Cytogenetics of bisexual/unisexual species of Poecilia. IV. Sex chromosomes, sex chromatin composition and Ag-NOR polymorphisms in Poecilia latipinna: a population from Mexico

Sola, Luciana; Bressanello, S.; Rasch, Ellen M.; Monaco, Paul J.

doi:10.1038/hdy.1993.9

Cited by 9 publications

(6 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous work on the sex chromosomes of these species showed evidence for male heterogametic systems in P. reticulata (40), P. wingei (41), P. picta (43) and G. holbrooki (44), and a female heterogametic system in P. latipinna (45, 46). For each target species, we built scaffold-level de novo genome assemblies using SOAPdenovo (47) (Table S2).…”

Section: Resultsmentioning

confidence: 95%

Extreme heterogeneity in sex chromosome differentiation and dosage compensation in livebearers

Darolti

Wright

Sandkam

et al. 2019

Preprint

158

View full text Add to dashboard Cite

Once recombination is halted between the X and Y chromosome, sex chromosomes begin to differentiate and transition to heteromorphism. While there is a remarkable variation across clades in the degree of sex chromosome divergence, far less is known about variation in sex chromosome differentiation within clades. Here, we combined whole genome and transcriptome sequencing data to characterise the structure and conservation of sex chromosome systems across Poeciliidae, the livebearing clade that includes guppies. We found that the Poecilia reticulata XY system is much older than previously thought, being shared not only with its sister species, Poecilia wingei, but also with Poecilia picta, which diverged 30 mya. Despite the shared ancestry, we uncovered an extreme heterogeneity across these species in the proportion of the sex chromosome with suppressed recombination, and the degree of Y chromosome decay. The sex chromosomes in P. reticulata are largely homomorphic, with recombination persisting over a substantial fraction. However, the sex chromosomes in P. picta are completely non-recombining and strikingly heteromorphic. ln addition to being highly divergent, the sex chromosome system in P. picta includes a neo-sex chromosome, the result of a fusion between the ancestral sex chromosome and part of chromosome 7. Remarkably, the profound degradation of the ancestral Y chromosome in P. picta is counterbalanced by the evolution of complete dosage compensation in this species, the first such documented case in teleost fish. Our results offer important insight into the initial stages of sex chromosome evolution and dosage compensation.

show abstract

Section: Resultsmentioning

confidence: 95%

Extreme heterogeneity in sex chromosome differentiation and dosage compensation in livebearers

Darolti

Wright

Sandkam

et al. 2019

Preprint

158

View full text Add to dashboard Cite

show abstract

“…The two patterns described for the NOR-bearing chromosome pair represent a very low level of variability, compared with the very high variability of NORs, both in number and position, described in many freshwater neotropical fish (see Cestari and Galetti 1992;Sola et al 1992bSola et al , 1993aGaletti et al 1995;Almeida-Toledo et al 1996;among others). The only species of the genus Rivulus investigated for NORs, Rivulus agilis (Zoch et al 1989), shows a higher number of NORs, four, located on the short arms of two pairs of subtelocentric chromosomes.…”

Section: Discussionmentioning

confidence: 93%

Cytogenetic analysis of a self-fertilizing fish, Rivulus marmoratus: remarkable chromosomal constancy over a vast geographic range

Sola¹,

Marzovillo²,

Rossi³

et al. 1997

Genome

View full text Add to dashboard Cite

The aplocheiloid killifish Rivulus marmoratus is the only known self-fertilizing hermaphroditic vertebrate. Most natural populations consist almost entirely of hermaphrodites and comprise arrays of homozygous clones. However, in almost all populations thus far studied, clonal variation, as detected with molecular techniques, is very high. A karyological survey was carried out on specimens from Brazil, the Bahamas, Belize, and Florida (4 locales) by C-banding, silver staining, and fluorescent staining. The chromosome complement of R. marmoratus is surprisingly uniform over its vast geographic range, in terms of both chromosome number and morphology, heterochromatin distribution and composition, and nucleolar organizer region (NOR) distribution. The short arms of chromosome pair 15, where NORs are located, showed the only variation detected in this study: those of pattern A were consistently shorter than those of pattern B; moreover, the latter show positive heteropycnosis with Giemsa staining. The present data demonstrate that chromosomal variation is not a significant part of the clonal divergence in this species, even though its breeding system, by forming homozygotes for new rearrangements almost immediately, should make that variation easier to detect. The high chromosomal homogeneity is discussed in the light of the peculiar natural history of the species.

show abstract

“…This diploid number has been found in around 51% of the species currently described and it is considered modal number for the order Cyprinodontiformes ( Scheel 1972 , Oliveira et al 1988 , García et al 2001 ). However, variations at the ploidia level have been reported, especially in the genus Poecilia ( Oliveira et al 1988 , Sola et al 1990 , Galetti Jr and Rasch 1993 , Arkhipchuk 1999 ). Phylogenetic and biogeographic studies of the poeciliid fishes ( Hrbek et al 2007 ) report Fluviphylax as basal group for Poeciliidae family, corroborating the modal diploid number found in this study.…”

Section: Discussionmentioning

confidence: 99%

“…Some species of Poeciliidae have visible sex chromosome, such as the ZW/ZZ sex determining system in Gambusia puncticulata ( Ráb 1984 ), Poecilia latipinna ( Sola et al 1990 ), Poecilia formosa ( Sola et al 1993 ) and Poecilia sphenops ( Haaf and Schmid 1984 ) and the XX/XY system in Poecilia reticulata ( Feichtinger 1988 ), or both systems in Xiphophorus maculatus ( Gordon 1950 ). However, the two species of Fluviphylax analyzed here did not exhibit differentiated sex chromosomes.…”

Section: Discussionmentioning

confidence: 99%

Comparative cytogenetics of two of the smallest Amazonian fishes: Fluviphylax simplex Costa, 1996 and Fluviphylax zonatus Costa, 1996 (Cyprinodontiformes, Poeciliidae)

Souza¹,

Ribeiro²,

Feldberg³

et al. 2011

CCG

View full text Add to dashboard Cite

The genus Fluviphylax Whitley, 1965is comprized of five valid species (Fluviphylax pygmaeus Myers et Carvalho, 1955, Fluviphylax zonatus, Fluviphylax simplex, Fluviphylax obscurus Costa, 1996,and Fluviphylax palikur Costa et Le Bail, 1999), which are endemic to the Amazon region. These fishes are the smallest known South American vertebrates and among the smallest know vertebrates on Earth. All species but the type Fluviphylax pygmaeus have been described in late 1990’s, and much remains unknown about the biology, taxonomy and systematics of this group of fishes. The aims of the present study were to establish the diploid and haploid number of Fluviphylax zonatus and Fluviphylax simplex, and to find species-specific markers for the discrimination of taxa. The diploid number for both species was 48 chromosomes, with no sex chromosome heteromorphism. Fluviphylax zonatus exhibited the karyotypic formula 4m+8sm+22st+14a and FN=82, and Fluviphylax simplex exhibited 4m+16sm+18st+10a and FN=86. The determination of the total mean length of the chromosomes and their grouping into five size classes demonstrated different chromosome composition of the two species. This difference was further supported by the distribution of constitutive heterochromatin. The meiotic analysis revealed 24 bivalents in both species, but Fluviphylax zonatus exhibited chromosomes with late pairing of the telomeric portions in the pachytene. These data reveal that cytogenetic characterization is useful and important for the discrimination of these species. Our study further indicates that this method could be employed in the analysis of other species of small fishes that are difficult to distinguish using traditional morphological traits or are morphologically cryptic.

show abstract

Cytogenetics of bisexual/unisexual species of Poecilia. IV. Sex chromosomes, sex chromatin composition and Ag-NOR polymorphisms in Poecilia latipinna: a population from Mexico

Cited by 9 publications

References 11 publications

Extreme heterogeneity in sex chromosome differentiation and dosage compensation in livebearers

Extreme heterogeneity in sex chromosome differentiation and dosage compensation in livebearers

Cytogenetic analysis of a self-fertilizing fish, Rivulus marmoratus: remarkable chromosomal constancy over a vast geographic range

Comparative cytogenetics of two of the smallest Amazonian fishes: Fluviphylax simplex Costa, 1996 and Fluviphylax zonatus Costa, 1996 (Cyprinodontiformes, Poeciliidae)

Contact Info

Product

Resources

About