Increased genome size is caused by heterochromatin addition in two non-related bat species, Hesperoptenus doriae and Philetor brachypterus (Vespertilionidae, Chiroptera, Mammalia).

Autor: Volleth M; Department of Human Genetics, Otto-Von-Guericke University, Leipzigerstr. 44, 39120, Magdeburg, Germany. mvolleth19@gmail.com.; Triesdorf, Bahnhof 8, 91732, Merkendorf, Germany. mvolleth19@gmail.com., Greilhuber J; Department of Systematic and Evolutionary Botany, University of Vienna, Rennweg 14, 1030, Vienna, Austria., Heller KG; Triesdorf, Bahnhof 8, 91732, Merkendorf, Germany., Müller S; Institute of Human Genetics, Munich University Hospital, Ludwig-Maximilian University, Goethestr. 29, 80336, Munich, Germany., Yong HS; Institute of Biological Sciences, University of Malaya, 50603, Kuala Lumpur, Malaysia., Loidl J; Department of Chromosome Biology, Max Perutz Laboratories, University of Vienna, Dr.-Bohr-Gasse 9, 1030, Vienna, Austria.
Jazyk: angličtina
Zdroj: Chromosoma [Chromosoma] 2023 Nov; Vol. 132 (4), pp. 269-288. Date of Electronic Publication: 2023 Jun 16.
DOI: 10.1007/s00412-023-00802-w
Abstrakt: The average genome size (GS) of bats, which are the only mammals capable of powered flight, is approximately 18% smaller than that of closely related mammalian orders. The low nuclear DNA content of Chiroptera is comparable to that of birds, which are also characterized by a high metabolic rate. Only a few chiropteran taxa possess notable amounts of constitutive heterochromatin. Here, we studied the karyotypes of two non-related vesper bat species with unusually high amounts of constitutive heterochromatin: Hesperoptenus doriae and Philetor brachypterus. Conventional staining methods and whole-chromosome painting with probes derived from Myotis myotis (2n = 44), showing a karyotype close to that of the presumed ancestor of Vespertilionidae, revealed Robertsonian fusions as the main type of rearrangement leading to the exceptionally reduced diploid chromosome number of 2n = 26 in both species. Moreover, both karyotypes are characterized by large blocks of pericentromeric heterochromatin composed of CMA-positive and DA-DAPI-positive segments. In H. doriae, the heterochromatin accumulation has resulted in a genome size of 3.22 pg (1C), which is 40% greater than the mean genome size for the family. For P. brachypterus, a genome size of 2.94 pg was determined, representing an increase of about 28%. Most notably, in H. doriae, the presence of additional constitutive heterochromatin correlates with an extended mitotic cell cycle duration in vitro. A reduction in diploid chromosome number to 30 or lower is discussed as a possible cause of the accumulation of pericentromeric heterochromatin in Vespertilionidae.
(© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
Databáze: MEDLINE
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