In recent years, we have seen an increasing amount of evidence pointing to the existence of a non-genetic heredity of the effects of events such as separation from parents, threat to life, or other traumatising experiences such as famine. This heredity is often mediated by epigenetic regulations of gene expression and may be transferred even across several generations. In this review, we focus on studies which involve transgenerational epigenetic inheritance (TEI), with a short detour to intergenerational studies focused on the inheritance of trauma or stressful experiences. The reviewed studies show a plethora of universal changes which stress exposure initiates on multiple levels of organisation ranging from hormonal production and the hypothalamic-pituitary-adrenal (HPA) axis modulation all the way to cognition, behaviour, or propensity to certain psychiatric or metabolic disorders. This review will also provide an overview of relevant methodology and difficulties linked to implementation of epigenetic studies. A better understanding of these processes may help us elucidate the evolutionary pathways which are at work in the course of emergence of the diseases and disorders associated with exposure to trauma, either direct or in a previous generation.
- Keywords
- DNA methylation, HPA axis, RNA, stress, transgenerational epigenetic inheritance, trauma,
- MeSH
- Databases, Genetic MeSH
- Heredity * MeSH
- Epigenesis, Genetic * genetics MeSH
- Mammals genetics MeSH
- Inheritance Patterns MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Review MeSH
Neither the genetic basis nor the inheritance of apomixis is fully understood in plants. The present study is focused on the inheritance of parthenogenesis, one of the basic elements of apomixis, in Pilosella (Asteraceae). A complex pattern of inheritance was recorded in the segregating F(1) progeny recovered from reciprocal crosses between the facultatively apomictic hexaploid P. rubra and the sexual tetraploid P. officinarum. Although both female and male reduced gametes of P. rubra transmitted parthenogenesis at the same rate in the reciprocal crosses, the resulting segregating F(1) progeny inherited parthenogenesis at different rates. The actual transmission rates of parthenogenesis were significantly correlated with the mode of origin of the respective F(1) progeny class. The inheritance of parthenogenesis was significantly reduced in F(1) n + n hybrid progeny from the cross where parthenogenesis was transmitted by female gametes. In F(1) n + 0 polyhaploid progeny from the same cross, however, the transmission rate of parthenogenesis was high; all fertile polyhaploids were parthenogenetic. It appeared that reduced female gametes transmitting parthenogenesis preferentially developed parthenogenetically and only rarely were fertilized in P. rubra. The fact that the determinant for parthenogenesis acts gametophytically in Pilosella and the precocious embryogenesis in parthenogenesis-transmitting megagametophytes was suggested as the most probable explanations for this observation. Furthermore, we observed the different expression of complete apomixis in the non-segregating F(1) 2n + n hybrids as compared to their apomictic maternal parent P. rubra. We suggest that this difference is a result of unspecified interactions between the parental genomes.
- MeSH
- Apomixis genetics physiology MeSH
- Asteraceae genetics physiology MeSH
- Chromosomes, Plant genetics MeSH
- Genome, Plant genetics MeSH
- Hybridization, Genetic MeSH
- Parthenogenesis genetics physiology MeSH
- Polyploidy MeSH
- Flow Cytometry MeSH
- Reproduction MeSH
- Inheritance Patterns MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Gametogenesis produces gametes as a piece of genetic information transmitted to the offspring. While during sexual reproduction, progeny inherits a mix of genetic material from both parents, asexually reproducing organisms transfer a copy of maternal or paternal DNA to the progeny clonally. Parthenogenetic, gynogenetic and hybridogenetic animals have developed various mechanisms of gametogenesis, however, their inheritance is not fully understood. Here, we focused on the inheritance of asexual gametogenesis in hybrid Pelophylax esculentus (RL), emerging after crosses of P. lessonae (LL) and P. ridibundus (RR). To understand the mechanisms of gametogenesis in hybrids, we performed three-generation experiments of sexual P. ridibundus females and hybrids from all-male hybrid populations. Using fluorescent in situ hybridization, micronuclei analysis, flow cytometry and genotyping, we found that most adult hybrid males simultaneously produced two types of clonal sperm. Also, most male tadpole progeny in two successive backcrossed generations simultaneously eliminated L and R parental genomes, while some progeny produced only one type of sperm. We hypothesize that the reproductive variability of males producing two kinds of sperm is an adaptive mechanism to reproduce in mixed populations with P. ridibundus and may explain the extensive distribution of the all-male lineage across the European River Basin.
- Keywords
- Amphispermy, Crossing experiments, FISH., Male hybridogenesis, Micronuclei, Monospermic, Spermatogenesis,
- MeSH
- Genotype MeSH
- Hybridization, Genetic * MeSH
- In Situ Hybridization, Fluorescence MeSH
- Reproduction, Asexual * genetics MeSH
- Rana esculenta genetics MeSH
- Ranidae genetics physiology MeSH
- Spermatozoa physiology MeSH
- Inheritance Patterns genetics MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
OBJECTIVES: The aim of this study was the analysis of WNT10A variants in seven families of probands with various forms of tooth agenesis and self-reported family history of cancer. MATERIALS AND METHODS: We enrolled 60 young subjects (aged 13 to 17) from the Czech Republic with various forms of tooth agenesis. Dental phenotypes were assessed using Planmeca ProMax 3D (Planmeca Oy, Finland) with Planmeca Romexis software (version 2.9.2) together with oral examinations. After screening PAX9, MSX1, EDA, EDAR, AXIN2 and WNT10A genes on the Illumina MiSeq platform (Illumina, USA), we further analyzed the evolutionarily highly conserved WNT10A gene by capillary sequencing in the seven families. RESULTS: All the detected variants were heterozygous or compound heterozygous with various levels of phenotypic expression. The most severe phenotype (oligodontia) was found in a proband who was compound heterozygous for the previously identified WNT10A variant p.Phe228Ile and a newly discovered c.748G > A variant (p.Gly250Arg) of WNT10A. The newly identified variant causes substitution of hydrophobic glycine for hydrophilic arginine. CONCLUSIONS: We suggest that the amino acid changes in otherwise highly conserved sequences significantly affect the dental phenotype. No relationship between the presence of WNT10A variants and a risk of cancer has been found. CLINICAL RELEVANCE: Screening of PAX9, MSX1, EDA, EDAR, AXIN2 and WNT10A genes in hope to elucidate the pattern of inheritance in families.
- Keywords
- Cancer, DNA sequencing, Hypodontia, Oligodontia, WNT pathway, WNT10A variants,
- MeSH
- Anodontia * genetics MeSH
- Phenotype MeSH
- Humans MeSH
- Adolescent MeSH
- Mutation MeSH
- Neoplasms * MeSH
- Wnt Proteins genetics MeSH
- Self Report MeSH
- Check Tag
- Humans MeSH
- Adolescent MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Czech Republic MeSH
- Names of Substances
- Wnt Proteins MeSH
- WNT10A protein, human MeSH Browser
We have studied the inheritance of the epigenetic state of tobacco transgenes whose expression was post-transcriptionally silenced by an invertedly repeated silencer locus. We show that, in hybrids, the coding region of the target neomycin phosphotransferase (nptII) gene was almost exclusively methylated at CG configurations, and dense non-CG methylation occurred in the 3' untranslated region. Homologous sequences in the silencer locus were heavily methylated at both CG and non-CG motifs. After segregation of the silencer locus, the CG methylation but not the non-CG methylation of the target genes was transmitted to the progeny. In the segregants, we observed an overall increase of CG methylation in the target genes, associated with a re-distribution from the 3' end of the coding region towards the middle. This pattern was inherited with some fluctuation for at least two additional generations in the absence of a detectable T-DNA-derived small RNA fraction. Thus CG methylation is not cleared during meiosis and may be inherited over generations without RNA signals being present. These epi-allelic variants re-expressed the reporter gene immediately after segregation of the trigger, showing that relatively dense CG methylation (approximately 60-80%) imprinted on most of the coding region (>500 bp) did not reduce expression compared with the parental non-methylated locus. We propose that the genic CG methylation seen in euchromatic regions of the genome may originate from ancient post-transcriptional gene silencing events as a result of adventitiously produced methylation-directing RNA molecules.
- MeSH
- Alleles MeSH
- DNA, Bacterial metabolism MeSH
- DNA, Plant metabolism MeSH
- Plants, Genetically Modified genetics metabolism MeSH
- Crosses, Genetic MeSH
- DNA Methylation * MeSH
- Gene Expression Regulation, Plant MeSH
- RNA Interference * MeSH
- Nicotiana genetics metabolism MeSH
- Transgenes * MeSH
- Inheritance Patterns * MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- DNA, Bacterial MeSH
- DNA, Plant MeSH
- T-DNA MeSH Browser
Male infertility is a worldwide problem associated with genetic background, environmental factors, and diseases. One of the suspected contributing factors to male infertility is diabetes mellitus. We investigated the molecular and morphological changes in sperms and testicular tissue of diabetic males. The study was performed in streptozotocin-induced type 1 diabetes mouse model. Diabetes decreased sperm concentration and viability and increased sperm apoptosis. Changes in protamine 1/protamine 2 ratio indicated reduced sperm quality. The testicular tissue of diabetic males showed significant tissue damage, disruption of meiotic progression, and changes in the expression of genes encoding proteins important for spermiogenesis. Paternal diabetes altered sperm quality and expression pattern in the testes in offspring of two subsequent generations. Our study revealed that paternal diabetes increased susceptibility to infertility in offspring through gametic alternations. Our data also provide a mechanistic basis for transgenerational inheritance of diabetes-associated pathologies since protamines may be involved in epigenetic regulations.
- MeSH
- Biomarkers MeSH
- Diabetes Mellitus, Type 1 complications metabolism MeSH
- Phenotype MeSH
- Genetic Predisposition to Disease * MeSH
- Meiosis MeSH
- Infertility, Male etiology MeSH
- Mice MeSH
- Protamines metabolism MeSH
- Spermatogenesis MeSH
- Spermatozoa metabolism MeSH
- Testis metabolism MeSH
- Inheritance Patterns * MeSH
- Animals MeSH
- Check Tag
- Male MeSH
- Mice MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- Biomarkers MeSH
- Protamines MeSH
BACKGROUND: The inheritance of different coat colours in the Cane Corso Italiano dog has not been described thus far. We analysed data from 23,271 dogs and bitches using the Cane Corso Italiano Pedigree Database. We are describing for the first time the coat colour segregation ratios in Cane Corso Italiano offspring arising from crosses between parents of all possible coat colour combinations. RESULTS: Segregation ratios that do not follow a Mendelian pattern suggest that additional genes are active in the determination of coat colour. Segregation ratios of offspring produced by parental crossing (male colour A x female colour B) were compared with the ratios of offspring produced by reciprocal crossing (male colour B x female colour A) in all possible coat colour combinations. Most of the segregation ratios were the same, but some segregation ratios in reciprocal crosses differed. This result suggests that at least one gene responsible for coat colour is located on a sex chromosome. The sex ratio was analysed in the offspring of all colour groups. A ratio of 1:1 was not confirmed in 8 colour groups by the chi-square test. CONCLUSIONS: We described for the first time coat colour segregation ratios in Cane Corso Italiano dogs. Furthermore, we present the hypothesis that at least one gene responsible for coat colour is located on a sex chromosome.
- Keywords
- Cane Corso Italiano, Coat colour, Dog breed, Genetics, Inheritance, Sex chromosome,
- MeSH
- Pigmentation genetics MeSH
- Dogs MeSH
- Animals MeSH
- Animal Fur metabolism MeSH
- Check Tag
- Male MeSH
- Dogs MeSH
- Female MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Pregnancy-related complications (PRC) re-present a serious public health and healthcare challenge. In European countries, infertility among couples varies from 5 to 24 %. The cause of PRC may include autoimmune and metabolic factors, correctness of the karyotype and variants of selected genes. The impact magnitude of genetic variants in one of PRC, pregnancy loss (PL), is still unexplored. Therefore, in this study, raw data on 12 single-nucleotide polymorphisms (SNPs) that were published separately in 2017-2019 were re-examined. We analysed the co-inheritance of 12 SNPs: rs6025 FV, rs429358 and rs7412 ApoE, rs1799752 ACE, rs1799889 PAI-1, rs1799963 PT, rs1801133 MTHFR, rs9468 and rs1800547 INV 17q21.31, rs731236 and rs1544410 VDR, and rs10421768 HAMP. Each time, the same study group of 154 women with PL, mean age 33 (± 5.4) years, and 154 mothers without PL, mean age 31.4 (± 6.7) years, with at least one live-born child, a control group, was investigated. In Bosnian women, no relationship of the co-inheritance pattern of any of the studied variants with PL was confirmed: P was in the range 0.248-1.0. In conclusion, the role of co-inheritance of heterozygotes and homozygotes or homozygotes of selected genes in PL has not been fully confirmed.
- Keywords
- SNPs, co-inheritance, polymorphisms, pregnancy loss, risk variants,
- MeSH
- Child MeSH
- Adult MeSH
- Genetic Predisposition to Disease MeSH
- Genotype MeSH
- Homozygote MeSH
- Polymorphism, Single Nucleotide genetics MeSH
- Humans MeSH
- Risk Factors MeSH
- Abortion, Spontaneous * genetics MeSH
- Case-Control Studies MeSH
- Pregnancy MeSH
- Check Tag
- Child MeSH
- Adult MeSH
- Humans MeSH
- Pregnancy MeSH
- Female MeSH
- Publication type
- Journal Article MeSH
The considerable genome size variation in Arabidopsis thaliana has been shown largely to be due to copy number variation (CNV) in 45S ribosomal RNA (rRNA) genes. Surprisingly, attempts to map this variation by means of genome-wide association studies (GWAS) failed to identify either of the two likely sources, namely the nucleolus organizer regions (NORs). Instead, GWAS implicated a trans-acting locus, as if rRNA gene CNV was a phenotype rather than a genotype. To explain these results, we investigated the inheritance and stability of rRNA gene copy number using the variety of genetic resources available in A. thaliana - F2 crosses, recombinant inbred lines, the multiparent advanced-generation inter-cross population, and mutation accumulation lines. Our results clearly show that rRNA gene CNV can be mapped to the NORs themselves, with both loci contributing equally to the variation. However, NOR size is unstably inherited, and dramatic copy number changes are visible already within tens of generations, which explains why it is not possible to map the NORs using GWAS. We did not find any evidence of trans-acting loci in crosses, which is also expected since changes due to such loci would take very many generations to manifest themselves. rRNA gene copy number is thus an interesting example of "missing heritability"-a trait that is heritable in pedigrees, but not in the general population.
- Keywords
- 45S rRNA genes, Arabidopsis thaliana, natural variation, ribosomes,
- MeSH
- Arabidopsis genetics MeSH
- Genetic Loci MeSH
- Gene Dosage MeSH
- Inbreeding MeSH
- Crosses, Genetic MeSH
- Nucleolus Organizer Region genetics MeSH
- Recombination, Genetic genetics MeSH
- Repetitive Sequences, Nucleic Acid genetics MeSH
- RNA, Ribosomal genetics MeSH
- Genes, Plant * MeSH
- Inheritance Patterns genetics MeSH
- DNA Copy Number Variations genetics MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
- Names of Substances
- RNA, Ribosomal MeSH
- RNA, ribosomal, 45S MeSH Browser
Commercial Cydia pomonella granulovirus (CpGV) products have been successfully applied to control codling moth (CM) in organic and integrated fruit production for more than 30 years. Since 2005, resistance against the widely used isolate CpGV-M has been reported from different countries in Europe. The inheritance of this so-called type I resistance is dominant and linked to the Z chromosome. Recently, a second form (type II) of CpGV resistance in CM was reported from a field population (NRW-WE) in Germany. Type II resistance confers reduced susceptibility not only to CpGV-M but to most known CpGV isolates and it does not follow the previously described Z-linked inheritance of type I resistance. To further analyze type II resistance, two CM strains, termed CpR5M and CpR5S, were generated from parental NRW-WE by repeated mass crosses and selection using the two isolates CpGV-M and CpGV-S, respectively. Both CpR5M and CpR5S were considered to be genetically homogeneous for the presence of the resistance allele(s). By crossing and backcrossing experiments with a susceptible CM strain, followed by resistance testing of the offspring, an autosomal dominant inheritance of resistance was elucidated. In addition, cross-resistance to CpGV-M and CpGV-S was detected in both strains, CpR5M and CpR5S. To test the hypothesis that the autosomal inheritance of type II resistance was caused by a large interchromosomal rearrangement involving the Z chromosome, making type I resistance appear to be autosomal in these strains; fluorescence in situ hybridization with bacterial artificial chromosome probes (BAC-FISH) was used to physically map the Z chromosomes of different CM strains. Conserved synteny of the Z-linked genes in CpR5M and other CM strains rejects this hypothesis and argues for a novel genetic and functional mode of resistance in CM populations with type II resistance.
- MeSH
- Granulovirus genetics physiology MeSH
- Chromosomes, Insect genetics MeSH
- Genome, Viral genetics MeSH
- Hybridization, Genetic MeSH
- Moths genetics physiology virology MeSH
- Inheritance Patterns * MeSH
- Animals MeSH
- Check Tag
- Animals MeSH
- Publication type
- Journal Article MeSH