scholarly journals Studies on Metatherian Sex Chromosomes I. Inheritance and Inactivation of Sex-linked Allelic Genes determining Glucose-6-phosphate Dehydrogenase Variation in Kangaroos

1975 ◽  
Vol 28 (6) ◽  
pp. 567 ◽  
Author(s):  
PG Johnston ◽  
GB Sharman
Keyword(s):  
Sex Chromosomes ◽  
Backcross Progeny ◽  
Parental Origin ◽  
X Chromosomes ◽  
Parental Phenotype ◽  
The Cross ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Electrophoretic Phenotype

Wallaroos (Macropus robustus robustus), which have the G6PD-F electrophoretic phenotype, crossed with euros (M. r. erubescens), ofG6PD-S phenotype, produced F 1 animals which had only the maternal G6PD type regardless of the direction of the cross. When F 1 hybrids were backcrossed to wallaroos or euros, backcross progeny of either parental phenotype resulted. Sex-linked inheritance of allelic G6PD genes is shown to occur in wallaroos, euros and red kangaroos (M. rufus). Dose compensation for X chromosomes at the G6PD locus in kangaroos is achieved by inactivation of the allele of male parental origin.

scholarly journals Bisection of the X chromosome disrupts the initiation of chromosome silencing during meiosis in Caenorhabditis elegans

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yisrael Rappaport ◽  
Hanna Achache ◽  
Roni Falk ◽  
Omer Murik ◽  
Oren Ram ◽  
...  
Keyword(s):  
Caenorhabditis Elegans ◽  
Rna Polymerase Ii ◽  
X Chromosome ◽  
Sex Chromosomes ◽  
Sex Chromosome ◽  
Transcription Analysis ◽  
X Chromosomes ◽  
Unique Character ◽  
Active Transcription ◽  
Heterogametic Sex

AbstractDuring meiosis, gene expression is silenced in aberrantly unsynapsed chromatin and in heterogametic sex chromosomes. Initiation of sex chromosome silencing is disrupted in meiocytes with sex chromosome-autosome translocations. To determine whether this is due to aberrant synapsis or loss of continuity of sex chromosomes, we engineered Caenorhabditis elegans nematodes with non-translocated, bisected X chromosomes. In early meiocytes of mutant males and hermaphrodites, X segments are enriched with euchromatin assembly markers and active RNA polymerase II staining, indicating active transcription. Analysis of RNA-seq data showed that genes from the X chromosome are upregulated in gonads of mutant worms. Contrary to previous models, which predicted that any unsynapsed chromatin is silenced during meiosis, our data indicate that unsynapsed X segments are transcribed. Therefore, our results suggest that sex chromosome chromatin has a unique character that facilitates its meiotic expression when its continuity is lost, regardless of whether or not it is synapsed.

scholarly journals Localization of Male-Specifically Expressed MROS Genes of Silene latifolia by PCR on Flow-Sorted Sex Chromosomes and Autosomes

Genetics ◽  
2001 ◽  
Vol 158 (3) ◽  
pp. 1269-1277
Author(s):  
Eduard Kejnovský ◽  
Jan Vrána ◽  
Sachihiro Matsunaga ◽  
Přemysl Souček ◽  
Jiří Široký ◽  
...  
Keyword(s):  
Sex Chromosomes ◽  
Silene Latifolia ◽  
Homology Search ◽  
X Chromosomes ◽  
Dioecious Plants ◽  
Flow Sorting ◽  
Heteromorphic Sex Chromosomes ◽  
Copy Gene ◽  
Melandrium Album ◽  
Pcr Products

Abstract The dioecious white campion Silene latifolia (syn. Melandrium album) has heteromorphic sex chromosomes, XX in females and XY in males, that are larger than the autosomes and enable their separation by flow sorting. The group of MROS genes, the first male-specifically expressed genes in dioecious plants, was recently identified in S. latifolia. To localize the MROS genes, we used the flow-sorted X chromosomes and autosomes as a template for PCR with internal primers. Our results indicate that the MROS3 gene is located in at least two copies tandemly arranged on the X chromosome with additional copy(ies) on the autosome(s), while MROS1, MROS2, and MROS4 are exclusively autosomal. The specificity of PCR products was checked by digestion with a restriction enzyme or reamplification using nested primers. Homology search of databases has shown the presence of five MROS3 homologues in A. thaliana, four of them arranged in two tandems, each consisting of two copies. We conclude that MROS3 is a low-copy gene family, connected with the proper pollen development, which is present not only in dioecious but also in other dicot plant species.

scholarly journals DOSAGE COMPENSATION IN DROSOPHILA MELANOGASTER TRIPLOIDS. II. GLUCOSE-6-PHOSPHATE DEHYDROGENASE ACTIVITY

Genetics ◽  
1973 ◽  
Vol 74 (2) ◽  
pp. 331-342
Author(s):  
Gustavo Maroni ◽  
Walter Plaut
Keyword(s):  
Enzyme Activity ◽  
Dosage Compensation ◽  
Live Weight ◽  
Regulatory Mechanisms ◽  
Special Device ◽  
Regulatory Factor ◽  
X Chromosomes ◽  
Integral Number ◽  
Level Of Activity ◽  
Glucose 6 Phosphate Dehydrogenase

ABSTRACT The level of activity of the enzyme glucose-6-phosphate dehydrogenase was determinel in flies having seven different chromosomic constitutions. All those having an integral number of chromosomes [XAA, XXAA, XAAA, XXAAA, and XXXAAA (X=X chromosome, A=set of autosomes)] were found to have similar units of enzyme activity/mg live weight, while diploid females with a duplication and triploid females with a deficiency showed dosage effect. The amount of enzyme activity per cell, on the other hand, is also independent of the number of X's present but appears roughly proportional to the number of sets of autosomes.—It is proposed that dosage-compensated sex-linked genes are controlled by a positively acting regulatory factor(s) of autosomal origin. With this hypothesis it is possible to explain dosage compensation as a consequence of general regulatory mechanisms without invoking a special device which applies only to the X chromosomes.

In the platypus a meiotic chain of ten sex chromosomes shares genes with the bird Z and mammal X chromosomes

Nature ◽  
2004 ◽  
Vol 432 (7019) ◽  
pp. 913-917 ◽  
Author(s):  
Frank Grützner ◽  
Willem Rens ◽  
Enkhjargal Tsend-Ayush ◽  
Nisrine El-Mogharbel ◽  
Patricia C. M. O'Brien ◽  
...  
Keyword(s):  
Sex Chromosomes ◽  
X Chromosomes

scholarly journals Contingency in the convergent evolution of a regulatory network: Dosage compensation in Drosophila

2018 ◽  
Author(s):  
Doris Bachtrog ◽  
Chris Ellison
Keyword(s):  
Transposable Element ◽  
Dosage Compensation ◽  
Sex Chromosomes ◽  
Binding Sites ◽  
Evolutionary Biology ◽  
De Novo ◽  
Binding Motif ◽  
Sequence Motif ◽  
X Chromosomes ◽  
Msl Complex

The repeatability or predictability of evolution is a central question in evolutionary biology, and most often addressed in experimental evolution studies. Here, we infer how genetically heterogeneous natural systems acquire the same molecular changes, to address how genomic background affects adaptation in natural populations. In particular, we take advantage of independently formed neo-sex chromosomes in Drosophila species that have evolved dosage compensation by co-opting the dosage compensation (MSL) complex, to study the mutational paths that have led to the acquisition of 100s of novel binding sites for the MSL complex in different species. This complex recognizes a conserved 21-bp GA-rich sequence motif that is enriched on the X chromosome, and newly formed X chromosomes recruit the MSL complex by de novo acquisition of this binding motif. We identify recently formed sex chromosomes in the Drosophila repleta and robusta species groups by genome sequencing, and generate genomic occupancy maps of the MSL complex to infer the location of novel binding sites. We find that diverse mutational paths were utilized in each species to evolve 100s of de novo binding motifs along the neo-X, including expansions of microsatellites and transposable element insertions. However, the propensity to utilize a particular mutational path differs between independently formed X chromosomes, and appears to be contingent on genomic properties of that species, such as simple repeat or transposable element density. This establishes the “genomic environment” as an important determinant in predicting the outcome of evolutionary adaptations.

scholarly journals Studies on Metatherian Sex Chromosomes VII. Glucose-6-phosphate Dehydrogenase Expression in Tissues and Cultured Fibroblasts of Kangaroos

1978 ◽  
Vol 31 (4) ◽  
pp. 415 ◽  
Author(s):  
PG Johnston ◽  
GB Sharman ◽  
Elizabeth A James ◽  
DW Cooper
Keyword(s):  
Sex Chromosomes ◽  
Cultured Fibroblasts ◽  
Glucose 6 Phosphate Dehydrogenase

Expression of the sex-linked enzyme glucose-6-phosphate dehydrogenase (G6PD) was examined electrophoretically in tissues and cultured fibroblasts of female kangaroo heterozygotes ranging in age from 26 days post part urn to adult. All tissues expressed only the maternally derived allele irrespective of which allele was maternal or paternal in origin.

Chromatin loop structure of the human X chromosome: relevance to X inactivation and CpG clusters

1989 ◽  
Vol 9 (6) ◽  
pp. 2322-2331
Author(s):  
A H Beggs ◽  
B R Migeon
Keyword(s):  
Cpg Islands ◽  
Phosphoglycerate Kinase ◽  
Housekeeping Genes ◽  
Factor Ix ◽  
Clotting Factor ◽  
Order Structure ◽  
Chromatin Loop ◽  
X Chromosomes ◽  
Alpha Galactosidase ◽  
Glucose 6 Phosphate Dehydrogenase

Part of the higher-order structure of chromatin is achieved by constraining DNA in loops ranging in size from 30 to 100 kilobase pairs; these loops have been implicated in defining functional domains and replicons and possibly in facilitating transcription. Because the human active and inactive X chromosomes differ in transcriptional activity and replication, we looked for differences in their chromatin loop structures. Since the islands of CpG-rich DNA at the 5' ends of X-linked housekeeping genes are the regions where functional differences in DNA methylation and nuclease sensitivity are found, we looked for scaffold association of these sequences after extraction of histones with lithium diiodosalicylate. Specifically, we examined the 5' CpG islands within the hypoxanthine phosphoribosyltransferase, glucose 6-phosphate dehydrogenase, P3, GdX, phosphoglycerate kinase type 1, and alpha-galactosidase loci in human lymphoblasts obtained from individuals with 1 to 4 X chromosomes. Although we detected no scaffold-associated regions near these genes, we found several such regions at the ornithine transcarbamylase and blood clotting factor IX loci. Our results suggest that the CpG islands are excluded from the nuclear scaffold and that even though transcriptionally active, housekeeping genes are less likely than X-linked tissue-specific genes to be scaffold associated. In all cases, the pattern of scaffold association was the same for loci on active and inactive X chromosomes.

scholarly journals Paroxysmal Nocturnal Hemoglobinuria with Glucose-6-Phosphate Dehydrogenase Deficiency: A Case Report and Review of the Literature

2019 ◽  
Vol 12 (3) ◽  
pp. 838-844
Author(s):  
Mahmoud S. Eisa ◽  
Shehab F. Mohamed ◽  
Firyal Ibrahim ◽  
Khalid Shariff ◽  
Nagham Sadik ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
G6pd Deficiency ◽  
Paroxysmal Nocturnal Hemoglobinuria ◽  
Dehydrogenase Deficiency ◽  
Response To Treatment ◽  
X Chromosomes ◽  
Financial Status ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Real Challenge ◽  
And Oxidative Stress

In this study, we are describing a female patient with paroxysmal nocturnal hemoglobinuria (PNH) and glucose-6-phosphate dehydrogenase (G6PD) deficiency. Both diseases are known to cause hemolytic anemia that mediates the hemolysis of RBCs through several mechanisms. In PNH the hemolysis is mediated through complement activation and oxidative stress. G6PD enzyme is crucial in preventing damage to cellular structures caused by oxygen-free radicles. In G6PD deficiency the hemolysis is mediated through the oxidative stress created by oxygen-free radicles. Since both diseases mediate hemolysis through the oxidative stress, we hypothesize that both conditions have facilitated an effect on each other and this will reflect on the response to treatment, and this response to treatment could vary based on whether the two mutations occurred in the same gene or in two different X chromosomes. Having diagnosed PNH, the management is very expensive and not all the patients can afford it, especially our patient who is a maid by occupation. So, the real challenge in our case is to monitor her in subsequent visits and to plan the treatment keeping in mind her financial status.

scholarly journals A Syntenic Region Conserved from Fish to Mammalian X Chromosome

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Guijun Guan ◽  
Meisheng Yi ◽  
Tohru Kobayashi ◽  
Yunhan Hong ◽  
Yoshitaka Nagahama
Keyword(s):  
X Chromosome ◽  
Sex Chromosomes ◽  
Random Amplified Polymorphic Dna ◽  
Comparative Genomic ◽  
X Chromosomes ◽  
Ancestral Origin ◽  
Dna Contents ◽  
Determining Factors ◽  
Unpaired Region ◽  
Syntenic Segment

Sex chromosomes bearing the sex-determining gene initiate development along the male or female pathway, no matter which sex is determined by XY male or ZW female heterogamety. Sex chromosomes originate from ancient autosomes but evolved rapidly after the acquisition of sex-determining factors which are highly divergent between species. In the heterogametic male system (XY system), the X chromosome is relatively evolutionary silent and maintains most of its ancestral genes, in contrast to its Y counterpart that has evolved rapidly and degenerated. Sex in a teleost fish, the Nile tilapia (Oreochromis niloticus), is determined genetically via an XY system, in which an unpaired region is present in the largest chromosome pair. We defined the differences in DNA contents present in this chromosome with a two-color comparative genomic hybridization (CGH) and the random amplified polymorphic DNA (RAPD) approach in XY males. We further identified a syntenic segment within this region that is well conserved in several teleosts. Through comparative genome analysis, this syntenic segment was also shown to be present in mammalian X chromosomes, suggesting a common ancestral origin of vertebrate sex chromosomes.

DIFFERENTIAL DNA REPLICATION IN THE XX AND XY CELLS OF MUSCA DOMESTICA L. OCRA STRAIN

1970 ◽  
Vol 12 (3) ◽  
pp. 461-473 ◽  
Author(s):  
K. Y. Jan ◽  
J. W. Boyes
Keyword(s):  
Dna Replication ◽  
Musca Domestica ◽  
Sex Chromosomes ◽  
Chromosome Length ◽  
Final Part ◽  
X Chromosomes ◽  
Y Chromosomes ◽  
Heteromorphic Sex Chromosomes ◽  
Autosomal Pair ◽  
Differential Dna Replication

The karyotype of Musca domestica L. ocra strain, consists of the sex chromosomes and five autosomal pairs. The heteromorphic sex chromosomes are heterochromatic and mitotically unpaired, whereas the autosomes are euchromatic and mitotically paired. All autosomal pairs and both X and Y chromosomes are cytologically recognizable.The relative labelling rate, R (in terms of the number of grains counted per 100 labelled metaphases per μ of chromosome length) for the sex chromosomes and for each autosomal pair was followed from 1.5 hours to 8 hours after H3TdR injection. The pattern of labelling rate was similar for the different autosomal pairs in the XX cells but this pattern for the autosomal pairs in the XY cells, though also similar for the different pairs, differed appreciably from that found in the XX cells. The pattern of the labelling rate for the X chromosomes was similar in the XX and XY cells. Also the pattern of labelling rate for the X and Y chromosomes was similar during the final part of the replication period. The two X chromosomes in the XX cells and the X and Y chromosomes in the XY cells completed labelling later than the autosomes.

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