Cell fusion for genetic analysis of two nonconditional Rous sarcoma virus replication mutants

Steimer, Kathelyn S.; Boettiger, David

doi:10.1128/jvi.32.1.175-186.1979

Cited by 5 publications

(3 citation statements)

References 48 publications

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“…Avian cells and viruses were propagated by standard techniques (9). Virus strains and avian cells have been previously described (7,10). The procedures for host range studies, interference assays, and virus cloning were as described previously (l0) .…”

Section: Cell Culturementioning

confidence: 99%

Serum-free growth of normal and transformed fibroblasts in milk: differential requirements for fibronectin.

Steimer¹,

Klagsbrun²

1981

The Journal of Cell Biology

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Bovine milk may be used as a supplement for the serum-free growth of certain fibroblastic cells in culture. The growth properties of three representative cell types in milksupplemented medium were examined ; fibroblastic cell strains, fibroblastic cell lines, and transformed fibroblasts . Transformed fibroblasts, which included RNA and DNA tumor virustransformed cells and carcinogen-transformed cells, grew in milk . Instead of growing attached to the culture dishes, as they normally do in serum, transformed fibroblasts grew in milk as large clusters in suspension . In contrast, nontransformed fibroblastic cell strains and cell lines did not grow in milk-supplemented medium . Fibroblasts transformed by a temperaturesensitive transformation mutant of Rous sarcoma virus were temperature-sensitive for growth in milk . The failure of cells to adhere to the substratum in milk-supplemented medium suggested that milk might be deficient in attachment factors for fibroblasts . When the attachment of fibroblastic cells in milk-supplemented medium was facilitated by pretreating culture dishes with fibronectin, (a) transformed cells grew attached rather than in suspension, (b) normal cell lines attached and grew to confluence, and (c) normal cell strains adhered and survived but did not exhibit appreciable cell proliferation.The physiological function of milk is to provide substances important to the nutrition, growth, and development of the newborn. In addition, mammalian milk contains viable cells (1, 2) . Both human and bovine milks contain up to 4 X 10 6 cells/ml, primarily macrophages, T lymphocytes, and B lymphocytes. In previous studies, we demonstrated that both human (3, 4) and bovine (5) milks contain polypeptide growth factors that stimulate DNA synthesis and cell division of confluent cultures of fibroblasts. The presence of mitogens and viable cells in milk prompted us to evaluate milk as a replacement for serum in cell culture. In an initial report, we demonstrated that milk could support the long-term growth of epithelial cells in culture (6). Only colostrum, a highly enriched milk produced by mammals in the first day or two after birth of the newborn, was effective in supporting epithelial cell proliferation. In addition, colostrum was selective, supporting the growth of epithelial cells but not fibroblasts. When plated in either colostrum or regular milk, fibroblasts adhered very poorly to the substratum, suggesting that milk lacks factors that are necessary for the attachment of fibroblasts. This ob-294 servation prompted us to investigate whether milk would be selective for the growth of cells that do not require attachment to the substratum to proliferate. In this report, we show that transformed fibroblasts grow readily in milk-supplemented medium as suspension cultures . On the other hand, normal fibroblasts do not grow in milk unless the attachment of cells is mediated by an adhesion-promoting factor, such as fibronectin . MATERIALS AND METHODS Cell CultureRat embryo cultures (LRI) prepared fro...

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Section: Cell Culturementioning

confidence: 99%

Serum-free growth of normal and transformed fibroblasts in milk: differential requirements for fibronectin.

Steimer¹,

Klagsbrun²

1981

The Journal of Cell Biology

Self Cite

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“…In a previous report (26), the genetic characterization of a novel nonconditional envelope mutant, rdPN3/2-SR-D (abbreviated PN3/2; also referred to as LR3/2 virus), was described. This mutant was isolated by using nonpermissive mammalian cells rather than permissive avian cells as hosts for establishing clonal RSVtransformed cell lines.…”

mentioning

confidence: 99%

“…Avian RNA tumor viruses are classified into subgroups on the basis of their host range, interference properties, and antigenicity (6,14,31). The virus produced by clones of PN3/2 virusinfected chicken cells exhibited the host range of parental Schmidt-Ruppin D (SRD) virus when titrated on avian cells with various genetic susceptibilities (26). Viral interference studies also indicate that PN3/2 virus is a subgroup D virus ( Table 1).…”

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confidence: 99%