Fatty Acid Profiles of Leishmania major Derived from Human and Rodent Hosts in Endemic Cutaneous Leishmaniasis Areas of Tunisia and Algeria

Leishmaniasis is a protozoal vector-borne disease that affects both humans and animals. In the Mediterranean Basin, the primary reservoir hosts of Leishmania spp. are mainly rodents and canids. Lipidomic approaches have allowed scientists to establish Leishmania spp. lipid profiles for the identification of cell stage specific biomarkers, drug mechanisms of action, and host immune response. Using an in silico approach of global network interaction between genes involved in fatty acid (FA) synthesis followed by the GC-MS approach, we were able to characterize the fatty acid profiles of L. major derived from human and rodent hosts. Our results revealed that the lipid profile of L. major showed similarities and differences with those already reported for other Leishmania species. Phospholipids are the predominant lipid class. FA composition of rodent parasites was characterized by a lower abundance of the precursor C18:2(n-6). One of the rodent clones, which also expressed the lowest lipid abundance in PL and TAG, was the least sensitive clone to the miltefosine drug and has the lowest infection efficiency. Our findings suggest that the lipid composition variation may explain the response of the parasite toward treatment and their ability to infect their host.

The Common Coordinate Framework (CCF) Organ VR Gallery

The CCF Organ VR Gallery lets the user explore 21 human organs, journeying from the Whole Body, to the Organ, to the Cell stage and back, presented in real-world size and 3D. The user discovers hidden regions by exploding and collapsing organs into their individual anatomical structures. We show cell type populations for a kidney using a data-driven dot density visualization. The organ models were developed to map trillions of cells for the Human BioMolecular Atlas Program (HuBMAP).

Red Fluorescent Protein Expression in Transgenic Founder of Angelfish (Pterophyllum sp) Driven by Zebrafish Myosin Light Chain 2 Promoter

Angelfish (Pterophyllum sp.) are attractive fish popular with aquarists. The introduction of fluorescent protein genes into angelfish has been reported, but specific techniques have not been revealed. This study aimed to develop a strategy to produce red fluorescent protein (RFP) transgenic angelfish driven by the myosin light chain 2 (mylz2) promoter from zebrafish. A 1999 bp Mylz2 promoter fragment was isolated from zebrafish muscle genomic DNA. This promoter fragment was then cloned into the plasmid pDsred2-1 open-loop at restriction enzyme SacI and AgeI sites to create the final transgene construct pMylz2-RFP. Angelfish embryos at one cell stage were microinjected with approximately 100 pg of the plasmid pMylz2-RFP. From 524 microinjected embryos, 16 successfully hatched, while 12 showed red fluorescence signals. Two larvae survived to 2 months of age. They showed significant red fluorescence expression in the muscles, suggesting that the angelfish could be used as potential transgenic founders to evaluate the next generation of stable red fluorescence expression transgenic fish.

Deletion of Orc4 during oogenesis severely reduces polar body extrusion and blocks zygotic DNA replication

Origin Recognition Complex subunit 4 (ORC4) is a DNA binding protein required for DNA replication. During oocyte maturation, after the last oocyte DNA replication step and before zygotic DNA replication, the oocyte undergoes two meiotic cell divisions in which half the DNA is ejected in much smaller polar bodies. We previously demonstrated that ORC4 forms a cytoplasmic cage around the DNA that is ejected in both polar body extrusion (PBE) events. Here, we used ZP3 activated Cre to delete exon 7 of Orc4 during oogenesis to test how it affected both predicted functions of ORC4: its recently discovered role in PBE and its well-known role in DNA synthesis. Orc4 deletion severely reduced PBE. Almost half of Orc4-depleted GV oocytes cultured in vitro arrested before anaphase I (48%), and only 25% produced normal first polar bodies. This supports the role of ORC4 in PBE and suggests that transcription of the full length Orc4 during oogenesis is required for efficient PBE. Orc4 deletion also abolished zygotic DNA synthesis. A reduced number of Orc4-depleted oocytes developed to the MII stage and after activation these oocytes arrested at the 2-cell stage, without undergoing DNA synthesis. This confirms that transcription of full length Orc4 after the primary follicle stage is required for zygotic DNA replication. The data also suggest that MII oocytes do not have a replication licensing checkpoint since cytokinesis progressed without DNA synthesis. Together the data confirm that oocyte ORC4 is important for both PBE and zygotic DNA synthesis.

Differential Expression Profiles and Potential Intergenerational Functions of tRNA-Derived Small RNAs in Mice After Cadmium Exposure

Cadmium (Cd) is a toxic heavy metal and ubiquitous environmental endocrine disruptor. Previous studies on Cd-induced damage to male fertility mainly focus on the structure and function of testis, including cytoskeleton, blood-testis barrier, and steroidogenesis. Nevertheless, to date, no studies have investigated the effects of Cd exposure on sperm epigenetic inheritance and intergenerational inheritance. In our study, we systematically revealed the changes in sperm tRNA-derived small RNAs (tsRNA) profiles and found that 14 tsRNAs (9 up-regulated and 5 down-regulated) were significantly altered after Cd exposure. Bioinformatics of tsRNA-mRNA-pathway interactions revealed that the altered biological functions mainly were related to ion transmembrane transport, lipid metabolism and cell membrane system. In addition, we focused on two stages of early embryo development and selected two organs to study the impact of these changes on cell membrane system, especially mitochondrion and lysosome, two typical membrane-enclosed organelles. Surprisingly, we found that the content of mitochondrion was significantly decreased in 2-cell stage, whereas remarkably increased in the morula stage. The contents of mitochondrion and lysosome were increased in the testes of 6-day-old offspring and livers of adult offspring, whereas remarkably decreased in the testes of adult offspring. This provides a possible basis to further explore the effects of paternal Cd exposure on offspring health.

Arginine Regulates Zygotic Genome Activation in Porcine Embryos through Promoting Polyamine Synthesis☆

Background:Arginine has a positive effect on preimplantation development in pigs. However, the exact mechanism by which arginine promotes embryonic development to the blastocyst stage is not undefined. Here, single-cell RNA-sequencing technology was applied to porcine in vivo pre-implantation embryos from zygote to morula to determine transcription patterns of arginine metabolism-related genes during preimplantation embryonic development.Results:Transcriptome sequencing showed that arginine metabolism-related genes clearly changed from the 2-cell stage to the 4-cell stage, where zygotic genome activation (ZGA) occurred in porcine embryos. Further analysis of the correlation between arginine metabolism and ZGA shows that arginine metabolism-related genes are significantly correlated with key ZGA genes such as ZSCAN4, DPPA2 and EIF1A, indicating that arginine metabolism may be an indicator of porcine ZGA. To explore the correlation between arginine metabolism and ZGA, embryos cultured in the medium that removes all the amino acids, proteins and pyruvate in the PZM3 medium were employed to generate the ZGA blocked embryo model. The 4-cell arrest rate significantly increased at 72 h after activation, indicating impeded embryonic development. Meanwhile, results of immunofluorescent staining showed that the expression of SIRT1 protein during ZGA was significantly inhibited. Results of quantitative PCR showed that the expression of zygotic genes (ZSCAN4, DPPA2 and EIF1A) was significantly decreased. The above results indicate that the ZGA blocked embryo model was successfully established. Adding of arginine recovered embryonic development, SIRT1 and zygotic genes expression levels and initiated the ZGA. In addition, ROS content significantly increased when ZGA was blocked, and the GSH, ATP and lipid droplet content significantly decreased. After the addition of arginine in the block group, the ROS content significantly decreased, and the GSH, ATP and lipid droplet content significantly increased. Moreover, the ornithine decarboxylase (ODC) inhibitor difluoromethylornithine (DFMO) and arginine were added to the block group at the same time, and the effect of arginine was found to be inhibited. Conclusions: Arginine is essential for ZGA in porcine embryos. Arginine contributes to porcine ZGA by promoting polyamine synthesis in porcine embryos.

A Decade of Molecular Preimplantation Genetic Diagnosis of 350 Blastomeres for Beta-Thalassemia Combined with HLA Typing, Aneuploidy Screening and Sex Selection in Iran

Background: Preimplantation genetic diagnosis (PGD) has been developed to detect genetic disorders before pregnancy which is usually done on blastomeres biopsied from 8-cell stage embryos obtained from in vitro fertilization method (IVF).Here we report molecular PGD results for diagnosing of beta thalassemia (beta-thal) which are usually accompanied with evaluating chromosomal aneuploidies, HLA typing and sex selection.Methods: In this study, haplotype analysis was performed using short tandem repeats (STRs) in a multiplex nested PCR and the causative mutation was detected by Sanger sequencing.Results: We have performed PGDs on 350 blastomeres from 55 carrier couples; 142 blastomeres for beta-thal only, 75 for beta-thal and HLA typing, 76 for beta-thal in combination with sex selection, and 57 for beta-thal and aneuploidy screening. 150 blastomeres were transferable, 15 pregnancies were happened, and 11 babies born.We used 6 markers for beta-thal, 36 for aneuploidy screening, 32 for sex selection, and 35 for HLA typing. To our knowledge combining all these markers together and the number of STR markers are much more than any other studies which have ever done.Conclusions: PGD is a powerful diagnostic tool for carrier couples who desire to have a healthy child and wish to avoid medical abortion.

Whole-Genome DNA Methylation Dynamics of Sheep Preimplantation Embryo Investigated by Single-Cell DNA Methylome Sequencing

The early stages of mammalian embryonic development involve the participation and cooperation of numerous complex processes, including nutritional, genetic, and epigenetic mechanisms. However, in embryos cultured in vitro, a developmental block occurs that affects embryo development and the efficiency of culture. Although the block period is reported to involve the transcriptional repression of maternal genes and transcriptional activation of zygotic genes, how epigenetic factors regulate developmental block is still unclear. In this study, we systematically analyzed whole-genome methylation levels during five stages of sheep oocyte and preimplantation embryo development using single-cell level whole genome bisulphite sequencing (SC-WGBS) technology. Then, we examined several million CpG sites in individual cells at each evaluated developmental stage to identify the methylation changes that take place during the development of sheep preimplantation embryos. Our results showed that two strong waves of methylation changes occurred, namely, demethylation at the 8-cell to 16-cell stage and methylation at the 16-cell to 32-cell stage. Analysis of DNA methylation patterns in different functional regions revealed a stable hypermethylation status in 3′UTRs and gene bodies; however, significant differences were observed in intergenic and promoter regions at different developmental stages. Changes in methylation at different stages of preimplantation embryo development were also compared to investigate the molecular mechanisms involved in sheep embryo development at the methylation level. In conclusion, we report a detailed analysis of the DNA methylation dynamics during the development of sheep preimplantation embryos. Our results provide an explanation for the complex regulatory mechanisms underlying the embryo developmental block based on changes in DNA methylation levels.

Case Report: Persistent Hypogammaglobulinemia More Than 10 Years After Rituximab Given Post-HSCT

Rituximab (RTX) is an anti-CD20 monoclonal antibody that targets B cells—from the immature pre-B-cell stage in the bone marrow to mature circulating B cells—while preserving stem cells and plasma cells. It is used to treat autoimmune diseases, hematological malignancies, or complications after hematopoietic stem cell transplantation (HSCT). Its safety profile is acceptable; however, a subset of patients can develop persistent hypogammaglobulinemia and associated severe complications, especially in pediatric populations. We report the unrelated cases of two young men aged 17 and 22, presenting with persistent hypogammaglobulinemia more than 7 and 10 years after treatment with RTX, respectively, and administered after HSCT for hemolytic anemia and Epstein–Barr virus reactivation, respectively. Both patients’ immunological workups showed low levels of total immunoglobulin, vaccine antibodies, and class switched-memory B cells but an increase in naive B cells, which can also be observed in primary immunodeficiencies such as those making up common variable immunodeficiency. Whole exome sequencing for one of the patients failed to detect a pathogenic variant causing a Mendelian immunological disorder. Annual assessments involving interruption of immunoglobulin replacement therapy each summer failed to demonstrate the recovery of endogenous immunoglobulin production or normal numbers of class switched-memory B cells 7 and 10 years after the patients’ respective treatments with RTX. Although the factors that may lead to prolonged hypogammaglobulinemia after rituximab treatment (if necessary) remain unclear, a comprehensive immunological workup before treatment and long-term follow-up are mandatory to assess long-term complications, especially in children.

Human embryos arrest in a quiescent-like state characterized by metabolic and zygotic genome activation problems

Around 60% of in vitro fertilized (IVF) human embryos irreversibly arrest before compaction between the 3-8-cell stage, posing a significant clinical problem. The mechanisms behind this arrest are unclear. Here, we show that the arrested embryos enter a quiescent-like state, marked by cell cycle arrest, the downregulation of ribosomes and histones and downregulation of MYC and p53 activity. Mechanistically, the arrested embryos can be divided into three types. Type I embryos fail to complete the maternal-zygotic transition, and type II/III embryos have erroneously low levels of glycolysis and variable levels of oxidative phosphorylation. Treatment with resveratrol or nicotinamide riboside (NR) can partially rescue the arrested phenotype. The mechanism of reactivation involves the upregulation of SIRT1, and activation of glycolysis and fatty acid oxidation which forces the embryos out of a quiescent state. Overall, our data reveal how human embryo arrest can be overcome by modulating metabolic pathways.