Rare sex chromosome variation 48, XXYY : An integrative review

2020 ◽  
Vol 184 (2) ◽  
pp. 386-403
Author(s):  
Amy A. Blumling ◽  
Kristy Martyn ◽  
Amy Talboy ◽  
Sharron Close
Keyword(s):  
Sex Chromosome ◽  
Integrative Review ◽  
Chromosome Variation

scholarly journals Cytotaxonomic considerations on the sex chromosome variation observed within Acomys ngurui Verheyen et al. 2011 (Rodentia Muridae)

Zootaxa ◽  
2012 ◽  
Vol 3493 (1) ◽  
pp. 35 ◽  
Author(s):  
RICCARDO CASTIGLIA ◽  
FLAVIA ANNESI
Keyword(s):  
New Species ◽  
Dna Sequences ◽  
Sex Chromosome ◽  
East African ◽  
Chromosome Variation ◽  
Mtdna Sequence ◽  
Two New Species ◽  
Morphologic Analysis ◽  
The One ◽  
Future Work

The taxonomy of the East African Muridae belonging to the Acomys spinosissimus Peters 1852 species complex has been recently revised (Verheyen et al., 2011). Two new species have been described by means of external morphologic analysis, craniometry, enzymes, mitochondrial DNA sequences and karyological information. For one of the two new species, Acomys ngurui Verheyen et al. 2011, a polymorphic karyotype has been observed. In fact, for 19 of the 22 karyotyped individuals, the karyotype is identical to the one described for A. spinosissimus s. s. (2n = 60, aFN = 68), characterized by a sex chromosome constitution of the XX/XY type, with an acrocentric X and a submetacentric Y (Dippenaar and Rautenbach, 1986). The remaining three females possess a karyotype that resembles the one reported by Matthey (1965) and Barome et al. (2001) characterized by a unique giant metacentric X chromosome (Xg), and by a variable diploid number (2n = 59–62). These females were found in the three localities in Tanzania together with specimens with the typical ‘spinosissimus’ karyotype. Specimens carrying the Xg were not distinguishable on the basis of their mtDNA sequence or morphology from the other specimens with XY karyotype (Verheyen et al., 2011). The authors concluded that the available evidence did not allow one to give taxonomic value to this chromosomal configuration, characterized by a particular sex determination, hoping for future work that will study the animals bearing this typical karyotype in more detail.

Sex chromosome evolution and population differentiation in the Eusimulium aureum group of black flies

Genome ◽  
1989 ◽  
Vol 32 (4) ◽  
pp. 543-549 ◽  
Author(s):  
K. G. Leonhardt ◽  
R. M. Feraday
Keyword(s):  
Sex Chromosomes ◽  
Population Differentiation ◽  
Chromosome Evolution ◽  
Sex Chromosome ◽  
Species Group ◽  
Exceptional Case ◽  
Black Flies ◽  
Sex Chromosome Evolution ◽  
Chromosome Variation ◽  
Adaptive Process

The pattern of sex-chromosome variation within and between species of the Eusimulium aureum species group of black flies is examined and used to support the argument that speciation in black flies is often an adaptive process. A pair of homosequential species in this group is presented as an exceptional case in black flies that does not argue against the chromosomally mediated speciation model.Key words: black flies, sex chromosomes, evolution.

scholarly journals Diversity of reptile sex chromosome evolution revealed by cytogenetic and linked-read sequencing

2021 ◽  
Author(s):  
Zexian Zhu ◽  
Kazumi Matsubara ◽  
Foyez Shams ◽  
Jason Dobry ◽  
Erik Wapstra ◽  
...  
Keyword(s):  
Sex Determination ◽  
Dosage Compensation ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Cost Effective ◽  
Chromosome Variation ◽  
Specific Expression ◽  
Monitor Lizard ◽  
Compensation Mechanisms ◽  
Cryptic Sex

Reptile sex determination is attracting much attention because the great diversity of sex-determination and dosage compensation mechanisms permits us to approach fundamental questions about sex chromosome turnover and evolution. However, reptile sex chromosome variation remains largely uncharacterized and no reptile master sex determination genes have yet been identified. Here we describe a powerful and cost-effective chromosomics approach, combining probes generated from the microdissected sex chromosomes with transcriptome sequencing to explore this diversity in non-model Australian reptiles with heteromorphic or cryptic sex chromosomes. We tested the pipeline on a turtle, a gecko, and a worm-lizard, and we also identified sequences located on sex chromosomes in a monitor lizard using linked-read sequencing. Genes identified on sex chromosomes were compared to the chicken genome to identify homologous regions among the four species. We identified candidate sex determining genes within these regions, including conserved vertebrate sex-determining genes pdgfa, pdgfra amh and wt1, and demonstrated their testis or ovary-specific expression. All four species showed gene-by-gene rather than chromosome-wide dosage compensation. Our results imply that reptile sex chromosomes originated by the independent acquisition of sex-determining genes on different autosomes, as well as translocations between different ancestral macro- and micro-chromosomes. We discuss the evolutionary drivers of the slow differentiation, but rapid turnover, of reptile sex chromosomes.

Chromosome Variation in the Males of Some Australian Lygaeidae (Hemiptera: Heteroptera).

1979 ◽  
Vol 27 (5) ◽  
pp. 709 ◽  
Author(s):  
MB Malipatil
Keyword(s):  
Chromosome Number ◽  
Chromosome Pair ◽  
Sex Chromosome ◽  
Supporting Evidence ◽  
Chromosome Variation

Twenty-one species of Australian lygaeids belonging to six subfamilies have been examined cytologically. The two species of Lygaeinae both have 2n B = 14 including an XY sex chromosome pair. While all the remaining species were also XY in the male, diploid numbers of 12, 14, 16, 20 and 22 were found. which included a minute m-chromosome pair which is not represented in the Lygaeinae. The observed variation in chromosome number and size provides supporting evidence for the occurrence of both fusion and fission within the Heteroptera.

Sex chromosome variation and cytotaxonomy of the onchocerciasis vector Simulium squamosum in Cameroon and Nigeria

2001 ◽  
Vol 15 (2) ◽  
pp. 219-223 ◽  
Author(s):  
M. Traore-Lamizana ◽  
S. Somiari ◽  
H. B. Mafuyai ◽  
C. G. Vajime ◽  
R. J. Post
Keyword(s):  
Sex Chromosome ◽  
Chromosome Variation
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