scholarly journals Analysis of maize brittle-1 alleles and a defective Suppressor-mutator-induced mutable allele.

1991 ◽  
Vol 3 (12) ◽  
pp. 1337-1348 ◽  
Author(s):  
T D Sullivan ◽  
L I Strelow ◽  
C A Illingworth ◽  
R L Phillips ◽  
O E Nelson
Keyword(s):  
Mutable Allele

scholarly journals Transposition Pattern of the Maize Element Ac from the Bz-M2(ac) Allele.

Genetics ◽  
1989 ◽  
Vol 122 (2) ◽  
pp. 447-457 ◽  
Author(s):  
H K Dooner ◽  
A Belachew
Keyword(s):  
Donor Site ◽  
Receptor Site ◽  
Receptor Sites ◽  
Mutable Allele ◽  
Ac Transposition ◽  
P Locus

Abstract The pattern of transposition of Ac from the mutable allele bz-m2(Ac) has been investigated. Stable (bz-s) and finely spotted (bz-m(F)) exceptions were selected from coarsely spotted bz-m2(Ac) ears. The presence or absence of a transposed Ac (trAc) in the genome was determined and, when present, the location of the trAc was mapped relative to the flanking markers sh and wx. The salient general features of Ac transposition to sites linked to bz are that the receptor sites tend to be clustered on either side of the bz donor site and that transposition is bidirectional and nonpolar. Thus, the symmetrical clustering in the distribution of receptor sites adjacent to bz differs from the asymmetrical clustering reported in 1984 for the P locus by I. M. GREENBLATT. Though Ac tends to transpose preferentially to closely linked sites, an appreciable fraction of Ac transpositions from bz-m2(Ac) is to unlinked sites: 41% among bz-s derivatives and 59% among bz-m(F) derivatives. Many transposition events among the bz-m(F) selections result in kernels carrying a genetically noncorresponding embryo. These can be interpreted as twin sectors arising at one of the megagametophytic mitoses. The bz locus data fit the earlier (1962) model of I. M. GREENBLATT and R. A. BRINK in which transposition takes place from a replicated donor site to either an unreplicated or replicated receptor site.

scholarly journals CONTROL OF ANTHOCYANIN SYNTHESIS IN PETUNIA HYBRIDA BY MULTIPLE ALLELIC SERIES OF THE GENES An1 AND An2

Genetics ◽  
1984 ◽  
Vol 106 (3) ◽  
pp. 501-508
Author(s):  
Anton G M Gerats ◽  
Eliane Farcy ◽  
Marco Wallroth ◽  
Steven P C Groot ◽  
André Schram
Keyword(s):  
Petunia Hybrida ◽  
Anthocyanin Synthesis ◽  
Continuous Series ◽  
Wild Type ◽  
Allelic Series ◽  
Multiple Series ◽  
Anthocyanin Concentration ◽  
Mutable Allele ◽  
Multiple Allelic Series ◽  
Composition Changes

ABSTRACT A mutable allele of the An1 locus in Petunia hybrida has given rise to a multiple series of stable derivative alleles. Anthocyanin concentration in mature flowers of these mutants (an1  +/p/an1) decreases from the wild-type red to the recessive white in a continuous series. Anthocyanin composition changes regularly: the ratio of peonidin to cyanidin is 3.5 for an an1  +/+/an1 and 1.2 for an an1  +/p5/an1 mutant. Analysis of anthocyanins during flower development indicates that these differences in composition are due to the specific state of the An1 locus and not to anthocyanin concentration. Anthocyanin concentration in flowers of the allelic series for An1 correlates with the activity of the enzymes UDP-glucose: flavonoid-3-O-glucosyltransferase and SAM: anthocyanin-3′-O-methyltransferase. The same correlations were found for members of a comparable allelic series at the An2 locus. The possibility that the correlation between the enzyme activities is due to the occurrence of a multienzyme complex is discussed.

scholarly journals Ds-INDUCED ALLELES AT THE OPAQUE-2 LOCUS OF MAIZE

Genetics ◽  
1986 ◽  
Vol 112 (1) ◽  
pp. 121-133
Author(s):  
Mario Motto ◽  
Renzo Marotta ◽  
Natale Di Fonzo ◽  
Carlo Soave ◽  
Francesco Salamini
Keyword(s):  
Transposable Elements ◽  
Transposon Mutagenesis ◽  
Dna Fragments ◽  
Wild Type ◽  
Genetic Analyses ◽  
Somatic Instability ◽  
Mutable Allele ◽  
Recessive Phenotype ◽  
Maize Plants ◽  
Ds Element

ABSTRACT Transposon mutagenesis has been used to isolate mutable alleles at the Opaque-2 (O2) locus of maize. Plants with the Activator-Dissociation (Ac-Ds) system of transposable elements and O2 were crossed as males to a stable o2 tester line. Among a population of 200,000 kernels, 198 exceptional kernels with somatic instability were recovered. In four cases, designated O2-m1, o2-m2, O2-m3 and O2-m4, variegated phenotypes appeared in F2 and subsequent generations. Genetic analyses indicated that the presence of Ds near or within the O2 gene was responsible for the observed somatic instability at the O2 locus. The phenotypes of the newly induced alleles were of two types. Alleles O2-m1, O2-m3 and O2-m4, in the absence of Ac, were characterized by kernel phenotypes indistinguishable from the wild type; in the presence of Ac they generated kernels with opaque sectors interspersed within a vitreous background. In contrast, the mutable allele o2-m2, in the absence of Ac, was characterized by kernels with a recessive phenotype similar to o2 recessive mutants. In the presence of Ac, it reverted somatically to wild-type-producing kernels with vitreous spots in an o2 background. The association of the Ds element with the O2 locus may prove a valuable tool directed to the isolation of DNA fragments bearing the O2 gene.

Inheritance of a mutable phenotype that is activated in alfalfa tissue culture

Genome ◽  
1991 ◽  
Vol 34 (1) ◽  
pp. 35-40 ◽  
Author(s):  
I. M. Ray ◽  
E. T. Bingham
Keyword(s):  
Tissue Culture ◽  
Preliminary Evidence ◽  
Anthocyanin Synthesis ◽  
In Planta ◽  
Reversion Frequency ◽  
Dosage Effects ◽  
Mutable Allele ◽  
Basic Color ◽  
Unstable Transmission

Mutable alleles, typically regulated by transposable elements, have been identified in a number of plant species. Tissue culture induced genomic shocks may activate such elements. A mutable recessive condition arose in tissue culture of alfalfa and was highly unstable in subsequent cycles of culture. The mutable allele, designated c2-m4, is allelic to the C2 locus, a basic color factor locus involved in anthocyanin synthesis. Current research has focused on the inheritance and instability of c2-m4 in new genetic backgrounds as well as on dosage effects of the allele. We have confirmed a previous report that c2-m4 reverts to function at much higher frequencies in vitro (reversion frequency ca. 0.23) than in planta (reversion frequency < 0.001). Over sexual generations c2-m4 continues to be unstable. Transmission of the mutable phenotype to selfed, testcross, and F2 populations demonstrated monofactorial inheritance patterns (P > 0.25). In populations expected to have some plants carrying two or more c2-m4 alleles, individuals were found that reverted in vitro at significantly higher frequencies than their parent (0.67 ± 0.04 and 0.44 ± 0.08 versus 0.20 ± 0.09). In planta reversion also increased with increasing c2-m4 dosage. Preliminary evidence indicates that as c2-m4 dosage increases, each allele maintains its original capacity to revert.Key words: somaclonal variation, transposable element, tissue culture, mutable allele.

A MUTABLE ALLELE AT THE E LOCUS IN NICOTIANA

Genetics ◽  
1971 ◽  
Vol 67 (1) ◽  
pp. 61-73
Author(s):  
Seaward A Sand
Keyword(s):  
Mutable Allele

scholarly journals CHARACTERIZATION OF AN Spm-CONTROLLED BRONZE-MUTABLE ALLELE IN MAIZE

Genetics ◽  
1984 ◽  
Vol 106 (4) ◽  
pp. 769-779
Author(s):  
Oliver E Nelson ◽  
Anita S Klein
Keyword(s):  
Zea Mays ◽  
Zea Mays L ◽  
High Rate ◽  
Aleurone Layer ◽  
Mutable Allele ◽  
Anthocyanin Production ◽  
Seed Phenotype

ABSTRACT The association of a receptor (Rs) of the Spm system with a Bz-1 allele has created a two-element Spm-controlled bz-mutable allele (bz-m13) of maize (Zea mays L.). In the absence of Spm, one copy of bz-m13 (bz/bz/bz-m13) conditions full anthocyanin production in the aleurone layer of the seed. In the presence of this Spm, bz-m13 produces a unique, coarsely variegated seed phenotype and has a high rate (50–83%) of gametic change to stable bz′ or Bz′ derivatives. Even one copy of a Bz′ derivative allele conditions full anthocyanin production in the aleurone, but the enzyme (UFGT) level of the progenitor Bz-1 allele is not restored in most Bz′ derivatives.

A New Allele at the w4m Locus Derived from the w4-m Mutable Allele in Soybean

1993 ◽  
Vol 84 (4) ◽  
pp. 297-300 ◽  
Author(s):  
R. G. Palmer ◽  
R. W. Groose
Keyword(s):  
Mutable Allele
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