The past decade has witnessed a tremendous increase in interest in polyploidy, which may partly be related to the development of new powerful genetic and genomic tools. These have provided numerous insights into mainly genetic and genomic consequences of polyploidy, dramatically improving our understanding of the dynamics of the polyploidization process and its importance as a mechanism in animal evolution. In contrast, several other aspects of polyploidization, such as physiology, ecology and development, have received considerably less attention. Our aim is not to make an exhaustive review of current knowledge about animal polyploidy, but rather to thoroughly elaborate on some very fundamental questions which still remain open or even neglected. In particular, we show that properties of new polyploid lineages largely depend upon the proximate way in which they arose, but the evolutionary pathways to polyploidy are often unresolved. To help researchers orientate amongst the number of pathways to polyploidy, we provide an extensive review of particular scenarios proposed in distinct animal taxa. We discuss how polyploidy relates to hybridization, particularly with respect to asexuality, and elaborate on whether clonal triploids may help to overcome the constraints of aneuploidy, thereby serving as a triploid bridge towards the establishment of new polyploid species. We further show that in most animal asexual complexes clonal lineages may become established only under one ploidy level (usually either di- or triploidy), and that it is rather rare to see the coexistence of successful clones of different ploidies. We discuss why the rate of polyploidization is higher in some taxa than in others, and what tools we have to evaluate the rate of polyploidization. Finally, we review some of the immediate physiological and developmental effects of polyploidy which are related to the genome size/cell size relation and show how studies of polyploidy may enhance the study of macroecology and developmental biology. See also the sister article focusing on plants by Weiss-Schneeweiss et al. in this themed issue.

• MeSH
• aneuploidie MeSH
• délka genomu MeSH
• diploidie MeSH
• ekosystém MeSH
• fenotyp MeSH
• fylogeneze MeSH
• hybridizace genetická MeSH
• molekulární evoluce * MeSH
• polyploidie * MeSH
• velikost buněčného jádra MeSH
• velikost buňky MeSH
• vznik druhů (genetika) MeSH
• žáby klasifikace   genetika   MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• přehledy MeSH

MicroRNAs (miRNAs) are ubiquitous small RNAs guiding post-transcriptional gene repression in countless biological processes. However, the miRNA pathway in mouse oocytes appears inactive and dispensable for development. We propose that marginalization of the miRNA pathway activity stems from the constraints and adaptations of RNA metabolism elicited by the diluting effects of oocyte growth. We report that miRNAs do not accumulate like mRNAs during the oocyte growth because miRNA turnover has not adapted to it. The most abundant miRNAs total tens of thousands of molecules in growing (∅ 40 μm) and fully grown (∅ 80 μm) oocytes, a number similar to that observed in much smaller fibroblasts. The lack of miRNA accumulation results in a 100-fold lower miRNA concentration in fully grown oocytes than in somatic cells. This brings a knock-down-like effect, where diluted miRNAs engage targets but are not abundant enough for significant repression. Low-miRNA concentrations were observed in rat, hamster, porcine and bovine oocytes, arguing that miRNA inactivity is not mouse-specific but a common mammalian oocyte feature. Injection of 250,000 miRNA molecules was sufficient to restore reporter repression in mouse and porcine oocytes, suggesting that miRNA inactivity comes from low-miRNA abundance and not from some suppressor of the pathway.

• MeSH
• buňky 3T3 MeSH
• druhová specificita MeSH
• křečci praví MeSH
• krysa rodu rattus MeSH
• kultivované buňky MeSH
• messenger RNA genetika   metabolismus   MeSH
• mikro RNA genetika   metabolismus   MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• oocyty cytologie   metabolismus   MeSH
• oogeneze * MeSH
• prasata MeSH
• skot MeSH
• teoretické modely MeSH
• vývojová regulace genové exprese MeSH
• zvířata MeSH
• Check Tag
• křečci praví MeSH
• krysa rodu rattus MeSH
• myši MeSH
• skot MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Neurodevelopmental disorders (NDDs) result from highly penetrant variation in hundreds of different genes, some of which have not yet been identified. Using the MatchMaker Exchange, we assembled a cohort of 27 individuals with rare, protein-altering variation in the transcriptional coregulator ZMYM3, located on the X chromosome. Most (n = 24) individuals were males, 17 of which have a maternally inherited variant; six individuals (4 male, 2 female) harbor de novo variants. Overlapping features included developmental delay, intellectual disability, behavioral abnormalities, and a specific facial gestalt in a subset of males. Variants in almost all individuals (n = 26) are missense, including six that recurrently affect two residues. Four unrelated probands were identified with inherited variation affecting Arg441, a site at which variation has been previously seen in NDD-affected siblings, and two individuals have de novo variation resulting in p.Arg1294Cys (c.3880C>T). All variants affect evolutionarily conserved sites, and most are predicted to damage protein structure or function. ZMYM3 is relatively intolerant to variation in the general population, is widely expressed across human tissues, and encodes a component of the KDM1A-RCOR1 chromatin-modifying complex. ChIP-seq experiments on one variant, p.Arg1274Trp, indicate dramatically reduced genomic occupancy, supporting a hypomorphic effect. While we are unable to perform statistical evaluations to definitively support a causative role for variation in ZMYM3, the totality of the evidence, including 27 affected individuals, recurrent variation at two codons, overlapping phenotypic features, protein-modeling data, evolutionary constraint, and experimentally confirmed functional effects strongly support ZMYM3 as an NDD-associated gene.

• MeSH
• fenotyp MeSH
• histondemethylasy genetika   MeSH
• jaderné proteiny genetika   MeSH
• lidé MeSH
• malformace nervového systému * MeSH
• mentální retardace * genetika   MeSH
• neurovývojové poruchy * genetika   MeSH
• obličej MeSH
• regulace genové exprese MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Physiological constraints on colouration have been widely reported; especially in birds, which trade-off antioxidant responses against colourful costly signals. One female extended phenotypic trait, which might also highlight important physiological trade-offs, is the pigmentation of their eggshells. In ground-nesting species, producing eggs that are visually undetectable by predators is the best camouflage strategy. However, the condition-dependence of eggshell pigmentation, and the pigments role in oxidative stress, may constrain females to trade-off between their antioxidant capacity and maximising the camouflage of their eggs when they deposit eggshell pigments. Developmental stress is one factor that influences female antioxidant capacity, and could lead to variations in eggshell pigmentation that might have crucial consequences on individual fitness if egg crypsis is compromised especially under stressful conditions. We investigated the interaction between developmental and breeding conditions with respect to eggshell pigmentation in Japanese quail. We studied 30 females that bred under both control and stressful conditions, and were exposed to pre- and/or post-natal stress, or neither. Pre- and post-natal stress independently influenced eggshell pigmentation strategies under stressful breeding conditions. Under stressful reproduction, eggshell protoporphyrin concentration and maculation were affected by pre-natal stress, whereas eggshell reflectance and biliverdin concentration were influenced by post-natal stress. These changes may reflect potential adaptive strategies shaped by developmental stress, but additional data on the benefit of egg crypsis in quail, combined with studies on the role of both pigments on chick survival, will help to clarify whether early life stress can enhance fitness through eggshell pigmentation when developmental and reproductive environments match.

• MeSH
• chov MeSH
• Coturnix fyziologie   MeSH
• fyziologický stres * MeSH
• novorozená zvířata MeSH
• pigmentace fyziologie   MeSH
• rozmnožování fyziologie   MeSH
• tělesná hmotnost MeSH
• vaječná skořápka fyziologie   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Life underground has constrained the evolution of subterranean mammals to maximize digging performance. However, the mechanisms modulating morphological change and development of fossorial adaptations in such taxa are still poorly known. We assessed the morpho-functional diversity and early postnatal development of fossorial adaptations (bone superstructures) in the appendicular system of the African mole-rats (Bathyergidae), a highly specialized subterranean rodent family. Although bathyergids can use claws or incisors for digging, all genera presented highly specialized bone superstructures associated with scratch-digging behavior. Surprisingly, Heterocephalus glaber differed substantially from other bathyergids, and from fossorial mammals by possessing a less specialized humerus, tibia and fibula. Our data suggest strong functional and developmental constraints driving the selection of limb specializations in most bathyergids, but more relaxed pressures acting on the limbs of H. glaber. A combination of historical, developmental and ecological factors in Heterocephalus are hypothesized to have played important roles in shaping its appendicular phenotype.

• MeSH
• aklimatizace * MeSH
• fenotyp MeSH
• fyziologická adaptace MeSH
• mikroftalmičtí podzemní hlodavci * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

We tested whether two basic thermal requirements for insect development, lower developmental thresholds, i.e. temperatures at which development ceases, and sums of effective temperatures, i.e. numbers of day degrees above the lower developmental thresholds necessary to complete development, differ among insect species that proved to be successful invaders in regions outside their native range and those that did not. Focusing on species traits underlying invasiveness that are related to temperature provides insights into the mechanisms of insect invasions. The screening of thermal requirements thus could improve risk-assessment schemes by incorporating these traits in predictions of potentially invasive insect species. We compared 100 pairs of taxonomically-related species originating from the same continent, one invasive and the other not reported as invasive. Invasive species have higher lower developmental thresholds than those never recorded outside their native ranges. Invasive species also have a lower sum of effective temperatures, though not significantly. However, the differences between invasive and non-invasive species in the two physiological measures were significantly inversely correlated. This result suggests that many species are currently prevented from invading by low temperatures in some parts of the world. Those species that will overcome current climatic constraints in regions outside their native distribution due to climate change could become even more serious future invaders than present-day species, due to their potentially faster development.

• MeSH
• biologické modely MeSH
• ekosystém MeSH
• hmyz klasifikace   růst a vývoj   fyziologie   MeSH
• klimatické změny MeSH
• teplota MeSH
• zavlečené druhy * MeSH
• zvířata MeSH
• Check Tag
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH

In ephemeral habitats, the same genotypes cope with unpredictable environmental conditions, favouring the evolution of developmental plasticity and alternative life-history strategies (ALHS). We tested the existence of intrapopulation ALHS in an annual killifish, Nothobranchius furzeri, inhabiting temporary pools. The pools are either primary (persisting throughout the whole rainy season) or secondary (refilled after desiccation of the initial pool), representing alternative niches. The unpredictable conditions led to the evolution of reproductive bet-hedging with asynchronous embryonic development. We used a common garden experiment to test whether the duration of embryonic period is associated with post-embryonic life-history traits. Fish with rapid embryonic development (secondary pool strategy, high risk of desiccation) produced phenotypes with more rapid life-history traits than fish with slow embryonic development (primary pool strategy). The fast fish were smaller at hatching but had larger yolk sac reserves. Their post-hatching growth was more rapid, and they matured earlier. Further, fast fish grew to a smaller body size and died earlier than slow fish. No differences in fecundity, propensity to mate or physiological ageing were found, demonstrating a combination of plastic responses and constraints. Such developmentally related within-population plasticity in life history is exceptional among vertebrates.

• MeSH
• analýza přežití MeSH
• ekosystém * MeSH
• fenotyp MeSH
• fertilita fyziologie   MeSH
• Fundulidae embryologie   růst a vývoj   fyziologie   MeSH
• rybníky MeSH
• velikost těla fyziologie   MeSH
• zvířata MeSH
• Check Tag
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Afrika MeSH

The arrangement of chromatin within interphase nuclei seems to be caused by topological constraints and related to gene expression depending on tissue and developmental stage. In yeast and animals it was found that homologous and heterologous chromatin association are required to realize faithful expression and DNA repair. To test whether such associations are present in plants we analyzed Arabidopsis thaliana interphase nuclei by FISH using probes from different chromosomes. We found that chromatin fiber movement and variable associations, although in general relatively seldom, may occur between euchromatin segments along chromosomes, sometimes even over large distances. The combination of euchromatin segments bearing high or low co-expressing genes did not reveal different association frequencies probably due to adjacent genes of deviating expression patterns. Based on previous data and on FISH analyses presented here, we conclude that the global interphase chromatin organization in A. thaliana is relatively stable, due to the location of its 10 centromeres at the nuclear periphery and of the telomeres mainly at the centrally localized nucleolus. Nevertheless, chromatin movement enables a flexible spatial genome arrangement in plant nuclei.

• Publikační typ
• časopisecké články MeSH

Úvod: Komunitní porodní asistence nabízí alternativní přístup k porodní péči, který se zaměřuje na individualizovanou podporu těhotných žen v jejich přirozeném prostředí. Tento model poskytuje ženám možnost hlubšího vztahu s porodní asistentkou a je často považován za prospěšný jak pro matku, tak pro novorozence. V České republice je však komunitní porodní asistence stále ve fázi rozvoje a čelí mnoha výzvám, včetně legislativních a finančních omezení. Cíl: Cílem příspěvku je analyzovat význam komunitní porodní asistence v České republice a poukázat na její přínosy pro ženy a rodiny, jakož i na překážky, které brání jejímu širšímu uplatnění v rámci zdravotnického systému. Závěr: Komunitní porodní asistence představuje významný přínos v oblasti individualizované péče a podpory rodiny. Tento model péče posiluje důvěru mezi ženou a porodní asistentkou a podporuje přirozený proces porodu. Nicméně, pro plné rozvinutí komunitní porodní asistence v České republice je nezbytné překonat legislativní překážky a zajistit adekvátní finanční podporu.

Introduction: Community midwifery offers an alternative approach to maternity care, focusing on individualized support for pregnant women in their natural environment. This model allows women to build a deeper relationship with their midwife and is often considered beneficial for both the mother and the newborn. However, in the Czech Republic, community midwifery is still in the developmental phase and faces many challenges, including legislative and financial constraints. Aim: The aim of the article is to analyze the significance of community midwifery in the Czech Republic and to highlight its benefits for women and families, as well as the barriers that prevent its broader implementation within the healthcare system. Conclusion: Community midwifery represents a significant contribution to the field of individualized care and family support. This care model enhances the trust between the woman and the midwife and supports the natural process of childbirth. However, for community midwifery to fully develop in the Czech Republic, it is essential to overcome legislative barriers and secure adequate financial support.

• MeSH
• komunitní ošetřovatelská péče dějiny   metody   organizace a řízení   trendy   výchova   MeSH
• porodní asistentky MeSH
• porodnické ošetřovatelství MeSH
• Geografické názvy
• Česká republika MeSH

Auxin directs plant ontogenesis via differential accumulation within tissues depending largely on the activity of PIN proteins that mediate auxin efflux from cells and its directional cell-to-cell transport. Regardless of the developmental importance of PINs, the structure of these transporters is poorly characterized. Here, we present experimental data concerning protein topology of plasma membrane-localized PINs. Utilizing approaches based on pH-dependent quenching of fluorescent reporters combined with immunolocalization techniques, we mapped the membrane topology of PINs and further cross-validated our results using available topology modeling software. We delineated the topology of PIN1 with two transmembrane (TM) bundles of five α-helices linked by a large intracellular loop and a C-terminus positioned outside the cytoplasm. Using constraints derived from our experimental data, we also provide an updated position of helical regions generating a verisimilitude model of PIN1. Since the canonical long PINs show a high degree of conservation in TM domains and auxin transport capacity has been demonstrated for Arabidopsis representatives of this group, this empirically enhanced topological model of PIN1 will be an important starting point for further studies on PIN structure-function relationships. In addition, we have established protocols that can be used to probe the topology of other plasma membrane proteins in plants.

• MeSH
• Arabidopsis cytologie   metabolismus   MeSH
• buněčná membrána metabolismus   MeSH
• cytoplazma metabolismus   MeSH
• extracelulární prostor metabolismus   MeSH
• hydrofobní a hydrofilní interakce MeSH
• kyseliny indoloctové metabolismus   MeSH
• membránové transportní proteiny chemie   metabolismus   MeSH
• proteinové domény MeSH
• proteiny huseníčku chemie   metabolismus   MeSH
• transport proteinů MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH