Overexpression of miR-25 Downregulates the Expression of ROBO2 in Idiopathic Intellectual Disability.

Idiopathic intellectual disability (IID) encompasses the cases of intellectual disability (ID) without a known cause and represents approximately 50% of all cases. Neural progenitor cells (NPCs) from the olfactory neuroepithelium (NEO) contain the same information as the cells found in the brain, but they are more accessible. Some miRNAs have been identified and associated with ID of known etiology. However, in idiopathic ID, the effect of miRNAs is poorly understood. The aim of this study was to determine the miRNAs regulating the expression of mRNAs that may be involved in development of IID. Expression profiles were obtained using NPC-NEO cells from IID patients and healthy controls by microarray. A total of 796 miRNAs and 28,869 mRNAs were analyzed. Several miRNAs were overexpressed in the IID patients compared to controls. miR-25 had the greatest expression. In silico analysis showed that ROBO2 was the target for miR-25, with the highest specificity and being the most down-regulated. In vitro assay showed an increase of miR-25 expression induced a decrease in ROBO2 expression. In neurodevelopment, ROBO2 plays a crucial role in episodic learning and memory, so its down-regulation, caused by miR-25, could have a fundamental role in the intellectual disability that, until now, has been considered idiopathic.

Opposite Auxin Dynamics Determine the Gametophytic and Embryogenic Fates of the Microspore.

The microspore can follow two different developmental pathways. In vivo microspores follow the gametophytic program to produce pollen grains. In vitro, isolated microspores can be reprogrammed by stress treatments and follow the embryogenic program, producing doubled-haploid embryos. In the present study, we analyzed the dynamics and role of endogenous auxin in microspore development during these two different scenarios, in Brassica napus. We analyzed auxin concentration, cellular accumulation, the expression of the TAA1 auxin biosynthesis gene, and the PIN1-like efflux carrier gene, as well as the effects of inhibiting auxin biosynthesis by kynurenine on microspore embryogenesis. During the gametophytic pathway, auxin levels and TAA1 and PIN1-like expression were high at early stages, in tetrads and tapetum, while they progressively decreased during gametogenesis in both pollen and tapetum cells. In contrast, in microspore embryogenesis, TAA1 and PIN1-like genes were upregulated, and auxin concentration increased from the first embryogenic divisions. Kynurenine treatment decreased both embryogenesis induction and embryo production, indicating that auxin biosynthesis is required for microspore embryogenesis initiation and progression. The findings indicate that auxin exhibits two opposite profiles during these two microspore developmental pathways, which determine the different cell fates of the microspore.

Overcoming the unprecedented: Micro, small and medium hospitality enterprises under COVID-19.

The sudden irruption of COVID-19 has paralysed, even devastated, numerous industries. Academic and industry publications also convey the destructive impacts of this phenomenon on hospitality and tourism businesses. While business owners and managers are still constrained by unpredictability, restrictions, and ongoing uncertainty, those vying to continue will need to build their adaptive skill repertoire to cope with the crisis-related regime. This study is primarily concerned with businesses' adaptation phase from owners/managers' viewpoints, including how they manage and envision a future coexistence with COVID-19 threats. Drawing on an international sample of owners/managers of hospitality and tourism businesses, and considering the foundations of the dynamic capabilities framework, eight dimensions emerged from the findings. Five of these, persevering, dynamic, austere restrictions, business environment, and stakeholder, strongly suggest the relevance of reconfiguring, a cluster of dynamic capabilities. Together, the dimensions demonstrate participants' strong commitment to navigate through the threat while pursuing socioeconomic sustainability.

COVID-19 and gastrointestinal symptoms in Mexico, a systematic review: does location matter?

BACKGROUND: Covid-19 in Mexico is on the rise in different parts of the country. We aimed to study the symptoms and comorbidities that associate with this pandemic in 3 different regions of Mexico. METHODS: We analyzed data from SARS-CoV-2 positive patients evaluated at healthcare centers and hospitals of Mexico (n = 1607) including Northwest Mexico (Sinaloa state), Southeast Mexico (Veracruz state) and West Mexico (Jalisco state) between March 1 and July 30, 2020. Mexico consists of a total population that exceeds 128 million. Demographics, comorbidities and clinical symptoms were collected. Statistical descriptive analysis and correlation analyses of symptoms, comorbidities and mortality were performed. RESULTS: A total of 1607 hospitalized patients positive for COVID-19 across all 3 regions of Mexico were included. The average age was 54.6 years and 60.4% were male. A mortality rate of 33.1% was observed. The most common comorbidities were hypertension (43.2%), obesity (30.3%) and diabetes (31.4%). Hypertension was more frequent in West (45%), followed by Northwest (37%) and Southeast Mexico (29%). Obesity was around 30% in Northwest and West whereas an 18% was reported in Southeast. Diabetes was most common in West (34%) followed by Northwest (22%) and Southeast (13%). This might be related to the highest mortality rate in Northwest (31%) and West (37%) when compared to Southeast. Most common symptoms in our overall cohort were fever (80.8%), cough (79.8%), headache (66%), dyspnea (71.1%), myalgia (53.8%), joints pain (50.8%) and odynophagia (34.8%). Diarrhea was the main gastrointestinal (GI) symptom (21.3%), followed by abdominal pain (18%), and nausea/ vomiting (4.5%). Diarrhea and abdominal pain were more common in West (23.1 and 21%), followed by Southeast (17.8, and 9.8%) and Northwest (11.4 and 3.1%). CONCLUSION: Our study showed a high mortality rate likely related to high frequencies of comorbidities (hypertension, obesity and diabetes). Mortality was different across regions. These discrepancies might be related to the differences in the frequencies of comorbidities, and partially attributed to differences in socio-economic conditions and quality of care. Thus, our findings stress the need for improved strategies to get better outcomes in our population.

COVID-19, aftermath, impacts, and hospitality firms: An international perspective.

Drawing on the theory of resilience, and on an international sample of 45 predominantly small hospitality businesses, this exploratory study extends knowledge about the key concerns, ways of coping, and the changes and adjustments undertaken by these firms' owners and managers during the COVID-19 outbreak. The various emergent relationships between the findings and the considered conceptual underpinnings of the literature on resilience, revealed nine theoretical dimensions. These dimensions critically illuminate and extend understanding concerning the actions and alternatives owners-managers resorted to when confronted with an extreme context. For instance, with financial impacts and uncertainty being predominant issues among participants, over one-third indicated actioning alternative measures to create much-needed revenue streams, and preparing for a new post-COVID-19 operational regime, respectively. Furthermore, 60 percent recognised making changes to the day-to-day running of the business to respond to initial impacts, or biding time in anticipation of a changing business and legal environment.

Can Herbivore-Induced Volatiles Protect Plants by Increasing the Herbivores' Susceptibility to Natural Pathogens?

In response to insect herbivory, plants mobilize various defenses. Defense responses include the release of herbivore-induced plant volatiles (HIPVs) that can serve as signals to alert undamaged tissues and to attract natural enemies of the herbivores. Some HIPVs can have a direct negative impact on herbivore survival, but it is not well understood by what mechanisms. Here, we tested the hypothesis that exposure to HIPVs renders insects more susceptible to natural pathogens. Exposure of the caterpillars of the noctuid Spodoptera exigua to indole and linalool, but not exposure to (Z)-3-hexenyl acetate, increased the susceptibility to Spodoptera exiguamultiple nucleopolyhedrovirus (SeMNPV). We also found that exposure to indole, but not exposure to linalool or (Z)-3-hexenyl acetate, increased the pathogenicity of Bacillus thuringiensis Additional experiments revealed significant changes in microbiota composition after forty-eight hours of larval exposure to indole. Overall, these results provide evidence that certain HIPVs can strongly enhance the susceptibility of caterpillars to pathogens, possibly through effects on the insect gut microbiota. These findings suggest a novel mechanism by which HIPVs can protect plants from herbivorous insects.IMPORTANCE Multitrophic interactions involving insect pests, their natural enemies, microorganisms, and plant hosts are increasingly being recognized as relevant factors in pest management. In response to herbivory attacks, plants activate a wide range of defenses that aim to mitigate the damage. Attacked plants release herbivore-induced plant volatiles (HIPVs), which can act as priming signals for other plants and attract natural enemies of herbivores, and which may have a direct negative impact on herbivore survival. In the present work, we show that exposure of the insects to the induced volatiles could increase the insects' susceptibility to the entomopathogens naturally occurring in the plant environment. These findings suggest a novel role for plant volatiles by influencing insect interactions with natural pathogens, probably mediated by alterations in the insect microbiota composition. In addition, this work provides evidence for selectable plant traits (production of secondary metabolites) that can have an influence on the ecology of the pests and could be relevant in the improvement of pest management strategies using natural entomopathogens.

Engineering of the baculovirus expression system for optimized protein production.

Baculoviruses are arthropod-specific large circular double-stranded DNA viruses successfully used for the control of multiple insect pests. In addition to their application in pest control, baculoviruses have become a versatile and powerful eukaryotic vector for the production of large quantities of recombinant proteins for research and biomedical purposes. Since the first recombinant protein was expressed in 1983 using the baculovirus expression system (BEVS), different strategies have been developed for the generation of recombinant viruses and to increase the stability, yield, and posttranslational modifications of recombinant proteins. In this review, we summarize the main methods and elements playing a role in the BEVS emphasizing recent progresses and future developments with respect to the main aspects involved in protein production using the BEVS.

Autophagy is activated and involved in cell death with participation of cathepsins during stress-induced microspore embryogenesis in barley.

Microspores are reprogrammed towards embryogenesis by stress. Many microspores die after this stress, limiting the efficiency of microspore embryogenesis. Autophagy is a degradation pathway that plays critical roles in stress response and cell death. In animals, cathepsins have an integral role in autophagy by degrading autophagic material; less is known in plants. Plant cathepsins are papain-like C1A cysteine proteases involved in many physiological processes, including programmed cell death. We have analysed the involvement of autophagy in cell death, in relation to cathepsin activation, during stress-induced microspore embryogenesis in Hordeum vulgare. After stress, reactive oxygen species (ROS) and cell death increased and autophagy was activated, including HvATG5 and HvATG6 up-regulation and increase of ATG5, ATG8, and autophagosomes. Concomitantly, cathepsin L/F-, B-, and H-like activities were induced, cathepsin-like genes HvPap-1 and HvPap-6 were up-regulated, and HvPap-1, HvPap-6, and HvPap-19 proteins increased and localized in the cytoplasm, resembling autophagy structures. Inhibitors of autophagy and cysteine proteases reduced cell death and promoted embryogenesis. The findings reveal a role for autophagy in stress-induced cell death during microspore embryogenesis, and the participation of cathepsins. Similar patterns of activation, expression, and localization suggest a possible connection between cathepsins and autophagy. The results open up new possibilities to enhance microspore embryogenesis efficiency with autophagy and/or cysteine protease modulators.

Antimicrobial Susceptibility of Cutibacterium acnes Isolated from Ecuadorian Patients with Acne Vulgaris.

Antimicrobial resistance to Cutibacterium acnes has become a worldwide problem in the last century, but there are no previous studies on antibiotic susceptibility patterns of this bacterium in Ecuador. A total of 129 skin swabs were collected from patients with acne vulgaris (AV) attending the dermatology department of a hospital in Quito, Ecuador, from July to August 2015. The patients selected had received registered antimicrobial therapy on at least one occasion before sampling. Microbiological procedures were performed according to conventional methods. The species of isolates were identified using a mass spectrometer system (matrix-assisted laser desorption ionization time-offlight [MALDI-TOF]). Antibiotic susceptibility tests on isolated Cutibacterium were performed using an anaerobe-sensitive panel (ANO2; Thermo Fisher; TREK Diagnostic Systems Ltd., West Sussex, UK).

Clinical features and short-term outcomes of cancer patients with suspected and unsuspected pulmonary embolism: the EPIPHANY study.

The study aimed to identify predictors of overall 30-day mortality in cancer patients with pulmonary embolism including suspected pulmonary embolism (SPE) and unsuspected pulmonary embolism (UPE) events. Secondary outcomes included 30- and 90-day major bleeding and venous thromboembolism (VTE) recurrence.The study cohort included 1033 consecutive patients with pulmonary embolism from the multicentre observational ambispective EPIPHANY study (March 2006-October 2014). A subgroup of 497 patients prospectively assessed for the study were subclassified into three work-up scenarios (SPE, truly asymptomatic UPE and UPE with symptoms) to assess outcomes.The overall 30-day mortality rate was 14%. The following variables were associated with the overall 30-day mortality on multivariate analysis: VTE history, upper gastrointestinal cancers, metastatic disease, cancer progression, performance status, arterial hypotension <100 mmHg, heart rate >110 beats·min-1, basal oxygen saturation <90% and SPE (versus overall UPE).The overall 30-day mortality was significantly lower in patients with truly asymptomatic UPE events (3%) compared with those with UPE-S (20%) and SPE (21%) (p<0.0001). Thirty- and 90-day VTE recurrence and major bleeding rates were similar in all the groups.In conclusion, variables associated with the severity of cancer and pulmonary embolism were associated with short-term mortality. Our findings may help to develop pulmonary embolism risk-assessment models in this setting.

Expression of the lef5 gene from Spodoptera exigua multiple nucleopolyhedrovirus contributes to the baculovirus stability in cell culture.

Baculoviruses are a broad group of viruses infecting insects, predominately of the order Lepidoptera. They are used worldwide as biological insecticides and as expression vectors to produce recombinant proteins. Baculoviruses replicate in their host, although several cell lines have been developed for in vitro replication. Nevertheless, replication of baculoviruses in cell culture involves the generation of defective viruses with a decrease in productivity and virulence. Transcriptional studies of the Spodoptera exigua multiple nucleopolyhedrovirus (SeMNPV) and the Autographa californica multiple nucleopolyhedrovirus (AcMNPV) infective process revealed differences in the expression patterns when the virus replicated under in vitro (Se301 cells) or in vivo (S. exigua larvae) conditions. The late expression factor 5 (lef5) gene was found to be highly overexpressed when the virus replicates in larvae. To test the possible role of lef5 expression in viral stability, recombinant AcMNPV expressing the lef5 gene from SeMNPV (Se-lef5) was generated and its stability was monitored during successive infection passages in Sf21 cells by evaluating the loss of several essential and non-essential genes. The gfp transgene was more stable in those viruses expressing the Se-LEF5 protein and the GFP-defective viruses were accumulated at a lower level when compared to its control viruses, confirming the positive influence of lef5 in viral stability during the multiplication process. This work describes for the first time a viral factor involved in transgene stability when baculoviruses replicate in cell culture, opening new ways to facilitate the in vitro production of recombinant proteins using baculovirus.

BnPME is progressively induced after microspore reprogramming to embryogenesis, correlating with pectin de-esterification and cell differentiation in Brassica napus.

BACKGROUND: Pectins are one of the main components of plant cell walls. They are secreted to the wall as highly methylesterified forms that can be de-esterified by pectin methylesterases (PMEs). The degree of methylesterification of pectins changes during development, PMEs are involved in the cell wall remodeling that occurs during diverse plant developmental processes. Nevertheless, the functional meaning of pectin-related wall remodeling in different cell types and processes remains unclear. In vivo, the microspore follows the gametophytic pathway and differentiates to form the pollen grain. In vitro, the microspore can be reprogrammed by stress treatments becoming a totipotent cell that starts to proliferate and follows the embryogenic pathway, a process known as microspore embryogenesis. RESULTS: To investigate if the change of developmental programme of the microspore towards embryogenesis involves changes in pectin esterification levels, which would cause the cell wall remodeling during the process, in the present study, dynamics of PME expression and degrees of pectin esterification have been analysed during microspore embryogenesis and compared with the gametophytic development, in Brassica napus. A multidisciplinary approach has been adopted including BnPME gene expression analysis by quantitative RT-PCR, fluorescence in situ hybridization, immuno-dot-blot and immunofluorescence with JIM5 and JIM7 antibodies to reveal low and highly-methylesterified pectins. The results showed that cell differentiation at advanced developmental stages involved induction of BnPME expression and pectin de-esterification, processes that were also detected in zygotic embryos, providing additional evidence that microspore embryogenesis mimics zygotic embryogenesis. By contrast, early microspore embryogenesis, totipotency and proliferation were associated with low expression of BnPME and high levels of esterified pectins. CONCLUSIONS: The results show that the change of developmental programme of the microspore involves changes in pectin esterification associated with proliferation and differentiation events, which may cause the cell wall remodeling during the process. The findings indicate pectin-related modifications in the cell wall during microspore embryogenesis, providing new insights into the role of pectin esterification and cell wall configuration in microspore totipotency, embryogenesis induction and progression.

Atypical diagnosis diagnosis by endoscopic capsule: Whipple's disease.

Whipple's disease is a chronic systemic infection produced by the actinomycete Tropheryma whipplei. Endoscopic tests are key in the diagnosis as they allow biopsy and histopathological examination for definitive diagnosis of this entity. We present a case of Whipple's disease where capsule endoscopy, uncommon for the diagnosis of this condition, was essential for it and its performance before and after antibiotic treatment allows to describe the macroscopic evolution of the findings in the small bowel. This case illustrates the utility of capsule endoscopy to allow complete examination of the small bowel disease in which up to 30% of patients may present with normal endoscopy.

Auxin Biosynthesis, Accumulation, Action and Transport are Involved in Stress-Induced Microspore Embryogenesis Initiation and Progression in Brassica napus.

Isolated microspores are reprogrammed in vitro by stress, becoming totipotent cells and producing embryos and plants via a process known as microspore embryogenesis. Despite the abundance of data on auxin involvement in plant development and embryogenesis, no data are available regarding the dynamics of auxin concentration, cellular localization and the expression of biosynthesis genes during microspore embryogenesis. This work involved the analysis of auxin concentration and cellular accumulation; expression of TAA1 and NIT2 encoding enzymes of two auxin biosynthetic pathways; expression of the PIN1-like efflux carrier; and the effects of inhibition of auxin transport and action by N-1-naphthylphthalamic acid (NPA) and α-(p-chlorophenoxy) isobutyric acid (PCIB) during Brassica napus microspore embryogenesis. The results indicated de novo auxin synthesis after stress-induced microspore reprogramming and embryogenesis initiation, accompanying the first cell divisions. The progressive increase of auxin concentration during progression of embryogenesis correlated with the expression patterns of TAA1 and NIT2 genes of auxin biosynthetic pathways. Auxin was evenly distributed in early embryos, whereas in heart/torpedo embryos auxin was accumulated in apical and basal embryo regions. Auxin efflux carrier PIN1-like gene expression was induced in early multicellular embryos and increased at the globular/torpedo embryo stages. Inhibition of polar auxin transport (PAT) and action, by NPA and PCIB, impaired embryo development, indicating that PAT and auxin action are required for microspore embryo progression. NPA also modified auxin embryo accumulation patterns. These findings indicate that endogenous auxin biosynthesis, action and polar transport are required in stress-induced microspore reprogramming, embryogenesis initiation and progression.

The impact of IFN-γ receptor on SLPI expression in active tuberculosis: association with disease severity.

Interferon (IFN)-γ displays a critical role in tuberculosis (TB), modulating the innate and adaptive immune responses. Previously, we reported that secretory leukocyte protease inhibitor (SLPI) is a pattern recognition receptor with anti-mycobacterial activity against Mycobacterium tuberculosis (Mtb). Herein, we determined whether IFN-γ modulated the levels of SLPI in TB patients. Plasma levels of SLPI and IFN-γ were studied in healthy donors (HDs) and TB patients. Peripheral blood mononuclear cells from HDs and patients with TB or defective IFN-γ receptor 1* were stimulated with Mtb antigen and SLPI, and IFN-γR expression levels were measured. Both SLPI and IFN-γ were significantly enhanced in plasma from those with TB compared with HDs. A direct association between SLPI levels and the severity of TB was detected. In addition, Mtb antigen stimulation decreased the SLPI produced by peripheral blood mononuclear cells from HDs, but not from TB or IFN-γR patients. Neutralization of IFN-γ reversed the inhibition of SLPI induced by Mtb antigen in HDs, but not in TB patients. Furthermore, recombinant IFN-γ was unable to modify the expression of SLPI in TB patients. Finally, IFN-γR expression was lower in TB compared with HD peripheral blood mononuclear cells. These results show that Mtb-induced IFN-γ down-modulated SLPI levels by signaling through the IFN-γR in HDs. This inhibitory mechanism was not observed in TB, probably because of the low expression of IFN-γR detected in these individuals.

Epigenetic changes accompany developmental programmed cell death in tapetum cells.

The tapetum, the nursing tissue inside anthers, undergoes cellular degradation by programmed cell death (PCD) during late stages of microspore-early pollen development. Despite the key function of tapetum, little is known about the molecular mechanisms regulating this cell death process in which profound nuclear and chromatin changes occur. Epigenetic features (DNA methylation and histone modifications) have been revealed as hallmarks that establish the functional status of chromatin domains, but no evidence on the epigenetic regulation of PCD has been reported. DNA methylation is accomplished by DNA methyltransferases, among which DNA methyl transferase 1 (MET1) constitutes one of the CG maintenance methyltransferase in plants, also showing de novo methyltransferase activity. In this work, the changes in epigenetic marks during the PCD of tapetal cells have been investigated by a multidisciplinary approach to reveal the dynamics of DNA methylation and the pattern of expression of MET1 in relation to the main cellular changes of this PCD process which have also been characterized in two species, Brassica napus and Nicotiana tabacum. The results showed that tapetum PCD progresses with the increase in global DNA methylation and MET1 expression, epigenetic changes that accompanied the reorganization of the nuclear architecture and a high chromatin condensation, activity of caspase 3-like proteases and Cyt c release. The reported data indicate a relationship between the PCD process and the DNA methylation dynamics and MET1 expression in tapetal cells, suggesting a possible new role for the epigenetic marks in the nuclear events occurring during this cell death process and providing new insights into the epigenetic control of plant PCD.

Early markers are present in both embryogenesis pathways from microspores and immature zygotic embryos in cork oak, Quercus suber L.

BACKGROUND: In Quercus suber, cork oak, a Mediterranean forest tree of economic and social interest, rapid production of isogenic lines and clonal propagation of elite genotypes have been achieved by developing in vitro embryogenesis from microspores and zygotic embryos respectively. Despite its high potential in tree breeding strategies, due to their recalcitrancy, the efficiency of embryogenesis in vitro systems in many woody species is still very low since factors responsible for embryogenesis initiation and embryo development are still largely unknown. The search for molecular and cellular markers during early stages of in vitro embryogenesis constitutes an important goal to distinguish, after induction, responsive from non-responsive cells, and to elucidate the mechanisms involved in embryogenesis initiation for their efficient manipulation. In this work, we have performed a comparative analysis of two embryogenesis pathways derived from microspores and immature zygotic embryos in cork oak in order to characterize early markers of reprogrammed cells in both pathways. Rearrangements of the cell structural organization, changes in epigenetic marks, cell wall polymers modifications and endogenous auxin changes were analyzed at early embryogenesis stages of the two in vitro systems by a multidisciplinary approach. RESULTS: Results showed that early embryo cells exhibited defined changes of cell components which were similar in both embryogenesis in vitro systems, cellular features that were not found in non-embryogenic cells. DNA methylation level and nuclear pattern, proportion of esterified pectins in cell walls, and endogenous auxin levels were different in embryo cells in comparison with microspores and immature zygotic embryo cells from which embryos originated, constituting early embryogenesis markers. CONCLUSIONS: These findings suggest that DNA hypomethylation, cell wall remodeling by pectin esterification and auxin increase are involved in early in vitro embryogenesis in woody species, providing new evidences of the developmental pattern similarity between both embryogenesis pathways, from microspores and immature zygotic embryos, in woody species.

Changes in DNA methylation levels and nuclear distribution patterns after microspore reprogramming to embryogenesis in barley.

Under specific stress treatments, the microspore can be induced in vitro to deviate from its gametophytic development and to reprogram towards embryogenesis, becoming a totipotent cell and forming haploid embryos. These can further regenerate homozygous plants for production of new isogenic lines, an important biotechnological tool for crop breeding. DNA methylation constitutes a prominent epigenetic modification of the chromatin fiber which regulates gene expression. Changes in DNA methylation accompany the reorganization of the nuclear architecture during plant cell differentiation and proliferation; however, the relationship between global DNA methylation and genome-wide expression patterns is still poorly understood. In this work, the dynamics of global DNA methylation levels and distribution patterns were analyzed during microspore reprogramming to embryogenesis and during pollen development in Hordeum vulgare. Quantification of global DNA methylation levels and 5-methyl-deoxycytidine (5mdC) immunofluorescence were conducted at specific stages of pollen development and after reprogramming to embryogenesis to analyze the epigenetic changes that accompany the change of developmental program and cell fate. The results showed low DNA methylation levels in microspores and a high increase along pollen development and maturation; an intense 5mdC signal was concentrated in the generative and sperm nuclei whereas the vegetative nucleus exhibited a weaker DNA methylation signal. After inductive stress treatment, low methylation levels and faint 5mdC signals were observed in nuclei of reprogrammed microspores and 2-4-cell proembryos. This data revealed a global DNA hypomethylation during the change of the developmental program and first embryogenic divisions. This is in contrast with the hypermethylation of generative and sperm cells of the male germline during pollen maturation, suggesting an epigenetic regulation after induction of microspore embryogenesis. At later embryogenesis stages, global DNA methylation progressively increased, accompanying embryo development and differentiation events like in zygotic embryos, corroborating that DNA methylation is critical for the regulation of gene expression in microspore embryogenesis.

Changes in histone methylation and acetylation during microspore reprogramming to embryogenesis occur concomitantly with Bn HKMT and Bn HAT expression and are associated with cell totipotency, proliferation, and differentiation in Brassica napus.

In response to stress treatments, microspores can be reprogrammed to become totipotent cells that follow an embryogenic pathway producing haploid and double-haploid embryos which are important biotechnological tools in plant breeding. Recent studies have revealed the involvement of DNA methylation in regulating this process, but no information is available on the role of histone modifications in microspore embryogenesis. Histone modifications are major epigenetic marks controlling gene expression during plant development and in response to environmental changes. Lysine methylation of histones, accomplished by histone lysine methyltransferases (HKMTs), can occur on different lysine residues, with histone H3K9 methylation being mainly associated with transcriptionally silenced regions. In contrast, histone H3 and H4 acetylation is carried out by histone acetyltransferases (HATs) and is associated with actively transcribed genes. In this work, we analyzed 3 different histone epigenetic marks: dimethylation of H3K9 (H3K9me2) and acetylation of H3 and H4 (H3Ac and H4Ac) during microspore embryogenesis in Brassica napus by Western blot and immunofluorescence assays. The expression patterns of histone methyltransferase BnHKMT and histone acetyltransferase BnHAT genes have also been analyzed by qPCR. Our results revealed different spatial and temporal distribution patterns for methylated and acetylated histone variants during microspore embryogenesis and their similarity with the expression profiles of BnHKMT and BnHAT, respectively. The data presented suggest the participation of H3K9me2 and HKMT in embryo cell differentiation and heterochromatinization events, whereas H3Ac, H4Ac, and HAT would be involved in transcriptional activation, totipotency, and proliferation events during cell reprogramming and embryo development.

Clinical and molecular characterization of a patient with 15q21.2q22.2 deletion syndrome.

We report on a 16-year-old girl with a complex phenotype, including intellectual disability, facial dysmorphisms, and obesity. During her infancy, she presented with weak sucking, global developmental delay, and later with excessive eating with central obesity. The girl was clinically diagnosed with probable Prader-Willi syndrome. Chromosomal analysis showed a de novo deletion 46,XX,del(15)(q21q22). However, the use of the Affymetrix CytoScan HD Array defined the exact breakpoints of the deleted 15q21q22 region. The imbalance, about 10.5 Mb in size, is to date the second largest deletion ever described in this chromosomal region. In addition, our patient carries a microdeletion in the 1q44 region and a gain in 9p24. The array result was arr[hg19] 9p24.1(6,619,823-6,749,335)×3, 1q44(248,688,586-248,795,277)×1, 15q21.2 q22.2(50,848,301-61,298,006)×1. Although our patient presents additional chromosomal alterations, we provide a correlation between the clinical findings and the phenotype of the 15q21 deletion syndrome.