Some new host-range phenotypes of T4D bacteriophage and their genetic control

Virology ◽  
1960 ◽  
Vol 12 (3) ◽  
pp. 422-430 ◽  
Author(s):  
Yoh Tanami
Keyword(s):  
Plant Disease ◽  
2019 ◽  
Vol 103 (10) ◽  
pp. 2512-2519 ◽  
Author(s):  
Brian W. Bahder ◽  
Noemi Soto ◽  
Ericka E. Helmick ◽  
Kishore K. Dey ◽  
Lidia Komondy ◽  
...  

The 16SrIV-D phytoplasma was first identified in Florida in 2006. Since its discovery, it has spread throughout most of the state. It is most prevalent in the central part of Florida, from Hillsborough County on the west coast to St. Lucie County on the east coast. The 16SrIV-D phytoplasma is the causal agent of lethal bronzing disease (LBD), which is also known as Texas Phoenix palm decline (TPPD). It affects a variety of common and economically important ornamental palm species as well as the native and ecologically important species, Sabal palmetto. It has spread into the southern portions of Florida, where the palm species diversity is higher. The aims of this survey were to document the spread of disease in terms of geographic and host range one decade after its introduction into Florida, and to assess the risk that LBD poses to the nursery and landscaping industries. The survey included samples received from stakeholders throughout the state, covering 18 counties, as well as a systematic sampling of palms at the Fort Lauderdale Research and Education Center (FLREC), where the disease is spreading actively. The findings of this survey resulted in the detection of LBD in eight new counties, including Collier, Hernando, Jefferson, Martin, Miami-Dade, Monroe, Seminole, and St. Johns, and the expansion of LBD into four new host species, Cocos nucifera, Livistona chinensis, Butia capitata, and Carpentaria acuminata. These findings are crucial for stakeholders because they highlight new hosts of 16SrIV-D phytoplasma and the geographic expansion of the disease, indicating that vigilance is needed when surveying declining palms.


2009 ◽  
Vol 10 (1) ◽  
pp. 34
Author(s):  
Frank M. Dugan ◽  
Dean A. Glawe ◽  
Renuka N. Attanayake ◽  
Weidong Chen

Accurate and timely reports of new host-fungus records are essential for diagnostics and identification, management, and prevention of plant diseases. Important also are venues to publish these reports in a timely manner and the ability to rapidly search for the information contained in these reports. Presented herein are examples of first reports of fungal pathogens on regional crops, including ornamentals and turf grasses, which illustrate how first reports contribute to preparedness, accurate diagnostics, and knowledge of biogeography and host range. We provide a guide to sources of host-fungus records, discuss venues for publishing new records, and review the information important in a new record, including deposition of voucher specimens. We appeal to plant health professionals to increase their efforts of discovering, documenting, and reporting new records. Accepted for publication 13 March 2009. Published 12 May 2009.


2020 ◽  
Vol 110 (6) ◽  
pp. 732-742
Author(s):  
Issaka Zida ◽  
Souleymane Nacro ◽  
Rémy Dabiré ◽  
Laura Moquet ◽  
Hélène Delatte ◽  
...  

AbstractIn Western Burkina Faso, the host range of fruit flies was evaluated in three plant formations between May 2017 and April 2019. Samples of 61 potential hosts were collected and incubated for fruit fly emergence. Twenty-seven hosts including cultivated and wild fruit were identified. Among cultivated fruit species, mango, and guava were the most infested while high infestation incidences were observed in the fruit of the indigenous plants Vitellaria paradoxa, Annona senegalensis, Sarcocephalus latifolius, and Saba senegalensis. Low infestation rates were observed in Anacardium occidentale, Citrus species, Opilia celtidifolia, and Cissus populnea. The highest infestation index (1648.57 flies kg−1) was observed from V. paradoxa. Eleven new host fruit infested with many fruit fly species are reported in Burkina Faso. A total of 18 fruit fly species were reared; Bactrocera dorsalis (42.94%), Ceratitis cosyra (29.93%), and Ceratitis silvestrii (22.33%) dominated those that emerged. Four fruit fly species have been detected for the first time in Burkina Faso. The main suitable fruit hosts are abundant and available from May through August during the rainy season and become rare and have low infestation from November to April during the dry season. This is the first study of its kind in the region. This study shows that the three plant formations had an impact on population dynamics of the three tephritid species of economic importance in Western Burkina Faso. This information should be integrated into the development of a fruit fly pests management strategy.


1965 ◽  
Vol 43 (2) ◽  
pp. 217-230 ◽  
Author(s):  
Wolf G. Ziller

Results from controlled inoculation experiments show that conifers of six genera (Abies, Larix, Picea, Pinus, Psendotsuga, and Tsuga) are susceptible to the poplar (Populus) rusts of western Canada. Twenty-one new host records are established. It is suggested that Melampsora albertensis Arth. be reduced to synonymy with M. medusae Thüm., because they appear to be indistinguishable from each other in morphology, life history, host range, and host reaction.


2020 ◽  
Vol 117 (30) ◽  
pp. 17937-17948
Author(s):  
Peter V. Lidsky ◽  
Raul Andino

Species-specific limits to lifespan (lifespan setpoint) determine the life expectancy of any given organism. Whether limiting lifespan provides an evolutionary benefit or is the result of an inevitable decline in fitness remains controversial. The identification of mutations extending lifespan suggests that aging is under genetic control, but the evolutionary driving forces limiting lifespan have not been defined. By examining the impact of lifespan on pathogen spread in a population, we propose that epidemics drive lifespan setpoints’ evolution. Shorter lifespan limits infection spread and accelerates pathogen clearance when compared to populations with longer-lived individuals. Limiting longevity is particularly beneficial in the context of zoonotic transmissions, where pathogens must undergo adaptation to a new host. Strikingly, in populations exposed to pathogens, shorter-living variants outcompete individuals with longer lifespans. We submit that infection outbreaks can contribute to control the evolution of species’ lifespan setpoints.


1967 ◽  
Vol 9 (2) ◽  
pp. 149-158 ◽  
Author(s):  
B. de Groot

Analysis of the inheritance of the three bar-properties of bacteriophage T4: exclusion of T2 from the progeny of crosses, glucosylation of the hydroxymethylcytosine (HMC)moiety of the DNA according to T4, and plating with large plaques on E. coli K strains, was carried out by means of marker rescue from T4 by T2 on E. coli K (λh) as a selective indicator. Five of the strains isolated plated with large plaques on K (λh), but did not exclude T2 and showed T2 glucosylation; plating on E. coli K (λh) was found to segregate from the other two bar-properties. The sixth isolate showed, in addition to plating with large plaques on K, partial non-excludability by the parental T4 and T4 glucosylation of HMC. If partial non-excludability is the result of T4 glucosylation, the role of the additional glucose substitutions might be a protective effect on the DNA against the exclusion factor of T4. This proposal is supported by the analysis of the progeny from a single burst from a cross of T4 and T2. The following T2 genes were partially excluded: host-range, no exclusion of parental T2, sensitivity to ultraviolet, and limited plating efficiency on E. coli K (λh). The exclusion factor of T4 is not transmitted to all progeny and does not behave like a bar-property. Only resistance to exclusion and T4 glucosylation were transmitted to all twenty-seven progeny of the single burst. The elimination of sensitivity to exclusion and T2 glucosylation is explained by assuming that the recombinant class with the exclusion factor of T4 and T2 α-glucosylation will exclude itself and be suicidal upon infection of a new host. Exclusion and differential glucosylation are discussed with regard to restriction and modification, respectively.


1969 ◽  
Vol 47 (2) ◽  
pp. 265-266 ◽  
Author(s):  
George W. Frame

Two surf scoters (Melanitta perspicillata L.) from near Juneau, Alaska, were examined; a total of 22 Tristriata anatis Belopolskaia, 1953, were removed from the ceca and large intestine. This is the second reported discovery of T. anatis, the first in North America, and a new host record. The species description is expanded. Morphology and the influence of methods on interpretation of structures are discussed.


2010 ◽  
Vol 84 (19) ◽  
pp. 9978-9986 ◽  
Author(s):  
Olivier Moncorgé ◽  
Manuela Mura ◽  
Wendy S. Barclay

ABSTRACT Typical avian influenza A viruses do not replicate efficiently in humans. The molecular basis of host range restriction and adaptation of avian influenza A viruses to a new host species is still not completely understood. Genetic determinants of host range adaptation have been found on the polymerase complex (PB1, PB2, and PA) as well as on the nucleoprotein (NP). These four viral proteins constitute the minimal set for transcription and replication of influenza viral RNA. It is widely documented that in human cells, avian-derived influenza A viral polymerase is poorly active, but despite extensive study, the reason for this blockade is not known. We monitored the activity of influenza A viral polymerases in heterokaryons formed between avian (DF1) and human (293T) cells. We have discovered that a positive factor present in avian cells enhances the activity of the avian influenza virus polymerase. We found no evidence for the existence of an inhibitory factor for avian virus polymerase in human cells, and we suggest, instead, that the restriction of avian influenza virus polymerases in human cells is the consequence of the absence or the low expression of a compatible positive cofactor. Finally, our results strongly suggest that the well-known adaptative mutation E627K on viral protein PB2 facilitates the ability of a human positive factor to enhance replication of influenza virus in human cells.


2018 ◽  
Author(s):  
Colin S. Maxwell

AbstractThe role of phenotypic plasticity in the evolution of new traits is controversial due to a lack of direct evidence. Phage host-range becomes plastic in the presence of restriction-modification (R-M) systems in their hosts. I modeled the evolution of phage host-range in the presence of R-M systems. The model makes two main predictions. First, that offspring of the first phage to gain a new methylation pattern by infecting a new host make up a disproportionate fraction of the subsequent specialist population, indicating that the plastically-produced phenotype is highly predictive of evolutionary outcome. Second, that the first phage gain this pattern is not always genetically distinct from other phages in the population. Taken together, these results suggest that plasticity could play a causal role on par with mutation during the evolution of phage host range. This uniquely tractable system could enable the first direct test of ‘plasticity first’ evolution.


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