Recombination in single and double heterozygotes for two partially overlapping inversions in chromosome 1 of the house mouse

Gorlov, Ivan P.; Бородин, П. М.

doi:10.1038/hdy.1995.114

Cited by 8 publications

(4 citation statements)

References 25 publications

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“…Intriguingly, in carriers of a double inversion of chromosome 1 in mice, a reduction of chiasmata has been seen in single heterozygotes but an increase in the double heterozygotes, the latter associated with a reduced strength of interference [83]. In order to provide an adequate explanation in particular for the apparent decrease in strength of interference in the double hetrozygote it would be helpful to obtain additional information on the relation between synapsis [84] and crossovers by way of MLH1 analysis at the Pachytene stage (see section 2).…”

Section: Resultsmentioning

confidence: 99%

On the origin of crossover interference: A chromosome oscillatory movement (COM) model

Hultén

2011

Mol Cytogenet

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BackgroundIt is now nearly a century since it was first discovered that crossovers between homologous parental chromosomes, originating at the Prophase stage of Meiosis I, are not randomly placed. In fact, the number and distribution of crossovers are strictly regulated with crossovers/chiasmata formed in optimal positions along the length of individual chromosomes, facilitating regular chromosome segregation at the first meiotic division. In spite of much research addressing this question, the underlying mechanism(s) for the phenomenon called crossover/chiasma interference is/are still unknown; and this constitutes an outstanding biological enigma.ResultsThe Chromosome Oscillatory Movement (COM) model for crossover/chiasma interference implies that, during Prophase of Meiosis I, oscillatory movements of the telomeres (attached to the nuclear membrane) and the kinetochores (within the centromeres) create waves along the length of chromosome pairs (bivalents) so that crossing-over and chiasma formation is facilitated by the proximity of parental homologs induced at the nodal regions of the waves thus created. This model adequately explains the salient features of crossover/chiasma interference, where (1) there is normally at least one crossover/chiasma per bivalent, (2) the number is correlated to bivalent length, (3) the positions are dependent on the number per bivalent, (4) interference distances are on average longer over the centromere than along chromosome arms, and (5) there are significant changes in carriers of structural chromosome rearrangements.ConclusionsThe crossover/chiasma frequency distribution in humans and mice with normal karyotypes as well as in carriers of structural chromosome rearrangements are those expected on the COM model. Further studies are underway to analyze mechanical/mathematical aspects of this model for the origin of crossover/chiasma interference, using string replicas of the homologous chromosomes at the Prophase stage of Meiosis I. The parameters to vary in this type of experiment will include: (1) the mitotic karyotype, i.e. ranked length and centromere index of the chromosomes involved, (2) the specific bivalent/multivalent length and flexibility, dependent on the way this structure is positioned within the nucleus and the size of the respective meiocyte nuclei, (3) the frequency characteristics of the oscillatory movements at respectively the telomeres and the kinetochores.

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Section: Resultsmentioning

confidence: 99%

On the origin of crossover interference: A chromosome oscillatory movement (COM) model

Hultén

2011

Mol Cytogenet

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“…Most studies used murine models and produced quite heterogeneous results. Gorlov and Borodin (1995) [ 43 ], for instance, showed that a large inversion had no effect on the global recombination rate. In an earlier study, the same authors had observed a reduction of recombination due to a decrease in the number of chiasmata in the inverted region [ 44 ].…”

Section: Discussionmentioning

confidence: 99%

Meiotic Recombination Analyses in Pigs Carrying Different Balanced Structural Chromosomal Rearrangements

et al. 2016

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Correct pairing, synapsis and recombination between homologous chromosomes are essential for normal meiosis. All these events are strongly regulated, and our knowledge of the mechanisms involved in this regulation is increasing rapidly. Chromosomal rearrangements are known to disturb these processes. In the present paper, synapsis and recombination (number and distribution of MLH1 foci) were studied in three boars (Sus scrofa domestica) carrying different chromosomal rearrangements. One (T34he) was heterozygote for the t(3;4)(p1.3;q1.5) reciprocal translocation, one (T34ho) was homozygote for that translocation, while the third (T34Inv) was heterozygote for both the translocation and a pericentric inversion inv(4)(p1.4;q2.3). All three boars were normal for synapsis and sperm production. This particular situation allowed us to rigorously study the impact of rearrangements on recombination. Overall, the rearrangements induced only minor modifications of the number of MLH1 foci (per spermatocyte or per chromosome) and of the length of synaptonemal complexes for chromosomes 3 and 4. The distribution of MLH1 foci in T34he was comparable to that of the controls. Conversely, the distributions of MLH1 foci on chromosome 4 were strongly modified in boar T34Inv (lack of crossover in the heterosynaptic region of the quadrivalent, and crossover displaced to the chromosome extremities), and also in boar T34ho (two recombination peaks on the q-arms compared with one of higher magnitude in the controls). Analyses of boars T34he and T34Inv showed that the interference was propagated through the breakpoints. A different result was obtained for boar T34ho, in which the breakpoints (transition between SSC3 and SSC4 chromatin on the bivalents) seemed to alter the transmission of the interference signal. Our results suggest that the number of crossovers and crossover interference could be regulated by partially different mechanisms.

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“…Mouse embryonic fibroblast (MEF) cultures were prepared from 13-day-old embryos derived from DD/c mice (Kruglova et al 2008), designated as dMEF, and from 12-day-old embryos derived from C57BL-I(I)1Rk mice marked by an inversion in chromosome 1 described earlier (Gorlov and Borodin 1995), designated as iMEF. dMEF and iMEF cells were cultured in Dulbecco's modified Eagle's medium (DMEM; Sigma, Germany) containing 10% FBS (Hyclon, Germany) and 100 µg/ml penicillin and streptomycin.…”

Section: Methodsmentioning

confidence: 99%

Dominance of parental genomes in embryonic stem cell/fibroblast hybrid cells depends on the ploidy of the somatic partner

et al. 2010

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Two dozen hybrid clones were produced by fusion of diploid embryonic stem (ES) cells positive for green fluorescent protein (GFP) with tetraploid fibroblasts derived from DD/c and C57BL-I(I)1RK mice. Cytogenetic analysis demonstrated that most cells from these hybrid clones contained near-hexaploid chromosome sets. Additionally, the presence of chromosomes derived from both parental cells was confirmed by polymerase chain reaction (PCR) analysis of polymorphic microsatellites. All hybrid cells were positive for GFP and demonstrated growth characteristics and fibroblast-like morphology. In addition, most hybrid cells were positive for collagen type I, fibronectin, and lamin A/C but were negative for Oct4 and Nanog proteins. Methylation status of the Oct4 and Nanog gene promoters was evaluated by bisulfite genomic sequencing analysis. The methylation sites (CpG-sites) of the Oct4 and Nanog gene promoters were highly methylated in hybrid cells, whereas the CpG-sites were unmethylated in the parental ES cells. Thus, the fibroblast genome dominated the ES genome in the diploid ES cell/tetraploid fibroblast hybrid cells. Immunofluorescent analysis of the pluripotent and fibroblast markers demonstrated that establishment of the fibroblast phenotype occurred shortly after fusion and that the fibroblast phenotype was further maintained in the hybrid cells. Fusion of karyoplasts and cytoplast derived from tetraploid fibroblasts with whole ES cells demonstrated that karyoplasts were able to establish the fibroblast phenotype of the reconstructed cells but not fibroblast cytoplasts. Thus, these data suggest that the dominance of parental genomes in hybrid cells of ES cell/somatic cell type depends on the ploidy of the somatic partner.

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Recombination in single and double heterozygotes for two partially overlapping inversions in chromosome 1 of the house mouse

Cited by 8 publications

References 25 publications

On the origin of crossover interference: A chromosome oscillatory movement (COM) model

On the origin of crossover interference: A chromosome oscillatory movement (COM) model

Meiotic Recombination Analyses in Pigs Carrying Different Balanced Structural Chromosomal Rearrangements

Dominance of parental genomes in embryonic stem cell/fibroblast hybrid cells depends on the ploidy of the somatic partner

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