Conserved expression of the PRELI domain containing 2 gene (Prelid2) during mid-later-gestation mouse embryogenesis

Cells of the adult human heart

Cardiovascular disease is the leading cause of death worldwide. Advanced insights into disease mechanisms and therapeutic strategies require a deeper understanding of the molecular processes involved in the healthy heart. Knowledge of the full repertoire of cardiac cells and their gene expression profiles is a fundamental first step in this endeavour. Here, using state-of-the-art analyses of large-scale single-cell and single-nucleus transcriptomes, we characterize six anatomical adult heart regions. Our results highlight the cellular heterogeneity of cardiomyocytes, pericytes and fibroblasts, and reveal distinct atrial and ventricular subsets of cells with diverse developmental origins and specialized properties. We define the complexity of the cardiac vasculature and its changes along the arterio-venous axis. In the immune compartment, we identify cardiac-resident macrophages with inflammatory and protective transcriptional signatures. Furthermore, analyses of cell-to-cell interactions highlight different networks of macrophages, fibroblasts and cardiomyocytes between atria and ventricles that are distinct from those of skeletal muscle. Our human cardiac cell atlas improves our understanding of the human heart and provides a valuable reference for future studies.

Genome-wide association study for reproductive traits in a Large White pig population

Using the PorcineSNP80 BeadChip, we performed a genome‐wide association study for seven reproductive traits, including total number born, number born alive, litter birth weight, average birth weight, gestation length, age at first service and age at first farrowing, in a population of 1207 Large White pigs. In total, we detected 12 genome‐wide significant and 41 suggestive significant SNPs associated with six reproductive traits. The proportion of phenotypic variance explained by all significant SNPs for each trait ranged from 4.46% (number born alive) to 11.49% (gestation length). Among them, 29 significant SNPs were located within known QTL regions for swine reproductive traits, such as corpus luteum number, stillborn number and litter size, of which one QTL region associated with litter size contained the ALGA0098819 SNP for total number born. Subsequently, we found that 376 functional genes contained or were near these significant SNPs. Of these, 14 genes—BHLHA15, OCM2, IL1B2, GCK, SMAD2, HABP2, PAQR5, GRB10, PRELID2, DMKN, GPI, GPIHBP1, ADCY2 and ACVR2B—were considered important candidates for swine reproductive traits based on their critical roles in embryonic development, energy metabolism and growth development. Our findings contribute to the understanding of the genetic mechanisms for reproductive traits and could have a positive effect on pig breeding programs.

Phosphatidylserine transport by Ups2-Mdm35 in respiration-active mitochondria

Phosphatidylethanolamine, an essential phospholipid for mitochondrial functions, is synthesized at the mitochondrial inner membrane. Miyata et al. demonstrate that Ups2–Mdm35, a protein complex in the mitochondrial intermembrane space, mediates phosphatidylserine transport for phosphatidylethanolamine synthesis in respiration-active mitochondria of Saccharomyces cerevisiae.

Phosphatidylethanolamine (PE) is an essential phospholipid for mitochondrial functions and is synthesized mainly by phosphatidylserine (PS) decarboxylase at the mitochondrial inner membrane. In Saccharomyces cerevisiae, PS is synthesized in the endoplasmic reticulum (ER), such that mitochondrial PE synthesis requires PS transport from the ER to the mitochondrial inner membrane. Here, we provide evidence that Ups2–Mdm35, a protein complex localized at the mitochondrial intermembrane space, mediates PS transport for PE synthesis in respiration-active mitochondria. UPS2- and MDM35-null mutations greatly attenuated conversion of PS to PE in yeast cells growing logarithmically under nonfermentable conditions, but not fermentable conditions. A recombinant Ups2–Mdm35 fusion protein exhibited phospholipid-transfer activity between liposomes in vitro. Furthermore, UPS2 expression was elevated under nonfermentable conditions and at the diauxic shift, the metabolic transition from glycolysis to oxidative phosphorylation. These results demonstrate that Ups2–Mdm35 functions as a PS transfer protein and enhances mitochondrial PE synthesis in response to the cellular metabolic state.

Identification of two inherited copy number variants in a male with autism supports two-hit and compound heterozygosity models of autism

Autism is a childhood-onset neurodevelopmental disorder with complex genetic mechanism underlying its etiology. Recent studies revealed that a few single de novo copy number variants of genomic DNA (copy number variants [CNVs]) are pathogenic and causal in some sporadic cases, adding support to the hypothesis that some sporadic autism might be caused by single rare mutation with large clinical effect. In this study, we report the detection of two novel private CNVs simultaneously in a male patient with autism. These two CNVs include a microduplication of ~4.5 Mb at chromosome 4q12-13.1 that was transmitted from his mother and a microdeletion of ~1.8 Mb at 5q32 that was transmitted from his father. Several genes such as LPHN3, POU4F3, SH3RF2, and TCERG1 mapped to these two regions have psychiatric implications. However, the parents had only mild degree of attention deficit symptoms but did not demonstrate any obvious autistic symptoms or psychopathology. Our findings indicate that each of these two CNVs alone may not be pathogenic enough to cause clinical symptoms in their respective carriers, and hence they can be transmitted within each individual family. However, concomitant presence of these two CNVs might result in the clinical phenotypes of the affected patient reported here. Thus, our report of this family may represent an example to show that two hits of CNV and the presence of compound heterozygosity might be important mechanisms underlying the pathogenesis of autism.

Imprinting and expression analysis of a non-coding RNA gene in the mouse Dlk1-Dio3 domain

The Dlk1-Dio3 imprinted domain not only is implicated growth and development of the embryo and placenta, but also affects adult metabolism and brain function. In this study, we identified the imprinting status of a mouse non-coding RNA gene, B830012L14Rik, mapped to the Dlk1-Dio3 domain by the polymorphism- and sequencing-based approach. Imprinting analysis showed that the gene was expressed maternally at E15.5, E18.5 and postnatal day 1 mice. Two transcripts of approximately 1.9 and 3.5 kb were detected by northern blot. Furthermore, we examined the spatiotemporal expression patterns of the gene during the mouse development. In situ hybridization analysis showed that B830012L14Rik was mainly expressed in forebrain, pituitary, cartilage primordium of spinal column, lung and liver at E13.5 and E15.5. The results of real-time quantitative RT-PCR showed that the B830012L14Rik expression in brain, heart, lung and liver was higher at E15.5 than at E12.5 and E18.5. Furthermore, the gene expression increased progressively in brain from E12.5 to E15.5 whereas decreased from E15.5 to E19.5. This study may provide further insights into the imprinting, genomic features and expression regulation of the Dlk1-Dio3 imprinted cluster.

Chromosomal minimal critical regions in therapy-related leukemia appear different from those of de novo leukemia by high-resolution aCGH

Therapy-related acute leukemia (t-AML), is a severe complication of cytotoxic therapy used for primary cancer treatment. The outcome of these patients is poor, compared to people who develop de novo acute leukemia (p-AML). Cytogenetic abnormalities in t-AML are similar to those found in p-AML but present more frequent unfavorable karyotypes depending on the inducting agent. Losses of chromosome 5 or 7 are observed after alkylating agents while balanced translocations are found after topoisomerase II inhibitors. This study compared t-AML to p-AML using high resolution array CGH in order to find copy number abnormalities (CNA) at a higher resolution than conventional cytogenetics. More CNAs were observed in 30 t-AML than in 36 p-AML: 104 CNAs were observed with 63 losses and 41 gains (mean number 3.46 per case) in t-AML, while in p-AML, 69 CNAs were observed with 32 losses and 37 gains (mean number of 1.9 per case). In primary leukemia with a previously "normal" karyotype, 18% exhibited a previously undetected CNA, whereas in the (few) t-AML with a normal karyotype, the rate was 50%. Several minimal critical regions (MCRs) were found in t-AML and p-AML. No common MCRs were found in the two groups. In t-AML a 40 kb deleted MCR pointed to RUNX1 on 21q22, a gene coding for a transcription factor implicated in frequent rearrangements in leukemia and in familial thrombocytopenia. In de novo AML, a 1 Mb MCR harboring ERG and ETS2 was observed from patients with complex aCGH profiles. High resolution cytogenomics obtained by aCGH and similar techniques already published allowed us to characterize numerous non random chromosome abnormalities. This work supports the hypothesis that they can be classified into several categories: abnormalities common to all AML; those more frequently found in t-AML and those specifically found in p-AML.