Sterile Species Research Articles

Additional glial cell line-derived neurotrophic factor in vitro promotes the proliferation of undifferentiated spermatogonia from sterile cattleyak

Cattleyak is a typically male sterile species. The meiosis process is blocked and the scarcity of spermatogenic stems cells are both contributing factors to the inability of male cattleyak to produce sperm. While Glial cell line-derived neurotrophic factor (GDNF) is the first discovered growth factor known to promote the proliferation and self-renewal of spermatogenic stem cells, its relationship to the spermatogenesis arrest of cattleyak remains unclear. In this report, we studied the differential expression of GDNF in the testis of yak and cattleyak, and discussed the optimal concentration of GDNF in the culture medium of undifferentiated spermatogonia (UDSPG) of cattleyak in vitro and the effect of GDNF on the proliferation of cattleyak UDSPG. The results indicated that GDNF expression in the testicular tissue of cattleyak was inferior to that of yak. Moreover, the optimum value for the UDSPG in vitro culture was determined to be 20–30 ng/mL for cattleyak. In vitro, the proliferation activity of UDSPG was observed to increase with additional GDNF due to the up-regulation of proliferation-related genes and the down-regulation of differentiation-related genes. We hereby report that the scarcity of cattleyak UDSPG is due to insufficient expression of GDNF, and that the addition of GDNF in vitro can promote the proliferation of cattleyak UDSPG by regulating the expression of genes related to proliferation and differentiation. This work provides a new insight to solve the issue of spermatogenic arrest in cattleyak.

The Neutrino Mass Problem: From Double Beta Decay to Cosmology

The neutrino is perhaps the most elusive member of the particle zoo. The questions about its nature, namely: Dirac or Majorana, the value of its mass and the interactions with other particles, the number of its components including sterile species, are long standing ones and still remain to a large extent without conclusive answers. From the side of the nuclear structure and nuclear reactions, both theories and experiments, the need to elucidate these questions has, and still has, prompt crucial developments in the fields of double beta decay, double charge exchange and neutrino induced reactions. The measurements of neutrino flavor oscillation parameters contribute largely to restrict models with massless neutrinos. From the particle physics side, the possibilities to extend the standard model of electroweak interactions to incorporate a right-handed sector of the electroweak Lagrangian are directly linked to the adopted neutrino model. Here, I would like to address another aspect of the problem by asking the question of the neutrino mass mechanism in the cosmological context, and particularly about dark matter.

Chaetomium albiziae, a new endophytic species from Albizia lebbeck in Iran

The silk tree (Albizia lebbeck (L.) Benth) is one of the ornamental plants in Ahvaz (southwest of Iran). Two endophytic fungal strains, isolated from the leaves of this plant, were characterized. Molecular phylogenetic analyses based on a combined matrix of the internal transcribed spacer regions 1 and 2 including the intervening 5.8S nuclear ribosomal DNA (ITS), and partial regions of the β-tubulin (tub2) and RNA polymerase II second largest subunit (rpb2) indicated that both strains represent a new Chaetomium species, C. albiziae sp. nov. in the family Chaetomiaceae. Chaetomium albiziae formed a sister lineage with sterile species C. cucumericola. This new species can be characterized by ostiolate perithecia with septate lateral and terminal setae, clavate asci and aseptate ellipsoidal to ovoid ascospores with an apical germ pore. In addition, this is the first report of the endophytic association of the genus Chaetomium with Albizia lebbeck worldwide.

The Low‐Scale Seesaw Solution to the MW$M_W$ and (g−2)μ$(g-2)_\umu$ Anomalies

AbstractThe recent CDF‐II measurement of the W‐boson mass shows a strong tension with the corresponding Standard Model prediction. Once active neutrino masses are explained in the context of the Low‐Scale Seesaw mechanisms, this tension can be resolved. We investigate the possibility of explaining the longstanding muon anomalous magnetic moment anomaly within the same frameworks. We present a simplified extension of the Standard Model, accounting only for the second lepton generation, that describes a massive active neutrino and provides a combined solution to these anomalies. The model is renormalisable and introduces in the spectrum, beyond the sterile species of the Low‐Scale Seesaw mechanism, only one pair of exotic vector‐like leptons, doublets under the electroweak symmetry. We moreover discuss the extension of this model to the realistic three‐family case.

Resonant production of light sterile neutrinos in compact binary merger remnants

The existence of eV-mass sterile neutrinos is not ruled out because of persistent experimental anomalies. Upcoming multi-messenger detections of neutron-star merger remnants could provide indirect constraints on the existence of these particles. We explore the active-sterile flavor conversion phenomenology in a two-flavor scenario (1 active + 1 sterile species) as a function of the sterile neutrino mixing parameters, neutrino emission angle from the accretion torus, and temporal evolution of the merger remnant. The torus geometry and the neutron richness of the remnant are responsible for the occurrence of multiple resonant active-sterile conversions. The number of resonances strongly depends on the neutrino emission direction above or inside the remnant torus and leads to large production of sterile neutrinos (and no antineutrinos) in the proximity of the polar axis as well as more sterile antineutrinos than neutrinos in the equatorial region. As the black hole torus evolves in time, the shallower baryon density is responsible for more adiabatic flavor conversion, leading to larger regions of the mass-mixing parameter space being affected by flavor mixing. Our findings imply that the production of sterile states could have indirect implications on the disk cooling rate, its outflows, and related electromagnetic observables which remain to be assessed.

Morphology, Structure and Potential of Bulbils Yield as a Planting Material of Onion in Tropical Region

Onion is one of the essential horticultural commodities in Indonesia. The productivity of onion in 2019 is only 7.27 t/ha. Low productivity levels are a problem faced by farmers in Indonesia. One of the causes of low productivity is the low quality of planting material. The majority of onion cultivars can only be propagated vegetatively through bulbs and are known as sterile species. Therefore, other planting materials that have high production potential are needed. Bulbils are possible as planting material. Several onion varieties have a tendency to produce bulbils, one of which is the Tawangmangu Baru variety. Tawangmangu varieties of onion include the type of softneck that can form bulbils. This study aims to examine the morphological characteristics and structure of bulbils and to determine the yield potential of onion bulbils. Field experiments were carried out descriptively by planting onion bulbils. Each Tawangmangu Baru variety plant is capable of forming 1-5 bulbils. Bulbils that are formed have a small size with a single bulb shape. Bulbils and cloves have the same morphological and structural characteristics as the embryo. However, there is a difference in size between bulbils and clove bulbs, bulbils are smaller in length, size and weight. The longitudinal cross-section of the clove bulbs' bulbils is the first foliar leaf, leaf clove base storage. The cross-section of the bulbils and cloves consists of the carrier bundle, embryonic parenchyma, embryonic epidermis, bulb parenchyma. Growing bulbils require controlled environmental and climatic conditions. Bulbils can grow and produce bulbs with a productivity of 6 - 8 tons/ha. Bulbils have the potential to be developed as planting material.

Unravelling the diversity of the lichen genus Porina (Porinaceae) in Mauritius

Background and aims – Despite the publication of a recent checklist for Mauritius, a small archipelago in the south-western Indian Ocean, our knowledge of the lichen flora of this region remains incomplete. The present contribution is part of an ongoing study of lichen diversity of the islands of Mauritius and Rodrigues. It aims to unravel the diversity of the genus Porina s.l. on these islands and to improve the taxonomy and the phylogeny of the family Porinaceae following the morphological study and the sequencing of recently collected material.Material and methods – Lichens were collected in 2016 and 2019 in a range of environments, from lowland dry habitats up to dense evergreen upland forests on the islands of Mauritius and Rodrigues. In total, 85 samples of Porina were examined using light microscopy. A molecular study using mtSSU sequences was performed in order to investigate the phylogenetic position of the species of Porina occurring in the study area.Key results – The analyses revealed the presence of 23 species of Porina s.l. in Mauritius, while only four were previously accepted for this country. Five new species are described: Porina covidii, P. griffithsii, P. mauritiana, P. nuculoides, and P. rupicola, while two sterile species remain unidentified. The mtSSU phylogenetic tree includes 19 of the 23 species occurring in Mauritius. These species are dispersed throughout the phylogenetic tree, in at least eight main and strongly supported lineages, suggesting multiple colonizations of Mauritius. A new lineage only including Paleotropical and mainly foliicolous species (P. epiphylloides, P. longispora, P. mauritiana, and P. mazosioides) is revealed. Pseudosagedia crocynioides, a species that was previously known only from Florida, is newly reported from Mauritius, highlighting a remarkable disjunct distribution. Photos of each taxon are provided, along with an identification key to all species.Conclusion – The study of the genus Porina in Mauritius highlights a rich flora. The true diversity of Porina species in the south-western Indian Ocean is certainly underestimated and in need of further investigation, while a taxonomic-phylogenetic revision of tropical Porina at a broader geographical scale is highly desirable. The identity of several Mauritian specimens remains uncertain despite the use of molecular data.

Limits on active-sterile neutrino mixing parameters using heavy nuclei abundances

The production of heavy-mass elements due to the rapid neutron-capture mechanism ([Formula: see text]-process) is associated with astrophysical scenarios, such as supernovae and neutron-star mergers. In the [Formula: see text]-process the capture of neutrons is followed by [Formula: see text]-decays until nuclear stability is reached. A key element in the chain of nuclear weak-decays leading to the production of isotopes may be the change of the parameters controlling the neutrino sector, due to the mixing of active and sterile species. In this work, we have addressed this question and calculated [Formula: see text]-decay rates for the nuclei involved in the [Formula: see text]-process chains as a function of the neutrino mixing parameters. These rates are then used in the calculation of the abundance of the heavy elements produced in core-collapse supernova and in neutron-star mergers, starting from different initial mass-fraction distributions. The analysis shows that the core-collapse supernova environment contributes with approximately [Formula: see text] of the total heavy nuclei abundance while the neutron-star merger contributes with about [Formula: see text] of it. Using available experimental data we have performed a statistical analysis to set limits on the active-sterile neutrino mixing angle and found a best-fit value [Formula: see text], a value comparable with those found in other studies reported in the literature.

Globally rare oceanic-montane liverworts with disjunct distributions: evidence for long-distance dispersal

Disjunct distributions in bryophytes are well known, but when it comes to the mechanisms that have shaped these distributions, especially for apparently sterile species, the historical processes leading to inter-continental disjunctions remain enigmatic. In this study, we developed microsatellite markers to investigate the spatial distribution and extent of genotypic diversity of 147 Anastrophyllum alpinum samples collected from three populations each in Nepal and Scotland (UK). For a more general insight into genetic differences, sequence divergence in A. alpinum and eight other globally rare and disjunct oceanic-montane liverworts was also assessed. A nested allele distribution of Scottish populations of A. alpinum within the allele range of the Nepalese populations, and lower levels of genetic diversity within Scottish samples indicate that the Scottish populations likely have their origins in the Sino-Himalaya. The evidence for long-distance dispersal was supported by a lack of sequence divergence in chloroplast DNA between Scottish and Nepalese populations, with only a single substitution detected from 5160 bp of plastid sequence. Low levels of sequence divergence were also detected in species with similar distributions. While Scottish populations of A. alpinum do not appear to produce spores, they do still harbour a considerable genetic diversity. This indicates that sexual reproduction has been important at some point in their history. However, the current absence of evidence for sexual reproduction needs to be taken into account when designing conservation actions for these montane species, to ensure population maintenance and ability to track suitable climate and habitat space.

A new species of Synarthonia from Luxembourg, and a new combination in the genus Reichlingia (Arthoniaceae)

AbstractA new species of Synarthonia, S. leproidica, is described from Luxembourg. Phylogenetic analyses of mtSSU and RPB2 sequences were used to determine the generic affiliation of this sterile species. Synarthonia leproidica differs from all other species of the genus by the combination of a leproid thallus and the production of psoromic acid. It is the sister species to S. muriformis in our phylogenetic analyses. The discovery of the new species suggests that other strictly sorediate lichen species might have been overlooked in Europe, even in intensely explored countries such as Luxembourg. Phylogenetic analyses further confirm the placement of Reichlingia anombrophila in the genus Reichlingia and of Synarthonia astroidestera in the genus Synarthonia. Arthonia atlantica is transferred to the genus Reichlingia as R. dendritica.

Identification of clonemates and genetic lineages using next-generation sequencing (ddRADseq) guides conservation of a rare species, Bossiaea vombata (Fabaceae)

Plant species capable of clonal reproduction range from rare, sterile species that have a high extinction risk to invasive plants that influence the structure of ecosystems. There is increasing evidence that clonality in combination with reduced fecundity and limited dispersal capacity increases extinction risk. As many conservation targets are not well-characterised genetically, our objective was to determine the utility of sequencing a reduced representation of the genome to inform the conservation of a non-model plant species. We sequenced a single DNA library from a recently described, rare, clonal species; Bossiaea vombata. Multiple assemblies of that library were used to evaluate our ability to assess genetic variation and clonal assignment, to identify chloroplast haplotypes and to obtain phylogenetic information. Next generation sequencing (ddRADseq) provided a cost and time effective method for identifying clones and assigning clonemates despite increased levels of missing data in comparison to more traditional methods (e.g. microsatellites). We applied a threshold of genetic difference to determine whether individual samples belonged to the same or different clones. Bossiaea vombata, was found to comprise only five clones with all but one site being monoclonal - indicating that the genotypic diversity of the species cannot be determined from a census of stems. The ddRADseq method showed utility for phylogenetic analysis but we identified possible shortcomings in chloroplast haplotyping using loci from the same library.

A study of the type material of Lithophyllum hibernicum (Lithophyllaceae, Corallinales, Rhodophyta) with comments on L. bathyporum and L. incrustans

ABSTRACTThe original material of Lithophyllum hibernicum Foslie was re-examined and two different species, unequally represented in the collection were found: most thalli belong to a sterile species of Lithophyllum, represented in the protologue by elements related to cell size and coaxial arrangement. A few sterile thalli belong to Lithothamnion cf. corallioides, and this species is also represented in the protologue by a single statement of branch size. Yet, the species of Lithophyllum is the sole representative in Foslie's unpublished materials included in the type collection in TRH. A previous lectotypification, contradicting Art. 9.14 (that demands the type to correspond to its original description rather than to a certain taxonomic concept), is sustained because it preserves Foslie's intent. The lectotype of L. hibernicum is a sterile, branched rhodolith with characteristic cup- or funnel-shaped formations on its thallus. Syntypes are inhabited by an endo-, epiphytic species of Gelidiales forming openings resembling conceptacle ostioles. Molecular comparison with topotypes is needed before synonymy with the common epilithic species Lithophyllum bathyporum in the NE Atlantic should be accepted.

Neuroaxonal Dystrophy in a mule: first case reported

ABSTRACT A 12-month-old mule (sterile hybrid equine species) presented unspecific neurological changes (symmetric ataxia, dysmetria, conscious proprioceptive deficit and weakness). Due to poor prognosis and to the fact that a sibling from the previous generation exhibited similar clinical signs that were not definitively diagnosed, the animal was euthanized. Diagnosis of neuroaxonal dystrophy was confirmed by anatomohistopathological analysis. This is the first clinical case of neuronal dystrophy in a mule reported in the world. The clinical and histopathological characteristics of this disease were very similar to those reported for several equine breeds. Therefore, the disease should also be considered in the diagnosis of neurological conditions in mules and donkeys.

DNA barcoding approach fails to discriminate Central European bladderworts (Utricularia, Lentibulariaceae), but provides insights concerning their evolution

The main features to distinguish the seven native Utricularia species occurring in central Europe are found in flower shape, but being rarely flowering identification is often doubtful and uncertain. A recent morphometric work highlighted that there are no univocal reliable extra-floral morphological features allowing a safe identification at species level. Therefore, DNA barcoding approach is attempted here. Molecular analyses were performed to search for DNA barcodes using nuclear ITS (rDNA), plastid (cpDNA) trnL-trnF IGS and rps16 intron sequences. Generally, the barcoding approach failed to discriminate Utricularia species, although it could be of some help in the U. minor aggregate. With few exceptions, U. bremii shows peculiar DNA regions different from U. minor for both plastid markers investigated. However, interesting hypotheses could be derived from the obtained networks, including hybridization events to explain the rise of mostly sterile species, such as U. stygia. This species clusters with the other species of the U. intermedia aggregate in plastid phylogenetic graphs, while it is closely related to species of the U. minor aggregate in ITS phylogenetic graphs. Additionally to U. stygia, U. ochroleuca also shows some incongruences in the different markers, at least for some accessions, pointing to the possible occurrence of hybrids.

Araceae of the Lita–San Lorenzo Region (Esmeraldas Province, Ecuador)—Part 1: Anthurium sect. Polyneurium

This paper is the first in an expected series of publications treating the Araceae of the Lita–San Lorenzo Region of northwestern Ecuador. An introduction to the physical and ecological characteristics of the area is given, and Anthurium Schott sect. Polyneurium Engl. is redefined and typified. Thirty-four species in section Polyneurium are fully described of which 13 are new species of Anthurium: A. bruxellense Croat, A. chuchubiense Croat, A. cornejoi Croat, A. decursivum Croat, A. hannoniae Croat, A. impolitoellipticum Croat, A. kinsingeriae Croat, A. longeinternodum Croat, A. mansellii Croat, A. pandurilaminum Croat, A. pseudotalamancae Croat, A. triangulohastatum Croat, and A. waramirezii Croat. In addition, six seemingly new but (sometimes) sterile species for the region are fully described but not formally named.

Ink Spot of Warm‐Season Golf Course Turfgrasses

Core Ideas Ink spot is a foliar disease of bermudagrass and zoysiagrass managed as golf course turf. Curvularia malina, a novel and sterile species, is the causal agent of ink spot. The turfgrass symptoms of ink spot include distinct, small chocolate‐brown to black spots. Curvularia malina is the causal agent of ink spot, a foliar disease of bermudagrass and zoysiagrasses used in golf course settings. Distinct, chocolate‐brown to black spots appear in conjunction with high amounts or frequent precipitation events in the southern United States. Foliar symptoms of ink spot consist of small, purplish‐black spots that develop into eye‐spot lesions on the leaves of zoysiagrasses but develop a round‐to‐elliptical lesion on bermudagrass leaves. Older, blighted leaves at the base of the plant cause the chocolate‐brown to black spots observed in the turfgrass sward. Crown and/or root rot has not been associated with ink spot. Isolation of C. malina is highly successful when using leaves of bermudagrass or zoysiagrass exhibiting ink spot symptoms. Curvularia malina is sterile; therefore, confirmation must be made using sequence data of ITS, GPD1, or TEF1. Curvularia malina has been isolated from bermudagrass and zoysiagrass expressing foliar symptoms of ink spot throughout the Gulf Coast region of the United States, which to date, includes Alabama, Mississippi, Tennessee, and Texas.

Opportunities and challenges for fish culture in Brazilian reservoirs: a review

Abstract Aim Aquaculture plays an important role in the world and in Brazil. Artificial construction of water bodies, such as ponds and reservoirs, has allowed for fish culture in cages in those environments, generating conflicts over the use of these public waters. The producers are seeking to increase production, and the ecosystem is susceptible to the impacts caused by production activity. The aim of this review was to identify questions about these conflicts (productivity × environment) and to indicate possible solutions to the main problems related to fish farming in reservoirs. Methods A bibliographical survey was carried out on the main aspects of cage fish farming in Brazilian reservoirs. Studies from 1977 to 2018 (scientific journals, books, and thesis) were revised using seven databases, the CAPES periodicals portal and Google Scholar websites. The main keywords used were “aquaculture”, “reservoir”, “cage”, “eutrophication”, “carrying capacity”, “impacts”, “oligotrophic”, “escapes”, “hybrids”, and “pollution”. Results We accessed approximately 330 and cited 151 documents. Conclusions The negative aspects associated with cage fish farming, as escapes of cultivated fish, and the possible solutions of this and others negative impacts were addressed, identifying mechanisms for reducing conflicts between environmental impacts and aquaculture production. Potential solutions include the use of native fish species or sterile species, implementation of monitoring systems of the surrounding area, adoption of measures to reduce the accidental escape of fish, use of multitrophic culture systems, use of highly digestible diets with appropriate food management, and use of computer programs that incorporate current and historical environmental data to calculate carrying capacity and choose the most appropriate location for production.

Epigenetic stability in Saffron (Crocus sativus L.) accessions during four consecutive years of cultivation and vegetative propagation under open field conditions

Saffron (Crocus sativus L.) is a sterile species that is vegetatively propagated in the field, year by year, via the production of new corms. While Saffron’s genetic variability is extremely low, phenotypic variation is frequently observed in the field and epigenetics could be a possible origin of these alternative phenotypes. Present day knowledge on Saffron epigenetics is very low or absent. In the present paper, to deepen existing knowledge, we focused on the epigenetic differences and stability among 17 Saffron accessions, of different geographic origin, during four consecutive years of vegetative propagation under open field conditions. Before the analysis, the selected accessions have been cultivated in the same field for at least three consecutive years. Despite the low genetic variability and the prolonged co-cultivation in the same environment, Methylation-Sensitive Amplified Fragment Length Polymorphism (MS-AFLP) analysis revealed a very high epigenetic difference among accessions, making it possible to discriminate them based on the epigenetic profiles. During the four years of the study, a little variation has been observed within accessions following different patterns, slightly modifying the accession epigenotypes but not enough to even them to a more uniform profile. These results confirm that, under natural conditions, Saffron epigenotypes are highly stable, supporting a role for epigenetics in phenotypic variability.

Obtention of new ornamental leaf variants of giant reed (Arundo donax L.) originated from somatic embryogenesis and their photosynthetic parameters

Giant reed (Arundo donax L.) is a perennial rhizomatous herbaceous plant, it has been widespread all over the world by human activities. It is a 2-8 meter high, polyploid, sterile species (not produce viable seeds), it can be propagated only by vegetative methods (rhizomes, stem cuttings, in vitro biotechnological methods). It has considered promising dedicated energy crop thanks to high biomass production (20-40 dry tons per hectare depending on microclimate), adaptability of different kind of soils and environment and low energy input required for its cultivation. It has been utilized for energetic purposes, biogas/bioethanol production, cellulose/paper production and ornamental purposes. The objectives of the present study were to determine morphological properties of new ornamental giant reed leaf variants originated from somatic embryogenesis and to evaluate their photosynthetic pigment content and photosynthetic activities. The most typical changes was the appearance of different colour (white, yellow, light green) longitudinal stripes on leaves (also on petiole and on leaf blade). It was significant differences (p<0.05) between green and leaf variants in case of photosynthetic pigments content and photosynthetic activity (Fv/Fm value). There was no detectable chlorophyll a or b content in the white bands of leaves and albino shoots. Total chlorophyll content of the white striped leaf variety was more than twice than the light green leaves. Photosynthetic activity and content of photosynthetic pigments also confirm and determine the morphological characteristics and growth habit of leaf variants.

Highway pollution effects on microhabitat community structure of corticolous lichens

We studied lichen communities on bole and base tree trunk segments along forest edge-to-interior gradients on opposite sides of a major highway and a control site in central North Carolina, U.S.A., to investigate if these two communities differ and if so, do they differ in response to highway pollution. At each site we measured various environmental parameters including ambient air NO2 concentrations, and sampled lichens on 5–7 trees along each of five parallel transects established at the forest edge and at 25, 60, 100 and 150 m into the forest. We compared lichen communities between the two trunk segments via species richness and composition by habit, photobiont type, and reproductive strategy. We then ran dual (bole and base) NMS ordinations with subsequent correlation/regression analyses to explore/test relationships of lichen parameters with environmental variables among the 15 sample transects combined. Species richness was similar between trunk segments at transect and site levels as well as overall. Bole and base communities were more compositionally similar to each other at the highway sites than they were at the control site, based on Bray-Curtis similarity indices (BC). Tree base communities differed in terms of functional groupings, with greater proportions of squamulose, cyanolichen and sterile species than found in tree bole communities, but varyingly so among sites. Patterns of bole-base BC values with distance from the forest edge were not apparent in any of the sites. Ordination analyses resulted in Axis 1 representing most of the variation for each trunk segment. Along this axis, correlations were similar between boles and bases, with the strongest ones involving lichen species richness (negative) and NO2 concentrations (positive); notably weak correlations involved tree species number, canopy cover and DBH. Similar patterns were found when lichen species number was correlated with environmental parameters directly, with NO2 concentration correlating strongest at each trunk segment. Among functional groups, % crustose and % fertile species on bases correlated significantly with NO2. Lichen species–NO2 relationships on boles and bases were both found to be highly significant quadratic relationships with base lichen richness being stronger.