Background Hybridization between divergent species can result in meiotic aberrations and the emergence of asexual reproduction. Yet, it remains poorly understood to what extent such outcomes arise from genome-wide incompatibilities versus more specific conflicts among individual chromosomes inherited from parental species, including their ability to pair during meiosis in hybrids. It is also unclear how interspecific hybrids cope with differences in sex determination systems, particularly in the context of increased ploidy. Addressing these questions requires high-quality, chromosome-level reference genomes of the parental species involved in hybrid formation.Findings Here, we present the first chromosome-level genome assemblies for three hybridizing Cobitis species (C. elongatoides, C. taenia, and C. tanaitica), providing a comprehensive framework for investigating the genomic and cytogenetic basis of hybrid sterility and the transition to asexuality. By integrating genome scaffolding, male/female pooled sequencing (Pool-Seq), and molecular cytogenetics, we uncover extensive structural variation among homologous chromosomes of the three species, despite overall karyotype conservation. Population-level analyses revealed that each species possesses distinct, non-homologous sex chromosomes, highlighting rapid sex chromosome turnover in this recently diverged lineage. Finally, the design of chromosome-specific painting probes, which we applied to meiotic metaphase I spreads of diploid hybrids. This approach revealed striking differences in the pairing success of orthologous chromosomes.Conclusions Our results demonstrate that individual orthologous chromosomes differ markedly in their ability to form bivalents during meiosis in hybrids, indicating that hybrid meiotic behaviour is shaped by chromosome-specific incompatibilities rather than uniform genome-wide failure. We also found that even closely related parental species possess distinct, non-homologous sex chromosomes, highlighting rapid turnover of sex determination systems in hybridizing lineages. Together, these findings provide a high-resolution genomic and cytogenetic framework to explore how the architecture of inherited parental genomes influences sex-specific reproductive outcomes in hybrids-ranging from male sterility to the establishment of fertile, clonally reproducing female lineages-and how such asymmetries may contribute to the emergence of asexuality in vertebrates.

The apparent absence of numerous conserved vertebrate genes from avian genomes has puzzled researchers for over a decade. In recent years, a subset of these genes has been identified; however, their sequences are unusually problematic, often evading detection by standard sequencing technologies. This limitation has hindered detailed investigation of the phenomenon-until recent progress in long read technologies, which are more robust against sequencing biases. This enabled us to classify real gene losses extensively, which strikingly revealed that a large number of the genes residing on so-called dot chromosomes were indeed lost during avian evolution. We demonstrate that dot microchromosomes-small, repeat-dense avian chromosomes-harbor widespread gene attrition, with 29% of ohnologs (duplicates from ancestral genome doublings) eliminated, far exceeding rates on other chromosomes. Moreover, we reveal that genes retained on these dot chromosomes exhibit a previously undescribed form of dynamic genetic instability. This instability, which we term sequence stuttering, is characterized by a massive expansion of short sequences within intronic regions. Intriguingly, in some cases, the expanding sequences appear to originate from neighboring exons. As a result, intron lengths vary extensively among individual chickens, suggesting that these events are evolutionarily recent. Since this phenomenon has not been reported in any other vertebrate species, our findings lay the groundwork for future research into its underlying mechanisms, evolutionary implications, and potential identification of similar loci across vertebrate genomes.

Human endogenous retroviruses (HERVs) constitute a significant fraction of the human genome and are increasingly recognized for their roles in both physiological and pathological processes. Despite their biological importance, the annotation of HERV elements remains inconsistent across major public databases. In this study, we present a comprehensive comparative analysis of three key HERV annotation resources: DFAM, Human Endogenous Retroviruses Database (HERVd), and RepBase. We systematically examine their content, classification schemes, and postprocessing workflows and assess the concordance of their annotations based on genomic coordinates. Our analysis reveals substantial discrepancies in element counts, genome coverage, and repeat fragmentation strategies, which we trace back to differences in curation methodologies—ranging from DFAM’s hidden Markov model-based automated detection to HERVd’s semimanual defragmentation. Using refined matching criteria, we demonstrate that up to 93% of HERV records can be reconciled across databases, yet each source still contributes a substantial proportion of unique elements. We highlight the complementary strengths of these resources and provide practical recommendations for their usage in HERV research. Our findings underscore the need for harmonized standards in retroelement annotation and may inform future efforts toward unified and comprehensive HERV cataloging, particularly in light of emerging genome assemblies such as T2T-CHM13.

The aim of this prospective study was to assess the duration of culture-viable SARS-CoV-2 and to monitor the emergence of mutations in a cohort of 23 kidney transplant recipients (KTRs) from June 2022 to June 2023. Combined nares/oropharyngeal swabs were collected weekly starting as soon as possible after symptom onset. The time from symptom onset to a negative culture was 11 days (interquar tile range, 8-14), while the time to negative reverse transcriptase quantitative polymerase chain reaction was 18 days (inter quartile range, 15-30). Beyond the first swab, 21.7% had a positive culture, and 8.7% replicated viable virus for longer than 30 days. T cell depletion (rate ratio, 2.5; 95% confidence interval [95% CI], 1.9-3.3; P <.001) and time from transplantation (rate ratio, 0.93; 95% CI, 0.90-0.97; P 1/4.006) were associated with the time of viable virus shedding. A cycle threshold value of 24.2 demonstrated a 91.3% negative predictive value of viability (95% credible interval [95% CrI], 76-100). The odds of viability decreased by 69% per week of infection (odds ratio, 0.31; 95% CrI, 0.12-0.76). Overall, ribonucleic acid sequencing did not show accelerated molecular evolution though mutation rate could be increased in molnupiravir-treated KTRs. In conclusion, viable SARS-CoV-2 is eliminated rapidly, the risk of virus evolution is low, and prolonged self-isolation is generally unnecessary for most KTRs.

In the wake of transformative advances in sequencing technologies, ELIXIR CZ is spearheading efforts to unravel the genomic mysteries of life on Earth. Our commitment aligns with global initiatives like the Earth BioGenome Project, focusing on decoding the DNA of all living organisms. As we delve into this ambitious era, ELIXIR CZ strategically concentrates on key research areas with a rich legacy of excellence in sequencing in the Czech Republic.What We Do:• Annotation of Repetitive DNA: Developing tools such as RepeatExplorer andTAREAN to identify and document repetitive DNA elements.• Phylogenomics and Barcoding: Harnessing large-scale genomic data to studyevolutionary relationships and support conservation efforts, enhanced by toolslike the AmtDB database.• Targeted Genomic Studies: Specializing in the genomics of parasitic protists,neglected crops, and complex microbial communities, backed by resources likethe GlobalFungi database.Our Goals:• Innovate and Integrate: Promote the development of cutting-edgecomputational tools and databases, ensuring their integration into internationalframeworks – such as Galaxy platform.• Enhance Support for Genomic Projects: Provide the necessary hardware andexpertise to manage and share the burgeoning volume of genomic data.• Democratize Access: Offer user-friendly tools and training to empowerresearchers across various disciplines, making advanced genomicsaccessible to all.

Molecular surveillance was widely used during the COVID-19 pandemic to detect rapidly emerging variants and monitor the transmission of SARS-CoV-2 within communities. In 2021, the Czech COVID-19 Genomics Consortium (COG-CZ) was set up to coordinate a new SARS-CoV-2 molecular surveillance network. In the Czech Republic, molecular surveillance employed whole genome sequencing (WGS) and variant discrimination polymerase chain reaction (VD-PCR) on samples collected through passive, active and sentinel surveillance. All WGS data was uploaded to GISAID and the PANGO lineages used by GISAID were compared to the main variants determined by VD-PCR. To assess the effectiveness and reliability of the gathered data in adapting pandemic responses, the capabilities and turnaround times of the molecular surveillance methods are evaluated. VD-PCR results were available within 48 h of sample collection for 81.5% of cases during the Delta/Omicron transition. WGS enabled the detection of low-frequency novel variants in infection clusters. WGS surveillance showed there was community spread of AY.20.1, a variant that gained novel mutations within the Czech Republic. Molecular surveillance informed the implementation of public health measures; temporal comparisons of restrictions and outcomes are described. Further areas for improvement have been identified for monitoring and managing future pandemics.

Background Whole exome sequencing (WES) and whole genome sequencing (WGS) have become standard methods in human clinical diagnostics as well as in population genomics (POPGEN). Blood-derived genomic DNA (gDNA) is routinely used in the clinical environment. Conversely, many POPGEN studies and commercial tests benefit from easy saliva sampling. Here, we evaluated the quality of variant call sets and the level of genotype concordance of single nucleotide variants (SNVs) and small insertions and deletions (indels) for WES and WGS using paired blood- and saliva-derived gDNA isolates employing genomic reference-based validated protocols. Methods The genomic reference standard Coriell NA12878 was repeatedly analyzed using optimized WES and WGS protocols, and data calls were compared with the truth dataset published by the Genome in a Bottle Consortium. gDNA was extracted from the paired blood and saliva samples of 10 participants and processed using the same protocols. A comparison of paired blood–saliva call sets was performed in the context of WGS and WES genomic reference-based technical validation results. Results The quality pattern of called variants obtained from genomic-reference-based technical replicates correlates with data calls of paired blood–saliva-derived samples in all levels of tested examinations despite a higher rate of non-human contamination found in the saliva samples. The F1 score of 10 blood-to-saliva-derived comparisons ranged between 0.8030–0.9998 for SNVs and between 0.8883–0.9991 for small-indels in the case of the WGS protocol, and between 0.8643–0.999 for SNVs and between 0.7781–1.000 for small-indels in the case of the WES protocol. Conclusion Saliva may be considered an equivalent material to blood for genetic analysis for both WGS and WES under strict protocol conditions. The accuracy of sequencing metrics and variant-detection accuracy is not affected by choosing saliva as the gDNA source instead of blood but much more significantly by the genomic context, variant types, and the sequencing technology used.

To shed light on the enigmatic origin of the vertebrate head, our study employs an integrated approach that combines single-cell transcriptomics, perturbations in signaling pathways, and cis-regulatory analysis in amphioxus. As a representative of a basal lineage within the chordate phylum, amphioxus retains many characteristics thought to have been present in the common chordate ancestor. Through cell type characterization, we identify the presence of prechordal plate-like, pre-migratory, and migratory neural crest-like cell populations in the developing amphioxus embryo. Functional analysis establishes conserved roles of the Nodal and Hedgehog signaling pathways in prechordal plate-like populations, and of the Wnt signaling pathway in neural crest-like populations’ development. Furthermore, our trans-species transgenic experiments highlight similarities in the regulatory environments that drive neural crest-like and prechordal plate-like developmental programs in both vertebrates and amphioxus. Our findings provide evidence that the key features of vertebrate head development can be traced back to the common ancestor of all chordates. Vertebrate evolution necessitated changes to the basic structure of the head, but these structural origins have remained unclear. Here they analyze the chordate amphioxus to show that essential aspects of vertebrate head development originated from a common ancestor.

Nicotinamide adenine dinucleotide (NAD) is a critical component of the cellular metabolism and also serves as an alternative 5' cap on various RNAs. However, the function of the NAD RNA cap is still under investigation. We studied NAD capping of RNAs in HIV-1-infected cells because HIV-1 is responsible for the depletion of the NAD/NADH cellular pool and causing intracellular pellagra. By applying the NAD captureSeq protocol to HIV-1-infected and uninfected cells, we revealed that four snRNAs (e.g., U1) and four snoRNAs lost their NAD cap when infected with HIV-1. Here, we provide evidence that the presence of the NAD cap decreases the stability of the U1/HIV-1 pre-mRNA duplex. Additionally, we demonstrate that reducing the quantity of NAD-capped RNA by overexpressing the NAD RNA decapping enzyme DXO results in an increase in HIV-1 infectivity. This suggests that NAD capping is unfavorable for HIV-1 and plays a role in its infectivity.

Chromatin remodeling complexes are required for many distinct nuclear processes such as transcription, DNA replication, and DNA repair. However, the contribution of these complexes to the development of complex tissues within an organism is poorly characterized. Imitation switch (ISWI) proteins are among the most evolutionarily conserved ATP-dependent chromatin remodeling factors and are represented by yeast Isw1/Isw2, and their vertebrate counterparts Snf2h (Smarca5) and Snf2l (Smarca1). In this study, we focused on the role of the Snf2h gene during the development of the mammalian retina. We show that Snf2h is expressed in both retinal progenitors and post-mitotic retinal cells. Using Snf2h conditional knockout mice (Snf2h cKO), we found that when Snf2h is deleted, the laminar structure of the adult retina is not retained, the overall thickness of the retina is significantly reduced compared with controls, and the outer nuclear layer (ONL) is completely missing. The depletion of Snf2h did not influence the ability of retinal progenitors to generate all the differentiated retinal cell types. Instead, the Snf2h function is critical for the proliferation of retinal progenitor cells. Cells lacking Snf2h have a defective S-phase, leading to the entire cell division process impairments. Although all retinal cell types appear to be specified in the absence of the Snf2h function, cell-cycle defects and concomitantly increased apoptosis in Snf2h cKO result in abnormal retina lamination, complete destruction of the photoreceptor layer, and consequently, a physiologically non-functional retina.

The germline-restricted chromosome (GRC) of songbirds represents a taxonomically widespread example of programmed DNA elimination. Despite its apparent indispensability, we still know very little about the GRC's genetic composition, function, and evolutionary significance. Here we assemble the GRC in two closely related species, the common and thrush nightingale. In total we identify 192 genes across the two GRCs, with many of them present in multiple copies. Interestingly, the GRC appears to be under little selective pressure, with the genetic content differing dramatically between the two species and many GRC genes appearing to be pseudogenized fragments. Only one gene, cpeb1, has a complete coding region in all examined individuals of the two species and shows no copy number variation. The acquisition of this gene by the GRC corresponds with the earliest estimates of the GRC origin, making it a good candidate for the functional indispensability of the GRC in songbirds.

The Picornavirales include viruses that infect vertebrates, insects, and plants. It was believed that they pack only their genomic mRNA in the particles; thus, we envisaged these viruses as excellent model systems for studies of mRNA modifications. We used LC-MS to analyze digested RNA isolated from particles of the sacbrood and deformed wing iflaviruses as well as of the echovirus 18 and rhinovirus 2 picornaviruses. Whereas in the picornavirus RNAs we detected only N-6-methyladenosine and 2'-O-methylated nucleosides, the iflavirus RNAs contained a wide range of methylated nucleosides, such as 1-methyladenosine (m(1)A) and 5-methylcytidine (m(5)C). Mapping of m(1)A and m(5)C through RNA sequencing of the SBV and DWV RNAs revealed the presence of tRNA molecules. Both modifications were detected only in tRNA. Further analysis revealed that tRNAs are present in form of 3' and 5' fragments and they are packed selectively. Moreover, these tRNAs are typically packed by other viruses.

Abstract The transition of free-living organisms to parasitic organisms is a mysterious process that occurs in all major eukaryotic lineages. Parasites display seemingly unique features associated with their pathogenicity; however, it is important to distinguish ancestral preconditions to parasitism from truly new parasite-specific functions. Here, we sequenced the genome and transcriptome of anaerobic free-living Mastigamoeba balamuthi and performed phylogenomic analysis of four related members of the Archamoebae, including Entamoeba histolytica, an important intestinal pathogen of humans. We aimed to trace gene histories throughout the adaptation of the aerobic ancestor of Archamoebae to anaerobiosis and throughout the transition from a free-living to a parasitic lifestyle. These events were associated with massive gene losses that, in parasitic lineages, resulted in a reduction in structural features, complete losses of some metabolic pathways, and a reduction in metabolic complexity. By reconstructing the features of the common ancestor of Archamoebae, we estimated preconditions for the evolution of parasitism in this lineage. The ancestor could apparently form chitinous cysts, possessed proteolytic enzyme machinery, compartmentalized the sulfate activation pathway in mitochondrion-related organelles, and possessed the components for anaerobic energy metabolism. After the split of Entamoebidae, this lineage gained genes encoding surface membrane proteins that are involved in host–parasite interactions. In contrast, gene gains identified in the M. balamuthi lineage were predominantly associated with polysaccharide catabolic processes. A phylogenetic analysis of acquired genes suggested an essential role of lateral gene transfer in parasite evolution (Entamoeba) and in adaptation to anaerobic aquatic sediments (Mastigamoeba).

The vertebrate eye is derived from the neuroepithelium, surface ectoderm, and extracellular mesenchyme. The neuroepithelium forms an optic cup in which the spatial separation of three domains is established, namely, the region of multipotent retinal progenitor cells (RPCs), the ciliary margin zone (CMZ)-which possesses both a neurogenic and nonneurogenic potential-and the optic disk (OD), the interface between the optic stalk and the neuroretina. Here, we show by genetic ablation in the developing optic cup that Meis1 and Meis2 homeobox genes function redundantly to maintain the retinal progenitor pool while they simultaneously suppress the expression of genes characteristic of CMZ and OD fates. Furthermore, we demonstrate that Meis transcription factors bind regulatory regions of RPC-, CMZ-, and OD-specific genes, thus providing a mechanistic insight into the Meis-dependent gene regulatory network. Our work uncovers the essential role of Meis1 and Meis2 as regulators of cell fate competence, which organize spatial territories in the vertebrate eye.

Despite its inherent costs, sexual reproduction is ubiquitous in nature, and the mechanisms to protect it from a competitive displacement by asexuality remain unclear. Popular mutation‐based explanations, like the Muller's ratchet and the Kondrashov's hatchet, assume that purifying selection may not halt the accumulation of deleterious mutations in the nonrecombining genomes, ultimately leading to their degeneration. However, empirical evidence is scarce and it remains particularly unclear whether mutational degradation proceeds fast enough to ensure the decay of clonal organisms and to prevent them from outcompeting their sexual counterparts. To test this hypothesis, we jointly analysed the exome sequences and the fitness‐related phenotypic traits of the sexually reproducing fish species and their clonal hybrids, whose evolutionary ages ranged from F1 generations to 300 ky. As expected, mutations tended to accumulate in the clonal genomes in a time‐dependent manner. However, contrary to the predictions, we found no trend towards increased nonsynonymity of mutations acquired by clones, nor higher radicality of their amino acid substitutions. Moreover, there was no evidence for fitness degeneration in the old clones compared with that in the younger ones. In summary, although an efficacy of purifying selection may still be reduced in the asexual genomes, our data indicate that its efficiency is not drastically decreased. Even the oldest investigated clone was found to be too young to suffer fitness consequences from a mutation accumulation. This suggests that mechanisms other than mutation accumulation may be needed to explain the competitive advantage of sex in the short term.

Hybridization and polyploidization are important evolutionary processes whose impacts range from the alteration of gene expression and phenotypic variation to the triggering of asexual reproduction. We investigated fishes of the Cobitis taenia-elongatoides hybrid complex, which allowed us to disentangle the direct effects of both processes, due to the co-occurrence of parental species with their diploid and triploid hybrids. Employing morphological, ecological, and RNAseq approaches, we investigated the molecular determinants of hybrid and polyploid forms. In contrast with other studies, hybridization and polyploidy induced relatively very little transgressivity. Instead, Cobitis hybrids appeared intermediate with a clear effect of genomic dosing when triploids expressed higher similarity to the parent contributing two genome sets. This dosage effect was symmetric in the germline (oocyte gene expression), interestingly though, we observed an overall bias toward C. taenia in somatic tissues and traits. At the level of individual genes, expression-level dominance vastly prevailed over additivity or transgressivity. Also, trans-regulation of gene expression was less efficient in diploid hybrids than in triploids, where the expression modulation of homoeologs derived from the "haploid" parent was stronger than those derived from the "diploid" parent. Our findings suggest that the apparent intermediacy of hybrid phenotypes results from the combination of individual genes with dominant expression rather than from simple additivity. The efficiency of cross-talk between trans-regulatory elements further appears dosage dependent. Important effects of polyploidization may thus stem from changes in relative concentrations of trans-regulatory elements and their binding sites between hybridizing genomes. Links between gene regulation and asexuality are discussed.

The mechanism of action of various viruses has been the primary focus of many studies. Yet, the data on RNA modifications in any type of virus are scarce. Methods for the sensitive analysis of RNA modifications have been developed only recently and they have not been applied to viruses. In particular, the RNA composition of HIV-1 virions has never been determined with sufficiently exact methods. Here, we reveal that the RNA of HIV-1 virions contains surprisingly high amount of the 1-methyladenosine. We are the first to use a liquid chromatography-mass spectrometry analysis (LC/MS) of virion RNA, which we combined with m1A profiling and deep sequencing. We found that m1A was present in the tRNA, but not in the genomic HIV-1 RNA and the abundant 7SL RNA. We were able to calculate that an HIV-1 virion contains per 2 copies of genomic RNA and 14 copies of 7SL RNA also 770 copies of tRNA, which is approximately 10 times more than thus far expected. These new insights into the composition of the HIV-1 virion can help in future studies to identify the role of nonprimer tRNAs in retroviruses. Moreover, we present a promising new tool for studying the compositions of virions.

Ancient mitochondrial DNA is used for tracing human past demographic events due to its population-level variability. The number of published ancient mitochondrial genomes has increased in recent years, alongside with the development of high-throughput sequencing and capture enrichment methods. Here, we present AmtDB, the first database of ancient human mitochondrial genomes. Release version contains 1107 hand-curated ancient samples, freely accessible for download, together with the individual descriptors, including geographic location, radiocarbon dating, and archaeological culture affiliation. The database also features an interactive map for sample location visualization. AmtDB is a key platform for ancient population genetic studies and is available at https://amtdb.org.

Event Abstract Back to Event The legacy of sexual ancestors in phenotypic variability, gene expression and homoeolog regulation of clonal fish hybrids and polyploids Karel Janko1*, Oldřich Bartoš1, Jan Roslein1, Jan Kotusz2, Ladislav Pekárik3, Miloslav Petrtýl4 and Jan Pačes5 1 Institute of Animal Physiology and Genetics (ASCR), Czechia 2 University of Wrocław, Poland 3 Slovak Academy of Sciences (SAS), Slovakia 4 Czech University of Life Sciences Prague, Czechia 5 Academy of Sciences of the Czech Republic (ASCR), Czechia Hybridization and polyploidization are important evolutionary processes whose impact ranges from alteration of gene expression and phenotypic variation to triggering of asexual reproduction. We investigated fishes of the Cobitis taenia-elongatoides hybrid complex, which allows disentangling the direct effects of both processes, due to co-occurrence of parental species with their diploid and triploid hybrids. Employing morphological, ecological and RNAseq approaches we investigated molecular determinants of hybrid and polyploid forms. In contrast to other studies, hybridization or polyploidy induced relatively very little transgressivity. Instead, Cobitis hybrids appeared intermediate with a clear effect of genomic dose when triploids expressed higher similarity to the parent contributing two genome sets. Such dosage effect was asymmetric in the germline (oocyte gene expression), but interestingly we observed overall bias toward C. taenia in somatic traits including liver gene expression, habitat preference and morphology. At the level of individual genes, expression-level dominance vastly prevailed over additivity or transgressivity. We noticed that trans-regulation of gene expression was less efficient in diploid hybrids than in triploids, where the expression modulation of homoeologues derived from the 'haploid' parent was stronger than of those derived from the ‘diploid’ one. Our findings suggest that apparent intermediacy of hybrid phenotypes results from combination of individual genes with dominant expression rather than from simple additivity. The efficiency of cross-talk between trans-regulatory elements further appears dosage-dependent. Important effects of polyploidization may thus stem from changes in relative concentrations of trans-regulatory elements and their binding sites between hybridizing genomes. Links between gene regulation and asexuality are discussed. Acknowledgements We are grateful for financial support from the Czech Academy of Sciences of the Czech Republic grant no. RVO67985904, Czech Science Foundation grant nos. 13-12580S, 17-09807S, the Ministry of Education, Youth and Sports of the Czech Republic grant EXCELLENCE CZ.02.1.01/0.0/0.0/15_003/0000460 OP RDE, 7AMB14PL Keywords: Gene expreesion regulation, hybridization, Polyploidy, phenotype, Genotyp x environment interaction, Microhabitat adaptation, Geometric morphology Conference: XVI European Congress of Ichthyology, Lausanne, Switzerland, 2 Sep - 6 Sep, 2019. Presentation Type: Oral Topic: EVOLUTIONARY GENOMICS OF FISHES Citation: Janko K, Bartoš O, Roslein J, Kotusz J, Pekárik L, Petrtýl M and Pačes J (2019). The legacy of sexual ancestors in phenotypic variability, gene expression and homoeolog regulation of clonal fish hybrids and polyploids. Front. Mar. Sci. Conference Abstract: XVI European Congress of Ichthyology. doi: 10.3389/conf.fmars.2019.07.00045 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 06 Jun 2019; Published Online: 14 Aug 2019. * Correspondence: Mx. Karel Janko, Institute of Animal Physiology and Genetics (ASCR), Prague, Czechia, janko@iapg.cas.cz Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Karel Janko Oldřich Bartoš Jan Roslein Jan Kotusz Ladislav Pekárik Miloslav Petrtýl Jan Pačes Google Karel Janko Oldřich Bartoš Jan Roslein Jan Kotusz Ladislav Pekárik Miloslav Petrtýl Jan Pačes Google Scholar Karel Janko Oldřich Bartoš Jan Roslein Jan Kotusz Ladislav Pekárik Miloslav Petrtýl Jan Pačes PubMed Karel Janko Oldřich Bartoš Jan Roslein Jan Kotusz Ladislav Pekárik Miloslav Petrtýl Jan Pačes Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.