Keywords: b-chromosome

Non-Mendelian transmission of accessory chromosomes in fungi

J. Komluski, E. H. Stukenbrock and M. Habig,  Chromosome Research,  2022.
Non-Mendelian transmission has been reported for various genetic elements, ranging from small transposons to entire chromosomes. One prime example of such a transmission pattern are B chromosomes in plants and animals. Accessory chromosomes in fungi are similar to B chromosomes ...
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Rye B chromosomes differently influence the expression of A chromosome-encoded genes depending on the host species

A. Boudichevskaia, A. Fiebig, K. Kumke, A. Himmelbach and A. Houben,  Chromosome Research,  2022.
The B chromosome (B) is a dispensable component of the genome in many species. To evaluate the impact of Bs on the transcriptome of the standard A chromosomes (A), comparative RNA-seq analyses of rye and wheat anthers with and without additional rye Bs were conducted. In both ...
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Meiotic behavior, transmission and active genes of B chromosomes in the cichlid Astatotilapia latifasciata: new clues about nature, evolution and maintenance of accessory elements

A. L. Cardoso, N. B. Venturelli, I. da Cruz, F. M. de Sá Patroni, D. de Moraes, R. A. de Oliveira, R. Benavente and C. Martins,  Molecular Genetics and Genomics,  2022.
Supernumerary B chromosomes (Bs) are dispensable genetic elements widespread in eukaryotes and are poorly understood mainly in relation to mechanisms of maintenance and transmission. The cichlid Astatotilapia latifasciata can harbor Bs in a range of 0 (named B -) and 1-2 (named ...
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Non-Mendelian segregation and transmission drive of B chromosomes

J. P. M. Camacho,  Chromosome Research,  2022.
Selfish genetic elements (SGE) get a transmission advantage (drive) thanks to their non-Mendelian inheritance. Here I identify eight steps during the reproductive cycle that can be subverted by SGEs to thrive in natural populations. Even though only three steps occur during ...
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Mendelian nightmares: the germline-restricted chromosome of songbirds

P. Borodin, A. Chen, W. Forstmeier, S. Fouché, L. Malinovskaya, Y. Pei, R. Reifová, F. J. Ruiz-Ruano, S. A. Schlebusch, M. Sotelo-Muñoz, A. Torgasheva, N. Vontzou and A. Suh,  Chromosome Res,  2022.
Germline-restricted chromosomes (GRCs) are accessory chromosomes that occur only in germ cells. They are eliminated from somatic cells through programmed DNA elimination during embryo development. GRCs have been observed in several unrelated animal taxa and show peculiar modes of ...
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The non-Mendelian behavior of plant B chromosomes

J. Chen, J. A. Birchler and A. Houben,  Chromosome Res,  2022.
B chromosomes, also known as supernumerary chromosomes, are dispensable elements in the genome of many plants, animals, and fungi. Many B chromosomes have evolved one or more drive mechanisms to transmit themselves at a higher frequency than predicted by Mendelian genetics, and ...
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B-A Chromosome Translocations Possessing an A Centromere Partly Overcome the Root-Restricted Process of Chromosome Elimination in Aegilops speltoides

D. Li, A. Ruban, J. Fuchs, H. Kang and A. Houben,  Frontiers in Cell and Developmental Biology,  10. 2022.
Some eukaryotes exhibit dramatic genome size differences between cells of different organs, resulting from the programmed elimination of chromosomes. Aegilops speltoides is an annual diploid species from the Poaceae family, with a maximum number of eight B chromosomes (Bs) in ...
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Studying the active role of the maize B chromosome in the modulation of gene expression

University of Missouri,  Phys Org,  2022.
A team of University of Missouri biologists has made a new discovery that provides novel insights into the function and properties of the maize B chromosome. The study was led by Dr. Xiaowen Shi and Dr. Hua Yang, postdoctoral fellows in the Birchler lab, and reported in the ...
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Effect of aneuploidy of a nonessential chromosome on gene expression in maize

X. Shi, H. Yang, C. Chen, J. Hou, T. Ji, J. Cheng and J. A. Birchler,  Plant Journal,  2022.
The nonessential supernumerary maize B chromosome (B) has recently been shown to contain active genes and be capable of impacting gene expression of the A chromosomes. However, the effect of the B chromosome on gene expression is still unclear. In addition, it is unknown whether ...
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Evolution of B Chromosomes: From Dispensable Parasitic Chromosomes to Essential Genomic Players

M. Johnson Pokorná and R. Reifová,  Frontiers in Genetics,  12:727570. 2021.
B chromosomes represent additional chromosomes found in many eukaryotic organisms. Their origin is not completely understood but recent genomic studies suggest that they mostly arise through rearrangements and duplications from standard chromosomes. They can occur in single or ...
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The supernumerary B chromosome of maize: drive and genomic conflict

J. A. Birchler and H. Yang,  Open Biol,  11:210197. 2021.
The supernumerary B chromosome of maize is dispensable, containing no vital genes, and thus is variable in number and presence in lines of maize. In order to be maintained in populations, it has a drive mechanism consisting of nondisjunction at the pollen mitosis that produces ...
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Meiotic self-pairing of the Psalidodon (Characiformes, Characidae) iso-B chromosome: A successful perpetuation mechanism

D. Silva, C. Araya-Jaime, M. Yamashita, M. R. Vidal, C. Oliveira, F. Porto-Foresti, R. F. Artoni and F. Foresti,  Genetics and Molecular Biology,  44:e20210084. 2021.
B chromosomes are non-essential additional genomic elements present in several animal and plant species. In fishes, species of the genus Psalidodon (Characiformes, Characidae) harbor great karyotype diversity, and multiple populations carry different types of non-essential B ...
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A supernumerary “B-sex” chromosome drives male sex determination in the Pachón cavefish, Astyanax mexicanus

B. Imarazene, K. Du, S. Beille, E. Jouanno, R. Feron, Q. Pan, J. Torres-Paz, C. Lopez-Roques, A. Castinel, L. Gil, C. Kuchly, C. Donnadieu, H. Parrinello, L. Journot, C. Cabau, M. Zahm, C. Klopp, T. Pavlica, A. Al-Rikabi, T. Liehr, S. A. Simanovsky, J. Bo,  Current Biology,  2021.
Sex chromosomes are generally derived from a pair of classical type-A chromosomes, and relatively few alternative models have been proposed up to now.(1)(,)(2) B chromosomes (Bs) are supernumerary and dispensable chromosomes with non-Mendelian inheritance found in many plant and ...
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Selfish genetic elements and male fertility

R. L. Verspoor, T. A. R. Price and N. Wedell,  Philosophical Transactions of the Royal Society B-Biological Sciences,  375:7. 2020.
Selfish genetic elements (SGEs) are diverse and near ubiquitous in Eukaryotes and can be potent drivers of evolution. Here, we discuss SGEs that specifically act on sperm to gain a transmission advantage to the next generation. The diverse SGEs that affect sperm often impose ...
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