National Repository of Grey Literature 31 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Insights into the karyotype evolution of pseudoscorpions (Arachnida:Pseodoscorpiones)
Šťáhlavský, František ; Smrž, Jaroslav (advisor) ; Marec, František (referee) ; Ráb, Petr (referee)
6. ZÁVĚRY 1. Pro studium karyotypu štírků je u většiny druhů nejvhodnější doba rozmnožování. Ve střední Evropě se dá v tomto období (duben - červen) u většiny druhů získat z gonád samců i samic dostačující množství spermatogoniálních mitóz a u samců i různá meiotická stadia vhodná pro analýzu karyotypu. 2. Primární konstrikce řady druhů jsou drobné a obtížně detekovatelné. Pro přesné vyhodnocení morfologie chromosomů jsou proto daleko vhodnější metafáze II samců. V této fázy jsou chromatidy chromosomů spojeny pouze v oblasti centromer, poloha primárních konstrikcí se tedy dá přesně stanovit. 3. Štírci jsou charakterističtí velkou mezidruhovou variabilitou v počtu a morfologii chromosomů. Diploidní počet chromosomů se v rámci celého řádu pohybuje od 7 až po 137. Nejnižší počty chromosomů má čeleď Olpiidae (2n=7-23), nízké počty chromosmů mají také čeledi Chthoniidae (2n=10-38), Geogarypidae (2n=15-23) a Garypinidae (2n=33). Nejvyšší počty chromosomů má čeleď Atemnidae (2n=93-137). 4. Původním systémem chromosomového určení pohlaví štírků je patrně X0. S výjimkou čeledi Larcidae byl tento systém nalezen u všech studovaných čeledí. V rámci čeledí Neobisiidae a Larcidae byl zjištěn také systém XY, jež vzniká pravděpodobně přestavbami mezi chromosomem X a autosomy. 5. Pohlavní chromosom se v průběhu meiosy...
Microanatomy and cytogenetics of non-marine ostracods-an insight into evolutionary biology of their reproductive modes
Symonová, Radka ; Smrž, Jaroslav (advisor) ; Keyser, Dietmar (referee) ; Weyda, František (referee)
SUMMARYOF THEPh.D.THESIS The main objectivesof this dissertationwere to contributeto generarunderstandingand to fill some major gaps in our knowledgeof ostracodbiology.Ostracodsareotherwisea very well exploredgroup of crusta-cea :f ff:#'1"'';i,:T*"ortneirooosfil;I"TilffJ:,X'H::':;:: reconstructions,tn,..Lll?,1',i#r:T::il ff: "t"" usedinpataeoecorogicar knownabouthepatopancreasandnothins "oor,,Jl1ll,f"filH, ]i:.ffil:Further,there is no properdescriptionof the com ;':il'i:?l,Tll;l':*'*'ornsemnaton*":fflilli::fi:ff H*::: onryavairabledata on ,lxisted concerningthe karyologyof freshwaterostracods.rhe with exceptionssome 'eshwater ostracodkaryologycamefrom the i930s to 1950s *#jli:.:.,:ru$"::lt:_,:ri::1,i:iJ.["::.13[*:Nonetheress,tn"r"n,nn,lTi"""t"t"iffil]ogenetic remaleshadbeen*,*o "*.contextortheirreproduJtivemodesremaine;-;il::*o:nfoTl.."l';n";;u"''",n"For these reasons, ostracod microanatomyand cytogeneticsin rerationto theevotutionarybiologyof theirreproductiu",o0". *"of this thesis.Moreouer,other topicsreratedto ,n",'t" 'nu"tt'n"ted in the framework also taken into account. -r;J;._:::,:: tn"'t reproductionbiorogyhad been manipu,atorsinoucinsparililj:"gnJfl:ffi:nTffi:i1"J:fi#["il:obtainedby microscopicanatysisof the FRO in liduring holotomographic Investigation of cretac tng animals has been utilized...
Consumption of some micromycetes by Tyrophagus putrescentiae (Acari: Acaridida) and its microanatomical and microbiological characteristics
Soukalová, Hana ; Smrž, Jaroslav (advisor) ; Hubert, Jan (referee)
Mycophagy should not be considered as a single and homogeneous category of nutritional biology due to the specific symbiotic chitinolytic bacteria associated with mites and fungi. To test interaction amongmites, fungi, and chitinolytic bacteria, experiments were conducted on the model species Tyrophagus putrescentiae (Schrank). Mucor sp, Alternaria alternata, Penicillium claviforme, P. griseofulvum, and Verticillium sp. were plated onto malt agar and offeredto T. putrescentiae in the laboratory. Mites were evaluated utilizing microanatomical examination based on histology, excrement analysis using fluorescence microscopy, bacterial plating, impact of mite homogenate on fungi in Petri dishes, reproduction of mites feeding upon each fungus, and isolation of associated bacteria inside mites. There were clear differences regarding the digested spores of different fungi passing through the gut and subsequently in the feces. Abundances of bacterial cells in excrement also corresponded to the fungi offered. The extracts from mites had chitinolytic activity, and the plated bacteria are known to produce exochitinases. The various feeding patterns observed were caused by differences in the cell wall structures of the tested fungi. The study illustrates that mycophagy in saprophagous mites does not consist of...
Dead vertebrate bodies - factor of the soil environment
Jourová, Barbora ; Smrž, Jaroslav (advisor) ; Růžička, Jan (referee)
Microhabitats are a very interesting phenomenon in nature. They can be studied on many levels. Nevertheless, their common characteristic is the fact, that they create a unique community of organisms that are very different from the surroundings. One of the most interesting types of microhabitat is the dead body of a large vertebrate. Oasis of nutrients is formed on the small area on, beneath and around the body. It provides a space for living to many thousands of animals, mainly from phylum Arthropoda. The dead body is also an unpredictable factor. That is why many animals, mainly from order Diptera, specialized their life strategy on seeking of those dead bodies. The reaction of soil community on the decomposing body is fascinating, but it received in Czech republic a very little attention among scientists. Many body fluids are released into the soil beneath the body, and those fluids change pH in the soil that causes substantial changes in the composition of the soil community. This work is focused on the decomposition of pig carcass (Sus domestica). It captures all the stages of decomposition from the fresh body to skeletal remains. Furthermore, the change of soil mite community is described here. Mites were chosen because of their high species diversity and large abundance in soil. In this...
Bacteria associated to red poultry mite (Dermanyssus gallinae)
Molva, Vít ; Hubert, Jan (advisor) ; Smrž, Jaroslav (referee)
The poultry red mite (Dermanyssus gallinae) (Acari: Mesostigmata) is a hematophagous ectoparasite of poultry, cage birds, mammals and humans. Infection of poultry by poultry red mites (PRM) induce the decrease of egg production, weight gain and fitness. The massive infestation of the PRM can cause the death of the bird. The PRM is danger for human due to his ability of transport bacteria and virus of one host to the other. This review summarize the association of putative pathogenic and symbiotic bacteria with the PRM. There are studies, when PRM is considered as a vector of pathogenic bacteria. The transmission of Salmonella spp. has been observed frequently using PCR and/or cultivation. Listeria monocytogenes has been associated with the PRM only in one study, in which is not clear if the PRM really transport this bacteria or they just appear in the same time and the same place. The transport of Erysipelothrix rhusiopathiae was in one work approved, but the demonstration of transport wasn't successful in other experiment. The role of the PRM in transport Bartonella quintana (causative agent of trench fever) is also not clear. The PRM and B. quintana appeared in the same time in the bird nest near the attic and there were attacked a family with high socioeconomic status by trench fever. However is...
Parasitic bacteria Arsenophonus in honeybee and its parasite Varroa destructor
Hejdánková, Sylvie ; Hubert, Jan (advisor) ; Smrž, Jaroslav (referee)
Arsenophonus is vertically and horizontally transmitted parasitic bacteria and strengthens its transfer through phenomenon called son killing. Arsenophonus has been detected in the arthropod hosts, insects, ticks and the garden spider Araneus diadematus. The aim of this study is detection parasitic bacteria Arsenophonus in honeybees and its parasite Varroa destructor. We find out that bacteria Arsenophonus is present in both hosts and it is identified as Arsenophonus nasoniae. Detection of bacteria Arsenophonus is discovered for the first time in Varroa destructor mites. We proved that the frequency of bacteria Arsenophonus in mites Varroa destructor is significantly higher than in honeybees. This study shows that the mite Varroa destructor could act as a vector for transmission parasitic bacteria Arsenophonus among honeybees. Results of this study could lead to the future application of Arsenophonus as a biological control for the mite Varroa destructor.
The role of soil macrofauna in organic matter decomposition and stabilisation
Špaldoňová, Alexandra ; Frouz, Jan (advisor) ; Tajovský, Karel (referee) ; Smrž, Jaroslav (referee)
Slowdown of plant litter decomposition is one of the many ways how to increase the amount of organic matter in soil and thus contribute to both the restoration of organic matter in soil and reduction of the amount of carbon dioxide in the atmosphere. Here we focused on the long-term effect of soil macrofauna on organic matter decomposition and stabilization. In two long-term microcosm experiments, common isopod (Armadillidium vulgare) greatly affected both leaf litter decomposition and organic matter chemistry. Microbial decomposition was lower in excrements than in litter or unconsumed leaf fragments. At the same time, moisture and temperature fluctuations and addition of nutrients increased decomposition much more in litter than in the excrements. Chemical analyses revealed preferential loss of polysaccharide carbon and accumulation of lignin with some modification to aromatic carbon in excrements when compared to litter; the two substrates also differed in lignin quality. Additionally, we observed that phenolics content in leaf litter is considerably affected by both microbial and isopod feeding activities. In the third long-term microcosms experiment, we compared consequence of bioturbation of the epigeic earthworm (Lumbricus rubellus) and mechanical mixing of organic matter into soil on carbon...

National Repository of Grey Literature : 31 records found   1 - 10nextend  jump to record:
See also: similar author names
4 SMRŽ, Jan
4 Smrž, Jan
7 Smrž, Jiří
1 Smrž, Josef
Interested in being notified about new results for this query?
Subscribe to the RSS feed.