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Out-of-position telomeres in meiotic leptotene appear responsible for chiasmate pairing in an inversion heterozygote in wheat (Triticum aestivum L.).
- Source :
-
Chromosoma [Chromosoma] 2019 Mar; Vol. 128 (1), pp. 31-39. Date of Electronic Publication: 2018 Nov 27. - Publication Year :
- 2019
-
Abstract
- Chromosome pairing in meiosis usually starts in the vicinity of the telomere attachment to the nuclear membrane and congregation of telomeres in the leptotene bouquet is believed responsible for bringing homologue pairs together. In a heterozygote for an inversion of a rye (Secale cereale L.) chromosome arm in wheat, a distal segment of the normal homologue is capable of chiasmate pairing with its counterpart in the inverted arm, located near the centromere. Using 3D imaging confocal microscopy, we observed that some telomeres failed to be incorporated into the bouquet and occupied various positions throughout the entire volume of the nucleus, including the centromere pole. Rye telomeres appeared ca. 21 times more likely to fail to be included in the telomere bouquet than wheat telomeres. The frequency of the out-of-bouquet rye telomere position in leptotene was virtually identical to the frequency of telomeres deviating from Rabl's orientation in the nuclei of somatic cells, and was similar to the frequency of synapsis of the normal and inverted chromosome arms, but lower than the MI pairing frequency of segments of these two arms normally positioned across the volume of the nucleus. Out-of-position placement of the rye telomeres may be responsible for reduced MI pairing of rye chromosomes in hybrids with wheat and their disproportionate contribution to aneuploidy, but appears responsible for initiating chiasmate pairing of distantly positioned segments of homology in an inversion heterozygote.
- Subjects :
- Cell Nucleus genetics
Cell Nucleus ultrastructure
Centromere chemistry
Centromere ultrastructure
Chimera genetics
Chromosome Pairing
Chromosomes, Plant chemistry
Heterozygote
Image Processing, Computer-Assisted statistics & numerical data
Imaging, Three-Dimensional methods
In Situ Hybridization, Fluorescence
Microscopy, Confocal
Plant Cells metabolism
Plant Cells ultrastructure
Secale ultrastructure
Species Specificity
Telomere chemistry
Triticum ultrastructure
Chromosome Inversion
Chromosomes, Plant ultrastructure
Meiotic Prophase I
Secale genetics
Telomere ultrastructure
Triticum genetics
Subjects
Details
- Language :
- English
- ISSN :
- 1432-0886
- Volume :
- 128
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Chromosoma
- Publication Type :
- Academic Journal
- Accession number :
- 30483879
- Full Text :
- https://doi.org/10.1007/s00412-018-0686-5