Recent results 2015

Maternal overweigth  influences  fertility and  might affect delivered offspring

The relationship between alterations of body condition in mammals and reproductive disorders is important, but controversial issue. The majority of clinical and experimental studies have reported negative effects of maternal obesity in humans or maternal overweight arising from elevated accumulation of body fat in animals on various reproductive parameters. However, there are still numerous studies showing no or even positive influence. In our study we investigated the effects of maternal body condition on oocyte quality and zygote production and possible consequences on somatic parameters and behavior of naturally delivered offspring. To produce females with various types of body condition, a previously established two-generation animal model was used. When compared to normal controls, fertilized mice females with slightly elevated amount of body fat showed increased number of spontaneously ovulated oocytes and elevated fertilization index. On the other hand, mice with slightly and highly elevated amount of body fat showed increased number of isolated immature oocytes and degenerates, significantly lowered deposits of neutral lipids in the cytoplasm of mature oocytes and lower reduction of DNA cytosine methylation signal in parental pronuclei of zygotes. Highly elevated amount of body fat in mothers was accompanied also with lowered weight of newborns and 5 week old offspring, and several deviations from normal behavior in them (Open field, Forced swimming test). We might conclude that alterations in maternal body condition might affect reproductive process at several steps, including the period of ovulation, fertilization and early embryo development in vivo. Furthermore, they might affect somatic phenotype and behavior of delivered offspring as well. The effect of obesity-like phenotype is dependent on its level (i.e. amount of maternal body fat deposits) and it might impact particular reproductive parameters in opposite manner. Nevertheless, in summary, negative effect dominates. Besides, data suggest that changes in offspring might originate in epigenetic or metabolic modifications established even at the earliest stages of conceptus development.
FABIAN, Dušan – KUBANDOVÁ, Janka – ČIKOŠ, Štefan – BURKUŠ, Ján – FABIANOVÁ, Kamila – RAČEKOVÁ, Eniko – CZIKKOVÁ, Soňa – KOPPEL, Juraj. The effect of maternal body condition on in vivo production of zygotes and behavior of delivered offspring in mice. In Theriogenology : international journal of animal reproduction Theriogenology (Los Altos), 2015, vol. 83, p. 577-589. (1.798 – IF2014). ISSN 0093-691X. DOI: 10.1016/j.theriogenology.2014.10.025

Chlorophyll as a modulator of probiotic effect

Long-term applications of probiotic strains from the group of lactic acid bacteria may disturb the acid-base balance because of increased production of organic acids in the gastrointestinal tract. For this reason, combination of our selected strain Lactobacillus fermentum CCM 7421 and chlorophyll as substance with alkaline properties was tested. Results obtained under in vitro conditions showed the possibility to combine them at a concentration of 0.05 to 0.25 % (copper gluconate of chlorophyllin was used) without negative impact on growth of probiotic strain CCM 7421 and with slight decrease of counts at a concentration of 1% (up to 1.1 log CFU/ml). On the contrary, addition of 1 % chlorophyllin caused significant growth reduction of tested staphylococci, Listeria monocytogenes and Citrobacter freundii.  Experiment in vivo tested effect of 14-day application of chlorophyllin alone (60 mg/day/dog) as well as in combination with L. fermentum CCM 7421 (10⁸ CFU/day/dog). The counts of lactic acid bacteria in faeces remained without changes in both groups but counts of coliform bacteria decreased significantly in the group with alone application of chlorophyllin. The counts of Clostridium-like bacteria were lower in the combinative group. Some buffering effect of chlorophyllin was detected in combinative group since pH values were lower by 0.7 in dogs after alone application of strain in comparison with dogs of combinative group. Testing of non-specific cellular immunity parameters revealed stimulation of phagocytic activity of leukocytes and their respiratory burst after addition of strain and chlorophyllin. Therefore, combination of probiotic bacteria and chlorophyll is practically possible and more suitable than the sole application of chlorophyll (because of more liquid faeces after chlorophyllin apllication alone). However, it is necessary to ensure the homogeneous distribution of chlorophyll in the diet by the use of concentrated preparation or alternatively to administer them separately during the daytime.
STROMPFOVÁ, Viola – KUBAŠOVÁ, Ivana – FARBÁKOVÁ, J. – GANCARČÍKOVÁ, Soňa – MUDROŇOVÁ, Dagmar – MAĎARI, Aladár – LAUKOVÁ, Andrea. Experimental application of Lactobacillus fermentum CCM 7421 in combination with chlorophyllin in dogs. In Applied Microbiology and Biotechnology, 2015, vol. 99, p. 8681-8690. (3.337 – IF2014). DOI: 10.1007/s00253-015-6724-9

New bacteria from Varroa destructor mite

Varroa bee hives (Varroa destructor) attack is a serious and common problem in bee-keeping and fight against this parasite has become often discussed topic within the professional and general public. Despite devastating effect on honey bee health it could serve as a vector of several other microbial diseases. Using a cultivation approach the cultivable ecto-microflora of Varroa as a potential source of bacterial diseases in bee communities was analysed. Multiple bacterial strains isolated from Varroa mites were isolated and identified by combination of MALDI-TOF (Matrix-assisted laser desorption/ionization – time of flight) mass spectrometry and 16S rRNA based methods. The Varroa mite ecto-bacterial population was found to be dominated by Gram-positive bacteria of Bacillus (B. altitudinis, B. cereus) and Microbacterium (M. oxydans, M. paraoxydans) genera. Gram-negative bacteria were represented by members of Brevundimonas (B. vesicularis) and Rhizobium (R. radiobacter) genera. No honey bee pathogenic bacteria were detected and the most of the identified species have not been associated with Varroa mite, honey bee or honey before. B. altitudinis and M. oxydans related isolates are probably representatives of new bacterial taxa.
VANÍKOVÁ, Slavomíra – NOSKOVÁ, Alena – PRISTAŠ, Peter – JÚDOVÁ, Jana – JAVORSKÝ, Peter. Heterotrophic bacteria associated with Varroa destructor mite. In Apidologie, 2015, vol. 46, no.3, p. 369-379. (1.676 – IF2014). DOI: 10.1007/s13592-014-0327-9

Polo-like kinase 1 orchestrates important cell events

New activities of PLK1 protein kinase were determined on the mouse oocyte experimental model. The results were created in cooperation with Institute Animal Physiology and Genetics (Academy of Sci of Czech rep., Liběchov). Experiments show that PLK1 becomes activated at meiotic resumption on microtubule organizing centers (MTOCs) and later at kinetochores. Activity of PLK1 is required for efficient meiotic resumption by promoting nuclear envelope breakdown independently of CDK1. PLK1 is also needed to recruit centrosomal proteins to acentriolar MTOCs to promote normal spindle formation, as well as for stable kinetochore-microtubule attachment. Consequently, PLK1 inhibition leads to metaphase I arrest with misaligned chromosomes activating the spindle assembly checkpoint (SAC). Unlike in mitosis, the metaphase I arrest is not bypassed by the inactivation of the SAC. We show that PLK1 is required for the full activation of the anaphase promoting complex/cyclosome (APC/C) by promoting the degradation of the APC/C inhibitor EMI1 and is therefore essential for entry into anaphase I. Moreover, our data suggest that PLK1 is required for proper chromosome segregation and the maintenance of chromosome condensation during the meiosis I-II transition, independently of the APC/C. Thus, our results define the meiotic roles of PLK1 in oocytes and reveal interesting differential requirements of PLK1 between mitosis and oocyte meiosis in mammals.
ŠOLC, Peter – KITAJIMA, T. – YOSHIDA, S. – BRZAKOVÁ, Adéla – KAIDO, M. – BARAN, Vladimír – MAYER, A. – SAMALOVÁ, Pavlína – MOTLÍK, Jan – ELLENBERG, J. Multiple requirements of PLK1 during mouse oocyte. In PLoS ONE, 2015, vol. 10., iss. 2, article nr. e0116783. (3.234 – IF2014). ISSN 1932-6203. DOI: 10.1371/journal.pone.0116783, p.1-25