title: Long-term adaptation of the Bombyx mori BmN4 cell line to grow in serum-free culture.
abstract: Bombyx mori ovary-derived BmN4 cells have been successfully adapted to a commercial serum-free medium (SFM; SF900-II) by gradually reducing the serum-containing TC-100 medium content from 100 to 0% (v/v). The BmN4 cells adapted to the SFM (BmN-SFM) adhered strongly to the culture flask and showed altered cell morphology. The BmN-SFM was subcultured 200 times, and the population doubling time was 4.70 d. Infection studies showed that BmN-SFM cells were easily susceptible to B. mori nucleopolyhedrovirus (BmNPV), and both the multiplication of budded virus and the promoter activity of the polyhedrin gene in BmN-SFM cells were almost the same as those in BmN4 cells before adaptation. Additionally, mouse interleukin-3 expressed by a recombinant BmNPV was normally secreted and modified with N-linked glycans in BmN-SFM cells. These findings indicate that BmN-SFM is particularly useful for a BmNPV-based baculovirus expression vector system with serum-free conditions.
authors.affiliation: Department of Agrobiology and Bioresources, Faculty of Agriculture, Utsunomiya University, Mine-machi 350, Utsunomiya-shi, Tochigi, 321-8505, Japan, iwanaga@cc.utsunomiya-u.ac.jp.
authors.forename: Masashi
authors.initials: M
authors.lastname: Iwanaga
authors.forename: Yuka
authors.initials: Y
authors.lastname: Adachi
authors.forename: Koudai
authors.initials: K
authors.lastname: Uchiyama
authors.forename: Keita
authors.initials: K
authors.lastname: Tsukui
authors.forename: Susumu
authors.initials: S
authors.lastname: Katsuma
authors.forename: Hideki
authors.initials: H
authors.lastname: Kawasaki
mesh_terms: D000222:Adaptation, Physiological; D000818:Animals; D012831:Bombyx / Q000166:cytology* / Q000821:virology; D018929:Cell Culture Techniques; D002460:Cell Line; D005822:Genetic Vectors; D007377:Interleukin-3 / Q000235:genetics / Q000378:metabolism; D007814:Larva; D051379:Mice; D017924:Nucleopolyhedroviruses / Q000235:genetics
chemical_list: D007377:Interleukin-3