on-Matrigel cultures, the expression levels of BNC-specific genes and molecules were enhanced in the BT cells. The expression levels of bERVE-A and BERV-K1 env were also increased in the BT cells during on-Matrigel culturing. The BT cell expression levels of these ERV elements were consistent with those of BNC-specific genes during on-Matrigel culturing (P < 0.01). CONCLUSIONS: These results suggest that bERVE-A and BERV-K1 env are involved in the expression of BNC-specific genes and the progression of bovine trophoblastic cell binucleation, as their expression levels increased during periods of increased BNC-specific molecule expression, which is strongly suggestive of the development of BNC from mononucleate trophoblastic cells. The on-Matrigel culture system is a convenient in vitro tool for studying bovine trophoblastic cell lineages. FAU - Koshi, Katsuo AU - Koshi K AD - Laboratory of Veterinary Physiology, Department of Veterinary Medicine, Faculty of Agriculture, Iwate University, 3-18-8 Ueda, Morioka, Iwate 020-8550, Japan. FAU - Suzuki, Yasunori AU - Suzuki Y FAU - Nakaya, Yuki AU - Nakaya Y FAU - Imai, Kei AU - Imai K FAU - Hosoe, Misa AU - Hosoe M FAU - Takahashi, Toru AU - Takahashi T FAU - Kizaki, Keiichiro AU - Kizaki K FAU - Miyazawa, Takayuki AU - Miyazawa T FAU - Hashizume, Kazuyoshi AU - Hashizume K LA - eng PT - Journal Article PT - Research Support, Non-U.S. Gov't DEP - 20120525 PL - England TA - Reprod Biol Endocrinol JT - Reproductive biology and endocrinology : RB&E JID - 101153627 RN - 0 (Gene Products, env) RN - 0 (Viral Proteins) SB - IM MH - Animals MH - Cattle MH - Cell Differentiation/genetics MH - Cell Line MH - Endogenous Retroviruses/*physiology MH - Female MH - Gene Products, env/*biosynthesis MH - Trophoblasts/*cytology/physiology/virology MH - Viral Proteins/*biosynthesis PMC - PMC3419082 EDAT- 2012/05/29 06:00 MHDA- 2012/12/10 06:00 PMCR- 2012/05/25 CRDT- 2012/05/29 06:00 PHST- 2011/11/24 00:00 [received] PHST- 2012/05/25 00:00 [accepted] PHST- 2012/05/29 06:00 [entrez] PHST- 2012/05/29 06:00 [pubmed] PHST- 2012/12/10 06:00 [medline] PHST- 2012/05/25 00:00 [pmc-release] AID - 1477-7827-10-41 [pii] AID - 10.1186/1477-7827-10-41 [doi] PST - epublish SO - Reprod Biol Endocrinol. 2012 May 25;10:41. doi: 10.1186/1477-7827-10-41.