Heinz Saedler - Academia.edu (original) (raw)
Papers by Heinz Saedler
Transforming Proteins of DNA Tumor Viruses
Current Topics in Microbiology and Immunology, 1989
It is surprising, and even disappointing, that there have been very few meetings and published vo... more It is surprising, and even disappointing, that there have been very few meetings and published volumes resulting from these meetings that focus attention upon all of the groups of DNA tumor viruses. Historically, separate meetings were held each year for the adenovirus-SV40-polyoma researchers, the herpes viruses, hepatitis B virus and the papillomaviruses. It was as if these four virus groups were four fields of study developing independently with a literature and culture of their own. When a virologist crossed the field from the adenovirus group to the herpesvirus or papillomaviruses, he or she was lost to their former group because of the structure of separate meetings and remote literature. This, of course, has resulted from historical accident and is being rectified by the rapid progress made in our understanding of how these viruses contribute to the causation of cancer in animals and humans. It was pre cisely because of these factors that it was time to hold a meeting and publish its proceedings on the subject of transforming proteins of DNA tumor viruses. For the first time, DNA tumor viruses were defined as all of the virus groups that can contribute to cancer in animals with the exception, unfortunately, of the . poxviruses. The purpose of the meeting was to bring together scientists who rarely attend meetings together but actually work on the same problems with different viruses."
[Antibiotic resistance factors and "jumping" genes (author's transl)]
Arzneimittel-Forschung, 1980
Antibiotics are natural products inhibiting the growth of bacteria. In research they play an impo... more Antibiotics are natural products inhibiting the growth of bacteria. In research they play an important role in studying the details of bacterial macromolecular synthesis. However, their major importance lies in application, i.e., in treatment of infectious bacterial diseases and as additives to livestock feed. The application of antibiotics, however, presents serious problems: the development and spread of antibiotic-resistant bacterial strains which impede therapy.
Expression analysis of multigene families by RFLP-coupled domain-directed differential display (RC4D)
A key to understanding the molecular basis of important biological processes such as cell cycling... more A key to understanding the molecular basis of important biological processes such as cell cycling, reproduction, development and response to environmental factors is the highly specific regulation of genes in space and time. Surprisingly, the central importance of differential gene expression is not reflected by the availability of reliable and easy-to-handle, convenient methods for its analysis. After the subtractive hybridization approach had been published as early as 1965 [1], no real-breakthrough has been achieved in this field for nearly three decades. Only in 1992 this picture began to change, when the principle of arbitrarily primed PCR [2] was applied to the analysis of complex mixtures of cDNA molecules representing the transcripts of a particular tissue under investigation [3, 4]. To analyze differences in the expression of genes between two tissues, arbitrarily primed and radiolabeled RT-PCR products from both tissues are generated and run side by side on acrylamide gels. The fingerprint patterns obtained by autoradiography are compared, and differential bands, which represent genes differentially expressed between both tissues, are cut out of the gel. After reamplification the PCR fragments can be cloned and further analyzed. One major advantage of this approach compared to traditional methods to investigate differential gene expression (subtractive hybridization, differential screening) is the requirement of only small amounts of tissue, which, e.g., made this method suitable for expression analysis of mouse preimplantation embryos [5].
Transposable Elements in Plants
Elsevier eBooks, 2001
Proceedings of the National Academy of Sciences of the United States of America, Jun 6, 1995
In this paper, a reverse-transcriptase PCRbased protocol suitable for efficient expression analys... more In this paper, a reverse-transcriptase PCRbased protocol suitable for efficient expression analysis of multigene families is presented. The method combines restriction fragment length polymorphism (RFLP) technology with
The EMBO Journal, Dec 1, 1988
Zuchtungsforschung, 5000 Koin 30, FRG Communicated by H.Saedler TnpA protein, the function encode... more Zuchtungsforschung, 5000 Koin 30, FRG Communicated by H.Saedler TnpA protein, the function encoded by the most abundant transcript of En-i was expressed in Escherichia coli. DNA binding experiments with partially purified tnpA protein revealed that it binds to the subterminal repetitive region of En-i. TnpA protein recognizes a 12-bp-long sequence motif which is reiterated several times at the termini of En-1. Binding is reduced if the cytosine residues of CG dinucleotides and CNG trinucleotides within the motif are methylated. These data suggest a model in which the product of tnpA serves as a regulator of element activity.
Cloning And Analysis Of Two Genes For Chalcone Synthase Of Petunia Hybrida
De Gruyter eBooks, Dec 31, 1986
Molecular Analysis of the Regulation of the Anthocyanin Biosynthetic Pathway in Zea mays
Springer eBooks, 1987
The biosynthesis of the pigment anthocyanin requires many enzymatic activities. Six loci have bee... more The biosynthesis of the pigment anthocyanin requires many enzymatic activities. Six loci have been identified genetically, scattered over the 10 chromosomes of Zea mays. Four of these loci have already been cloned molecularly. In addition, at least eight loci are known to affect pigmentation in a more complex manner; they either regulate the expression of the above structural genes or control the distribution of the pigment in various tissues of the plant. These loci can be grouped into: intensifiers, distributors, tissue specific regulators and general regulators.
Development, 1991
deficiens, together with other homeotic genes, is involved in the genetic control of floral morph... more deficiens, together with other homeotic genes, is involved in the genetic control of floral morphogenesis in A. majus. Mutations in this gene cause homeotic transformations of petals to sepals and stamens to carpels, thus producing male sterile flowers. The deduced DEF A protein shows homology to the DNA-binding domain of the transcription factors SRF of mammals (activating c-fos) and MCM1 of yeast (regulating mating type), suggesting that DEF A has a possible regulatory function as a transcription factor. Interestingly, DEF A belongs to a family of putative transcription factors, called the MADS box genes, whose DNA-binding domains show conserved homology. Two members of this family correlate with known morphogenetic mutants of Antirrhinum. DEF A is constantly expressed during flower development in all floral organs; it is strongly expressed in petals and stamens, but only at a low basal level in the other organs. Molecular, genetic and morphological observations with deficiens morphoalleles indicate that transcriptional and post-transcriptional control of deficiens specifies and diversifies its function in space and time.
Genetics, Feb 1, 2003
To increase the utility of Antirrhinum for genetic and evolutionary studies, we constructed a mol... more To increase the utility of Antirrhinum for genetic and evolutionary studies, we constructed a molecular linkage map for an interspecific hybrid A. majus ϫ A. molle. An F 2 population (n ϭ 92) was genotyped at a minimum of 243 individual loci. Although distorted transmission ratios were observed at marker loci throughout the genome, a mapping strategy based on a fixed framework of codominant markers allowed the loci to be placed into eight robust linkage groups consistent with the haploid chromosome number of Antirrhinum. The mapped loci included 164 protein-coding genes and a similar number of unknown sequences mapped as AFLP, RFLP, ISTR, and ISSR markers. Inclusion of sequences from mutant loci allowed provisional alignment of classical and molecular linkage groups. The total map length was 613 cM with an average interval of 2.5 cM, but most of the loci were aggregated into clusters reducing the effective distance between markers. Potential causes of transmission ratio distortion and its effects on map construction were investigated. This first molecular linkage map for Antirrhinum should facilitate further mapping of mutations, major QTL, and other coding sequences in this model genus.
The EMBO Journal, Oct 1, 1988
Communicated by H.Saedler Genetic and molecular analysis has revealed a specific En-element delet... more Communicated by H.Saedler Genetic and molecular analysis has revealed a specific En-element deletion derivative (En-1102) which reduces En/Spm-induced mutability. In the presence of En-1102 the excision frequency of both the autonomous En-i element and the inhibitor element Spm-15719A is reduced and excision occurs later in development. The 3697 bp long En-1102 element is derived from En-1 by an internal deletion of 4590 bp removing nucleotides 1862-6451. The promoter at the left end and sequences required for polyadenylation are retained in En-1102. It is transcribed to yield predominantly a 1.8 kb poly(A) RNA. cDNA analysis of this transcript indicated that it contains the coding capacity for a 386 amino acid polypeptide. This polypeptide shares homology with En/Spm encoded functions and we suggest that it interferes with transposition at the protein level. Key words: excision/gene structure/transposable element/Zea mays the inserted I element does not lead to complete inactivation, but to an intermediate level of Al gene expression. In the absence of an En/Spm element such a mutation is stable. However, in the presence of the autonomous element, the S-function abolishes the residual Al gene expression and the M-function mediates excision (transposition) of the I element. In order to provide more insight into the structure and function of the En/Spm system the autonomous En-I element was isolated in the wx-844 allele (Peterson, 1985) and molecularly cloned (Pereira et al., 1985). The DNA sequence of the 8287 bp long element was determined and the structure of a gene (tnpA) which encodes the predominant En transcript was established (Gierl et al., 1985; Pereira et al., 1986). In this report we describe the genetic analysis and the molecular characterization of an inhibitor element (En-I102). Unlike other defective En/Spm elements, it affects the activity of the autonomous element. En-I102 encodes an aberrant product which might act as a competitive inhibitor and reduces the En-mediated excisions. Results The autonomous En element has been designated En-I (Pereira et al., 1986). Since inhibitor (I) elements are defective deletion derivatives of En or Spm elements we term these elements En-I or Spm-I, respectively, and add the allelic number to indicate the origin of the particular I element.
The EMBO Journal, May 1, 1986
The c locus of Zea mays, involved in the regulation of anthocyanin biosynthesis, has been cloned ... more The c locus of Zea mays, involved in the regulation of anthocyanin biosynthesis, has been cloned by transposon tagging. A clone (# 18En) containing a full size Eni element was initially isolated from the En element-induced mutable allele c-m668655. Sequences of clone # 18En flanking the Eni element were used to clone other c mutants, whose structure was predicted genetically. Clone # 23En (isolated from c-m668613) contained a full size Eni element, clone # 3Ds (isolated from c-m2) a Ds element and clone # 5 (isolated from c+) had no element on the cloned fragment. From these data we conclude that the clones obtained contain at least part of the c locus. Preliminary data on transcript analysis using a 1-kb DNA fragment from wild-type clone #5 showed that at least three transcripts are encoded by that part of the locus, indicating that c is a complex locus.
The EMBO Journal, Dec 1, 1987
A wild-type allele of the Al gene of Zea mays contains a 1.1-kb-long insert termed Cin4-1, which ... more A wild-type allele of the Al gene of Zea mays contains a 1.1-kb-long insert termed Cin4-1, which alters the structure of the transcription unit compared to other Al alleles. The Cin4-1 element is a member of a family of elements occurring in 50-100 copies in the maize genome. Genomic cloning and sequence analysis of several family members and their flanking regions allowed classification of Cin4 as a nonviral retrotransposon. Individual Cin4 elements terminate in an oligo(A) track of variable size (6-11 residues) at their 3'-end. The 5'-ends of family members are heterogeneously truncated with respect to the longest Cin4 element. Cin4 elements are flanked by small direct duplications, the size of which varies between 3 and 16 bp. On the basis of a comparison of the target sequence and the sequence of Cin4 we suggest and discuss a model of the mechanism of Cin4 integration via in situ cDNA synthesis on an RNA template. The longest Cin4 element analysed so far has two non-overlapping open reading frames (ORFs) comprising 2793 nucleotides (ORFi) and 3489 nucleotides (ORF2). The putative 1163 amino acid long Cin4 protein derived from the sequence of ORF2 has the capacity to encode a reverse transcriptase-like protein and a DNAbinding domain. The conservation pattern of these two domains and the overall organisation of Cin4 is similar to that detected in nonviral retrotransposons in animals. The origin and function of Cin4 are discussed.
Transposition and Regulation of the En Elements of Maize Assayed in Transformed Tobacco
Current plant science and biotechnology in agriculture, 1988
The En transposable element of maize has great potential as a versatile gene delivery and tagging... more The En transposable element of maize has great potential as a versatile gene delivery and tagging system. En-I is a two component system composed of the autonomous En element which encodes transposase, and receptor elements, called I. “I” represents any deletion derivative of En that looses transposase function but can transpose when an autonomous element supplies transposase in trans.
Dna Rearrangements in IS2 That Form New Promoters
Elsevier eBooks, 1980
ABSTRACT A system was developed that allowed the selection of mutations which had promoter activi... more ABSTRACT A system was developed that allowed the selection of mutations which had promoter activity. A variety of different events was observed. A mutation was found that increased the frequency of one particular class of events but not of a second class. This mutation was not in the polA locus.
The EMBO Journal, Oct 1, 1985
Communicated by H.Saedler Two states of the al-ml allele featuring different phenotypes in the ab... more Communicated by H.Saedler Two states of the al-ml allele featuring different phenotypes in the absence as well as in the presence of Spm or En have been cloned and sequenced. The insertion site and orientation of the Inhibitor (1) element within the two alleles is identical. The sizes of the I elements differ, being 2.2 kb in state 6078 and 789 bp in state 5719A-1. The internal deletion in state 5719A-1 affects sequences within one side of the terminal inverted repeats of the I element. This alteration can be correlated with the decreased response of this state to the Mutator function of Spm. A model for the interaction between Spm (En)-encoded functions and the receptor element is discussed explaining the phenotypic differences between the states of the locus.
The EMBO Journal, Sep 1, 1991
Two chalcone synthase genes in maize have been cloned and molecularly characterized to be the C2 ... more Two chalcone synthase genes in maize have been cloned and molecularly characterized to be the C2 and the Whp (white pollen) locus. The two genes have highly homologous exon sequences but differ considerably in sequences 5' upstream and 3' downstream of the coding region, as well as in their introns. Northern and Western experiments of chalcone synthase expression in various tissues and in different genotypes indicated that C2 and Whp are differently regulated. The expression of Whp in maize aleurone is dependent on the presence of the recessive allele of the gene intensifier (in). The regulatory effect of in on Whp expression is not detectable at the transcriptional level, but seems to take place during translation.
The Role of IS-Elements in E. coli
The chromosome of Escherichia coli is a circular double-stranded DNA molecule with a length of ab... more The chromosome of Escherichia coli is a circular double-stranded DNA molecule with a length of about 1 mm, which is folded in a unique way. This DNA molecule has a coding capacity of some 3000–4000 average-sized polypeptide chains. The genes coding for these proteins are thought to be arranged in the chromosome in a sequence characteristic for a given bacterial species.
Transforming Proteins of DNA Tumor Viruses
Current Topics in Microbiology and Immunology, 1989
It is surprising, and even disappointing, that there have been very few meetings and published vo... more It is surprising, and even disappointing, that there have been very few meetings and published volumes resulting from these meetings that focus attention upon all of the groups of DNA tumor viruses. Historically, separate meetings were held each year for the adenovirus-SV40-polyoma researchers, the herpes viruses, hepatitis B virus and the papillomaviruses. It was as if these four virus groups were four fields of study developing independently with a literature and culture of their own. When a virologist crossed the field from the adenovirus group to the herpesvirus or papillomaviruses, he or she was lost to their former group because of the structure of separate meetings and remote literature. This, of course, has resulted from historical accident and is being rectified by the rapid progress made in our understanding of how these viruses contribute to the causation of cancer in animals and humans. It was pre cisely because of these factors that it was time to hold a meeting and publish its proceedings on the subject of transforming proteins of DNA tumor viruses. For the first time, DNA tumor viruses were defined as all of the virus groups that can contribute to cancer in animals with the exception, unfortunately, of the . poxviruses. The purpose of the meeting was to bring together scientists who rarely attend meetings together but actually work on the same problems with different viruses."
[Antibiotic resistance factors and "jumping" genes (author's transl)]
Arzneimittel-Forschung, 1980
Antibiotics are natural products inhibiting the growth of bacteria. In research they play an impo... more Antibiotics are natural products inhibiting the growth of bacteria. In research they play an important role in studying the details of bacterial macromolecular synthesis. However, their major importance lies in application, i.e., in treatment of infectious bacterial diseases and as additives to livestock feed. The application of antibiotics, however, presents serious problems: the development and spread of antibiotic-resistant bacterial strains which impede therapy.
Expression analysis of multigene families by RFLP-coupled domain-directed differential display (RC4D)
A key to understanding the molecular basis of important biological processes such as cell cycling... more A key to understanding the molecular basis of important biological processes such as cell cycling, reproduction, development and response to environmental factors is the highly specific regulation of genes in space and time. Surprisingly, the central importance of differential gene expression is not reflected by the availability of reliable and easy-to-handle, convenient methods for its analysis. After the subtractive hybridization approach had been published as early as 1965 [1], no real-breakthrough has been achieved in this field for nearly three decades. Only in 1992 this picture began to change, when the principle of arbitrarily primed PCR [2] was applied to the analysis of complex mixtures of cDNA molecules representing the transcripts of a particular tissue under investigation [3, 4]. To analyze differences in the expression of genes between two tissues, arbitrarily primed and radiolabeled RT-PCR products from both tissues are generated and run side by side on acrylamide gels. The fingerprint patterns obtained by autoradiography are compared, and differential bands, which represent genes differentially expressed between both tissues, are cut out of the gel. After reamplification the PCR fragments can be cloned and further analyzed. One major advantage of this approach compared to traditional methods to investigate differential gene expression (subtractive hybridization, differential screening) is the requirement of only small amounts of tissue, which, e.g., made this method suitable for expression analysis of mouse preimplantation embryos [5].
Transposable Elements in Plants
Elsevier eBooks, 2001
Proceedings of the National Academy of Sciences of the United States of America, Jun 6, 1995
In this paper, a reverse-transcriptase PCRbased protocol suitable for efficient expression analys... more In this paper, a reverse-transcriptase PCRbased protocol suitable for efficient expression analysis of multigene families is presented. The method combines restriction fragment length polymorphism (RFLP) technology with
The EMBO Journal, Dec 1, 1988
Zuchtungsforschung, 5000 Koin 30, FRG Communicated by H.Saedler TnpA protein, the function encode... more Zuchtungsforschung, 5000 Koin 30, FRG Communicated by H.Saedler TnpA protein, the function encoded by the most abundant transcript of En-i was expressed in Escherichia coli. DNA binding experiments with partially purified tnpA protein revealed that it binds to the subterminal repetitive region of En-i. TnpA protein recognizes a 12-bp-long sequence motif which is reiterated several times at the termini of En-1. Binding is reduced if the cytosine residues of CG dinucleotides and CNG trinucleotides within the motif are methylated. These data suggest a model in which the product of tnpA serves as a regulator of element activity.
Cloning And Analysis Of Two Genes For Chalcone Synthase Of Petunia Hybrida
De Gruyter eBooks, Dec 31, 1986
Molecular Analysis of the Regulation of the Anthocyanin Biosynthetic Pathway in Zea mays
Springer eBooks, 1987
The biosynthesis of the pigment anthocyanin requires many enzymatic activities. Six loci have bee... more The biosynthesis of the pigment anthocyanin requires many enzymatic activities. Six loci have been identified genetically, scattered over the 10 chromosomes of Zea mays. Four of these loci have already been cloned molecularly. In addition, at least eight loci are known to affect pigmentation in a more complex manner; they either regulate the expression of the above structural genes or control the distribution of the pigment in various tissues of the plant. These loci can be grouped into: intensifiers, distributors, tissue specific regulators and general regulators.
Development, 1991
deficiens, together with other homeotic genes, is involved in the genetic control of floral morph... more deficiens, together with other homeotic genes, is involved in the genetic control of floral morphogenesis in A. majus. Mutations in this gene cause homeotic transformations of petals to sepals and stamens to carpels, thus producing male sterile flowers. The deduced DEF A protein shows homology to the DNA-binding domain of the transcription factors SRF of mammals (activating c-fos) and MCM1 of yeast (regulating mating type), suggesting that DEF A has a possible regulatory function as a transcription factor. Interestingly, DEF A belongs to a family of putative transcription factors, called the MADS box genes, whose DNA-binding domains show conserved homology. Two members of this family correlate with known morphogenetic mutants of Antirrhinum. DEF A is constantly expressed during flower development in all floral organs; it is strongly expressed in petals and stamens, but only at a low basal level in the other organs. Molecular, genetic and morphological observations with deficiens morphoalleles indicate that transcriptional and post-transcriptional control of deficiens specifies and diversifies its function in space and time.
Genetics, Feb 1, 2003
To increase the utility of Antirrhinum for genetic and evolutionary studies, we constructed a mol... more To increase the utility of Antirrhinum for genetic and evolutionary studies, we constructed a molecular linkage map for an interspecific hybrid A. majus ϫ A. molle. An F 2 population (n ϭ 92) was genotyped at a minimum of 243 individual loci. Although distorted transmission ratios were observed at marker loci throughout the genome, a mapping strategy based on a fixed framework of codominant markers allowed the loci to be placed into eight robust linkage groups consistent with the haploid chromosome number of Antirrhinum. The mapped loci included 164 protein-coding genes and a similar number of unknown sequences mapped as AFLP, RFLP, ISTR, and ISSR markers. Inclusion of sequences from mutant loci allowed provisional alignment of classical and molecular linkage groups. The total map length was 613 cM with an average interval of 2.5 cM, but most of the loci were aggregated into clusters reducing the effective distance between markers. Potential causes of transmission ratio distortion and its effects on map construction were investigated. This first molecular linkage map for Antirrhinum should facilitate further mapping of mutations, major QTL, and other coding sequences in this model genus.
The EMBO Journal, Oct 1, 1988
Communicated by H.Saedler Genetic and molecular analysis has revealed a specific En-element delet... more Communicated by H.Saedler Genetic and molecular analysis has revealed a specific En-element deletion derivative (En-1102) which reduces En/Spm-induced mutability. In the presence of En-1102 the excision frequency of both the autonomous En-i element and the inhibitor element Spm-15719A is reduced and excision occurs later in development. The 3697 bp long En-1102 element is derived from En-1 by an internal deletion of 4590 bp removing nucleotides 1862-6451. The promoter at the left end and sequences required for polyadenylation are retained in En-1102. It is transcribed to yield predominantly a 1.8 kb poly(A) RNA. cDNA analysis of this transcript indicated that it contains the coding capacity for a 386 amino acid polypeptide. This polypeptide shares homology with En/Spm encoded functions and we suggest that it interferes with transposition at the protein level. Key words: excision/gene structure/transposable element/Zea mays the inserted I element does not lead to complete inactivation, but to an intermediate level of Al gene expression. In the absence of an En/Spm element such a mutation is stable. However, in the presence of the autonomous element, the S-function abolishes the residual Al gene expression and the M-function mediates excision (transposition) of the I element. In order to provide more insight into the structure and function of the En/Spm system the autonomous En-I element was isolated in the wx-844 allele (Peterson, 1985) and molecularly cloned (Pereira et al., 1985). The DNA sequence of the 8287 bp long element was determined and the structure of a gene (tnpA) which encodes the predominant En transcript was established (Gierl et al., 1985; Pereira et al., 1986). In this report we describe the genetic analysis and the molecular characterization of an inhibitor element (En-I102). Unlike other defective En/Spm elements, it affects the activity of the autonomous element. En-I102 encodes an aberrant product which might act as a competitive inhibitor and reduces the En-mediated excisions. Results The autonomous En element has been designated En-I (Pereira et al., 1986). Since inhibitor (I) elements are defective deletion derivatives of En or Spm elements we term these elements En-I or Spm-I, respectively, and add the allelic number to indicate the origin of the particular I element.
The EMBO Journal, May 1, 1986
The c locus of Zea mays, involved in the regulation of anthocyanin biosynthesis, has been cloned ... more The c locus of Zea mays, involved in the regulation of anthocyanin biosynthesis, has been cloned by transposon tagging. A clone (# 18En) containing a full size Eni element was initially isolated from the En element-induced mutable allele c-m668655. Sequences of clone # 18En flanking the Eni element were used to clone other c mutants, whose structure was predicted genetically. Clone # 23En (isolated from c-m668613) contained a full size Eni element, clone # 3Ds (isolated from c-m2) a Ds element and clone # 5 (isolated from c+) had no element on the cloned fragment. From these data we conclude that the clones obtained contain at least part of the c locus. Preliminary data on transcript analysis using a 1-kb DNA fragment from wild-type clone #5 showed that at least three transcripts are encoded by that part of the locus, indicating that c is a complex locus.
The EMBO Journal, Dec 1, 1987
A wild-type allele of the Al gene of Zea mays contains a 1.1-kb-long insert termed Cin4-1, which ... more A wild-type allele of the Al gene of Zea mays contains a 1.1-kb-long insert termed Cin4-1, which alters the structure of the transcription unit compared to other Al alleles. The Cin4-1 element is a member of a family of elements occurring in 50-100 copies in the maize genome. Genomic cloning and sequence analysis of several family members and their flanking regions allowed classification of Cin4 as a nonviral retrotransposon. Individual Cin4 elements terminate in an oligo(A) track of variable size (6-11 residues) at their 3'-end. The 5'-ends of family members are heterogeneously truncated with respect to the longest Cin4 element. Cin4 elements are flanked by small direct duplications, the size of which varies between 3 and 16 bp. On the basis of a comparison of the target sequence and the sequence of Cin4 we suggest and discuss a model of the mechanism of Cin4 integration via in situ cDNA synthesis on an RNA template. The longest Cin4 element analysed so far has two non-overlapping open reading frames (ORFs) comprising 2793 nucleotides (ORFi) and 3489 nucleotides (ORF2). The putative 1163 amino acid long Cin4 protein derived from the sequence of ORF2 has the capacity to encode a reverse transcriptase-like protein and a DNAbinding domain. The conservation pattern of these two domains and the overall organisation of Cin4 is similar to that detected in nonviral retrotransposons in animals. The origin and function of Cin4 are discussed.
Transposition and Regulation of the En Elements of Maize Assayed in Transformed Tobacco
Current plant science and biotechnology in agriculture, 1988
The En transposable element of maize has great potential as a versatile gene delivery and tagging... more The En transposable element of maize has great potential as a versatile gene delivery and tagging system. En-I is a two component system composed of the autonomous En element which encodes transposase, and receptor elements, called I. “I” represents any deletion derivative of En that looses transposase function but can transpose when an autonomous element supplies transposase in trans.
Dna Rearrangements in IS2 That Form New Promoters
Elsevier eBooks, 1980
ABSTRACT A system was developed that allowed the selection of mutations which had promoter activi... more ABSTRACT A system was developed that allowed the selection of mutations which had promoter activity. A variety of different events was observed. A mutation was found that increased the frequency of one particular class of events but not of a second class. This mutation was not in the polA locus.
The EMBO Journal, Oct 1, 1985
Communicated by H.Saedler Two states of the al-ml allele featuring different phenotypes in the ab... more Communicated by H.Saedler Two states of the al-ml allele featuring different phenotypes in the absence as well as in the presence of Spm or En have been cloned and sequenced. The insertion site and orientation of the Inhibitor (1) element within the two alleles is identical. The sizes of the I elements differ, being 2.2 kb in state 6078 and 789 bp in state 5719A-1. The internal deletion in state 5719A-1 affects sequences within one side of the terminal inverted repeats of the I element. This alteration can be correlated with the decreased response of this state to the Mutator function of Spm. A model for the interaction between Spm (En)-encoded functions and the receptor element is discussed explaining the phenotypic differences between the states of the locus.
The EMBO Journal, Sep 1, 1991
Two chalcone synthase genes in maize have been cloned and molecularly characterized to be the C2 ... more Two chalcone synthase genes in maize have been cloned and molecularly characterized to be the C2 and the Whp (white pollen) locus. The two genes have highly homologous exon sequences but differ considerably in sequences 5' upstream and 3' downstream of the coding region, as well as in their introns. Northern and Western experiments of chalcone synthase expression in various tissues and in different genotypes indicated that C2 and Whp are differently regulated. The expression of Whp in maize aleurone is dependent on the presence of the recessive allele of the gene intensifier (in). The regulatory effect of in on Whp expression is not detectable at the transcriptional level, but seems to take place during translation.
The Role of IS-Elements in E. coli
The chromosome of Escherichia coli is a circular double-stranded DNA molecule with a length of ab... more The chromosome of Escherichia coli is a circular double-stranded DNA molecule with a length of about 1 mm, which is folded in a unique way. This DNA molecule has a coding capacity of some 3000–4000 average-sized polypeptide chains. The genes coding for these proteins are thought to be arranged in the chromosome in a sequence characteristic for a given bacterial species.