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Andrzej Joachimiak - One of the best experts on this subject based on the ideXlab platform.
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chromosome landmarks and autosome sex chromosome translocations in rumex hastatulus a plant with xx xy1y2 sex chromosome system
Chromosome Research, 2015Co-Authors: Aleksandra Grabowskajoachimiak, Adam Kula, Tomasz Ksiązczyk, Joanna Chojnicka, Elwira Sliwinska, Andrzej JoachimiakAbstract:Rumex hastatulus is the North American endemic dioecious plant with heteromorphic sex chro- mosomes. It is differentiated into two chromosomal races: Texas (T) race characterised by a simple XX/ XY sex chromosome system and North Carolina (NC) race with a polymorphic XX/XY1Y2 sex chromosome system. The gross karyotype morphology in NC race resembles the derived type, but chromosomal changes thatoccurredduringits evolutionarepoorlyunderstood. Our C-banding/DAPI and fluorescence in situ hybridization (FISH) experiments demonstrated that Y chromosomes of both races are enriched in DAPI- positive sequences and that the emergence of polymor- phic sex chromosome system was accompanied by the break of ancestral Y chromosome and switch in the localization of 5S rDNA, from Autosomes to sex chro- mosomes (X and Y2). Two contrasting domains were detected within North Carolina Y chromosomes: the older, highly heterochromatinised, inherited from the original Y chromosome and the younger, euchromatic, representing translocated autosomal material. The flow- cytometric DNA estimation showed ∼3.5 % genome downsizing in the North Carolina race. Our results are in contradiction to earlier reports on the lack of hetero- chromatin within Y chromosomes of this species and enable unambiguous identification of Autosomes involved in the autosome-heterosome translocation, providing useful chromosome landmarks for further studies on the karyotype and sex chromosome differen- tiation in this species.
Aleksandra Grabowskajoachimiak - One of the best experts on this subject based on the ideXlab platform.
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chromosome landmarks and autosome sex chromosome translocations in rumex hastatulus a plant with xx xy1y2 sex chromosome system
Chromosome Research, 2015Co-Authors: Aleksandra Grabowskajoachimiak, Adam Kula, Tomasz Ksiązczyk, Joanna Chojnicka, Elwira Sliwinska, Andrzej JoachimiakAbstract:Rumex hastatulus is the North American endemic dioecious plant with heteromorphic sex chro- mosomes. It is differentiated into two chromosomal races: Texas (T) race characterised by a simple XX/ XY sex chromosome system and North Carolina (NC) race with a polymorphic XX/XY1Y2 sex chromosome system. The gross karyotype morphology in NC race resembles the derived type, but chromosomal changes thatoccurredduringits evolutionarepoorlyunderstood. Our C-banding/DAPI and fluorescence in situ hybridization (FISH) experiments demonstrated that Y chromosomes of both races are enriched in DAPI- positive sequences and that the emergence of polymor- phic sex chromosome system was accompanied by the break of ancestral Y chromosome and switch in the localization of 5S rDNA, from Autosomes to sex chro- mosomes (X and Y2). Two contrasting domains were detected within North Carolina Y chromosomes: the older, highly heterochromatinised, inherited from the original Y chromosome and the younger, euchromatic, representing translocated autosomal material. The flow- cytometric DNA estimation showed ∼3.5 % genome downsizing in the North Carolina race. Our results are in contradiction to earlier reports on the lack of hetero- chromatin within Y chromosomes of this species and enable unambiguous identification of Autosomes involved in the autosome-heterosome translocation, providing useful chromosome landmarks for further studies on the karyotype and sex chromosome differen- tiation in this species.
Jennifer A Marshallgraves - One of the best experts on this subject based on the ideXlab platform.
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comparative chromosome painting between two marsupials origins of an xx xy1y2 sex chromosome system
Mammalian Genome, 1997Co-Authors: Roland Toder, Rachel J Oneill, J Wienberg, Patricia C M Obrien, Lucille Voullaire, Jennifer A MarshallgravesAbstract:Cross-species chromosome painting was used to investigate genome rearrangements between tammar wallaby Macropus eugenii (2n = 16) and the swamp wallaby Wallabia bicolor (2n = 10♀/11♂), which diverged about 6 million years ago. The swamp wallaby has an XX female:XY1Y2 male sex chromosome system thought to have resulted from a fusion between an autosome and the small original X, not involving the Y. Thus, the small Y1 should represent the original Y and the large Y2 the original autosome. DNA paints were prepared from flow-sorted and micro-dissected chromosomes from the tammar wallaby. Painting swamp wallaby spreads with each tammar chromosome-specific probe gave extremely strong and clear signals in single-, two-, and three-color FISH. These showed that two tammar wallaby Autosomes are represented unchanged in the swamp wallaby, two are represented by different centric fusions, and one by a tandem fusion to make the very long arms of swamp wallaby Chromosome (Chr) 1. The large swamp wallaby X comprises the tammar X as its short arm, and a tandemly fused 7 and 2 as the long arm. The acrocentric swamp wallaby Y2 is a 2/7 fusion, homologous with the long arm of the X. The small swamp wallaby Y1 is confirmed as the original Y by its painting with the tammar Y. However, the presence of sequences shared between the microdissected tammar Xp and Y on the swamp wallaby Y2 implies that the formation of the compound sex chromosomes involved addition of autosome(s) to both the original X and Y. We propose that this involved fusion with an ancient pseudoautosomal region followed by fission proximal to this shared region.
Boris Vyskot - One of the best experts on this subject based on the ideXlab platform.
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Sex chromatin and nucleolar analyses inRumex acetosa L.
Protoplasma, 2001Co-Authors: Martina Lengerova, Boris VyskotAbstract:Rumex acetosa (sorrel) is a dioecious plant with a XX/XY_1Y_2 sex chromosome system. Both the Y chromosomes are nearly entirely heterochromatic and it has been hypothesised that they can persist as chromocenters in male interphase nuclei. Using specific antibodies against 5-methylcytosine and histone H4 acetylated at terminal lysine 5, global levels of DNA methylation and histone acetylation were studied on the sex chromosomes and Autosomes of both sexes. The heterochromatic Y chromosomes did not display a higher methylation level compared to the Autosomes. The only prominent hypermethylation signals were found at two nucleolar organising regions located on the autosome pair V, as confirmed by in situ hybridisation with 25S rDNA probe and staining. Immunoanalysis of DNA methylation on female and male interphase nuclei neither revealed any sex-specific differences. Two active (silverpositive) nucleoli and two likely inactive nucleolar organising regions (displaying prominent methylation signals) were found in both sexes. In a fraction of nuclei isolated from leaf cells, two peripheral bodies strongly positive for 4′,6-diamidino-2-phenylindole were observed only in males, never in females. These heterochromatin regions were depleted in histone H4 acetylation at terminal lysine 5 and corresponded, according to in situ hybridisation with a Y-chromosome-specific repetitive probe, to the two Y chromosomes. We conclude that the peripheral condensed bodies observed exclusively in male nuclei represent the constitutive heterochromatin of the Y chromosomes which is characterised by a substantial histone H4 underacetylation.
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localization of male specifically expressed mros genes of silene latifolia by pcr on flow sorted sex chromosomes and Autosomes
Genetics, 2001Co-Authors: Eduard Kejnovský, Jan Vrana, Sachihiro Matsunaga, Přemysl Soucek, Jiři Siroký, Jaroslav Doležel, Boris VyskotAbstract:The dioecious white campion Silene latifolia (syn. Melandrium album) has heteromorphic sex chromosomes, XX in females and XY in males, that are larger than the Autosomes and enable their separation by flow sorting. The group of MROS genes, the first male-specifically expressed genes in dioecious plants, was recently identified in S. latifolia. To localize the MROS genes, we used the flow-sorted X chromosomes and Autosomes as a template for PCR with internal primers. Our results indicate that the MROS3 gene is located in at least two copies tandemly arranged on the X chromosome with additional copy(ies) on the autosome(s), while MROS1, MROS2, and MROS4 are exclusively autosomal. The specificity of PCR products was checked by digestion with a restriction enzyme or reamplification using nested primers. Homology search of databases has shown the presence of five MROS3 homologues in A. thaliana, four of them arranged in two tandems, each consisting of two copies. We conclude that MROS3 is a low-copy gene family, connected with the proper pollen development, which is present not only in dioecious but also in other dicot plant species.
Adam Kula - One of the best experts on this subject based on the ideXlab platform.
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chromosome landmarks and autosome sex chromosome translocations in rumex hastatulus a plant with xx xy1y2 sex chromosome system
Chromosome Research, 2015Co-Authors: Aleksandra Grabowskajoachimiak, Adam Kula, Tomasz Ksiązczyk, Joanna Chojnicka, Elwira Sliwinska, Andrzej JoachimiakAbstract:Rumex hastatulus is the North American endemic dioecious plant with heteromorphic sex chro- mosomes. It is differentiated into two chromosomal races: Texas (T) race characterised by a simple XX/ XY sex chromosome system and North Carolina (NC) race with a polymorphic XX/XY1Y2 sex chromosome system. The gross karyotype morphology in NC race resembles the derived type, but chromosomal changes thatoccurredduringits evolutionarepoorlyunderstood. Our C-banding/DAPI and fluorescence in situ hybridization (FISH) experiments demonstrated that Y chromosomes of both races are enriched in DAPI- positive sequences and that the emergence of polymor- phic sex chromosome system was accompanied by the break of ancestral Y chromosome and switch in the localization of 5S rDNA, from Autosomes to sex chro- mosomes (X and Y2). Two contrasting domains were detected within North Carolina Y chromosomes: the older, highly heterochromatinised, inherited from the original Y chromosome and the younger, euchromatic, representing translocated autosomal material. The flow- cytometric DNA estimation showed ∼3.5 % genome downsizing in the North Carolina race. Our results are in contradiction to earlier reports on the lack of hetero- chromatin within Y chromosomes of this species and enable unambiguous identification of Autosomes involved in the autosome-heterosome translocation, providing useful chromosome landmarks for further studies on the karyotype and sex chromosome differen- tiation in this species.