A rare finding of double Barr bodies and X-monosomy/X-trisomy mosaicism in a dog with presumed idiopathic epilepsy.

A 4-year-old spayed female Border Collie dog presented to the Neurology and Neurosurgery service for an approximately five-month history of seizures. A complete neurodiagnostic workup was performed and did not reveal any significant abnormalities. The patient's seizures were well controlled with a combination of anticonvulsants. During a manual blood smear review at a follow-up appointment, double Barr bodies were identified in segmented neutrophils. Karyotyping revealed that the patient is mosaic for X-monosomy and X-trisomy, a finding that has never been reported in a dog and is rarely reported in people. This case demonstrates how the identification of abnormal neutrophil nuclear appendages may correlate with chromosomal abnormalities in dogs.

Degenerated, Undifferentiated, Rearranged, Lost: High Variability of Sex Chromosomes in Geometridae (Lepidoptera) Identified by Sex Chromatin.

Sex chromatin is a conspicuous body that occurs in polyploid nuclei of most lepidopteran females and consists of numerous copies of the W sex chromosome. It is also a cytogenetic tool used to rapidly assess the W chromosome presence in Lepidoptera. However, certain chromosomal features could disrupt the formation of sex chromatin and lead to the false conclusion that the W chromosome is absent in the respective species. Here we tested the sex chromatin presence in 50 species of Geometridae. In eight selected species with either missing, atypical, or normal sex chromatin patterns, we performed a detailed karyotype analysis by means of comparative genomic hybridization (CGH) and fluorescence in situ hybridization (FISH). The results showed a high diversity of W chromosomes and clarified the reasons for atypical sex chromatin, including the absence or poor differentiation of W, rearrangements leading to the neo-W emergence, possible association with the nucleolus, and the existence of multiple W chromosomes. In two species, we detected intraspecific variability in the sex chromatin status and sex chromosome constitution. We show that the sex chromatin is not a sufficient marker of the W chromosome presence, but it may be an excellent tool to pinpoint species with atypical sex chromosomes.

Chromosome compartments on the inactive X guide TAD formation independently of transcription during X-reactivation.

A hallmark of chromosome organization is the partition into transcriptionally active A and repressed B compartments, and into topologically associating domains (TADs). Both structures were regarded to be absent from the inactive mouse X chromosome, but to be re-established with transcriptional reactivation and chromatin opening during X-reactivation. Here, we combine a tailor-made mouse iPSC reprogramming system and high-resolution Hi-C to produce a time course combining gene reactivation, chromatin opening and chromosome topology during X-reactivation. Contrary to previous observations, we observe A/B-like compartments on the inactive X harbouring multiple subcompartments. While partial X-reactivation initiates within a compartment rich in X-inactivation escapees, it then occurs rapidly along the chromosome, concomitant with downregulation of Xist. Importantly, we find that TAD formation precedes transcription and initiates from Xist-poor compartments. Here, we show that TAD formation and transcriptional reactivation are causally independent during X-reactivation while establishing Xist as a common denominator.

Long Noncoding RNAs-Crucial Players Organizing the Landscape of the Neuronal Nucleus.

The ability to regulate chromatin organization is particularly important in neurons, which dynamically respond to external stimuli. Accumulating evidence shows that lncRNAs play important architectural roles in organizing different nuclear domains like inactive chromosome X, splicing speckles, paraspeckles, and Gomafu nuclear bodies. LncRNAs are abundantly expressed in the nervous system where they may play important roles in compartmentalization of the cell nucleus. In this review we will describe the architectural role of lncRNAs in the nuclei of neuronal cells.

Why Do Some Sex Chromosomes Degenerate More Slowly Than Others? The Odd Case of Ratite Sex Chromosomes.

The hallmark of sex chromosome evolution is the progressive suppression of recombination which leads to subsequent degeneration of the non-recombining chromosome. In birds, species belonging to the two major clades, Palaeognathae (including tinamous and flightless ratites) and Neognathae (all remaining birds), show distinctive patterns of sex chromosome degeneration. Birds are female heterogametic, in which females have a Z and a W chromosome. In Neognathae, the highly-degenerated W chromosome seems to have followed the expected trajectory of sex chromosome evolution. In contrast, among Palaeognathae, sex chromosomes of ratite birds are largely recombining. The underlying reason for maintenance of recombination between sex chromosomes in ratites is not clear. Degeneration of the W chromosome might have halted or slowed down due to a multitude of reasons ranging from selective processes, such as a less pronounced effect of sexually antagonistic selection, to neutral processes, such as a slower rate of molecular evolution in ratites. The production of genome assemblies and gene expression data for species of Palaeognathae has made it possible, during recent years, to have a closer look at their sex chromosome evolution. Here, we critically evaluate the understanding of the maintenance of recombination in ratites in light of the current data. We conclude by highlighting certain aspects of sex chromosome evolution in ratites that require further research and can potentially increase power for the inference of the unique history of sex chromosome evolution in this lineage of birds.

DMD genomic deletions characterize a subset of progressive/higher-grade meningiomas with poor outcome.

Progressive meningiomas that have failed surgery and radiation have a poor prognosis and no standard therapy. While meningiomas are more common in females overall, progressive meningiomas are enriched in males. We performed a comprehensive molecular characterization of 169 meningiomas from 53 patients with progressive/high-grade tumors, including matched primary and recurrent samples. Exome sequencing in an initial cohort (n = 24) detected frequent alterations in genes residing on the X chromosome, with somatic intragenic deletions of the dystrophin-encoding and muscular dystrophy-associated DMD gene as the most common alteration (n = 5, 20.8%), along with alterations of other known X-linked cancer-related genes KDM6A (n =2, 8.3%), DDX3X, RBM10 and STAG2 (n = 1, 4.1% each). DMD inactivation (by genomic deletion or loss of protein expression) was ultimately detected in 17/53 progressive meningioma patients (32%). Importantly, patients with tumors harboring DMD inactivation had a shorter overall survival (OS) than their wild-type counterparts [5.1 years (95% CI 1.3-9.0) vs. median not reached (95% CI 2.9-not reached, p = 0.006)]. Given the known poor prognostic association of TERT alterations in these tumors, we also assessed for these events, and found seven patients with TERT promoter mutations and three with TERT rearrangements in this cohort (n = 10, 18.8%), including a recurrent novel RETREG1-TERT rearrangement that was present in two patients. In a multivariate model, DMD inactivation (p = 0.033, HR = 2.6, 95% CI 1.0-6.6) and TERT alterations (p = 0.005, HR = 3.8, 95% CI 1.5-9.9) were mutually independent in predicting unfavorable outcomes. Thus, DMD alterations identify a subset of progressive/high-grade meningiomas with worse outcomes.

Cells have sex chromosomes and circadian clocks: Implications for organismal level functions.

A great number of stakeholders have a keen interest in issues surrounding sex differences. These participants in the discourse often use the same evidence to draw opposite conclusions, with implications for individuals and society as a whole. One part of the maelstrom and associated emotionality derives from confounds between the concepts of "sex" vs. "gender", even among professionals. Here, the oft-repeated point is made that evidence for gender differences can't be derived from the animal research, once the generally accepted conception of gender as a process unique to humans, is acknowledged. Nevertheless, considered at a more general level, the developmental and epigenetic mechanisms that give rise to differences in behavior among individuals and groups is exquisitely explored in animal studies but relatively poorly in research on humans. The focus on animal research here, starts with the fact that virtually each cell of the body has sex chromosomes (XX and XY), along with the intracellular genetic and cytoplasmic mechanisms associated with circadian (circa-about, dies-day) timing. The consequences of these sex×circadian interactions for physiology and behavior at cellular and higher levels of organization are considered in systems where compelling evidence is available. These include sex differences in the circadian timing system, the hypothalamic-pituitary-adrenal (HPA) axis, and in metabolism. The evidence highlights sex differences in cells throughout the body and thus has implications for higher level processes and systems such as sleep/wake patterns. In a more general sense, they point to mechanisms that could give rise to gender differences. In summary, the viewpoint presented here is that the circadian timing system can be used very elegantly to explore the contributions of genetic and hormonal sex differences on biological systems at many levels.

Caregivers of patients with amyotrophic lateral sclerosis: investigating quality of life, caregiver burden, service engagement, and patient survival.

Few studies in amyotrophic lateral sclerosis (ALS) have profiled disease-specific features of the condition in conjunction with assessment of caregivers' burden, distress, quality of life, and investigated patient survival. Eighty-four ALS patients and their primary caregivers were enrolled. Patients completed ALS-specific measures of physical and cognitive function, while caregivers completed measures of anxiety, depression, caregiver burden, and quality of life. Patient-caregiver dyads were interviewed about their health-service utilisation. Survival data were obtained through the Irish register for ALS. Participants were dichotomised into low/high groups according to the severity of self-reported caregiver burden, based on statistically derived cut-off scores. High-burdened caregivers (n = 43) did not significantly differ from low-burdened caregivers (n = 41) with respect to disease-specific characteristics, i.e., ALSFRS-R, bulbar- or spinal-onset ALS, disease duration, or survival data. However, significant differences were reported on subjective measures of anxiety (p < 0.000), depression (p < 0.001), distress (p < 0.000), and quality of life (p < 0.000). These data demonstrate the limited impact of ALS patient-related variables, i.e., ALSFRS-R and onset, on caregiver burden in ALS, and identify the importance of the psychological composition of caregivers. This study suggests that the subjective experience of individual caregivers is an important factor influencing the severity of experienced caregiver burden.

A Review of Autoimmune Disease Hypotheses with Introduction of the "Nucleolus" Hypothesis.

Numerous hypotheses have been proposed in order to explain the complexity of autoimmune diseases. These hypotheses provide frameworks towards understanding the relations between triggers, autoantigen development, symptoms, and demographics. However, testing and refining these hypotheses are difficult tasks since autoimmune diseases have a potentially overwhelming number of variables due to the influence on autoimmune diseases from environmental factors, genetics, and epigenetics. Typically, the hypotheses are narrow in scope, for example, explaining the diseases in terms of genetics without defining detailed roles for environmental factors or epigenetics. Here, we present a brief review of the major hypotheses of autoimmune diseases including a new one related to the consequences of abnormal nucleolar interactions with chromatin, the "nucleolus" hypothesis which was originally termed the "inactive X chromosome and nucleolus nexus" hypothesis. Indeed, the dynamic nucleolus can expand as part of a cellular stress response and potentially engulf portions of chromatin, leading to disruption of the chromatin. The inactive X chromosome (a.k.a. the Barr body) is particularly vulnerable due to its close proximity to the nucleolus. In addition, the polyamines, present at high levels in the nucleolus, are also suspected of contributing to the development of autoantigens.

Deciphering the Role of the Barr Body in Malignancy: An insight into head and neck cancer.

X chromosome inactivation is the epitome of epigenetic regulation and long non-coding ribonucleic acid function. The differentiation status of cells has been ascribed to X chromosome activity, with two active X chromosomes generally only observed in undifferentiated or poorly differentiated cells. Recently, several studies have indicated that the reactivation of an inactive X chromosome or X chromosome multiplication correlates with the development of malignancy; however, this concept is still controversial. This review sought to shed light on the role of the X chromosome in cancer development. In particular, there is a need for further exploration of the expression patterns of X-linked genes in cancer cells, especially those in head and neck squamous cell carcinoma (HNSCC), in order to identify different prognostic subpopulations with distinct clinical implications. This article proposes a functional relationship between the loss of the Barr body and the disproportional expression of X-linked genes in HNSCC development.

The making of a Barr body: the mosaic of factors that eXIST on the mammalian inactive X chromosome.

During X-chromosome inactivation (XCI), nearly an entire X chromosome is permanently silenced and converted into a Barr body, providing dosage compensation for eutherians between the sexes. XCI is facilitated by the upregulation of the long non-coding RNA gene, XIST, which coats its chromosome of origin, recruits heterochromatin factors, and silences gene expression. During XCI, at least two distinct types of heterochromatin are established, and in this review we discuss the enrichment of facultative heterochromatin marks such as H3K27me3, H2AK119ub, and macroH2A as well as pericentric heterochromatin marks such as HP1, H3K9me3, and H4K20me3. The extremely stable maintenance of silencing is a product of reinforcing interactions within and between these domains. This paper "Xplores" the current knowledge of the pathways involved in XCI, how the pathways interact, and the gaps in our understanding that need to be filled.

Human sperm chromatin epigenetic potential: genomics, proteomics, and male infertility.

The classical idea about the function of the mammalian sperm chromatin is that it serves to transmit a highly protected and transcriptionally inactive paternal genome, largely condensed by protamines, to the next generation. In addition, recent sperm chromatin genome-wide dissection studies indicate the presence of a differential distribution of the genes and repetitive sequences in the protamine-condensed and histone-condensed sperm chromatin domains, which could be potentially involved in regulatory roles after fertilization. Interestingly, recent proteomic studies have shown that sperm chromatin contains many additional proteins, in addition to the abundant histones and protamines, with specific modifications and chromatin affinity features which are also delivered to the oocyte. Both gene and protein signatures seem to be altered in infertile patients and, as such, are consistent with the potential involvement of the sperm chromatin landscape in early embryo development. This present work reviews the available information on the composition of the human sperm chromatin and its epigenetic potential, with a particular focus on recent results derived from high-throughput genomic and proteomic studies. As a complement, we provide experimental evidence for the detection of phosphorylations and acetylations in human protamine 1 using a mass spectrometry approach. The available data indicate that the sperm chromatin is much more complex than what it was previously thought, raising the possibility that it could also serve to transmit crucial paternal epigenetic information to the embryo.

The inactive X chromosome is epigenetically unstable and transcriptionally labile in breast cancer.

Disappearance of the Barr body is considered a hallmark of cancer, although whether this corresponds to genetic loss or to epigenetic instability and transcriptional reactivation is unclear. Here we show that breast tumors and cell lines frequently display major epigenetic instability of the inactive X chromosome, with highly abnormal 3D nuclear organization and global perturbations of heterochromatin, including gain of euchromatic marks and aberrant distributions of repressive marks such as H3K27me3 and promoter DNA methylation. Genome-wide profiling of chromatin and transcription reveal modified epigenomic landscapes in cancer cells and a significant degree of aberrant gene activity from the inactive X chromosome, including several genes involved in cancer promotion. We demonstrate that many of these genes are aberrantly reactivated in primary breast tumors, and we further demonstrate that epigenetic instability of the inactive X can lead to perturbed dosage of X-linked factors. Taken together, our study provides the first integrated analysis of the inactive X chromosome in the context of breast cancer and establishes that epigenetic erosion of the inactive X can lead to the disappearance of the Barr body in breast cancer cells. This work offers new insights and opens up the possibility of exploiting the inactive X chromosome as an epigenetic biomarker at the molecular and cytological levels in cancer.

Sex determination from pulp tissues of teeth subjected to different physical conditions and times after extraction.

BACKGROUND: The purpose of this study was to determine the reliability of sex determination from observation of Barr bodies in cells of tooth pulp tissue subjected to different physical conditions and duration of time after extraction. METHOD: The study comprised 150 teeth of subjects (male 50% and female 50%) who were randomly sampled. The teeth were grouped according to the conditions and times they were subjected to before extirpation of pulp tissues as follows: immediately after extraction; after 1 month in stagnant water; after staying at room temperature for 1 month, 3 months and 5 months post extraction and; after being subjected to varied degrees of temperature. The pulp tissues were fixed in 10% formal saline and processed for H&E stain. The presence of a cell with visible Barr body was considered positive for women. RESULTS: Sex chromatin were observable in the female preparations up to a duration of five months after extraction; teeth left in stagnant water for 1 month; and teeth subjected to temperature up to 400 degrees C. There was no positive cell in preparations of male subjects. CONCLUSION: Teeth pulp tissues are reliable evidence in forensic human identification by sex in varied physical conditions and times of death.

Dental pulp fibroblast and sex determination in controlled burial conditions / Fibroblastos de la pulpa dental y la determinación del sexo en condiciones controladas de enterramiento

The need to identify bodies that are found as a result of disappearances with a diversity of causes, illegal burials and massive disasters, represent a wide percentage of dentistry practice on forensic research. The following study determined the performance of Barr Body Test, in fibroblasts of healthy teeth, under different conditions of burial (in vitro) with variations in pH, humidity and salinity in terms of general accuracy and sensitivity for men and women. Analyzed sample considered 47 dental pulps, taken from teeth under burial conditions during a period of a month. From dental pulps samples, 265 histological cuts valid for this study, were obtained, which were observed with an optical microscope under conventional H/E staining. Results showed a 98.9% of well-diagnosed cases, which correspond to the overall accuracy of the method. Sensitivity for men was 97.5% and 100% for women, over the analyzed sample. In low humidity conditions, 3 samples of badly diagnosed cases in men were observed, with a group accuracy of a 90%, with a sensitivity of 25% for men and 100% for women. The present study establishes that based on these results, the performance of Barr Body Test in fibroblasts, proposed for healthy pulp teeth, is not affected by burial conditions in terms of pH (acid-alkaline), salinity (high-low) and high humidity.

La necesidad de identificar cuerpos que resultan como consecuencia de desapariciones de causas variadas, inhumaciones ilegales y desastres masivos representa un porcentaje amplio en el quehacer odontológico en un escenario de investigación forense. El presente estudio determinó el rendimiento de la prueba diagnóstica de observación del cuerpo de Barr en células de la pulpa de dientes sanos, sometidos a distintas condiciones de enterramiento (in vitro) con variación de pH, humedad y salinidad en términos de exactitud general y sensibilidad para hombres y mujeres. La muestra analizada consideró 47 pulpas dentales, extraídas de dientes sometidos a condiciones de enterramiento durante un mes. De las pulpas dentarias se obtuvieron 265 cortes histológicos válidos para el estudio, los cuales mediante la tinción convencional H/E, fueron observados al microscopio óptico. Los resultados arrojaron un 98,9% de casos bien diagnosticados, que correspondió a la exactitud general del método. La sensibilidad para hombres fue de 97,5% y para mujeres de 100% sobre el total de la muestra analizada. Las condiciones de pH (ácido y alcalino), salinidad (alta y baja) y alta humedad presentaron una exactitud de grupo de 100%, con una sensibilidad para hombres y mujeres de 100%. En la condición de baja humedad se observaron 3 muestras de hombres mal diagnosticadas con una exactitud de grupo de 90% y sensibilidad para hombres de 25% y para mujeres de 100%. A la luz de los resultados, el presente estudio establece que el rendimiento de la prueba diagnóstica de observación del cuerpo de Barr en fibroblastos, propuesto para pulpas de dientes sanos, no se afecta con las condiciones de enterramiento propuestas bajo pH ácido ­ alcalino, salinidad alta ­ baja y humedad alta.

Dynamics of the two heterochromatin types during imprinted X chromosome inactivation in vole Microtus levis.

In rodent female mammals, there are two forms of X-inactivation - imprinted and random which take place in extraembryonic and embryonic tissues, respectively. The inactive X-chromosome during random X-inactivation was shown to contain two types of facultative heterochromatin that alternate and do not overlap. However, chromatin structure of the inactive X-chromosome during imprinted X-inactivation, especially at early stages, is still not well understood. In this work, we studied chromatin modifications associated with the inactive X-chromosome at different stages of imprinted X-inactivation in a rodent, Microtus levis. It has been found that imprinted X-inactivation in vole occurs in a species-specific manner in two steps. The inactive X-chromosome at early stages of imprinted X-inactivation is characterized by accumulation of H3K9me3, HP1, H4K20me3, and uH2A, resembling to some extent the pattern of repressive chromatin modifications of meiotic sex chromatin. Later, the inactive X-chromosome recruits trimethylated H3K27 and acquires the two types of heterochromatin associated with random X-inactivation.

SSTY proteins co-localize with the post-meiotic sex chromatin and interact with regulators of its expression.

In mammals, X- and Y-encoded genes are transcriptionally shut down during male meiosis, but expression of many of them is (re)activated in spermatids after meiosis. Post-meiotic XY gene expression is regulated by active epigenetic marks, which are de novo incorporated in the sex chromatin of spermatids, and by repressive epigenetic marks inherited during meiosis; alterations in this process lead to male infertility. In the mouse, post-meiotic XY gene expression is known to depend on genetic information carried by the male-specific region of the Y chromosome long arm (MSYq). The MSYq gene Sly has been shown to be a key regulator of post-meiotic sex chromosome gene expression and is necessary for the maintenance/recruitment of repressive epigenetic marks on the sex chromatin, but studies suggest that another MSYq gene may also be required. The best candidate to date is Ssty, an MSYq multi-copy gene of unknown function. Here, we show that SSTY proteins are specifically expressed in round and elongating spermatids, and co-localize with post-meiotic sex chromatin. Moreover, SSTY proteins interact with SLY protein and its X-linked homolog SLX/SLXL1, and may be required for localization of SLX/SLY proteins in the spermatid nucleus and sex chromatin. Our data suggest that SSTY is a second MSYq factor involved in the control of XY gene expression during sperm differentiation. As Slx/Slxl1 and Sly genes have been shown to be involved in the XY intra-genomic conflict, which affects the offspring sex ratio, Ssty may constitute another player in this conflict.

Reliability of sexual dimorphism in blood.

BACKGROUND: Demonstration of sex chromatin forms an important aspect of human genetics. It also establishes the interrelationship between sex chromatin and an inactive X-chromosome. The term "sex chromatin" in blood refers to the "Drumsticks of polymorphonuclear leukocytes" or "Davidson's bodies". OBJECTIVE: This correlative study evaluates the presence of these drumsticks quantitatively and also highlights the concept of blood chimaerism in humans. METHOD: Leishman-stained peripheral blood smears from 60 individuals (30 males and 30 females) were obtained and studied under bright-field microscope (40X) for presence of Drumstick appendages. RESULTS AND CONCLUSION: On comparing mean numbers of Davidson's bodies in females and males, an extremely significant correlation (P < 0.0001) was seen. Hence, it could be surmised that the presence of appendages in neutrophils (Drumstick bodies) can be useful in gender differentiation.

Cytological assessment of Barr bodies using aceto-orcein and papanicolaou stains in buccal mucosal smears and their sex estimation efficacy in an Indian sample.

OBJECTIVE: Buccal epithelial cells in saliva traces found at a crime scene can be used for sex determination by examining the presence of Barr bodies in the nucleus. Papanicolaou (PAP) and fluorescent stains, among others, have been used in the past. Aceto-orcein (AO) is a relatively unexplored staining technique for this purpose. This study aims to assess the efficacy of sex determination using AO and PAP stains for the detection of Barr bodies in buccal mucosal scrapes. STUDY DESIGN: Buccal scrapings were collected from 120 healthy individuals (60 males and 60 females). They were stained with AO and PAP. Fifty cells in each sample were analyzed for identification of Barr bodies. Samples with a presence of Barr bodies ≤5% were recorded as male and those with >5% were recorded as female. The percentage accuracy in determining sex using both stains was evaluated. RESULTS: The percentage of Barr bodies in AO-stained slides ranged from 5 to 32 among females and from 0 to 8 in males, while with PAP the ranges recorded were 4-20 in females and 0-5 in males (p < 0.001). The sensitivity and specificity of AO for detecting sex accurately was around 98.3 and 95% for PAP. CONCLUSION: Sex determination using Barr bodies in the buccal cells is a simple method that provides up to 95-98% accuracy; making it a significant accessory for sex determination. AO proved to be a better stain than PAP for visualizing nuclear details, and its staining time was remarkably shorter. It also demonstrated enhanced sex estimation efficacy compared to PAP.