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At least 235 records · Page 13Linked to original sources

PubMed1994

Construction of a single-transposon-insertion mutant in Rhizobium sp. strain TAL1145 from a double-insertion mutant.

A method for developing a single-transposon-insertion mutant from a double-insertion mutant in Rhizobium is described. An exopolysaccharide (EPS)-defective mutant containing two Tn5-lacZ insertions was complemented with cloned wild-type DNA for EPS synthesis. One of the Tn5-lacZ insertions from the mutant was transferred to the complementing plasmid by homologous recombination. The plasmid containing the Tn5-lacZ insertion in the gene involved in EPS synthesis was transferred into the wild-type strain and the Tn5-lacZ was homogenized to obtain an EPS-defective mutant with a single Tn5-lacZ insertion.

Blotting, Southern↗

PubMed2001

Role of the ftsA1p promoter in the resistance of mucoid mutants of Salmonella enterica to mecillinam: characterization of a new type of mucoid mutant.

Mucoid mutants of Salmonella enterica serovar Typhimurium isolated by resistance to mecillinam include lon (27%) and rcsC (8%) mutants but the most frequent class (65%) is affected in a new gene (mucM) located at centisome 76. mucM cells are shorter than mucM+ cells and rcsB mutations normalize size and response to mecillinam. Expression of ftsA1p, the ftsA-ftsZ promoter submitted to RcsB stimulation, is greatly increased in mucM mutants, and this expression is dependent on RcsB and ftsA1p. It is proposed that the mucM product interferes with RcsB activation. Mucoidy results from the activation of cps genes and mecillinam resistance from ftsA-ftsZ overexpression, both traits caused by the increased activity of the RcsB effector. The same mechanism seems to be responsible for the resistance of mucoid rcsC mutants to mecillinam but the resistance of lon mutants is not dependent on RcsB and so responds to a different cause.

Amdinocillin↗

PubMed2002

Amino acid alterations in Gp38 of host range mutants of PP01 and evidence for their infection of an ompC null mutant of Escherichia coli O157:H7.

The previously isolated T-even type coliphage PP01, specifically infective to Escherichia coli O157:H7, uses the outer membrane protein OmpC as a receptor. The characterization of a spontaneous PP01-resistant strain indicated that it had lost ompC due to the deletion of a 14-kbp region upstream of and partially including ompC. Two host range mutants, able to infect an ompC null mutant, were isolated. Sequencing of gene 38, which codes for the receptor recognition protein Gp38, indicated three mutations in one mutant and two in the other. Both mutant proteins had a Gly208Arg, a Gly161Arg or Gly101His replacement, respectively, and the one mutant phage in addition a Trp189Arg replacement. These alterations suggest that the host range was mediated by a more positively charged Gp38.

Bacteriophages↗

PubMed1967

Azure mutants: a type of host-dependent mutant of the bacteriophage f2.

A new type of host-dependent mutant, azure mutant, of bacteriophage f2 has been isolated. Growth of these mutants was restricted specifically by amber suppressor genes in the host bacteria. Restriction of the formation of infective centers by different bacterial suppressor genes was 98 percent, 90 percent, and 70 percent with Su-3, Su-1, and Su-2 genes, respectively. Restriction, like suppression, was the dominant phenotype. The block in growth of the mutants occurred in an early stage of the infection cycle. Once infection was established, however, an infected cell produced approximately the same number of progeny phage as a cell without the suppressor genes did. It is proposed that the azure codon is the same as the amber codon (uracil, adenine, guanine) and that restriction results from improper termination of protein chains of the phage RNA polymerase. Similar mutants may exist in other systems.

Adenine↗

PubMed1980

Characterization of beta-lactamase-deficient (bla) mutants of the R plasmid R1 in Escherichia coli K-12 and comparison with similar mutants of RP1.

Thirty-eight mutants of R1, an R plasmid specifying the type IIIa (TEM) beta-lactamase, were isolated; these mutants are partially or totally unable to synthesize the type IIIa beta-lactamase. The loss of beta-lactamase activity was associated with a reduction in the level of penicillin resistance conferred by the mutants upon their host strain. At least two of the mutants synthesized a beta-lactamase with altered substrate specificity. These properties are compared with those of two beta-lactamase-deficient mutants of plasmid RP1. The results suggest that, for both R plasmids, penicillin resistance is entirely attributable to the presence of beta-lactamase activity. The properties of two R1 derivatives, pUB251 and pUB252, which have phenotypes similar to that of RP1, support this conclusion.

Chromosome Mapping↗

PubMed1998

Identification of three highly attenuated Salmonella typhimurium mutants that are more immunogenic and protective in mice than a prototypical aroA mutant.

A panel of Salmonella typhimurium 14028s mutants, which were previously shown to be highly attenuated in the BALB/c mouse model of infection, were analyzed for their potential as live Salmonella oral-vaccine candidates. A prototypical aroA mutant was chosen as a basis of comparison. From the panel of mutants initially chosen for this study, three mutants with comparable levels of attenuation elicited higher Salmonella-specific serum immunoglobulin G (IgG) and/or mucosal secretory-IgA antibody titers than the aroA vaccine strain. The three mutants, CL288, CL401, and CL554, also elicited a better protective immune response than the aroA control strain, after a single oral dose of 1 x 10(9) to 2 x 10(9) bacteria.

3-Phosphoshikimate 1-Carboxyvinyltransferase↗

PubMed1998

Comparison of loss of serum resistance by defined lipopolysaccharide mutants and an acapsular mutant of uropathogenic Escherichia coli O75:K5.

In order to determine the importance of the O75 O antigen versus the K5 capsular antigen and the bimodal distribution of lipopolysaccharides (LPSs) in protection from complement-mediated lysis, mutants were made by insertion of a cat or an aphA gene in or in place of genes necessary for the synthesis of LPS and/or the K antigen of an O75(+) K5(+) uropathogenic Escherichia coli strain, GR-12. Mutations were made in the following genes: the rfbD gene (required for the synthesis of TDP-rhamnose), the rfbKM genes (necessary for the synthesis of GDP-mannose), the rol gene (regulating O-antigen length), the kfiC gene (encoding a putative glycosyltransferase), and the kfiC-rfbD genes. The resulting phenotypes were rough (O75(-)), core plus one partial O-antigen subunit, random distribution of O-antigen chain lengths, acapsular (K5(-)), and O75(-) K5(-), respectively. All five mutants and GR-12 were analyzed for survival in 80% serum. The GR-12 parent was resistant, exhibiting a 500% increase in numbers. The rol, rfbKM, rfbD, and kfiC-rfbD mutants were sensitive, experiencing 99%, 99.9%, 99.9%, and at least 99.999% killing, respectively, in the first hour. The kfiC mutant, however, increased in numbers in the first hour but experienced delayed sensitivity, decreasing in viability by 80% in the third hour. Single mutants were complemented with the wild-type gene in trans, showing restoration of the wild-type phenotype and serum resistance. Therefore, the O75 antigen is more important for survival in serum than the K5 antigen, and regulation of the O75 O-antigen chain length is crucial for protection of the bacteria from complement-mediated lysis.

Bacterial Capsules↗

PubMed2005

Fsr-independent production of protease(s) may explain the lack of attenuation of an Enterococcus faecalis fsr mutant versus a gelE-sprE mutant in induction of endocarditis.

An Enterococcus faecalis gelE insertion disruption mutant (TX5128), which produces neither gelatinase (GelE) nor the cotranscribed (in the wild type) serine protease (SprE), was found to be attenuated in a rat endocarditis model with a significant decrease in the endocarditis induction rate versus wild-type E. faecalis OG1RF (GelE(+), SprE(+)). TX5266, which has a nonpolar deletion in fsrB and, like TX5128, is phenotypically GelE(-) under usual conditions, was also studied; fsrB is a homologue of agrB of staphylococci and participates in regulation of gelE-sprE expression. Unexpectedly, TX5266 approximated wild-type OG1RF in the endocarditis model and was significantly less attenuated than TX5128. This is in contrast to other models which have found fsr mutants to be as or more attenuated than TX5128. Further study found that the fsrB mutant produced very low levels of gelatinase activity after prolonged incubation in vitro versus no gelatinase activity with TX5128 and did not show the extensive chaining characteristic of TX5128. Reverse transcription-PCR confirmed that gelE was expressed in TX5266 at a very low level versus wild-type OG1RF and was not expressed at all in TX5128. Possible explanations for the increased induction of endocarditis by TX5266 versus TX5128 include the production of low levels of protease(s) or some other effect(s) of the inactivation of the E. faecalis fsr regulator. The equivalent ability of OG1RF and its fsr mutant to initiate endocarditis may explain why we did not find naturally occurring fsr mutants, which account for ca. 35% of E. faecalis isolates, unrepresented in endocarditis versus fecal isolates.

Animals↗

PubMed2001

Hyperactive glycogen synthase mutants of Saccharomyces cerevisiae suppress the glc7-1 protein phosphatase mutant.

A yeast glc7-1 mutant expressing a variant of protein phosphatase type 1 fails to accumulate glycogen. This defect is associated with hyperphosphorylated and inactive glycogen synthase, consistent with Glc7p acting directly to dephosphorylate and activate glycogen synthase. To characterize the glycogen synthesis defect of this mutant in more detail, we isolated 26 pseudorevertants of the glc7-1 mutant. All pseudoreversion events were due to missense mutations in GSY2, the gene encoding the major isoform of glycogen synthase. A majority of the mutations responsible for the suppression were in the 3' end of the gene, corresponding to the phosphorylated COOH terminus of Gsy2p. Phosphorylation of the mutant proteins was reduced, suggesting that they are poor substrates for glycogen synthase kinases. Suppressor mutations outside this domain did not decrease the phosphorylation of the resulting proteins, indicating that these proteins are immune to the regulatory effects of phosphorylation. Since no growth defect has been observed for strains with altered glycogen levels, the relative levels of fitness of GSY2 mutants that fail to accumulate glycogen and that hyperaccumulate glycogen were assayed by cocultivation experiments. A wild-type strain outcompeted both hypo- and hyperaccumulating strains, suggesting that glycogen levels contribute substantially to the fitness of yeast.

Amino Acid Sequence↗

PubMed1975

Growth studies of three phi chi 174 mutants in tsDNA mutants Escherichia coli.

Three mutants of phi chi 174 were examined for their abilities to grow in temperature-sensitive dna,A, dnaC, dnaE, or dnaG mutants of Escherichia coli. The results indicate that the phage mutants have acquired the ability to grow in some tsDNA mutants that normally block the replication of wild-type phi chi 174. Evidence is presented indicating that the phage mutants contain one or more altered structural proteins. Several models are presented to explain how altered phage structural proteins could affect phi chi 174 replication.

Carbon Radioisotopes↗

PubMed1977

Biological and biochemical studies of cells transformed by simian virus 40 temperature-sensitive gene A mutants and A mutant revertants.

The growth properties of hamster cells transformed by wild-type Simian virus 40 (SV40), by early SV40 temperature-sensitive mutants of the A complementation group, and by spontaneous revertants of these mutants were studied. All of the tsA mutant-transformed cells were temperature sensitive in their ability to form clones in soft agar and on monolayers of normal cells except for CHLA-30L1, which was not temperature sensitive in the latter property. All cells transformed by stable revertants of well-characterized tsA mutants possessed certain growth properties in common with wild-type-transformed cells at both temperatures. Virus rescued from tsA transformants including CHLA30L1 was temperature sensitive for viral DNA replication, whereas that rescued from revertant and wild-type transformants was not thermolabile in this regard. T antigen present in crude extracts of tsA-transformed cells including CHLA30L1, grown at 33 degreeC, was temperature sensitive by in vitro immunoassay, whereas that from wild-type-transformed cells was relatively stable. T antigen from revertant transformants was more stable than the tsA protein. Partially purified T antigen from revertant-transformed cells was nearly as stable as wild-type antigen in its ability to bind DNA after heating at 44 degrees C, whereas T antigen from tsA30 mutant-transformed cells was relatively thermolabile. These results further indicate that T antigen is a product of the SV40 A gene. Significantly more T antigen was found in extracts of CHLA30L1 grown to high density at the nonpermissive temperature than in any other tsA-transformed cell similarly grown. This is consistent with the suggestion that the amount of T antigen synthesized in CHLA30L1 is large enoughto allow partial expression of the transformed phenotype at the restrictive temperature. Alternatively, the increase in T antigen concentration may be secondary to one or more genetic alterations that independently affect the transformed phenotype of these cells.

Animals↗

PubMed1980

Alterations in glycoprotein gB specified by mutants and their partial revertants in herpes simplex virus type 1 and relationship to other mutant phenotypes.

The tsB5 mutant of herpes simplex virus type 1 (HSV-1) strain HFEM was shown previously to be temperature sensitive for accumulation of the mature form of glycoprotein gB, for production or activity of a factor required in virus-induced cell fusion, and for production of virions with normal levels of infectivity. In addition, a previous study showed that virions produced by tsB5 at permissive temperature were more thermolabile than HFEM virions and contained altered gB that did not assume the dimeric conformation characteristic of HFEM. Results presented here demonstrate that, at permissive temperature, tsB5 differs from HFEM in another respect: plaques formed by tsB5 are syncytial on Vero cells (but not on HEp-2 cells), whereas plaques formed by HFEM are nonsyncytial on both cell types. In addition, our results indicate that tsB5 produces an oligomeric form of gB, but that it differs in electrophoretic mobility and stability from the gB dimers of HFEM. The major purpose of this study was to investigate the dependence of the various tsB5 mutant phenotypes on the temperature sensitivity of gB accumulation and on the alterations in oligomeric conformation of gB produced at permissive temperature. For this work the following HSV-1 strains related to tsB5 or HFEM were analyzed: (i) phenotypic revertants selected from tsB5 stocks for nonsyncytial plaque morphology on Vero cells or for ability to form plaques at restrictive temperature (38.5 degrees C); (ii) a plaque morphology variant of HFEM selected for its syncytial phenotype on Vero cells; (iii) temperature-sensitive recombinants previously isolated from a cross between tsB5 and the non-temperature-sensitive syncytial strain HSV-1(MP); and (iv) a phenotypic revertant selected from one of the recombinant stocks for its ability to form plaques at 39 degrees C. These strains were all compared with tsB5 and HFEM at three different temperatures in two different cell lines with respect to plaque formation, yield of infectious progeny, virus-induced cell fusion, and accumulation of gB. The results of our analyses on all the strains tested revealed the following correlations between mutant phenotypes and the accumulation and oligomeric conformation of gB. (i) There was a direct and quantitative relationship between the accumulation in infected cells of infectious progeny and of the mature form of gB, providing strong support for the hypothesis that this form of gB is necessary to the production of infectious virions. The oligomeric conformation of gB characteristic of HFEM is apparently not required for virion infectivity; nor was virion thermostability necessarily related to the presence of the HFEM-like oligomeric form of gB. (ii) The previously reported correlation between temperature sensitivity of gB accumulation and virus-induced cell fusion was confirmed for tsB5 and extended to other virus strains, and coordinate reversion of these traits was also demonstrated, providing support for the hypothesis that gB has a role in virus-induced cell fusion. At 37 degrees C, intermediate between permissive and restrictive temperatures, some of the mutants and partial revertants induced cell fusion despite reduced accumulations of the mature form of gB, suggesting that the amount of mature gB present did not determine the extent of fusion and that other forms of gB as well as other factors should be investigated with regard to the process of cell fusion. (iii) Some of the mutants and partial revertants could form plaques at 38.5 degrees C despite reduced accumulations of gB and infectious progeny, indicating that the cell-to-cell transmission of viral infection may be at least in part independent of these factors.

Animals↗

PubMed1981

DNA sequence analysis of simian virus 40 mutants with deletions mapping in the leader region of the late viral mRNA's: mutants with deletions similar in size and position exhibit varied phenotypes.

The nucleotide sequences of 10 viable yet partially defective deletion mutants of simian virus 40 were determined. The deletions mapped within, and, in many cases, 5' to, the predominant leader sequence of the late viral mRNA's. They ranged from 74 to 187 nucleotide pairs in length. Six of the mutants had lost the sequence that corresponds to the "cap" site (5' terminus) of the most abundant class of 16S mRNA's. One of these mutants had a deletion that extended 103 nucleotide pairs into the region preceding this primary cap site and, therefore, was missing many secondary cap sites as well. A seventh mutant lacked the entire major 16S leader sequence except for the first six nucleotides at its 5' end and the last nine at its 3' end. Although these mutants differed in the size and position of their deletions, we were unable to discover any simple correlations between their growth characteristics and their DNA sequences. This finding indicates that the secondary structures of the RNA transcripts may play a more important role than the exact nucleotide sequence of the RNAs in determining how they function within the cell.

Base Sequence↗

PubMed1985

Characterization of a new simian virus 40 mutant, tsA3900, isolated from deletion mutant tsA1499.

The simian virus 40 (SV40) mutant tsA1499 contains an 81-base-pair deletion in the region of A gene encoding the C-terminal portion of the large T antigen. This mutant is particularly interesting, since it is a temperature-sensitive mutant that is apparently able to separate the lytic growth and transforming functions of the SV40 large T antigen at 38.5 degrees C. We report the isolation of a tsA1499 revertant (tsA1499-Rev) which is no longer temperature sensitive for lytic growth but still contains the 81-base-pair deletion of tsA1499. Marker rescue experiments with tsA1499-Rev or wild-type strain 830 (wt830) DNAs revealed that the original tsA1499 mutant contained a second mutation within the HindIII-Fnu4HI restriction fragment between 0.425 and 0.484 map units. Sequencing of this DNA fragment from the tsA1499, tsA1499-Rev, and wt830 viruses revealed that tsA1499 contained a single-base transversion (C to G) at 0.455 map units (nucleotide 4261). This transversion resulted in the creation of a new RsaI cleavage site in the tsA1499 DNA and predicts an arginine-to-threonine substitution at amino acid position 186 in the mutant large T antigen. The DNA sequence of the tsA1499-Rev HindIII-Fnu4HI fragment was identical to that of wt830. To determine whether tsA1499 was temperature sensitive for lytic growth solely as a result of the newly discovered point mutation or because of a combination of the point and deletion mutations, a series of viruses were constructed which contained the point mutation, the deletion mutation, both mutations, or neither. This was done by ligating the PstI A and B DNA fragments from either tsA1499 or wt830 and transfecting the ligated DNA into BSC-1H monkey kidney cells. This experiment revealed that all viruses containing the point mutation (the tsA1499 PstI A DNA fragment) were temperature sensitive for lytic growth, regardless of the presence of the 81-base-pair deletion (the tsA1499 PstI B DNA fragment). This newly discovered point mutation, at nucleotide 4261, is therefore unique, since to our knowledge it is the first tsA mutation to be described in the 0.455-map-unit region of the SV40 genome. We then tested the effect of this unique mutation on the ability of the SV40 virus to transform cultured rat cells to anchorage independence.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗

PubMed1997

Enhancement of the ncdD microtubule motor mutant by mutants of alpha Tub67C.

Ncd is a kinesin-related microtubule motor protein required for chromosome segregation in Drosophila oocytes and early embryos. In tests for interactions with other proteins, we find that mutants of alpha Tub67C, which affect an oocyte- and early embryo-specific alpha-tubulin, enhance meiotic nondisjunction and zygotic loss of ncdD, a partial loss-of-function mutant of ncd. The enhancement is dominant and allele-specific with respect to alpha Tub67C, and depends on the recessive effects of ncdD. Cytologically, embryos of alpha Tub67C/+ show delayed meiotic divisions and defective female pronucleus formation, while meiotic spindle assembly is abnormal in embryos of ncdD/ncdD. Doubly mutant alpha Tub67C ncdD/ncdD embryos are rescued for female pronucleus formation, but show delayed meiotic progression and defective pronuclear conjugation or fusion. Delayed completion of meiosis, together with failure of pronuclear fusion, prevents normal interactions of maternal with paternal chromosomes, enhancing the ncdD mutant phenotype. The genetics and cytology of doubly mutant embryos and the molecular defect of NcdD provide evidence for interaction of Ncd with alpha Tub67C in vivo. These results imply that a specific alpha-tubulin isoform is required for normal cellular function of a kinesin motor protein.

Animals↗

PubMed1976

[Murine model for experimental studies on attenuated mutants of a Pasteurella multocida strain with pathogenicity for the calf. 1. Isolation and biological characterization of streptomycin-dependent mutants (Sm-d) and their examination for immunogenicity in comparison with thermally inactivated pathogens].

An experimental study was conducted into the immunisation of mice to a strain of Pasteurella multocida with pathogenicity for calf. Here are the results: (a) Stable Sm-d mutants were isolated. (b) The genetic stability of this mutant type was established by unsubstantiable reversion up to the magnitude of 10(-8) or - in cases in which 20 Sm-id revertants maximum occurred in 10(-8) Sm-d germs--by prolongation of the generation period of these suppressor mutants which can be defined also as minus mutants. (c) Stable attenuation of selected Sm-d mutants has been established in mice by intraperitoneal application of 108 germs. (d) Live germs with restricted reproduction exhibited more immunogenicity to thermally inactivated antigen.

Animals↗

PubMed1999

Characterization of wild-type and mutant alpha2-antiplasmins: fibrinolysis enhancement by reactive site mutant.

During human blood clotting, alpha2-antiplasmin (alpha2AP) becomes covalently linked to fibrin when activated blood clotting factor XIII (FXIIIa) catalyzes the formation of an isopeptide bond between glutamine at position two in alpha2AP and a specific epsilon-lysyl group in each of the alpha-chains of fibrin. This causes fibrin to become resistant to plasmin-mediated lysis. We found that chemically Arg-modified alpha2AP, which lacked plasmin-inhibitory activity, competed effectively with native alpha2AP for becoming cross-linked to fibrin and as a consequence, enhanced fibrinolysis. Recombinant alpha2AP reported to date by other groups either lacked or possessed a low level of FXIIIa substrate activity. As a first step in the development of an engineered protein that might have potential as a localized fibrin-specific fibrinolytic enhancer, we expressed recombinant alpha2AP in Pichia pastoris yeast. Two forms of nonglycosylated recombinant alpha2AP were expressed, isolated and characterized: (1) wild-type, which was analogous to native alpha2AP, and (2) a mutant form, which had Ala substituted for the reactive-site Arg364. Both the wild-type and mutant forms of alpha2AP functioned as FXIIIa substrates with affinities and kinetic efficiencies comparable to those of native alpha2AP, despite each having an additional acetylated Met blocking group at their respective amino-termini. Wild-type recombinant alpha2AP displayed full plasmin inhibitory activity, while mutant alpha2AP had none. Neither the absence of glycosylation nor blockage of the amino-terminus affected plasmin-inhibitory or FXIIIa substrate activities of wild-type alpha2AP. When our mutant alpha2AP, which lacked plasmin-inhibitory function, was added to human plasma or whole blood clots, urokinase (UK)-induced clot lysis was enhanced in a dose-dependent manner, indicating that mutant alpha2AP augmented lysis by competing with native alpha2AP for FXIIIa-catalyzed incorporation into fibrin.

Cross-Linking Reagents↗

PubMed1999

Treatment of lacZ plasmid-based transgenic mice with benzo[a]pyrene: measurement of DNA adduct levels, mutant frequencies, and mutant spectra.

The evaluation of the relationship between the dose to DNA of a genotoxic carcinogen and in vivo somatic cell mutagenesis may provide important information on the mechanisms leading to induced mutational events. The induction of DNA adducts and DNA mutations in different tissues of lacZ plasmid-based transgenic mice has been investigated following a single intraperitoneal administration of the polycyclic aromatic hydrocarbon benzo[a]pyrene (B[a]P). DNA adducts were measured by (32)P-postlabeling at times between 1 and 28 days following injection and DNA mutations in the lacZ reporter gene were quantified using a highly efficient immunomagnetic purification of the lacZ-containing pUR288 plasmid, followed by electrotransformation of circularized plasmids into a host-restriction negative E. coli C (DeltalacZ, galE (-)) host. The major DNA adduct formed by B[a]P, N (2)-(10beta-[7beta,8alpha, 9alpha-trihydroxy-7,8,9, 10-tetrahydrobenzo(a)pyrene]yl-deoxyguanosine, reached maximum levels between 5 and 7 days followed by a gradual decrease. The induced mutant frequency reached a maximum between 7 and 14 days, after the DNA adduct level in a particular tissue had reached its apparent maximum between 5 and 7 days. The mutant spectrum, defined as the percentage of no-change and size-change mutations in a particular tissue, changed from predominantly size-change mutations in untreated tissues to predominantly no-change mutations in tissues displaying the highest B[a]P-induced mutant frequencies. Contrary to the assumption that there are no factors that can eliminate mutations once they exist, it was observed that mutant frequencies in the organs studied declined to background levels, which was accompanied by a change in the mutant spectrum from predominantly no-change mutations to predominantly size-change mutations.

Animals↗