DNA Replication in the Chromosomes of Eukaryotes

Callan, H. G.

doi:10.1101/sqb.1974.038.01.023

Cited by 147 publications

(99 citation statements)

References 24 publications

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“…These results contrast with earlier studies of S-phase length variation where only changes in origin spacing were observed (3,4,1) . Therefore, the length of the S phase can be changed in at least two different ways .…”

Section: Constancy Of the Fork Rate During S Phasecontrasting

confidence: 99%

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Replication fork rate and origin activation during the S phase of Saccharomyces cerevisiae.

Rivin¹,

Fangman²

1980

The Journal of Cell Biology

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When the growth rate of the yeast Saccharomyces cerevisiae is limited with various nitrogen sources, the duration of the S phase is proportional to cell cycle length over a fourfold range of growth rates (C . J . Rivin and W . L . Fangman, 1980, J. Cell Biol. 85:96-107) . Molecular parameters of the S phases of these cells were examined by DNA fiber autoradiography . Changes in replication fork rate account completely for the changes in S-phase duration . No changes in origin-to-origin distances were detected . In addition, it was found that while most adjacent replication origins are activated within a few minutes of each other, new activations occur throughout the S phase .Chromosome replication occurs during an interval which can change in length at different stages of development . This variation is especially dramatic from early to late embryogenesis in some organisms (19) . The duration of the S phase can be thought of as the product of three potentially ratelimiting parameters : the rate of DNA chain elongation (fork rate), the distance between replication origins, and the time in S when different origins become active .There have been two detailed studies of the basis of S-phase length variation . In the newt Triturus the S phase of spermatocytes is one hundred times as long as that of neurula cells, and four times as long as the S phase of somatic cells (3, 4) . Fork rate does not vary in the different cell types, and the changes in S-phase length could be accounted for by changes in inter-origin spacing . Even greater S-phase variation has been observed in Drosophila in which cultured cells have a 600-min S phase while the cleavage nuclei of early embryos complete replication in <3 .5 min (1) . Again, the replication fork rate does not vary, and the observed inter-origin distance was only fourfold shorter in the early embryos . The change in S-phase duration, therefore, may reflect a change in the temporal pattern of activation of origins (or clusters of origins) . The observations that the inactive mammalian X chromosome replicates later than the active one and that the times of replication of some mammalian chromosomes exhibit tissue specificity (6, 25) also suggest that changes in the temporal pattern of origin activation can occur. In these cases, however, no change in the length of S phase has been noted .We have begun a study of the relationships of the molecular parameters of the S phase in the budding yeast Saccharomyces cerevisiae . As in other eukaryotes, DNA synthesis in yeast proceeds bidirectionally from multiple replication origins (20,21) . Estimates of the replication fork rate (21, 15) are similar to those for mammalian cells . In addition, there is evidence that the replication of specific genes and, therefore, the activation of origins occurs at specific times in the S phase (2, 17) . However, it is not known whether replication origins are activated throughout the S phase of yeast as they are in the cells of higher eukaryotes J . CELL BIOLOGY

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Section: Constancy Of the Fork Rate During S Phasecontrasting

confidence: 99%

“…In the newt Triturus the S phase of spermatocytes is one hundred times as long as that of neurula cells, and four times as long as the S phase of somatic cells (3,4) . Fork rate does not vary in the different cell types, and the changes in S-phase length could be accounted for by changes in inter-origin spacing .…”

mentioning

confidence: 99%

Replication fork rate and origin activation during the S phase of Saccharomyces cerevisiae.

Rivin¹,

Fangman²

1980

The Journal of Cell Biology

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“…Several studies suggest that replicon size is under functional control (Blumenthal et al, 1973;Callan, 1972;Van't Hof, 1976;Taylor, 1977). This is confirmed by a recent study, in which the observed increase of the size of DNA loops in the course of differentiation (Buongiorno-Nardelli et al, 1982), appears to support the concept of the switching off of certain classes of replication origins during differentiation.…”

Section: Discussionmentioning

confidence: 57%

Comparative analysis of DNA loop length in nontransformed and transformed hamster cells

Linskens

Eijsermans

Dijkwel

1987

Mutation Research/Fundamental and Molecular Mechanisms of Mutag

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“…Culture experiments of extruded microsporocytes have demonstrated that the cells become irreversibly committed t ~ meiosis during the premeiotic interphase (54,63). The premeiotic DNA replication has been reported to be longer than somatic DNA replication (55,64) a characteristic found in all organisms investigated (3,17,19,50) and in particular in the newt Triturus (11,12,13). The major phase of premeiotic DNA replication terminates at the onset of leptotene (29,32,71) but biochemical analyses have demonstrated that 0.3 % of the DNA in Lilium is delayed in replication until zygotene (29,32).…”

Section: Introductionmentioning

confidence: 94%

The premeiotic DNA replication of euchromatin and heterochromatin in Lilium longiflorum (Thunb.)

Holm

1977

Carlsberg Res. Commun.

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The presynaptic stages of Lilium longiflorum have been analyzed in the light microscope. Seven substages can be defined on the basis of changes in morphology of the heterochromatin and the nucleoli. The duration of the presynaptic interval and the substages has been calculated from bud length measurements and cell stage gradients in the anthers. The premeiotic and somatic DNA replication has been investigated using 3H-thymidine autoradiography. The premeiotic S phase lasts 50 hours whereas the somatic S phase in root tip nuclei is six times shorter. Moreover, premeiotic S phase nuclei house 2-3 times more heterochromatin than somatic nuclei. The premeiotic DNA replication can be divided into three periods: In early S phase the DNA of euchromatin is replicated; in mid S phase synthesis is arrested for a minimum of 9 hours; and in late S phase the DNA of heterochromatin is replicated. DNA synthesis in heterochromatin is correlated with a dispersal of these chromatin regions. Determinations of volume and staining characteristics of heterochromatin after the application of C and Q banding procedures indicate that the premeiotic heterochromatin comprises C bands, Q bands and interbands. The premeiotic DNA replication is discussed in relation to the observed chromatin dynamics, and a proposal is made for the significance of the replication sequence to the formation of the leptotene chromosome and the control of crossing-over.

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DNA Replication in the Chromosomes of Eukaryotes

Cited by 147 publications

References 24 publications

Replication fork rate and origin activation during the S phase of Saccharomyces cerevisiae.

Replication fork rate and origin activation during the S phase of Saccharomyces cerevisiae.

Comparative analysis of DNA loop length in nontransformed and transformed hamster cells

The premeiotic DNA replication of euchromatin and heterochromatin in Lilium longiflorum (Thunb.)

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