Evolution of the degenerated Y-chromosome of the swamp guppy, Micropoecilia picta
Please always quote using this URN: urn:nbn:de:bvb:20-opus-267242
- The conspicuous colour sexual dimorphism of guppies has made them paradigmatic study objects for sex-linked traits and sex chromosome evolution. Both the X- and Y-chromosomes of the common guppy (Poecilia reticulata) are genetically active and homomorphic, with a large homologous part and a small sex specific region. This feature is considered to emulate the initial stage of sex chromosome evolution. A similar situation has been documented in the related Endler’s and Oropuche guppies (P. wingei, P. obscura) indicating a common origin of the YThe conspicuous colour sexual dimorphism of guppies has made them paradigmatic study objects for sex-linked traits and sex chromosome evolution. Both the X- and Y-chromosomes of the common guppy (Poecilia reticulata) are genetically active and homomorphic, with a large homologous part and a small sex specific region. This feature is considered to emulate the initial stage of sex chromosome evolution. A similar situation has been documented in the related Endler’s and Oropuche guppies (P. wingei, P. obscura) indicating a common origin of the Y in this group. A recent molecular study in the swamp guppy (Micropoecilia. picta) reported a low SNP density on the Y, indicating Y-chromosome deterioration. We performed a series of cytological studies on M. picta to show that the Y-chromosome is quite small compared to the X and has accumulated a high content of heterochromatin. Furthermore, the Y-chromosome stands out in displaying CpG clusters around the centromeric region. These cytological findings evidently illustrate that the Y-chromosome in M. picta is indeed highly degenerated. Immunostaining for SYCP3 and MLH1 in pachytene meiocytes revealed that a substantial part of the Y remains associated with the X. A specific MLH1 hotspot site was persistently marked at the distal end of the associated XY structure. These results unveil a landmark of a recombining pseudoautosomal region on the otherwise strongly degenerated Y chromosome of M. picta. Hormone treatments of females revealed that, unexpectedly, no sexually antagonistic color gene is Y-linked in M. picta. All these differences to the Poecilia group of guppies indicate that the trajectories associated with the evolution of sex chromosomes are not in parallel.…
Author: | Indrajit Nanda, Susanne Schories, Ivan Simeonov, Mateus Contar Adolfi, Kang Du, Claus Steinlein, Manfred Alsheimer, Thomas Haaf, Manfred Schartl |
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URN: | urn:nbn:de:bvb:20-opus-267242 |
Document Type: | Journal article |
Faculties: | Medizinische Fakultät / Institut für Humangenetik |
Fakultät für Biologie / Theodor-Boveri-Institut für Biowissenschaften | |
Language: | English |
Parent Title (English): | Cells |
ISSN: | 2073-4409 |
Year of Completion: | 2022 |
Volume: | 11 |
Issue: | 7 |
Article Number: | 1118 |
Source: | Cells (2022) 11:7, 1118. https://doi.org/10.3390/cells11071118 |
DOI: | https://doi.org/10.3390/cells11071118 |
Dewey Decimal Classification: | 5 Naturwissenschaften und Mathematik / 57 Biowissenschaften; Biologie / 570 Biowissenschaften; Biologie |
Tag: | 5-methylcytosine; Y chromosome degeneration; heterochromatin; meiosis; recombination; sex chromosomes; sex linked pigmentation pattern; sexual antagonistic genes; synaptonemal complex; testosterone |
Release Date: | 2023/04/11 |
Date of first Publication: | 2022/03/25 |
Open-Access-Publikationsfonds / Förderzeitraum 2022 | |
Licence (German): | CC BY: Creative-Commons-Lizenz: Namensnennung 4.0 International |