The occurrence and role of DNA synthesis during meiosis in wheat and rye

Flavell, R. B.; Walker, G. W. R.

doi:10.1016/0014-4827(73)90547-8

Cited by 19 publications

(8 citation statements)

References 20 publications

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“…We might ask, in the case of wheat can one distinguish between S3 (S) PMCs with thymidine-labeled nuclei containing SCs and PMCs with SCs in zygotene? There are some pieces of evidence which enable us to distinguish between the two stages: 1) Flavell and Walker (1973) could find no evidence of appreciable and unique DNA synthesis in zygotene of wheat. In fact, Stern and Hotta (1973) noted that synthesis of Z-DNA in Lilium had not been established as a general phenomenon and, in doing so, cited the work of Flavell and Walker.…”

Section: Resultsmentioning

confidence: 99%

Observations on Synaptonemal Complexes in Premeiotic Interphase of Wheat

McQuade

Pickles

1980

American J of Botany

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Synaptonemal complexes (SCs) were found in stage 3, premeiotic (S phase) pollen mother cell (PMC) nuclei of wheat which were labeled with 3H‐thymidine. Three nucleoli are present in PMC nuclei at the beginning of stage 3, premeiotic interphase (S3). During S3, nucleoli move toward the nuclear envelope and fuse to form one nucleolus near the end of the stage. PMC nuclei labeled with 3H‐thymidine were serially sectioned to show that more than one nucleolus was present and that SCs were also present in these DNA synthetic nuclei. Entire S3 PMC nuclei were serially sectioned to show the presence of SCs and all three nucleoli. Entire leptotene nuclei were also serially sectioned and segments of SCs were found. It is concluded that the association of homologous chromosomes in S3 of wheat is an early step in SC formation which proceeds through leptotene and is completed in zygotene and pachytene. Thus there is evidence that the continuum of chromosome pairing in wheat starts much earlier than was once thought.

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Section: Resultsmentioning

confidence: 99%

Observations on Synaptonemal Complexes in Premeiotic Interphase of Wheat

McQuade

Pickles

1980

American J of Botany

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“…Ito, Hotta and Stern (1967) conclude that the early zygotene DNA synthesis is essential for, and Involved in, chromosome pairing. Flavell and Walker (1973) indicated that extensive synthesis of DNA occurred in pachytene-dlplotene in wheat and rye. These reports Imply that the active DNA synthesis may occur during pre-meiosis, or early-or mid-prophase, depending upon the individual species.…”

Section: Discussionmentioning

confidence: 99%

Microspore development in maize: the maturation of upper and lower flowers among an assortment of genotypes

Hsu

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2.3. Stage Duration in MSG 54 3. MATERIALS AND METHODS 72 3.1. Statistical Symbols and Definition 72 of Terms 3.2. The Tassel and Male Spikelet of Zea Mays 76 3.3. Classification of Each Stage of 76 Microsporogenesis (MSG) 3.4. Genotype Classification 81 3.5. Classification of Tassel Maturity and 84 Spikelet Position 3.6. Field Experiment Design 84 3.7. Sampling and Microsporocyte Techniques 85 3.8. Methods in Anthesls Investigation 86 3.9. Methods in Data Processing 88 3.10. Methods in Statistical Analysis 89 4. RESULTS 99 4.1. Microsporogenesis (MSG) 100 4.2. Relationship Between Upper (U) and 127 Lower (L) Flowers in the Development of Microspores ill Page 4.3. Influence of Genotype Groups, Genotypes, 143 Tassel Maturities and Spikelet Positions on the Relationship Between Upper and Lower Flowers in the Development of Microspores 4.4. Influence of Interaction Effects on the 172 Relationship Between Upper and Lower Flowers in the Development of Microspores 4.5. Anthesis

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“…Early work had established that limited unscheduled synthesis occurred in connection with specialised cell stages, e.g. during meiosis (37), and unscheduled DNA synthesis following exposure to DNA damaging agents is, of course, well known. While unscheduled DNA synthesis following UV exposure has been shown by density labelling to reflect repair replication, this should not be an automatic assumption in other circumstances where gene amplification or other limited synthesis unrelated to repair might be involved.…”

Section: Postscriptmentioning

confidence: 99%

DNA turnover and mutation in resting cells

Bridges

1997

BioEssays

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There is growing evidence that mutations can arise in non-dividing cells (both bacterial and mammalian) in the absence of chromosomal replication. The processes that are involved are still largely unknown but may include two separate mechanisms. In the first, DNA lesions resulting from the action of endogenous mutagens may give rise to RNA transcripts with miscoded bases. If these confer the ability to initiate DNA replication, the DNA lesions may have an opportunity to miscode during replication and thus could give rise to apparently 'adaptive' mutations. A second mechanism is suggested by recent work in starved bacteria, showing that there is much more turnover of chromosomal DNA than has been previously thought. This could permit polymerase errors to lead to mutations in non-dividing cells. Such cryptic DNA synthesis, which may essentially replace existing DNA rather than duplicating it, could, in principle, act as an additional source of variability on which selection may act, initially in the absence of cell division. In mammals such processes would undoubtedly have implications for germ cell mutagenesis and carcinogenesis.

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The occurrence and role of DNA synthesis during meiosis in wheat and rye

Cited by 19 publications

References 20 publications

Observations on Synaptonemal Complexes in Premeiotic Interphase of Wheat

Observations on Synaptonemal Complexes in Premeiotic Interphase of Wheat

Microspore development in maize: the maturation of upper and lower flowers among an assortment of genotypes

DNA turnover and mutation in resting cells

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