Applications of Cell Culture to Toxicology: A Collaboration Between the Tissue Culture Association and the Society of Toxicology

1985 ◽  
Vol 21 (9) ◽  
pp. 488-488
Author(s):  
June A. Bradlaw ◽  
Daniel Acosta
Development ◽  
1964 ◽  
Vol 12 (4) ◽  
pp. 575-585
Author(s):  
Andrzej K. Tarkowski

A General description of the development of mouse chimaerae and an account of the techniques for their production were given in previous reports (Tarkowski, 1961, 1963). The chimaeric character of the embryos and young obtained was tentatively claimed in the first of these publications because (1) the actual union of two eggs into one blastocyst was seen in culture in vitro, (2) of the occurrence of intersexes, (3) pigment synthesis of the types of the dark component occurred in the majority of individuals developed from pairs of eggs differing genetically in factors for pigmentation. The last criterion was met only by macroscopic search for pigment in the eyes. The present report gives a more detailed description of the distribution of pigment forming cells in these animals, based on histological analysis. Some remarks on the validity and applicability of such a criterion for estimating the degree of chimaerism were made at the 13th Annual Meeting of the Tissue Culture Association (Tarkowski 1963).


Genome ◽  
1989 ◽  
Vol 32 (5) ◽  
pp. 762-770 ◽  
Author(s):  
David M. Stelly ◽  
D. W. Altman ◽  
R. J. Kohel ◽  
T. S. Rangan ◽  
E. Commiskey

Somaclonal variation occurs among regenerants from tissue culture of many plant species. Our objective was to determine whether cytogenetic variation contributes to somaclonal variation in cotton (Gossyptum hirsutum L.,2n = 4x = 52). Of 117 somaclones of cotton regenerated from 18-month-old callus cultures of 'SJ-2' and 'SJ-5' cultivars, 35 were analyzed for meiotic abnormalities. The population of somaclones was extremely varied in phenotype, most plants being strikingly aberrant in phenotype. Fertility was generally poor: 84% failed to set bolls and only 5% set 10 or more bolls in a field environment. Only one of the somaclones (3%) formed 26 bivalents at metaphase I. Fourteen were nonsynaptic to partially synaptic at metaphase I. Synaptic abnormalities impaired fertility and precluded thorough metaphase analysis. Chromosome numbers obtained for 32 plants ranged from 49 to 53, and only 1 plant was hyperaneuploid. No plant was polyploid. Chromosomal abnormalities in plants with normal metaphase pairing included univalents, unequal bivalents, rod bivalents, trivalents, open quadrivalents, and centric fragments. Seventeen hypoaneuploid plants formed a V-shaped trivalent at metaphase I, constituting a high frequency of tertiary monosomy. The high frequencies of aneuploidy and tertiary monosomy indicate that cytogenetic anomalies are a major source of somaclonal variation in cotton. It is hypothesized that (i) primary cytogenetic events during cotton cell culture give rise to breakage – fusion – bridge (BFB) cycles, (ii) BFB cycles accrue during culture, (iii) BFB cycles cause loss of chromatin, and (iv) BFB cycles are resolved by the formation of stable tertiary chromosomes with mono-centric activity. The hypothesis accounts mechanistically for the coincidence of chromatin deficiencies and chromatin exchange involved implicitly in tertiary monosomy, as well as for the relatively high frequency of tertiary monosomy among somaclones.Key words: aneuploid, monosomic, synaptic, sterility, Gossypium.


2015 ◽  
Vol 90 (3) ◽  
pp. 1345-1358 ◽  
Author(s):  
Zhongyan Lu ◽  
Masaru Yokoyama ◽  
Ning Chen ◽  
Tomoichiro Oka ◽  
Kwonil Jung ◽  
...  

ABSTRACTThe porcine sapovirus (SaV) (PoSaV) Cowden strain is one of only a few culturable enteric caliciviruses. Compared to the wild-type (WT) PoSaV Cowden strain, tissue culture-adapted (TC) PoSaV has two conserved amino acid substitutions in the RNA-dependent RNA polymerase (RdRp) and six in the capsid protein (VP1). By using the reverse-genetics system, we identified that 4 amino acid substitutions in VP1 (residues 178, 289, 324, and 328), but not the substitutions in the RdRp region, were critical for the cell culture adaptation of the PoSaV Cowden strain. The other two substitutions in VP1 (residues 291 and 295) reduced virus replicationin vitro. Three-dimensional (3D) structural analysis of VP1 showed that residue 178 was located near the dimer-dimer interface, which may affect VP1 assembly and oligomerization; residues 289, 291, 324, and 328 were located at protruding subdomain 2 (P2) of VP1, which may influence virus binding to cellular receptors; and residue 295 was located at the interface of two monomeric VP1 proteins, which may influence VP1 dimerization. Although reversion of the mutation at residue 291 or 295 from that of the TC strain to that of the WT reduced virus replicationin vitro, it enhanced virus replicationin vivo, and the revertants induced higher-level serum and mucosal antibody responses than those induced by the TC PoSaV Cowden strain. Our findings reveal the molecular basis for PoSaV adaptation to cell culture. These findings may provide new, critical information for the cell culture adaptation of other PoSaV strains and human SaVs or noroviruses.IMPORTANCEThe tissue culture-adapted porcine sapovirus Cowden strain is one of only a few culturable enteric caliciviruses. We discovered that 4 amino acid substitutions in VP1 (residues 178, 289, 324, and 328) were critical for its adaptation to LLC-PK cells. Two substitutions in VP1 (residues 291 and 295) reduced virus replicationin vitrobut enhanced virus replication and induced higher-level serum and mucosal antibody responses in gnotobiotic pigs than those induced by the tissue culture-adapted strain. Structural modeling analysis of VP1 suggested that residue 178 may affect VP1 assembly and oligomerization; residues 289, 291, 324, and 328 may influence virus binding to cellular receptors; and residue 295 may influence VP1 dimerization. Our findings will provide new information for the cell culture adaptation of other sapoviruses and possibly noroviruses.


Sign in / Sign up

Export Citation Format

Share Document