iments undertaken at Oxford University in Great only when both allee Meaningul UUlllUdhun Britain. two alleles and phenotypes can occur genetics, when are to coexist within the same cell or organism. In Mendelian with the forced gene that specifies dominant wins allele of a trait, the allele, by definition, specifying a recessive Figure 7.1 Experimental fusion of cells (A) When cells growing adjacent to one another in monolayer culture responds by expressing the phenotype of the dominant allele. are exposed to a fusogenic agent, such as inactivated Sendai virus or a confrontation between the alle. polyethylene glycol (PEG. they initially of cell fusion was well suited to force The technique les specifying normal growth and those directing malignant proliferation. In this pro cedure, cells of two different phenotypes (and often of different genotypes) are al. tured together in a Petri dish (Figure 7.1A) An agent is then used to induce fusion of form a heterokaryon with multiple nuclei, (Use of selection media and selectable marker genes can ensure the survival of bi- or multinucleated cells carrying nuclei deriving from two distinct parental types and the elimination of fused cells whose nuclei derive from only one parental cell type.) When the heterokaryon subsequently passes through mitosis, the two sets of nic parental chromosomes are pooled in a single nucleus. During propagation of the resulting tetraploid cell in culture, the descendant cells often shed some of these chromosomes, thereby reducing their chromosome complement to a quasi-triploid or hyperdiploid state first cycle of growth (B) In this image, radiolabeled mouse NIH and division 3T3 cells have been fused (using Sendai virus) with monkey kidney cells, resulting in a hybrid cell with two distinct nuclei. The (larger) mouse nucleus is identified by the silver grains that were formed during subsequent autoradiography. second cycle of (C) Polykaryons may form with equal or growth and division greater frequency following such fusions but are usually unable to proliferate and spawn progeny. This polykaryon contains ne nuclei (arrows). (B and C, court of S. Rozenblatt.) Solution The cell fusion experiment allows the emergence of either tumurogenic or non-tumorogenic cells. In the case, the non-virus-induced human tumors produces recessive cell lines of cancer which produces tumor suppressor proteins..

1. iments undertaken at Oxford University in Great only when both allee Meaningul UUlllUdhun
Britain. two alleles and phenotypes can occur genetics, when are to coexist within the same cell
or organism. In Mendelian with the forced gene that specifies dominant wins allele of a trait, the
allele, by definition, specifying a recessive Figure 7.1 Experimental fusion of cells (A) When
cells growing adjacent to one another in monolayer culture responds by expressing the
phenotype of the dominant allele. are exposed to a fusogenic agent, such as inactivated Sendai
virus or a confrontation between the alle. polyethylene glycol (PEG. they initially of cell fusion
was well suited to force The technique les specifying normal growth and those directing
malignant proliferation. In this pro cedure, cells of two different phenotypes (and often of
different genotypes) are al. tured together in a Petri dish (Figure 7.1A) An agent is then used to
induce fusion of form a heterokaryon with multiple nuclei, (Use of selection media and
selectable marker genes can ensure the survival of bi- or multinucleated cells carrying nuclei
deriving from two distinct parental types and the elimination of fused cells whose nuclei derive
from only one parental cell type.) When the heterokaryon subsequently passes through mitosis,
the two sets of nic parental chromosomes are pooled in a single nucleus. During propagation of
the resulting tetraploid cell in culture, the descendant cells often shed some of these
chromosomes, thereby reducing their chromosome complement to a quasi-triploid or
hyperdiploid state first cycle of growth (B) In this image, radiolabeled mouse NIH and division
3T3 cells have been fused (using Sendai virus) with monkey kidney cells, resulting in a hybrid
cell with two distinct nuclei. The (larger) mouse nucleus is identified by the silver grains that
were formed during subsequent autoradiography. second cycle of (C) Polykaryons may form
with equal or growth and division greater frequency following such fusions but are usually
unable to proliferate and spawn progeny. This polykaryon contains ne nuclei (arrows). (B and C,
court of S. Rozenblatt.)
Solution
The cell fusion experiment allows the emergence of either tumurogenic or non-tumorogenic
cells. In the case, the non-virus-induced human tumors produces recessive cell lines of cancer
which produces tumor suppressor proteins.