DNA N6-Methyladenosine modification role in transmitted variations from genomic DNA to RNA in Herrania umbratica.

BACKGROUND: DNA methylation is an important epigenetic modification. Recently the developed single-molecule real-time (SMRT) sequencing technology provided an efficient way to detect DNA N6-methyladenine (6mA) modification that played an important role in epigenetic and positively regulated gene expression. In addition, the gene expression was also regulated by genetic variation. However, the relationship between DNA 6mA modification and variation is still unknown. RESULTS: We collected the SMRT long-reads DNA, Illumina short reads DNA and RNA datasets from the young leaves of Herrania umbratica, and used them to detect 35,654 6mA modification sites, 829,894 DNA variations and 60,672 RNA variations respectively, among which, there are 303 DNA variations and 19 RNA variations with 6mA modification, and 57,468 transmitted genetic variations from DNA to RNA. The results illustrated that the genes with 6mA modification were significant disadvantage to mutate than those genes without modification (p-value< 4.9e-08). And result from the linear regression model showed the 6mA densities of genes were associated with the transmitted variations type 0/1 to 1/1 (p-value < 0.001). CONCLUSIONS: The variations of DNA and RNA in genes with 6mA modification were significant less than those in unmodified genes. Furthermore, the variations in 6mA modified genes were easily transmitted from DNA to RNA, especially the transmitted variation from DNA heterozygote to RNA homozygote.

The causative variants of amyloidosis in the autism.

PURPOSE: Autism spectrum disorders (ASD) consist of a group of neurodevelopmental disorders that include autistic behavior, Asperger's syndrome and pervasive developmental disabilities. According to the increasing observations that patients with mitochondrial disorders have symptoms associated with ASD, we have aimed to analyze the role of mitochondrial DNA (mtDNA) variation in autistic patients. MATERIAL AND METHODS: We selected children with autistic behaviors (15-60 CARS Score). The mitochondrial DNA extraction process was done by GeNet Bio DNA extraction kit. The regions of interest were amplified using independent PCR runs. After purification of PCR products, both strands were sequenced by Big Dye Termination system in a directly determined automated sequencing on an ABI 3700 capillary sequencer machine using both primers. All sequencing results were analyzed using bioinformatics' tools sequencher software 5. RESULTS: In this study, 31 samples were examined, which 15 unique variants were detected in genes related to COXI-III. The most frequent variant (30.76%) were related to COX1 with amino acid change A â†’ A. The only significant pathogenic variant was C8264G, except for C8264G, all variants seemed to be homoplasmic substitution. CONCLUSION: In our study, among the variations we found, one variant what probably had an interesting association with possible amyloidosis, had been reported in patient with autism previously. It is hoped that with finding more definable genetic and biological markers, the autistic children diagnosis and treatment will be more effective.

Use of next-generation sequencing to detect LDLR gene copy number variation in familial hypercholesterolemia.

Familial hypercholesterolemia (FH) is a heritable condition of severely elevated LDL cholesterol, caused predominantly by autosomal codominant mutations in the LDL receptor gene (LDLR). In providing a molecular diagnosis for FH, the current procedure often includes targeted next-generation sequencing (NGS) panels for the detection of small-scale DNA variants, followed by multiplex ligation-dependent probe amplification (MLPA) in LDLR for the detection of whole-exon copy number variants (CNVs). The latter is essential because ∼10% of FH cases are attributed to CNVs in LDLR; accounting for them decreases false negative findings. Here, we determined the potential of replacing MLPA with bioinformatic analysis applied to NGS data, which uses depth-of-coverage analysis as its principal method to identify whole-exon CNV events. In analysis of 388 FH patient samples, there was 100% concordance in LDLR CNV detection between these two methods: 38 reported CNVs identified by MLPA were also successfully detected by our NGS method, while 350 samples negative for CNVs by MLPA were also negative by NGS. This result suggests that MLPA can be removed from the routine diagnostic screening for FH, significantly reducing associated costs, resources, and analysis time, while promoting more widespread assessment of this important class of mutations across diagnostic laboratories.

Comparative DNA sequence analyses of Pyramimonas parkeae (Prasinophyceae) chloroplast genomes.

Prasinophytes form a paraphyletic assemblage of early diverging green algae, which have the potential to reveal the traits of the last common ancestor of the main two green lineages: (i) chlorophyte algae and (ii) streptophyte algae. Understanding the genetic composition of prasinophyte algae is fundamental to understanding the diversification and evolutionary processes that may have occurred in both green lineages. In this study, we sequenced the chloroplast genome of Pyramimonas parkeae NIES254 and compared it with that of P. parkeae CCMP726, the only other fully sequenced P. parkeae chloroplast genome. The results revealed that P. parkeae chloroplast genomes are surprisingly variable. The chloroplast genome of NIES254 was larger than that of CCMP726 by 3,204 bp, the NIES254 large single copy was 288 bp longer, the small single copy was 5,088 bp longer, and the IR was 1,086 bp shorter than that of CCMP726. Similarity values of the two strains were almost zero in four large hot spot regions. Finally, the strains differed in copy number for three protein-coding genes: ycf20, psaC, and ndhE. Phylogenetic analyses using 16S and 18S rDNA and rbcL sequences resolved a clade consisting of these two P. parkeae strains and a clade consisting of these plus other Pyramimonas isolates. These results are consistent with past studies indicating that prasinophyte chloroplast genomes display a higher level of variation than is commonly found among land plants. Consequently, prasinophyte chloroplast genomes may be less useful for inferring the early history of Viridiplantae than has been the case for land plant diversification.

Natural insertions in rice commonly form tandem duplications indicative of patch-mediated double-strand break induction and repair.

The insertion of DNA into a genome can result in the duplication and dispersal of functional sequences through the genome. In addition, a deeper understanding of insertion mechanisms will inform methods of genetic engineering and plant transformation. Exploiting structural variations in numerous rice accessions, we have inferred and analyzed intermediate length (10-1,000 bp) insertions in plants. Insertions in this size class were found to be approximately equal in frequency to deletions, and compound insertion-deletions comprised only 0.1% of all events. Our findings indicate that, as observed in humans, tandem or partially tandem duplications are the dominant form of insertion (48%), although short duplications from ectopic donors account for a sizable fraction of insertions in rice (38%). Many nontandem duplications contain insertions from nearby DNA (within 200 bp) and can contain multiple donor sources--some distant--in single events. Although replication slippage is a plausible explanation for tandem duplications, the end homology required in such a model is most often absent and rarely is >5 bp. However, end homology is commonly longer than expected by chance. Such findings lead us to favor a model of patch-mediated double-strand-break creation followed by nonhomologous end-joining. Additionally, a striking bias toward 31-bp partially tandem duplications suggests that errors in nucleotide excision repair may be resolved via a similar, but distinct, pathway. In summary, the analysis of recent insertions in rice suggests multiple underappreciated causes of structural variation in eukaryotes.

Mitochondrial DNA sequence variation is largely conserved at birth with rare de novo mutations in neonates.

OBJECTIVE: Mitochondrial DNA (mtDNA) encodes the proteins of the electron transfer chain to produce adenosine triphosphate through oxidative phosphorylation, and is essential to sustain life. mtDNA is unique from the nuclear genome in so much as it is solely maternally inherited (non-mendelian patterning), and shows a relatively high rate of mutation due to the absence of error checking capacity. While it is generally assumed that most new mutations accumulate through the process of heteroplasmy, it is unknown whether mutations initiated in the mother are inherited, occur in utero, or occur and accumulate early in life. The purpose of this study is to examine the maternally heritable and de novo mutation rate in the fetal mtDNA through high-fidelity sequencing from a large population-based cohort. STUDY DESIGN: Samples were obtained from 90 matched maternal (blood) and fetal (placental) pairs. In addition, a smaller cohort (n = 5) of maternal (blood), fetal (placental), and neonatal (cord blood) trios were subjected to DNA extraction and shotgun sequencing. The whole genome was sequenced on the Illumina HiSeq platform (Illumina Inc., San Diego, CA), and haplogroups and mtDNA variants were identified through mapping to reference mitochondrial genomes (NC_012920). RESULTS: We observed 665 single nucleotide polymorphisms and 82 insertions-deletions variants identified in the cohort at large. We achieved high sequencing depth of the mtDNA to an average depth of 65X (range, 20-171X) coverage. The proportions of haplogroups identified in the cohort are consistent with the patient's self-identified ethnicity (>90% Hispanic), and all maternal-fetal pairs mapped to the identical haplogroup. Only variants from samples with average depth >20X and allele frequency >1% were included for further analysis. While the majority of the maternal-fetal pairs (>90%) demonstrated identical variants at the single nucleotide level, we observed rare mitochondrial single nucleotide polymorphism discordance between maternal and fetal mitochondrial genomes. CONCLUSION: In this first in-depth sequencing analysis of mtDNA from maternal-fetal pairs at the time of birth, a low rate of de novo mutations appears in the fetal mitochondrial genome. This implies that these mutations likely arise from the maternal heteroplasmic pool (eg, in the oocyte), and accumulate later in the offspring's life. These findings have key implications for both the occurrence and screening for mitochondrial disorders.

BGMUT Database of Allelic Variants of Genes Encoding Human Blood Group Antigens.

The Blood group antigen Gene MUTation (BGMUT) database documents variations in genes of human blood group systems. In March 2014, the database, accessible at www.ncbi.nlm.nih.gov/gv/mhc/xslcgi.cgi?cmd=bgmut, listed 1,545 alleles of 44 genes of 34 blood group systems. Besides allelic information, the BGMUT resource also presents comprehensive and current information on blood group systems. This review describes the database and notes its utility for the transfusion medicine and human genetics communities.

Humanin variant P3S is associated with longevity in APOE4 carriers and resists APOE4-induced brain pathology.

The APOE4 allele is recognized as a significant genetic risk factor to Alzheimer's disease (AD) and influences longevity. Nonetheless, some APOE4 carriers exhibit resistance to AD even in advanced age. Humanin, a mitochondrial-derived peptide comprising 24 amino acids, has variants linked to cognitive resilience and longevity. Our research uncovered a unique humanin variant, P3S, specifically enriched in centenarians with the APOE4 allele. Through in silico analyses and subsequent experimental validation, we demonstrated a strong affinity between humanin P3S and APOE4. Utilizing an APOE4-centric mouse model of amyloidosis (APP/PS1/APOE4), we observed that humanin P3S significantly attenuated brain amyloid-beta accumulation compared to the wild-type humanin. Transcriptomic assessments of mice treated with humanin P3S highlighted its potential mechanism involving the enhancement of amyloid beta phagocytosis. Additionally, in vitro studies corroborated humanin P3S's efficacy in promoting amyloid-beta clearance. Notably, in the temporal cortex of APOE4 carriers, humanin expression is correlated with genes associated with phagocytosis. Our findings suggest a role of the rare humanin variant P3S, especially prevalent among individuals of Ashkenazi descent, in mitigating amyloid beta pathology and facilitating phagocytosis in APOE4-linked amyloidosis, underscoring its significance in longevity and cognitive health among APOE4 carriers.

[Characterization of sequences, expression profiling, and natural allelic variation analysis of the MYC gene family in sorghum (Sorghum bicolor)].

Sorghum aphid (Melanaphis sacchari) and head smut fungi (Sporisorium reilianum) infesting sorghum cause delayed growth and development, and reduce yield and quality. This study use bioinformatics and molecular biological approaches to profile the gene expression pattern during sorghum development and under pest infestation, and analyzed the natural allelic DNA variation of sorghum MYC gene family. The findings provide insights for potential application in breeding the stress resistant and high productivity sorghum varieties. The results indicated that there are 28 MYC genes identified in sorghum genome, distributed on 10 chromosomes. The bHLH_MYC_N and HLH domains are the conserved domains of the MYC gene in sorghum. Gene expression analysis showed that SbbHLH35.7g exhibited high expression levels in leaves, SbAbaIn showed strong expression in early grains, and SbMYC2.1g showed high expression levels in mature pollen. In anti-aphid strains at the 5-leaf stage, SbAbaIn, SbLHW.4g and SbLHW.2g were significantly induced in leaves, while SbbHLH35.7g displayed the highest expression level in panicle tissue, which was significantly induced by the infection of head smut. Promoter cis-element analysis identified methyl jasmonate (MJ), abscisic acid (ABA), salicylic acid (SA) and MYB-binding sites related to drought-stress inducibility. Furthermore, genomic resequencing data analysis revealed natural allelic DNA variations such as single nucleotide polymorphism (SNP) and insertion-deletion (INDEL) for the key SbMYCs. Protein interaction network analysis using STRING indicated that SbAbaIn interacts with TIFYdomain protein, and SbbHLH35.7g interacts with MDR and imporin. SbMYCs exhibited temporal and spatial expression patterns and played vital roles during the sorghum development. Infestation by sugarcane aphids and head smut fungi induced the expression of SbAbaIn and SbbHLH35.7g, respectively. SbAbaIn modulated the jasmonic acid (JA) pathway to regulate the expression of defensive genes, conferring resistance to insects. On the other hand, SbbHLH35.7g participated in detoxification reactions to defend against pathogens.

[Identification, expression and DNA variation analysis of high affinity nitrate transporter NRT2/3 gene family in Sorghum bicolor].

Nitrate is the main form of inorganic nitrogen that crop absorbs, and nitrate transporter 2 (NRT2) is a high affinity transporter using nitrate as a specific substrate. When the available nitrate is limited, the high affinity transport systems are activated and play an important role in the process of nitrate absorption and transport. Most NRT2 cannot transport nitrates alone and require the assistance of a helper protein belonging to nitrate assimilation related family (NAR2) to complete the absorption or transport of nitrates. Crop nitrogen utilization efficiency is affected by environmental conditions, and there are differences between varieties, so it is of great significance to develop varieties with high nitrogen utilization efficiency. Sorghum bicolor has high stress tolerance and is more efficient in soil nitrogen uptake and utilization. The S. bicolor genome database was scanned to systematically analyze the gene structure, chromosomal localization, physicochemical properties, secondary structure and transmembrane domain, signal peptide and subcellular localization, promoter region cis-acting elements, phylogenetic evolution, single nucleotide polymorphism (SNP) recognition and annotation, and selection pressure of the gene family members. Through bioinformatics analysis, 5 NRT2 gene members (designated as SbNRT2-1a, SbNRT2-1b, SbNRT2-2, SbNRT2-3, and SbNRT2-4) and 2 NAR2 gene members (designated as SbNRT3-1 and SbNRT3-2) were identified, the number of which was less than that of foxtail millet. SbNRT2/3 were distributed on 3 chromosomes, and could be divided into four subfamilies. The genetic structure of the same subfamilies was highly similar. The average value of SbNRT2/3 hydrophilicity was positive, indicating that they were all hydrophobic proteins, whereas α-helix and random coil accounted for more than 70% of the total secondary structure. Subcellular localization occurred on plasma membrane, where SbNRT2 proteins did not contain signal peptides, but SbNRT3 proteins contained signal peptides. Further analysis revealed that the number of transmembrane domains of the SbNRT2s family members was greater than 10, while that of the SbNRT3s were 2. There was a close collinearity between NRT2/3s of S. bicolor and Zea mays. Protein domains analysis showed the presence of MFS_1 and NAR2 protein domains, which supported executing high affinity nitrate transport. Phylogenetic tree analysis showed that SbNRT2/3 were more closely related to those of Z. mays and Setaria italic. Analysis of gene promoter cis-acting elements indicated that the promoter region of SbNRT2/3 had several plant hormones and stress response elements, which might respond to growth and environmental cues. Gene expression heat map showed that SbNRT2-3 and SbNRT3-1 were induced by nitrate in the root and stem, respectively, and SbNRT2-4 and SbNRT2-3 were induced by low nitrogen in the root and stem. Non-synonymous SNP variants were found in SbNRT2-4 and SbNRT2-1a. Selection pressure analysis showed that the SbNRT2/3 were subject to purification and selection during evolution. The expression of SbNRT2/3 gene and the effect of aphid infection were consistent with the expression analysis results of genes in different tissues, and SbNRT2-1b and SbNRT3-1 were significantly expressed in the roots of aphid lines 5-27sug, and the expression levels of SbNRT2-3, SbNRT2-4 and SbNRT3-2 were significantly reduced in sorghum aphid infested leaves. Overall, genome-wide identification, expression and DNA variation analysis of NRT2/3 gene family of Sorghum bicolor provided a basis for elucidating the high efficiency of sorghum in nitrogen utilization.