Reciprocal differences in DNA sequence and methylation status of the pollen DNA between F1 hybrids of Solanum tuberosum × S. demissum

The effects of growth of one genotype of flax in soil supplemented by either nitrogen, phosphorous and potassium (NPK) or nitrogen and potassium (NK) on its progeny produced by several generations of complete selfing were studied. The two types of progeny produced, genotroph L, induced by NPK and genotroph S induced by NK, and their F1 reciprocal hybrids were examined. L and S differed in plant weight and in the activities and relative mobilities of their corresponding anionic peroxidase and esterase isozymes. No reciprocal differences were detected and the mean F1 values for all characteristics were intermediate between the parents, with the exception of the peroxidase isozyme relative mobilities which displayed dominance of parent L. The genotrophs were known to exhibit a 16% difference in nuclear DNA content which could be reverted to 0%, without altering the genotroph fresh weight difference, by growing the genotrophs in lower than normal temperatures. Examination of the peroxidase and esterase isozymes of nDNA reverted genotrophs showed that, with one possible exception, there was no accompanying reversion of the activities and relative mobilities of the peroxidase or esterase isozymes.

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MEIOSIS IN SOLANUM TUBEROSUM HAPLOIDS AND HAPLOID-HAPLOID F1 HYBRIDS

Canadian Journal of Genetics and Cytology ◽

10.1139/g64-050 ◽

1964 ◽

Vol 6 (4) ◽

pp. 393-402 ◽

Cited By ~ 24

Author(s):

B. P. Yeh ◽

S. J. Peloquin ◽

R. W. Hougas

Keyword(s):

Solanum Tuberosum ◽

F1 Hybrids

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Heterosis of Apparent Photosynthesis Rate in Arachis hypogaea L.1

Peanut Science ◽

10.3146/i0095-3679-11-2-1 ◽

1984 ◽

Vol 11 (2) ◽

pp. 56-57 ◽

Cited By ~ 2

Author(s):

W. D. Branch ◽

J. E. Pallas

Keyword(s):

Arachis Hypogaea ◽

Environmental Conditions ◽

Photosynthesis Rate ◽

F1 Hybrids ◽

Diallel Crosses ◽

Photosynthetic Rates ◽

Arachis Hypogaea L ◽

Reciprocal Differences

Abstract Complete diallel crosses were made among three parental peanut (Arachis hypogaea L.) genotypes to gain a better understanding of photosynthetic inheritance. Highly controlled environmental conditions were used throughout the study to determine apparent photosynthetic rates. Results indicated significant differences among parents and F1 hybrids. Reciprocal differences were also observed between certain cross combinations. Dominance and overdominance effects were found under these test regimes which suggest a heterotic response for this important characteristic.

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Reciprocal differences between hybrids of Solanum tuberosum Groups Tuberosum (haploid) and Phureja

Euphytica ◽

10.1007/bf00041513 ◽

1987 ◽

Vol 36 (2) ◽

pp. 631-639 ◽

Cited By ~ 11

Author(s):

A. Hilali ◽

F. I. Lauer ◽

R. E. Veilleux

Keyword(s):

Solanum Tuberosum ◽

Reciprocal Differences

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Genomic Methylation: a Tool for Typing Helicobacter pylori Isolates

Applied and Environmental Microbiology ◽

10.1128/aem.00199-07 ◽

2007 ◽

Vol 73 (13) ◽

pp. 4243-4249 ◽

Cited By ~ 9

Author(s):

Filipa F. Vale ◽

Jorge M. B. Vítor

Keyword(s):

Helicobacter Pylori ◽

Dna Sequence ◽

Dna Methyltransferase ◽

Defense Mechanism ◽

Methylation Status ◽

Host Bacterium ◽

Selfish Genetic Elements ◽

Genomic Dnas ◽

H Pylori ◽

Genomic Methylation

ABSTRACT The genome sequences of three Helicobacter pylori strains revealed an abundant number of putative restriction and modification (R-M) systems within a small genome (1.60 to 1.67 Mb). Each R-M system includes an endonuclease that cleaves a specific DNA sequence and a DNA methyltransferase that methylates either adenosine or cytosine within the same DNA sequence. These are believed to be a defense mechanism, protecting bacteria from foreign DNA. They have been classified as selfish genetic elements; in some instances it has been shown that they are not easily lost from their host cell. Possibly because of this phenomenon, the H. pylori genome is very rich in R-M systems, with considerable variation in potential recognition sequences. For this reason the protective aspect of the methyltransferase gene has been proposed as a tool for typing H. pylori isolates. We studied the expression of H. pylori methyltransferases by digesting the genomic DNAs of 50 strains with 31 restriction endonucleases. We conclude that methyltransferase diversity is sufficiently high to enable the use of the genomic methylation status as a typing tool. The stability of methyltransferase expression was assessed by comparing the methylation status of genomic DNAs from strains that were isolated either from the same patient at different times or from different stomach locations (antrum and corpus). We found a group of five methyltransferases common to all tested strains. These five may be characteristic of the genetic pool analyzed, and their biological role may be important in the host/bacterium interaction.

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Reciprocal differences in female recombination associated with hybrid dysgenesis in Drosophila Melanogaster

Genetics Research ◽

10.1017/s001667230001747x ◽

1977 ◽

Vol 30 (1) ◽

pp. 77-88 ◽

Cited By ~ 30

Author(s):

Margaret Gale Kidwell

Keyword(s):

Close Association ◽

Hybrid Dysgenesis ◽

F1 Hybrids ◽

Crossing Over ◽

Clear Trend ◽

Female Progeny ◽

Male Recombination ◽

Reciprocal Differences ◽

Component Traits ◽

Chromosome Iii

SUMMARYLarge reciprocal differences in recombination frequencies were observed in F1 female progeny of a number of strain crosses. These reciprocal effects on recombination were found in several intervals of all three major chromosomes; they were greatest in intervals proximal to or spanning the centromere but were also found in some distal regions. The direction of recombination change was not consistent over different chromosomal intervals. There was no clear trend for reciprocal recombination differences to be associated with change of interference values between adjacent intervals. A close association was found between reciprocal female recombination effects, male recombination and other component traits of hybrid dysgenesis. However, reciprocal differences in female recombination were not restricted to dysgenic crosses. Backcross experiments demonstrated that reciprocal differences in the centromeric region of chromosome III were the result of increased crossing-over in dysgenic F1 hybrids rather than decreased crossing-over in the reciprocal hybrids. It is concluded that genotype-cytoplasm interaction can be a major factor influencing recombination frequencies and that the use of interstrain hybrids for recombination measurement may lead to errors in the estimation of intrastrain frequencies.

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