scholarly journals Paraphysoderma sedebokerense Infection in Three Economically Valuable Microalgae: Host Preference Correlates with Parasite Fitness

2021 ◽  
Vol 7 (2) ◽  
pp. 100
Author(s):  
David Alors ◽  
Sammy Boussiba ◽  
Aliza Zarka
Keyword(s):  
Host Species ◽  
Developmental Stages ◽  
Haematococcus Pluvialis ◽  
Reservoir Host ◽  
Algal Culture ◽  
Parasite Fitness ◽  
Fungal Propagules ◽  
Scenedesmus Dimorphus ◽  
Resting Cysts ◽  
First Time

The blastocladialean fungus Paraphysoderma sedebokerense parasitizes three microalgae species of economic interest: Haematococcus pluvialis, Chromochloris zofingiensis and Scenedesmus dimorphus. For the first time, we characterized the developmental stages of isolated fungal propagules in H. pluvialis co-culture, finding a generation time of 16 h. We established a patho-system to compare the infection in the three different host species for 48 h, with two different setups to quantify parameters of the infection and parameters of the parasite fitness. The prevalence of the parasite in H. pluvialis and C. zofingiensis cultures was 100%, but only 20% in S. dimorphus culture. The infection of S. dimorphus not only reached lower prevalence but was also qualitatively different; the infection developed preferentially on senescent cells and more resting cysts were produced, being consistent with a reservoir host. In addition, we carried out cross infection experiments and the inoculation of a mixed algal culture containing the three microalgae, to determine the susceptibility of the host species and to investigate the preference of P. sedebokerense for these microalgae. The three tested microalgae showed different susceptibility to P. sedebokerense, which correlates with blastoclad’s preference to the host in the following order: H. pluvialis > C. zofingiensis > S. dimorphus.

scholarly journals First record of Kermes echinatus on Quercus ilex

2017 ◽  
Vol 22 (1) ◽  
pp. 19 ◽  
Author(s):  
G. J. Stathas ◽  
E. D. Kartsonas ◽  
P. J. Skouras
Keyword(s):  
Natural Enemies ◽  
Host Species ◽  
Quercus Ilex ◽  
Developmental Stages ◽  
First Record ◽  
Scale Insect ◽  
Chilocorus Bipustulatus ◽  
First Instar ◽  
First Time

The scale insect Kermes echinatus Balachowsky (Hemiptera, Coccoidea, Kermesidae) was recorded on Quercus ilex in November 2012 in Kalamata and in December of the same year on the same host species in Athens. Quercus ilex is recorded for the first time as the host of this scale. This scale is first recorded in continental Greece. The population of the scale in both areas consisted mainly of first instar nymphs, whereas in Kalamata individuals of the scale in advanced developmental stages were recorded. Preliminary studies indicate that natural enemies are active against K. echinatus. Moultings of larvae and pupae and adults of Chilocorus bipustulatus L. (Coleoptera: Coccinellidae) were found on colonies of the scale. Parasitoid exit holes were recorded on female adults of the scale. Some data on morphology and infestation of the scale on Q. ilex are given.

Descriptions of the postembryonic developmental stages of Hatschekia bifurcata Yamaguti & Yamasu, 1959 (Copepoda, Siphonostomatoida, Hatschekiidae)

Crustaceana ◽  
2015 ◽  
Vol 88 (6) ◽  
pp. 709-725 ◽  
Author(s):  
Kunihiko Izawa
Keyword(s):  
Adult Female ◽  
Host Species ◽  
Developmental Stages ◽  
Growth Curves ◽  
Diagnostic Feature ◽  
Free Living ◽  
New Host ◽  
First Time ◽  
Ventral Process ◽  
New Host Species

A series of descriptions of postembryonic developmental stages of Hatschekia bifurcata Yamaguti & Yamasu, 1959 is presented based on free-living larvae reared from eggs detached from ovigerous females recovered from the branchial lamellae of Aulacocephalus temmincki Bleeker, 1855, as well as on copepodids I-VI from A. temmincki and Diploprion bifasciatum Cuvier, 1828 (Pisces, Perciformes, Serranidae). The number of naupliar stages preceding the infective copepodid I is three in this species as in H. multibarbatae Izawa, 2015. A diagnostic feature of the species, a hook-like ventral process on the fourth antennular segment of the female, is regarded as an enlarged seta and was found to appear after copepodid V. A correction in the previously given setation of leg 2 and a complemental description of the antennule of the adult female are made. The male of this species is herein described for the first time. The sexes become distinct at copepodid III, and then growth curves of both sexes diverge stage by stage, as in H. multibarbatae. Aulacocephalus temmincki is reported as a new host species for H. bifurcata.

scholarly journals Probing the floral developmental stages, bisexuality and sex reversions in castor (Ricinus communis L.)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sujatha Thankeswaran Parvathy ◽  
Amala Joseph Prabakaran ◽  
Thadakamalla Jayakrishna
Keyword(s):  
Developmental Stages ◽  
Ricinus Communis ◽  
Sex Expression ◽  
Pistil Abortion ◽  
Ricinus Communis L ◽  
Sex Reversion ◽  
Stage 4 ◽  
Meristem Development ◽  
Male Specific ◽  
First Time

AbstractCastor (Ricinus communis L) is an ideal model species for sex mechanism studies in monoecious angiosperms, due to wide variations in sex expression. Sex reversion to monoecy in pistillate lines, along with labile sex expression, negatively influences hybrid seed purity. The study focuses on understanding the mechanisms of unisexual flower development, sex reversions and sex variations in castor, using various genotypes with distinct sex expression pattern. Male and female flowers had 8 and 12 developmental stages respectively, were morphologically similar till stage 4, with an intermediate bisexual state and were intermediate between type 1 and type 2 flowers. Pistil abortion was earlier than stamen inhibition. Sex alterations occurred at floral and inflorescence level. While sex-reversion was unidirectional towards maleness via bisexual stage, at high day temperatures (Tmax > 38 °C), femaleness was restored with subsequent drop in temperatures. Temperature existing for 2–3 weeks during floral meristem development, influences sexuality of the flower. We report for first time that unisexuality is preceded by bisexuality in castor flowers which alters with genotype and temperature, and sex reversions as well as high sexual polymorphisms in castor are due to alterations in floral developmental pathways. Differentially expressed (male-abundant or male-specific) genes Short chain dehydrogenase reductase 2a (SDR) and WUSCHEL are possibly involved in sex determination of castor.

scholarly journals Updated and Validated Pan-Coronavirus PCR Assay to Detect All Coronavirus Genera

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 599
Author(s):  
Myndi G. Holbrook ◽  
Simon J. Anthony ◽  
Isamara Navarrete-Macias ◽  
Theo Bestebroer ◽  
Vincent J. Munster ◽  
...  
Keyword(s):  
Host Species ◽  
High Sensitivity ◽  
Respiratory Illness ◽  
Reservoir Host ◽  
Pcr Assay ◽  
Wildlife Reservoirs ◽  
Viral Surveillance ◽  
Reservoir Hosts

Coronavirus (CoV) spillover events from wildlife reservoirs can result in mild to severe human respiratory illness. These spillover events underlie the importance of detecting known and novel CoVs circulating in reservoir host species and determining CoV prevalence and distribution, allowing improved prediction of spillover events or where a human–reservoir interface should be closely monitored. To increase the likelihood of detecting all circulating genera and strains, we have modified primers published by Watanabe et al. in 2010 to generate a semi-nested pan-CoV PCR assay. Representatives from the four coronavirus genera (α-CoVs, β-CoVs, γ-CoVs and δ-CoVs) were tested and all of the in-house CoVs were detected using this assay. After comparing both assays, we found that the updated assay reliably detected viruses in all genera of CoVs with high sensitivity, whereas the sensitivity of the original assay was lower. Our updated PCR assay is an important tool to detect, monitor and track CoVs to enhance viral surveillance in reservoir hosts.

scholarly journals Combining QTL Mapping and Gene Expression Analysis to Elucidate the Genetic Control of ‘Crumbly’ Fruit in Red Raspberry (Rubus idaeus L.)

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 794
Author(s):  
Luca M. Scolari ◽  
Robert D. Hancock ◽  
Pete E. Hedley ◽  
Jenny Morris ◽  
Kay Smith ◽  
...  
Keyword(s):  
Genetic Control ◽  
Developmental Disorder ◽  
Molecular Mechanisms ◽  
Developmental Stages ◽  
Microarray Experiment ◽  
Rubus Idaeus ◽  
Red Raspberry ◽  
Genotype By Sequencing ◽  
First Time ◽  
Selection Of

‘Crumbly’ fruit is a developmental disorder in raspberry that results in malformed and unsaleable fruits. For the first time, we define two distinct crumbly phenotypes as part of this work. A consistent crumbly fruit phenotype affecting the majority of fruits every season, which we refer to as crumbly fruit disorder (CFD) and a second phenotype where symptoms vary across seasons as malformed fruit disorder (MFD). Here, segregation of crumbly fruit of the MFD phenotype was examined in a full-sib family and three QTL (Quantitative Trait Loci) were identified on a high density GbS (Genotype by Sequencing) linkage map. This included a new QTL and more accurate location of two previously identified QTLs. A microarray experiment using normal and crumbly fruit at three different developmental stages identified several genes that were differentially expressed between the crumbly and non-crumbly phenotypes within the three QTL. Analysis of gene function highlighted the importance of processes that compromise ovule fertilization as triggers of crumbly fruit. These candidate genes provided insights regarding the molecular mechanisms involved in the genetic control of crumbly fruit in red raspberry. This study will contribute to new breeding strategies and diagnostics through the selection of molecular markers associated with the crumbly trait.

scholarly journals Host density predicts the probability of parasitism by avian brood parasites

2019 ◽  
Vol 374 (1769) ◽  
pp. 20180204 ◽  
Author(s):  
Iliana Medina ◽  
Naomi E. Langmore
Keyword(s):  
Spatial Distribution ◽  
Reproductive Success ◽  
Host Species ◽  
Field Data ◽  
Host Density ◽  
Brood Parasites ◽  
Parasitism Rates ◽  
Analyse Data ◽  
First Time ◽  
Determining Factor

The spatial distribution of hosts can be a determining factor in the reproductive success of parasites. Highly aggregated hosts may offer more opportunities for reproduction but can have better defences than isolated hosts. Here we connect macro- and micro-evolutionary processes to understand the link between host density and parasitism, using avian brood parasites as a model system. We analyse data across more than 200 host species using phylogenetic comparative analyses and quantify parasitism rate and host reproductive success in relation to spatial distribution using field data collected on one host species over 6 years. Our comparative analysis reveals that hosts occurring at intermediate densities are more likely to be parasitized than colonial or widely dispersed hosts. Correspondingly, our intraspecific field data show that individuals living at moderate densities experience higher parasitism rates than individuals at either low or high densities. Moreover, we show for the first time that the effect of host density on host reproductive success varies according to the intensity of parasitism; hosts have greater reproductive success when living at high densities if parasitism rates are high, but fare better at low densities when parasitism rates are low. We provide the first evidence of the trade-off between host density and parasitism at both macro- and micro-evolutionary scales in brood parasites. This article is part of the theme issue ‘The coevolutionary biology of brood parasitism: from mechanism to pattern’.

scholarly journals Nematofauna of bank vole: Clethrionomys glareolus (Schreber, 1780) from Mt. Fruska gora (Serbia)

2009 ◽  
Vol 61 (3) ◽  
pp. 555-561 ◽  
Author(s):  
Olivera Bjelic-Cabrilo ◽  
Ester Popovic ◽  
Smiljka Simic ◽  
Desanka Kostic
Keyword(s):  
Bank Vole ◽  
Host Species ◽  
National Park ◽  
Nematode Species ◽  
Clethrionomys Glareolus ◽  
Parasite Invasion ◽  
Mean Intensity ◽  
Aspiculuris Tetraptera ◽  
First Time

The nematofauna of bank vole (Clethrionomys glareolus) was analyzed for the first time from samples collected in our country. The specimens were collected in Fruska Gora National Park (locality of Brankovac). The number of collected specimens was 138, and infestation with seven nematode species was determined: Heligmosomum mixtum (Schulz, 1954), Heligmosomoides glareoli (Baylis, 1928), Syphacia petrusewiczi (Bernard, 1966), S. stroma (Linstow, 1884), Capillaria murissylvatici (Dieseng, 1851), Trichocephalus muris Schrank, 1788, and Aspiculuris tetraptera (Nitzsch, 1821). The species Heligmosomum mixtum, Heligmosomoides glareoli, and Syphacia petrusewiczi represent the first records for the territory of our country. The species best represented in the sample were H. glareoli and S. petrusewiczi. There were no statistically significant differences between the sexes of host species regarding the prevalence, mean intensity, or mean abundance of parasite invasion.

scholarly journals Zeiform mouthbrooding in the deepsea – dispelling a myth

2020 ◽  
Author(s):  
Ralf ◽  
G. David Johnson ◽  
Kevin Conway
Keyword(s):  
Deep Water ◽  
Deep Sea ◽  
Developmental Stages ◽  
Extended Period ◽  
Marine Fishes ◽  
Early Developmental Stages ◽  
Water Fish ◽  
First Time ◽  
Early Developmental ◽  
Deep Sea Fauna

Mouthbrooding or oral incubation, the retention of early developmental stages inside of the mouth for an extended period of time, has evolved multiple times in bony fishes1,2. Though uncommon, this form of parental care has been documented and well-studied in several groups of freshwater fishes but is also known to occur in a small number of marine fishes, all inhabiting coastal waters1,2. A recent paper3, reported for the first time mouthbrooding in a deep-water fish species, the zeiform Parazen pacificus, which according to the authors “fills in a gap in the larval literature for this family of fishes and prompts further investigation into other novel reproductive modes of deep-sea fauna.”

scholarly journals Occurrence of Amblyomma rotundatum Koch, 1844 on Epicrates assisi Machado, 1945 in João Pessoa, Paraíba, Brazil

2021 ◽  
Vol 15 (4) ◽  
pp. 335-338
Author(s):  
Aksa Ingrid Vieira Batista ◽  
Gabriel Vinicius Carvalho de Lucena ◽  
Kleber Silva de Oliveira Filho ◽  
Thiago Ferreira Lopes Nery ◽  
Thiago Fernandes Martins ◽  
...  
Keyword(s):  
Host Species ◽  
Tick Species ◽  
Wide Distribution ◽  
Dorsal Region ◽  
Taxonomic Key ◽  
Caatinga Biome ◽  
First Occurrence ◽  
First Time ◽  
Semi Arid

The Caatinga rainbow boa (Epicrates assisi Machado, 1945) is a snake belonging to the order Squamata, family Boidae, and subfamily Boinae. It has a wide distribution in Brazil and can be found in the Caatinga biome. The present study aims to report the first occurrence of Amblyomma rotundatum on E. assisi in the municipality of João Pessoa, Paraíba State (PB). On March 3, 2020, a tick collection was performed on the dorsal region of the head of an E. assisi, which was captive at the Arruda Câmara Zoobotanical Park, João Pessoa-PB. After collecting the tick, it was transferred to a flask containing 70º alcohol and sent to the Laboratory of Animal Parasitology of the Federal Rural University of the Semi-Arid (UFERSA) for analysis. Identification was done with the aid of a stereomicroscope using a taxonomic key. The result identified this specimen as a nymph of A. rotundatum. The occurrence of this tick species on E. assisi is reported for the first time and constitutes new data applicable to the ectoparasites that occur in this host species in Brazil.

Colleters in the vegetative axis of Aechmea blanchetiana (Bromeliaceae): anatomical, ultrastructural and functional aspects

2018 ◽  
Vol 66 (5) ◽  
pp. 379 ◽  
Author(s):  
Igor Ballego-Campos ◽  
Elder Antônio Sousa Paiva
Keyword(s):  
Developmental Stages ◽  
Light And Electron Microscopy ◽  
Secretory Activity ◽  
Functional Roles ◽  
Reproductive Axis ◽  
Functional Aspects ◽  
The Family ◽  
Marginal Cells ◽  
First Time

Colleters are common among eudicotyledons, but few records exist for monocotyledons and other groups of plants. For Bromeliaceae, mucilage secretions that protect the young portions of the plant have been observed only in the reproductive axis, and little is known about the secretory systems behind this or even other kind of secretions in the family. We aimed to describe, for the first time, the occurrence of colleters associated with the vegetative shoot of Aechmea blanchetiana (Baker) L.B.Sm., and elucidate aspects of their structure, ultrastructure and secretory activity. Samples of various portions of the stem axis were prepared according to standard methods for light and electron microscopy. Colleters were found compressed in the axillary portion of leaves and in all leaf developmental stages. Secretory activity, however, was found to be restricted to young and unexpanded leaves. The colleters displayed a flattened hand-like shape formed by a multiseriate stalk and an expanded secretory portion bearing elongated marginal cells. Ultrastructural data confirmed that the secretory role of the colleters is consistent with mucilaginous secretion. The functional roles of the colleters are discussed with regard to environmental context and intrinsic features of the plant, such as the presence of a water-impounding tank.

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