Search results for "NIP"
showing 10 items of 775 documents
Kindness to the final host and vice versa: A trend for parasites providing easy prey?
2019
Traditionally the “extended phenotype” concept refers to parasites that manipulate host phenotype to increase parasite fitness. This includes parasites that render intermediate hosts more susceptible to predation by final hosts. We explore here the proposition that an evolutionary driver in such cases is the energetic benefit to the final host, in addition to increased parasite fitness. We will review some well-established host-manipulation models, where such a scenario seems likely. One example is provided by the protozoan Toxoplasma gondii, which conspicuously impairs predator avoidance in rodents. Pathologies in humans that acquire T. gondii are known, but infection in adult feline defin…
Positive density-dependent growth supports costs sharing hypothesis and population density sensing in a manipulative parasite.
2017
SUMMARYParasites manipulate their hosts’ phenotype to increase their own fitness. Like any evolutionary adaptation, parasitic manipulations should be costly. Though it is difficult to measure costs of the manipulation directly, they can be evaluated using an indirect approach. For instance, theory suggests that as the parasite infrapopulation grows, the investment of individual parasites in host manipulation decreases, because of cost sharing. Another assumption is that in environments where manipulation does not pay off for the parasite, it can decrease its investment in the manipulation to save resources. We experimentally infected rainbow trout Oncorhynchus mykiss with the immature larva…
Broad bean wilt virus 1 encoded VP47 and SCP are suppressors of plant post-transcriptional gene silencing
2020
Broad bean wilt virus 1 (BBWV-1, genus Fabavirus, family Secoviridae) is a bipartite positive single-stranded RNA (+ssRNA) virus infecting important horticultural and ornamental crops worldwide. RNA1 encodes proteins involved in virus replication, whereas RNA2 encodes the large and small coat proteins (LCP, and SCP, respectively) and two putative movement proteins with overlapping C-terminal but different sizes: 47.2 kDa (VP47) and 37 kDa (VP37). Post-transcriptional gene silencing (PTGS) is a mechanism of gene regulation and defense against pathogens such as viruses. However, most plant viruses encode proteins called viral suppressors of RNA silencing (VSRs) which able to inhibit PTGS. Pre…
Early developmental conditions affect stress response in juvenile but not in adult house sparrows (Passer domesticus).
2009
6 pages; International audience; The short- and long-term consequences of developmental conditions on fitness have received growing attention because the environmental conditions during early life may influence growth, condition at independence, recruitment, reproductive success or survival. We tested here, in a natural house sparrow population, if early conditions during nestling stage affected the stress response of the birds (i) shortly after fledging and (ii) next year, during their first breeding. We experimentally manipulated brood size to mimic different rearing conditions, creating reduced (-2 chicks) and enlarged broods (+2 chicks), while in a third group brood size was not manipul…
The effects of parasite age and intensity on variability in acanthocephalan-induced behavioural manipulation.
2008
10 pages; International audience; Numerous parasites with complex life cycles are able to manipulate the behaviour of their intermediate host in a way that increases their trophic transmission to the definitive host. Pomphorhynchus laevis, an acanthocephalan parasite, is known to reverse the phototactic behaviour of its amphipod intermediate host, Gammarus pulex, leading to an increased predation by fish hosts. However, levels of behavioural manipulation exhibited by naturally-infected gammarids are extremely variable, with some individuals being strongly manipulated whilst others are almost not affected by infection. To investigate parasite age and parasite intensity as potential sources o…
Fish community structure in mesotrophic and eutrophic lakes of southern Finland: the relative abundances of percids and cyprinids along a trophic gra…
2002
In 36 south Finnish lakes, the number of species, as well as the cyprinids:percids ratio, was dependent, not only on total phosphorus (TP), but also on lake size. Total fish biomass and cyprinid biomass increased along the TP gradient, whereas the dependence of percid biomass was less evident. Perch Perca fluviatilis and roach Rutilus rutilus strongly dominated mesotrophic lakes; in eutrophic lakes the proportion of other cyprinids and percids, such as white bream Blicca bjoerkna, bream Abramis brama, pikeperch Stizostedion lucioperca and ruffe Gymnocephalus cernuus, increased. Perch biomass was weakly related to abiotic factors but depended on roach biomass. Lake size and fish species comp…
Charipinae (Hymenoptera: Cynipoidea: Figitidae) present in the Museum of Natural History of the University of Wroclaw, with an identification key for…
2020
Charipinae (Cynipoidea: Figitidae) deposited in the Museum of Natural History of Wroclaw University (Poland) have been studied. Seven species are recorded for the first time from Poland: Alloxysta brachyptera (Hartig, 1840), A. castanea (Hartig, 1841), A. citripes (Thomson, 1862), A. consobrina (Zetterstedt, 1838), A. mullensis (Cameron, 1883), A. nottoni Ferrer-Suay & Pujade-Villar, 2015 and Phaenoglyphis heterocera (Hartig, 1841). The presence of previously recorded species is confirmed and new records are specified. A key to all Charipinae species ever recorded in Poland is given.
New Charipinae ( Hymenoptera : Cynipoidea : Figitidae ) records from China
2016
Abstract Charipinae material collected from different provinces of China has been studied. Twenty-one previously described species have been identified: Alloxysta arcuata, A. brevis , A. carinata , A. castanea , A. consobrina , A. fracticornis , A. leunisii , A. macrophadna , A. mullensis , A. obscurata , A. paretasmartinezi , A. pilipennis , A. pilosa , A. postica , A. sawoniewiczi , A. victrix , A. xanthopa , Dilyta subclavata , Phaenoglyphis chinensis , P. heterocera and P. villosa . All species, except for P. chinensis and P. villosa , are here recorded for the first time from China. Diagnosis, material studied and distribution are given for each species. Plates with the diagnostic morp…
Host manipulation in the face of environmental changes: Ecological consequences
2015
Several parasite species, particularly those having complex life-cycles, are known to induce phenotypic alterations in their hosts. Most often, such alterations appear to increase the fitness of the parasites at the expense of that of their hosts, a phenomenon known as “host manipulation”. Host manipulation can have important consequences, ranging from host population dynamics to ecosystem engineering. So far, the importance of environmental changes for host manipulation has received little attention. However, because manipulative parasites are embedded in complex systems, with many interacting components, changes in the environment are likely to affect those systems in various ways. Here, …
High-Quality Genome Assembly and Annotation of the Big-Eye Mandarin Fish (Siniperca knerii)
2020
Abstract The big-eye mandarin fish (Siniperca knerii) is an endemic species of southern China. It belongs to the family Sinipercidae, which is closely related to the well-known North American sunfish family Centrarchidae. Determining the genome sequence of S. knerii would provide a foundation for better examining its genetic diversity and population history. A novel sequenced genome of the Sinipercidae also would help in comparative study of the Centrarchidae using Siniperca as a reference. Here, we determined the genome sequence of S. knerii using 10x Genomics technology and next-generation sequencing. Paired-end sequencing on a half lane of HiSeq X platform generated 56 Gbp of raw data. R…