scholarly journals Amplified Fragments of an Autosome-Borne Gene Constitute a Significant Component of the W Sex Chromosome of Eremias velox (Reptilia, Lacertidae)

Genes ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 779
Author(s):  
Artem Lisachov ◽  
Daria Andreyushkova ◽  
Guzel Davletshina ◽  
Dmitry Prokopov ◽  
Svetlana Romanenko ◽  
...  
Keyword(s):  
Sex Chromosome ◽  
De Novo ◽  
Unknown Origin ◽  
Protein Product ◽  
W Chromosome ◽  
Protein Coding ◽  
X Chromosomes ◽  
Y Chromosomes ◽  
Total Female ◽  
Evolutionary Trajectories

Heteromorphic W and Y sex chromosomes often experience gene loss and heterochromatinization, which is frequently viewed as their “degeneration”. However, the evolutionary trajectories of the heterochromosomes are in fact more complex since they may not only lose but also acquire new sequences. Previously, we found that the heterochromatic W chromosome of a lizard Eremias velox (Lacertidae) is decondensed and thus transcriptionally active during the lampbrush stage. To determine possible sources of this transcription, we sequenced DNA from a microdissected W chromosome sample and a total female DNA sample and analyzed the results of reference-based and de novo assembly. We found a new repetitive sequence, consisting of fragments of an autosomal protein-coding gene ATF7IP2, several SINE elements, and sequences of unknown origin. This repetitive element is distributed across the whole length of the W chromosome, except the centromeric region. Since it retained only 3 out of 10 original ATF7IP2 exons, it remains unclear whether it is able to produce a protein product. Subsequent studies are required to test the presence of this element in other species of Lacertidae and possible functionality. Our results provide further evidence for the view of W and Y chromosomes as not just “degraded” copies of Z and X chromosomes but independent genomic segments in which novel genetic elements may arise.

scholarly journals Red queen's race: rapid evolutionary dynamics of an expanding family of meiotic drive factors and their hpRNA suppressors

2021 ◽  
Author(s):  
Jeffrey Vedanayagam ◽  
Ching-Jung Lin ◽  
Eric C. Lai
Keyword(s):  
Evolutionary Dynamics ◽  
Sex Chromosome ◽  
De Novo ◽  
Independent Set ◽  
Meiotic Drive ◽  
Sperm Chromatin ◽  
Arms Races ◽  
X Chromosomes ◽  
Selfish Genetic Elements ◽  
Satellite Repeats

Meiotic drivers are a class of selfish genetic elements that are widespread across eukaryotes. Their activities are often detrimental to organismal fitness and thus trigger drive suppression to ensure fair segregation during meiosis. Accordingly, their existence is frequently hidden in genomes, and their molecular functions are little known. Here, we trace evolutionary steps that generated the Dox meiotic drive system in Drosophila simulans (Dsim), which distorts male:female balance (sex-ratio) by depleting male progeny. We show that Dox emerged via stepwise mobilization and acquisition of portions of multiple D. melanogaster genes, including the sperm chromatin packaging gene protamine. Moreover, we reveal novel Dox homologs in Dsim and massive, recent, amplification of Dox superfamily genes specifically on X chromosomes of its closest sister species D. mauritiana (Dmau) and D. sechellia (Dsech). The emergence of Dox superfamily genes is tightly associated with 1.688 family satellite repeats that flank de novo genomic copies. In concert, we find coordinated emergence and diversification of autosomal hairpin RNA/siRNAs loci that target subsets of Dox superfamily genes across simulans clade species. Finally, an independent set of protamine amplifications the Y chromosome of D. melanogaster indicates that protamine genes are frequent and recurrent players in sex chromosome dynamics. Overall, we reveal fierce genetic arms races between meiotic drive factors and siRNA suppressors associated with recent speciation.

scholarly journals Rapid Y degeneration and dosage compensation in plant sex chromosomes

2015 ◽  
Vol 112 (42) ◽  
pp. 13021-13026 ◽  
Author(s):  
Alexander S. T. Papadopulos ◽  
Michael Chester ◽  
Kate Ridout ◽  
Dmitry A. Filatov
Keyword(s):  
Sex Chromosomes ◽  
Large Scale ◽  
De Novo ◽  
Silene Latifolia ◽  
Stop Codons ◽  
Y Chromosomes ◽  
Evolutionary Trajectories ◽  
Plant Sex Chromosomes ◽  
Two Kingdoms ◽  
Y Degeneration

The nonrecombining regions of animal Y chromosomes are known to undergo genetic degeneration, but previous work has failed to reveal large-scale gene degeneration on plant Y chromosomes. Here, we uncover rapid and extensive degeneration of Y-linked genes in a plant species, Silene latifolia, that evolved sex chromosomes de novo in the last 10 million years. Previous transcriptome-based studies of this species missed unexpressed, degenerate Y-linked genes. To identify sex-linked genes, regardless of their expression, we sequenced male and female genomes of S. latifolia and integrated the genomic contigs with a high-density genetic map. This revealed that 45% of Y-linked genes are not expressed, and 23% are interrupted by premature stop codons. This contrasts with X-linked genes, in which only 1.3% of genes contained stop codons and 4.3% of genes were not expressed in males. Loss of functional Y-linked genes is partly compensated for by gene-specific up-regulation of X-linked genes. Our results demonstrate that the rate of genetic degeneration of Y-linked genes in S. latifolia is as fast as in animals, and that the evolutionary trajectories of sex chromosomes are similar in the two kingdoms.

Sex Chromosome Translocations

2018 ◽  
Author(s):  
R. J McKinlay Gardner ◽  
David J Amor
Keyword(s):  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Transcriptional Silencing ◽  
The Other ◽  
X Chromosomes ◽  
Chromosome Form ◽  
Chromosome Translocations ◽  
Y Chromosomes ◽  
Autosomal Translocation

The sex chromosomes (gonosomes) are different, and sex chromosome translocations need to be considered separately from translocations between autosomes. A sex chromosome can engage in translocation with an autosome, with the other sex chromosome, or even with its homolog. The qualities of the sex chromosomes have unique implications in terms of the genetic functioning of gonosome-autosome translocations. This chapter acknowledges the specific peculiarities that the sex chromosomes imply: the X being subject to transcriptional silencing; and the very small Y gene complement being confined largely to sex-determining loci. It reviews translocations between sex chromosomes and autosomes; between X and Y chromosomes; and even the very rare circumstance of between X chromosomes and between Y chromosomes. The differences in assessing risk, according to chromosome form, in comparison with the autosomal translocation, are reviewed, and the biology behind these differences is discussed.

scholarly journals Complex Structure of Lasiopodomys mandarinus vinogradovi Sex Chromosomes, Sex Determination, and Intraspecific Autosomal Polymorphism

Genes ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 374 ◽  
Author(s):  
Svetlana A. Romanenko ◽  
Antonina V. Smorkatcheva ◽  
Yulia M. Kovalskaya ◽  
Dmitry Yu. Prokopov ◽  
Natalya A. Lemskaya ◽  
...  
Keyword(s):  
Sex Determination ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
De Novo ◽  
Complex Structure ◽  
X Chromosomes ◽  
Single Chromosome ◽  
Determination System ◽  
Sex Determination System ◽  
Mandarin Vole

The mandarin vole, Lasiopodomys mandarinus, is one of the most intriguing species among mammals with non-XX/XY sex chromosome system. It combines polymorphism in diploid chromosome numbers, variation in the morphology of autosomes, heteromorphism of X chromosomes, and several sex chromosome systems the origin of which remains unexplained. Here we elucidate the sex determination system in Lasiopodomys mandarinus vinogradovi using extensive karyotyping, crossbreeding experiments, molecular cytogenetic methods, and single chromosome DNA sequencing. Among 205 karyotyped voles, one male and three female combinations of sex chromosomes were revealed. The chromosome segregation pattern and karyomorph-related reproductive performances suggested an aberrant sex determination with almost half of the females carrying neo-X/neo-Y combination. The comparative chromosome painting strongly supported this proposition and revealed the mandarin vole sex chromosome systems originated due to at least two de novo autosomal translocations onto the ancestral X chromosome. The polymorphism in autosome 2 was not related to sex chromosome variability and was proved to result from pericentric inversions. Sequencing of microdissection derived of sex chromosomes allowed the determination of the coordinates for syntenic regions but did not reveal any Y-specific sequences. Several possible sex determination mechanisms as well as interpopulation karyological differences are discussed.

C-banded karyotypes of two Silene species with heteromorphic sex chromosomes

Genome ◽  
2002 ◽  
Vol 45 (2) ◽  
pp. 243-252 ◽  
Author(s):  
Aleksandra Grabowska-Joachimiak ◽  
Andrzej Joachimiak
Keyword(s):  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Silene Latifolia ◽  
Silene Dioica ◽  
Dna Amount ◽  
Metaphase Chromosomes ◽  
X Chromosomes ◽  
C Banding ◽  
Y Chromosomes ◽  
Heteromorphic Sex Chromosomes

Mitotic metaphase chromosomes of Silene latifolia (white campion) and Silene dioica (red campion) were studied and no substantial differences between the conventional karyotypes of these two species were detected. The classification of chromosomes into three distinct groups proposed for S. latifolia by Ciupercescu and colleagues was considered and discussed. Additionally, a new small satellite on the shorter arm of homobrachial chromosome 5 was found. Giemsa C-banded chromosomes of the two analysed species show many fixed and polymorphic heterochromatic bands, mainly distally and centromerically located. Our C-banding studies provided an opportunity to better characterize the sex chromosomes and some autosome types, and to detect differences between the two Silene karyotypes. It was shown that S. latifolia possesses a larger amount of polymorphic heterochromatin, especially of the centromeric type. The two Silene sex chromosomes are easily distinguishable not only by length or DNA amount differences but also by their Giemsa C-banding patterns. All Y chromosomes invariably show only one distally located band, and no other fixed or polymorphic bands on this chromosome were observed in either species. The X chromosomes possess two terminally located fixed bands, and some S. latifolia X chromosomes also have an extra-centric segment of variable length. The heterochromatin amount and distribution revealed by our Giemsa C-banding studies provide a clue to the problem of sex chromosome and karyotype evolution in these two closely related dioecious Silene species.Key words: dioecious plant, Silene dioica, Silene latifolia, karyotype, sex chromosomes, heterochromatin, C-banding.

Mixed-Up Sex Chromosomes: Identification of Sex Chromosomes in the X1X1X2X2/X1X2Y System of the Legless Lizards of the Genus Lialis (Squamata: Gekkota: Pygopodidae)

2016 ◽  
Vol 149 (4) ◽  
pp. 282-289 ◽  
Author(s):  
Michail Rovatsos ◽  
Martina Johnson Pokorná ◽  
Marie Altmanová ◽  
Lukáš Kratochvíl
Keyword(s):  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Comparative Genomic ◽  
X Chromosomes ◽  
Telomeric Sequences ◽  
Multiple Sex Chromosomes ◽  
Y Chromosomes ◽  
Heteromorphic Sex Chromosomes ◽  
Cytogenetic Analyses ◽  
Male Heterogamety

Geckos in general show extensive variability in sex determining systems, but only male heterogamety has been demonstrated in the members of their legless family Pygopodidae. In the pioneering study published more than 45 years ago, multiple sex chromosomes of the type X1X1X2X2/X1X2Y were described in Burton's legless lizard (Lialisburtonis) based on conventional cytogenetic techniques. We conducted cytogenetic analyses including comparative genomic hybridization and fluorescence in situ hybridization (FISH) with selected cytogenetic markers in this species and the previously cytogenetically unstudied Papua snake lizard (Lialis jicari) to better understand the nature of these sex chromosomes and their differentiation. Both species possess male heterogamety with an X1X1X2X2/X1X2Y sex chromosome system; however, the Y and one of the X chromosomes are not small chromosomes as previously reported in L. burtonis, but the largest macrochromosomal pair in the karyotype. The Y chromosomes in both species have large heterochromatic blocks with extensive accumulations of GATA and AC microsatellite motifs. FISH with telomeric probe revealed an exclusively terminal position of telomeric sequences in L. jicari (2n = 42 chromosomes in females), but extensive interstitial signals, potentially remnants of chromosomal fusions, in L.burtonis (2n = 34 in females). Our study shows that even largely differentiated and heteromorphic sex chromosomes might be misidentified by conventional cytogenetic analyses and that the application of more sensitive cytogenetic techniques for the identification of sex chromosomes is beneficial even in the classical examples of multiple sex chromosomes.

Karyotypes, constitutive heterochromatin, and genomic DNA values in the blowfly genera Chrysomya, Lucilia, and Protophormia (Diptera: Calliphoridae)

Genome ◽  
2006 ◽  
Vol 49 (6) ◽  
pp. 584-597 ◽  
Author(s):  
Fritz-Helmut Ullerich ◽  
Michael Schöttke
Keyword(s):  
Dna Content ◽  
Sex Chromosome ◽  
Repetitive Sequences ◽  
Centromeric Heterochromatin ◽  
Large Chromosome ◽  
X Chromosomes ◽  
C Banding ◽  
Y Chromosomes ◽  
Dna Contents ◽  
Size And Morphology

The karyotypes and C-banding patterns of Chrysomya species C. marginalis, C. phaonis, C. pinguis, C. saffranea, C. megacephala (New Guinean strain), Lucilia sericata, and Protophormia terraenovae are described. All species are amphogenic and have similar chromosome complements (2n = 12), including an XY–XX sex-chromosome pair varying in size and morphology between species. Additionally, the C-banding pattern of the monogenic species Chrysomya albiceps is presented. The DNA contents of these and of further species Chrysomya rufifacies, Chrysomya varipes, and Chrysomya putoria were assessed on mitotic metaphases by Feulgen cytophotometry. The average 2C DNA value of the male genomes ranged from 1.04 pg in C. varipes to 2.31 pg in C. pinguis. The DNA content of metaphase X chromosomes varied from 0.013 pg (= 1.23% of the total genome) in C. varipes to 0.277 pg (12.20%) in L. sericata; that of Y chromosomes ranged from 0.003 pg (0.27%) in C. varipes to 0.104 pg (5.59%) in L. sericata. In most species, the corresponding 5 large chromosome pairs showed similar relative DNA contents. The data suggest that the interspecific DNA differences in most species are mainly due to quantitative variation of (repetitive) sequences lying outside the centromeric heterochromatin blocks of the large chromosomes. The results are also discussed with regard to phylogenetic relationships of some species.Key words: DNA content, C value, C banding, sex determination, genome evolution.

Analysis of SINE and LINE repeat content of Y chromosomes in the platypus, Ornithorhynchus anatinus

2009 ◽  
Vol 21 (8) ◽  
pp. 964 ◽  
Author(s):  
R. Daniel Kortschak ◽  
Enkhjargal Tsend-Ayush ◽  
Frank Grützner
Keyword(s):  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Activity Patterns ◽  
Specific Sequence ◽  
X Chromosomes ◽  
Repeat Content ◽  
Y Chromosomes ◽  
Ornithorhynchus Anatinus ◽  
History Of ◽  
Sex Chromosome System

Monotremes feature an extraordinary sex-chromosome system that consists of five X and five Y chromosomes in males. These sex chromosomes share homology with bird sex chromosomes but no homology with the therian X. The genome of a female platypus was recently completed, providing unique insights into sequence and gene content of autosomes and X chromosomes, but no Y-specific sequence has so far been analysed. Here we report the isolation, sequencing and analysis of ~700 kb of sequence of the non-recombining regions of Y2, Y3 and Y5, which revealed differences in base composition and repeat content between autosomes and sex chromosomes, and within the sex chromosomes themselves. This provides the first insights into repeat content of Y chromosomes in platypus, which overall show similar patterns of repeat composition to Y chromosomes in other species. Interestingly, we also observed differences between the various Y chromosomes, and in combination with timing and activity patterns we provide an approach that can be used to examine the evolutionary history of the platypus sex-chromosome chain.

scholarly journals Sequence Differentiation Associated With an Inversion on the Neo-X Chromosome of Drosophila americana

Genetics ◽  
2003 ◽  
Vol 165 (3) ◽  
pp. 1317-1328 ◽  
Author(s):  
Bryant F McAllister
Keyword(s):  
X Chromosome ◽  
Sex Chromosomes ◽  
Chromosome Evolution ◽  
Sex Chromosome ◽  
Geographic Region ◽  
Sex Chromosome Evolution ◽  
Sequence Analyses ◽  
X Chromosomes ◽  
Y Chromosomes ◽  
Chromosomal Pair

Abstract Sex chromosomes originate from pairs of autosomes that acquire controlling genes in the sex-determining cascade. Universal mechanisms apparently influence the evolution of sex chromosomes, because this chromosomal pair is characteristically heteromorphic in a broad range of organisms. To examine the pattern of initial differentiation between sex chromosomes, sequence analyses were performed on a pair of newly formed sex chromosomes in Drosophila americana. This species has neo-sex chromosomes as a result of a centromeric fusion between the X chromosome and an autosome. Sequences were analyzed from the Alcohol dehydrogenase (Adh), big brain (bib), and timeless (tim) gene regions, which represent separate positions along this pair of neo-sex chromosomes. In the northwestern range of the species, the bib and Adh regions exhibit significant sequence differentiation for neo-X chromosomes relative to neo-Y chromosomes from the same geographic region and other chromosomal populations of D. americana. Furthermore, a nucleotide site defining a common haplotype in bib is shown to be associated with a paracentric inversion [In(4)ab] on the neo-X chromosome, and this inversion suppresses recombination between neo-X and neo-Y chromosomes. These observations are consistent with the inversion acting as a recombination modifier that suppresses exchange between these neo-sex chromosomes, as predicted by models of sex chromosome evolution.

scholarly journals Cognitive, Affective Problems and Renal Cross Ectopy in a Patient with 48,XXYY/47,XYY Syndrome

2015 ◽  
Vol 2015 ◽  
pp. 1-4 ◽  
Author(s):  
Sefa Resim ◽  
Faruk Kucukdurmaz ◽  
Nazım Kankılıc ◽  
Ozlem Altunoren ◽  
Erkan Efe ◽  
...  
Keyword(s):  
Sex Chromosome ◽  
Klinefelter Syndrome ◽  
Semen Analysis ◽  
Genetic Diagnosis ◽  
Psychomotor Retardation ◽  
Tall Stature ◽  
X Chromosomes ◽  
Y Chromosomes ◽  
The Right ◽  
Hormonal Evaluation

Klinefelter syndrome is the most common sex chromosome abnormality (SCA) in infertile patients and 47,XXY genomic configuration constitutes most of the cases. However, additional Xs and/or Y such as 48,XXYY, 48,XXXY, and 47,XYY can occur less frequently than 47,XXY. Those configurations were considered as variants of Klinefelter syndrome. In this report, we present an infertile man with tall stature and decreased testicular volume. Semen analysis and hormonal evaluation supported the diagnosis of nonobstructive azoospermia. Genetic investigation demonstrated an abnormal male karyotype with two X chromosomes and two Y chromosomes consistent with 48,XXYY(17)/47,XYY (13). Additionally, the patient expressed cognitive and affective problems which were documented by psychomotor retardation and borderline intelligence measured by an IQ value between 70 and 80. Systemic evaluation also revealed cross ectopy and malrotation of the right kidney in the patient. The couple was referred to microtesticular sperm extraction (micro-TESE)/intracytoplasmic sperm injection (ICSI) cycles and preimplantation genetic diagnosis (PGD). To the best of our knowledge, this is the first report of combination of XYY and XXYY syndromes associated with cognitive, affective dysfunction and renal malrotation.

Sign in / Sign up

Export Citation Format

Share Document