Základy půdní úrodnosti

Zvyšování půdní úrodnosti bylo pro průkopníky ekologického zemědělství základem veškerého jejich úsilí. Přesto zachování úrodné půdy mnohdy nebyla věnována dostatečná pozornost. Ekologické zemědělství je však na přirozené půdní úrodnosti závislé. Oslabená a poškozená půda nám nemůže poskytnout to, co od ní očekáváme. Udržet úrodnost půdy vyžaduje velkou péči. Předkládaná brožura ukazuje půdní úrodnost z různých úhlů pohledu. Naším záměrem však nebylo vytvořit obecně platný „návod k použití“. Informace mají být mnohem spíše podnětem k tomu, aby se o vztahu člověka k půdě smýšlelo jinak a aby se tento vztah utvářel ve prospěch budoucnosti

Identification and molecular characterisation of a homozygous missense mutation in the ADAMTS10 gene in a patient with Weill-Marchesani syndrome

Weill-Marchesani syndrome is a rare disorder of the connective tissue. Functional variants in ADAMTS10 are associated with Weill-Marchesani syndrome-1. We identified a homozygous missense mutation, c.41T>A, of the ADAMTS10 gene in a 19-year-old female with typical symptoms of WMS1: proportionate short stature, brachydactyly, joint stiffness, and microspherophakia. The ADAMTS10 missense mutation was analysed in silico, with conflicting results as to its effects on protein function, but it was predicted to affect the leader sequence. Molecular characterisation in HEK293 Ebna cells revealed an intracellular mis-targeting of the ADAMTS10 protein with a reduced concentration of the polypeptide in the endoplasmic reticulum. A large reduction in glycosylation of the cytoplasmic fraction of the mutant ADAMTS10 protein versus the wild-type protein and a lack of secretion of the mutant protein are also evident in our results.In conclusion, we identified a novel missense mutation of the ADAMTS10 gene and confirmed the functional consequences suggested by the in silico analysis by conducting molecular studies

Optical Genome Mapping in Routine Human Genetic Diagnostics—Its Advantages and Limitations

In recent years, optical genome mapping (OGM) has developed into a highly promising method of detecting large-scale structural variants in human genomes. It is capable of detecting structural variants considered difficult to detect by other current methods. Hence, it promises to be feasible as a first-line diagnostic tool, permitting insight into a new realm of previously unknown variants. However, due to its novelty, little experience with OGM is available to infer best practices for its application or to clarify which features cannot be detected. In this study, we used the Saphyr system (Bionano Genomics, San Diego, CA, USA), to explore its capabilities in human genetic diagnostics. To this end, we tested 14 DNA samples to confirm a total of 14 different structural or numerical chromosomal variants originally detected by other means, namely, deletions, duplications, inversions, trisomies, and a translocation. Overall, 12 variants could be confirmed; one deletion and one inversion could not. The prerequisites for detection of similar variants were explored by reviewing the OGM data of 54 samples analyzed in our laboratory. Limitations, some owing to the novelty of the method and some inherent to it, were described. Finally, we tested the successful application of OGM in routine diagnostics and described some of the challenges that merit consideration when utilizing OGM as a diagnostic tool

Asthenozoospermia in Mice with Targeted Deletion of the Sperm Mitochondrion-Associated Cysteine-Rich Protein (Smcp) Gene

The sperm mitochondria-associated cysteine-rich protein (SMCP) is a cysteine- and proline-rich structural protein that is closely associated with the keratinous capsules of sperm mitochondria in the mitochondrial sheath surrounding the outer dense fibers and axoneme. To investigate the function of SMCP, we generated mice with a targeted disruption of the gene Smcp by homologous recombination. Homozygous mutant males on a mixed genetic background (C57BL/6J × 129/Sv) are fully fertile, while they are infertile on the 129/Sv background, although spermatogenesis and mating are normal. Homozygous Smcp(−/−) female mice are fertile on both genetic backgrounds. Electron microscopical examination demonstrated normal structures of sperm head, mitochondria, and tail. In vivo experiments with sperm of Smcp(−/−) 129/Sv mice revealed that the migration of spermatozoa from the uterus into the oviduct is reduced. This result is supported by the observation that sperm motility as determined by the computer-assisted semen analysis system (CASA) is significantly affected as compared to wild-type spermatozoa. In vitro fertilization assays showed that Smcp-deficient spermatozoa are able to bind to the oocyte but that the number of fertilized eggs is reduced by more than threefold relative to the wild-type control. However, removal of the zona pellucida resulted in an unaffected sperm-egg fusion which was monitored by the presence of pronuclei and generation of blastocyts. These results indicate that the infertility of the male Smcp(−/−) mice on the 129/Sv background is due to reduced motility of the spermatozoa and decreased capability of the spermatozoa to penetrate oocytes

A human haploid gene trap collection to study lncRNAs with unusual RNA biology

<p>Many thousand long non-coding (lnc) RNAs are mapped in the human genome. Time consuming studies using reverse genetic approaches by post-transcriptional knock-down or genetic modification of the locus demonstrated diverse biological functions for a few of these transcripts. The Human Gene Trap Mutant Collection in haploid KBM7 cells is a ready-to-use tool for studying protein-coding gene function. As lncRNAs show remarkable differences in RNA biology compared to protein-coding genes, it is unclear if this gene trap collection is useful for functional analysis of lncRNAs. Here we use the uncharacterized <i>LOC100288798</i> lncRNA as a model to answer this question. Using public RNA-seq data we show that <i>LOC100288798</i> is ubiquitously expressed, but inefficiently spliced. The minor spliced <i>LOC100288798</i> isoforms are exported to the cytoplasm, whereas the major unspliced isoform is nuclear localized. This shows that <i>LOC100288798</i> RNA biology differs markedly from typical mRNAs. <i>De novo</i> assembly from RNA-seq data suggests that <i>LOC100288798</i> extends 289kb beyond its annotated 3' end and overlaps the downstream <i>SLC38A4</i> gene. Three cell lines with independent gene trap insertions in <i>LOC100288798</i> were available from the KBM7 gene trap collection. RT-qPCR and RNA-seq confirmed successful lncRNA truncation and its extended length. Expression analysis from RNA-seq data shows significant deregulation of 41 protein-coding genes upon <i>LOC100288798</i> truncation. Our data shows that gene trap collections in human haploid cell lines are useful tools to study lncRNAs, and identifies the previously uncharacterized <i>LOC100288798</i> as a potential gene regulator.</p

Outcome after Prenatal Diagnosis of Trisomy 13, 18, and 21 in Fetuses with Congenital Heart Disease

Fetal congenital heart disease (CHD) is often associated with chromosomal abnormalities. Our primary aim was to assess stillbirth and neonatal mortality rates for pregnancies complicated by trisomies 13, 18, and 21 in the presence of CHD, from a single tertiary referral center during 2000&ndash;2020 in a retrospective cohort study. The secondary aims were to investigate maternal morbidity in these pregnancies, and to study the gestational or neonatal age when mortality occurred. Inclusion criteria were the prenatal diagnosis of at least one structural CHD, together with prenatally diagnosed fetal trisomy 13, 18, or 21. One-hundred and sixty patients with fetal trisomy 13 (14.4%), fetal trisomy 18 (28.8%), and fetal trisomy 21 (56.9%) were evaluated. In total, 98 (61.3%) families opted for the termination of pregnancy (TOP). Of the remaining 62 (38.8%) pregnancies, 16 (25.8%) resulted in intrauterine fetal death/death during delivery. Ten out of twenty-one (47.6%) infants with trisomy 13 or 18 were born alive. The livebirth rate was 87.8% (36/41) for infants with trisomy 21. Early neonatal death was observed in nine (19.6%) infants. Thirty-one (86.1%) infants with trisomy 21 survived the first year of life. These data may be helpful for counseling affected parents when the decision to terminate or continue the pregnancy should be considered