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Almeida-Toledo, Lurdes Foresti de; Daniel-Silva, M.F.Z.; Lopes, C. E. Ferreira; Toledo-Filho, Silvio de Almeida

doi:10.1023/a:1009287630301

Cited by 46 publications

(30 citation statements)

References 8 publications

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“…Our data are consistent with other studies in teleost fish, where species with X 1 X 2 Y systems often have one less chromosome than sister taxa [46],[47]. If the G. wheatlandi X 1 X 2 Y male karyotype had been created by fission of an ancestral X rather than a Y-autosome fusion, we should have observed the diploid chromosome number 2n = 43 in males, rather than the observed 2n = 41 (Figure 3A).…”

Section: Discussionsupporting

confidence: 92%

“…In particular, several teleost fish species have X 1 X 2 Y sex chromosome systems [46], [47], [52]–[57]. While a benefit of fusion of sex chromosomes to autosomes has been suggested [25], to our knowledge this is the first report of the evolution of an X 1 X 2 Y system in which the fused Y comprises two chromosomes that are used as distinct Y chromosomes in two closely related species.…”

Section: Discussionmentioning

confidence: 88%

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Turnover of Sex Chromosomes in the Stickleback Fishes (Gasterosteidae)

et al. 2009

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Diverse sex-chromosome systems are found in vertebrates, particularly in teleost fishes, where different systems can be found in closely related species. Several mechanisms have been proposed for the rapid turnover of sex chromosomes, including the transposition of an existing sex-determination gene, the appearance of a new sex-determination gene on an autosome, and fusions between sex chromosomes and autosomes. To better understand these evolutionary transitions, a detailed comparison of sex chromosomes between closely related species is essential. Here, we used genetic mapping and molecular cytogenetics to characterize the sex-chromosome systems of multiple stickleback species (Gasterosteidae). Previously, we demonstrated that male threespine stickleback fish (Gasterosteus aculeatus) have a heteromorphic XY pair corresponding to linkage group (LG) 19. In this study, we found that the ninespine stickleback (Pungitius pungitius) has a heteromorphic XY pair corresponding to LG12. In black-spotted stickleback (G. wheatlandi) males, one copy of LG12 has fused to the LG19-derived Y chromosome, giving rise to an X1X2Y sex-determination system. In contrast, neither LG12 nor LG19 is linked to sex in two other species: the brook stickleback (Culaea inconstans) and the fourspine stickleback (Apeltes quadracus). However, we confirmed the existence of a previously reported heteromorphic ZW sex-chromosome pair in the fourspine stickleback. The sex-chromosome diversity that we have uncovered in sticklebacks provides a rich comparative resource for understanding the mechanisms that underlie the rapid turnover of sex-chromosome systems.

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Section: Discussionsupporting

confidence: 92%

Section: Discussionmentioning

confidence: 88%

Turnover of Sex Chromosomes in the Stickleback Fishes (Gasterosteidae)

et al. 2009

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“…Multiple sex chromosomes in fishes usually arise from centric or tandem fusions between ancestral sex chromosomes [15,22], and repetitive DNA sequences have proven to be useful markers of these processes. This is the case for d(GAG) 10 repeats in the present study.…”

Section: Discussionmentioning

confidence: 99%

Chromosomal mapping of microsatellite repeats in the rock bream fish Oplegnathus fasciatus, with emphasis of their distribution in the neo-Y chromosome

Liu

Bertollo

et al. 2013

Mol Cytogenet

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Despite the theoretical and experimental progress, our understanding on sex chromosome differentiation is still diagrammatic. The accumulation of repetitive DNA sequences is believed to occur in early stages of such differentiation. As fish species present a wide range of sex chromosome systems they are excellent models to examine the differentiation of these chromosomes. In the present study, the chromosomal distribution of 9 mono-, di- and tri-nucleotide microsatellites were analyzed using fluorescence in situ hybrization (FISH) in rock bream fish (Oplegnathus fasciatus), which is characterized by an X1X2Y sex chromosome system. Generally, the males and females exhibited the same autosomal pattern of distribution for a specific microsatellite probe. The male specific Y chromosome displays a specific amount of distinct microsatellites repeats along both arms. However, the accumulation of these repetitive sequences was not accompanied by a huge heterochromatinization process. The present data provide new insights into the chromosomal constitution of the multiple sex chromosomes and allow further investigations on the true role of the microsatellite repeats in the differentiation process of this sex system.

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“…In Rhamphichthyoidea, the available chromosome information comes from only six species (Table 2): Hypopomus artedi Kaup, 1856 with diploid number (2n) = 38, Fundamental Number (FN) = 70 and Karyotypic Formula (KF) = 32m/sm+6st/a; Hypopygus lepturus Hoedman, 1962with 2n = 50, FN = 86 and KF = 36m/sm+10st+4a; Brachyhypopomus brevirostris Steindachner, 1868, with 2n = 36, FN = 42 and KF = 6m/sm+30st/a (Almeida-Toledo et al 2000); Brachyhypopomus pinnicaudatus Hopkins, 1991, with 2n = 41 in males and 42 in females (X 1 X 2 Y sex system) and FN = 42, with all acrocentric chromosomes except the Y (Almeida-Toledo 1978); Steatogenys elegans Steindachner, 1880, with 2n = 50 (ZZ/ZW sex system), FN = 62 and KF = 12m/sm+38st/a; Steatogenys duidae La Monte, 1929, with 2n = 50, FN = 100 and KF=50m/sm (Cardoso et al 2011); and Rhamphichthys hahni Meinken, 1937, with 2n = 50, FN = 94 and FK = 44m/sm+6st/a (Mendes et al 2012). …”

Section: Introductionmentioning

confidence: 99%

Karyotypic similarities between two species of Rhamphichthys (Rhamphichthyidae, Gymnotiformes) from the Amazon basin

Silva¹,

Nagamachi²,

Silva³

et al. 2013

CCG

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The family Rhamphichthyidae includes three genera: Rhamphichthys Müller et Troschel, 1846, Gymnorhamphichthys M. M. Ellis, 1912 and Iracema Triques, 1996. From this family, only the species Rhamphichthys hanni Meinken, 1937 has had its karyotype described. Here, we describe the karyotypes of two additional Rhamphichthys species: Rhamphichthys marmoratus Castelnau, 1855 from the Reserva de Desenvolvimento Sustentável Mamirauá, Amazonas state and Rhamphichthys prope rostratus Linnaeus, 1766 from Pará state, both in Brazil. Our karyotypic analyses demonstrated that the diploid number is conserved for the genus (2n = 50), but the karyotypic formulas (KFs) differed between Rhamphichthys marmoratus (44m/sm+6a) and Rhamphichthys prope rostratus (42m/sm+8a). In both species, the constitutive heterochromatin (CH) was located in the centromeric region of most chromosomes. Large heterochromatic blocks were found on the long arms of pairs 4 and 14 in Rhamphichthys marmoratus and on chromosomes 3, 4 and 19 in Rhamphichthys prope rostratus, which also has a heteromorphism in chromosome pair 1. The CH was DAPI positive, indicating that it is rich in AT base pairs. The Nucleolus Organizer Region (NOR) showed staining at a single location in both species: the long arm of pair 1 in Rhamphichthys marmoratus and the long arm of pair 12 in Rhamphichthys prope rostratus, where it showed a size heteromorphism. CMA3 staining coincided with that of Ag-NOR, indicating that the ribosomal genes contain interspaced GC-rich sequences. FISH with an 18S rDNA probe confirmed that there is only one NOR site in each species. These results can be used as potential cytogenetic markers for fish populations, and comparative analysis of the karyotypes of Hypopygus Hoedman, 1962, Rhamphichthys and Steatogenys Boulenger, 1898 suggests that the first two genera diverged later that the third.

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Cited by 46 publications

References 8 publications

Turnover of Sex Chromosomes in the Stickleback Fishes (Gasterosteidae)

Turnover of Sex Chromosomes in the Stickleback Fishes (Gasterosteidae)

Chromosomal mapping of microsatellite repeats in the rock bream fish Oplegnathus fasciatus, with emphasis of their distribution in the neo-Y chromosome

Karyotypic similarities between two species of Rhamphichthys (Rhamphichthyidae, Gymnotiformes) from the Amazon basin

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