Transposition of the enhancer controlling element system in maize

Nowick, Elaine Maytag; Petérson, Peter A.

doi:10.1007/bf00268763

Cited by 44 publications

(19 citation statements)

References 21 publications

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“…It is therefore likely that they transpose by a similar mechanism involving association between donor and recipient sites and that this accounts for the observed preference for transposition of Ac to closely linked sites. There is also evidence that the maize element En (Spm) shows a preference for transposition to linked sites (Nowick and Peterson, 1981), suggesting that this type of element transposes by a similar mechanism.…”

Section: Resultsmentioning

confidence: 99%

A chromosome rearrangement suggests that donor and recipient sites are associated during Tam3 transposition in Antirrhinum majus

1989

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We describe the structure of a chromosome rearrangement which changes the spatial pattern of expression of the pallida gene of Antirrhinum majus. The rearrangement involves a chromosome inversion of ~6 map units with one breakpoint at the end of a copy of the transposable element Tam3 located in the promoter region of the pallida locus. The sequence at the breakpoints shows that 5‐7 bp, present once in the progenitor, has been duplicated and flanks both ends of the inversion. We propose that this structure arose from an aberrant Tam3 transposition, suggesting a model for normal transposition which involves physical association between donor and recipient sites. This may explain why transposition of plant transposable elements such as Ac in maize occurs preferentially to recipient sites closely linked to the donor site. Excision of the Tam3 copy located at the end of the chromosome inversion, results in a unique spatial pattern of pallida gene expression as a consequence of replacing all sequence 70 bp upstream of transcription by a new sequence. This pattern may be the result of deleting specific upstream components which regulate pallida expression and/or of changing the relative chromosome position of the pallida gene.

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Section: Resultsmentioning

confidence: 99%

A chromosome rearrangement suggests that donor and recipient sites are associated during Tam3 transposition in Antirrhinum majus

1989

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“…The maize En/Spm element preferentially transposes to linked loci (Peterson 1970;Nowick and Peterson 1981). Similarly, Tgm9 transposed into the DFR2 promoter (Figures 3 and 8).…”

Section: Discussionmentioning

confidence: 97%

Excision of an Active CACTA-Like Transposable Element From DFR2 Causes Variegated Flowers in Soybean [Glycine max (L.) Merr.]

Brar

Grosic

et al. 2010

Genetics

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Active endogenous transposable elements, useful tools for gene isolation, have not been reported from any legume species. An active transposable element was suggested to reside in the W4 locus that governs flower color in soybean. Through biochemical and molecular analyses of several revertants of the w4-m allele, we have shown that the W4 locus encodes dihydroflavonol-4-reductase 2 (DFR2). w4-m has arisen through insertion of Tgm9, a 20,548-bp CACTA-like transposable element, into the second intron of DFR2. Tgm9 showed high nucleic acid sequence identity to Tgmt *. Its 59 and 39 terminal inverted repeats start with conserved CACTA sequence. The 39 subterminal region is highly repetitive. Tgm9 carries TNP1-and TNP2-like transposase genes that are expressed in the mutable line, T322 (w4-m). The element excises at a high frequency from both somatic and germinal tissues. Following excision, reinsertions of Tgm9 into the DFR2 promoter generated novel stable alleles, w4-dp (dilute purple flowers) and w4-p (pale flowers). We hypothesize that the element is fractured during transposition, and truncated versions of the element in new insertion sites cause stable mutations. The highly active endogenous transposon, Tgm9, should facilitate genomics studies specifically that relate to legume biology. Figure 1) and purple hypocotyls. Mutations at the W4 locus in the W1_ background result in altered pigment accumulation patterns in petals and reduced levels of purple pigments in flowers and hypocotyls. Four mutant alleles, w4, w4-m, w4-dp, and w4-p have been mapped to this locus. The w4 allele represents a spontaneous mutation, which produces near-white flowers (Figure 1) and green hypocotyls (Hartwig and Hinson 1962;Groose and Palmer 1991). The w4-m allele was identified from a cross between two experimental breeding lines with white and purple flowers, respectively (Palmer et al. 1989;Weigelt et al. 1990). w4-m is characterized by variegated flowers (Figure 1) and green hypocotyls with purple sectors (Groose et al. 1988).w4-m has been proposed to harbor a class II transposable element (Palmer et al. 1989). Presumably, somatic excision of the putative transposable element results in the variegated (Groose et al. 1988) and germinal excision wild-type phenotypes, purple flowers and purple pigments on hypocotyls (Palmer et al. 1989;Groose et al. 1990). The mutable line carrying w4-m undergoes germinal reversion at a very high frequency, about 6% per generation ). Approximately 1% of the progeny derived from germinal revertants contain new mutations in unlinked loci, presumably resulting from reinsertion of the element (Palmer et al. 1989). For example, female partial-sterile 1 (Fsp1), female partial-sterile 2 (Fsp2), female partialsterile 3 (Fsp3), and female partial-sterile 4 (Fsp4) were isolated from progenies of germinal revertants with purple flowers and were mapped to molecular linkage groups (MLG) C2, A2, F, and G, respectively (Kato and Palmer 2004). Similarly, 36 male-sterile, female-sterile mutants mapped to t...

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“…In plants, although replicative transposition cannot be excluded, most classical genetic evidence gathered so far, in particular for the elements Ac and En (Spm), indicates that transposition occurs mainly by excision of a transposable element from one position in the genome and re-insertion of the same element at another site. One example of this kind of loss/gain mechanism of transposition can be observed in lines carrying an autonomous En regulatory element at the al locus (Peterson, 1970;Nowick and Peterson, 1981). Kernels of such mutants are variegated due to En-induced mutability of the al locus, but exceptional kernels with a stable colorless or pale phenotype occasionally appear.…”

Section: General Features Of Transposition In Plantsmentioning

confidence: 99%