This study reported facultative parthenogenetic cleavage development of sterlet sturgeon Acipenser ruthenus eggs and quantified the percentage of parthenogenetically developed eggs in relation to the fertilization ability of different females. When eggs were activated in freshwater, 5.1-13.7% of eggs developed parthenogenetically, while among those activated eggs 3.6-9.4% developed to 2 cells, 0.4-4.5% developed to 4 cells, and 0-0.8% developed to 8 cells. The mean percentage of fertilized and parthenogenetically activated eggs among the females was negatively correlated (R(2)=0.71, p=0.036), which indicates that parthenogenetic activation rate of sterlet eggs depends on the quality of eggs in terms of fertilization rate.
- MeSH
- ovum fyziologie MeSH
- partenogeneze fyziologie MeSH
- ryby fyziologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Orconectes limosus, a North American crayfish species, is one of the most important aquatic invaders in European inland waters. Despite more than 120 years occurrence in Europe and intense research, there are still gaps in knowledge of its life history and ecology. Investigation into O. limosus invasive success requires identifying the mechanisms that enabled them to establish dense and widespread populations from small initial numbers without observable limitation by an introduction bottleneck. In part, O. limosus success may lie in its ability to reproduce by facultative parthenogenesis. Moreover, there are possible other mating scenarios, because of two mating seasons (autumn and spring) in O. limosus. This work investigated the effect of four reproductive scenarios (autumn mating only, spring mating only, autumn and spring mating, and without mating) on the reproductive success of O. limosus. Females successfully reproduced in all tested mating regimes using parthenogenesis as well as log term sperm storage. This reproductive plasticity likely facilitates the overwhelming success of O. limosus spread and establishment in new localities. It can explain the spread of O. limosus from the initial introduction of 90 specimens to most of continental Europe and Great Britain. These conclusions imply a serious threat, not only for autochthonous European astacofauna, but for other aquatic organisms as well as entire ecosystems.
- MeSH
- ekologie MeSH
- ekosystém MeSH
- partenogeneze fyziologie MeSH
- roční období MeSH
- rozmnožování fyziologie MeSH
- severní raci fyziologie MeSH
- sladká voda MeSH
- spermie fyziologie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Evropa MeSH
Neither the genetic basis nor the inheritance of apomixis is fully understood in plants. The present study is focused on the inheritance of parthenogenesis, one of the basic elements of apomixis, in Pilosella (Asteraceae). A complex pattern of inheritance was recorded in the segregating F(1) progeny recovered from reciprocal crosses between the facultatively apomictic hexaploid P. rubra and the sexual tetraploid P. officinarum. Although both female and male reduced gametes of P. rubra transmitted parthenogenesis at the same rate in the reciprocal crosses, the resulting segregating F(1) progeny inherited parthenogenesis at different rates. The actual transmission rates of parthenogenesis were significantly correlated with the mode of origin of the respective F(1) progeny class. The inheritance of parthenogenesis was significantly reduced in F(1) n + n hybrid progeny from the cross where parthenogenesis was transmitted by female gametes. In F(1) n + 0 polyhaploid progeny from the same cross, however, the transmission rate of parthenogenesis was high; all fertile polyhaploids were parthenogenetic. It appeared that reduced female gametes transmitting parthenogenesis preferentially developed parthenogenetically and only rarely were fertilized in P. rubra. The fact that the determinant for parthenogenesis acts gametophytically in Pilosella and the precocious embryogenesis in parthenogenesis-transmitting megagametophytes was suggested as the most probable explanations for this observation. Furthermore, we observed the different expression of complete apomixis in the non-segregating F(1) 2n + n hybrids as compared to their apomictic maternal parent P. rubra. We suggest that this difference is a result of unspecified interactions between the parental genomes.
- MeSH
- apomixie genetika fyziologie MeSH
- Asteraceae genetika fyziologie MeSH
- chromozomy rostlin genetika MeSH
- genom rostlinný genetika MeSH
- hybridizace genetická MeSH
- partenogeneze genetika fyziologie MeSH
- polyploidie MeSH
- průtoková cytometrie MeSH
- rozmnožování MeSH
- typy dědičnosti MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
ESCs are most commonly derived from embryos originating from oocytes that reached metaphase II. We describe here a novel approach where ESCs with all pluripotency parameters were established from oocytes in which metaphase I was converted, from the cell cycle perspective, directly into metaphase II-like stage without the intervening anaphase to telophase I transition. The resulting embryos initiate development and reach the blastocyst stage from which the ESC lines are then established. Thus, our approach could represent an ethically acceptable method that can exploit oocytes that are typically discarded in in vitro fertilization clinics. Moreover, our results also indicate that the meiotic cell cycle can be converted into mitosis by modulating chromosomal contacts that are typical for meiosis with subsequent licensing of chromatin for DNA replication.
- MeSH
- buněčná diferenciace fyziologie MeSH
- buněčné kultury metody MeSH
- buněčné linie MeSH
- embryonální kmenové buňky cytologie fyziologie MeSH
- meióza fyziologie MeSH
- mitóza genetika fyziologie MeSH
- myši inbrední C57BL MeSH
- myši inbrední DBA MeSH
- myši MeSH
- oocyty cytologie fyziologie MeSH
- oogeneze fyziologie MeSH
- partenogeneze fyziologie MeSH
- těhotenství MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- myši MeSH
- těhotenství MeSH
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
Biological invasions are impacting biota worldwide, and explaining why some taxa tend to become invasive is of major scientific interest. North American crayfish species, particularly of the family Cambaridae, are prominent invaders in freshwaters, defying the "tens rule" which states that only a minority of species introduced to new regions become established, and only a minority of those become invasive and pests. So far, success of cambarid invaders has largely been attributed to rapid maturation, high reproductive output, aggressiveness, and tolerance to pollution. We provide experimental evidence that females of one cambarid species particularly widespread in Europe, the spiny-cheek crayfish Orconectes limosus, are capable of facultative parthenogenesis. Such reproductive mode has never before been recognized in decapods, the most diverse crustacean order. As shown by analysis of seven microsatellite loci, crayfish females kept physically separated from males produced genetically homogeneous offspring identical with maternal individuals; this suggests they reproduced by apomixis, unlike those females which mated with males and had a diverse offspring. Further research is needed to clarify what environmental conditions are necessary for a switch to parthenogenesis in O. limosus, and what role it plays in natural crayfish populations. However, if such reproductive plasticity is present in other cambarid crayfish species, it may contribute to the overwhelming invasive success of this group.
The aim of this work was to assess the FSH-stimulated expression of epidermal growth factor (EGF)-like peptides in cultured cumulus-oocyte complexes (COCs) and to find out the effect of the peptides on cumulus expansion, oocyte maturation, and acquisition of developmental competence in vitro. FSH promptly stimulated expression of amphiregulin (AREG) and epiregulin (EREG), but not betacellulin (BTC) in the cultured COCs. Expression of AREG and EREG reached maximum at 2 or 4 h after FSH addition respectively. FSH also significantly stimulated expression of expansion-related genes (PTGS2, TNFAIP6, and HAS2) in the COCs at 4 and 8 h of culture, with a significant decrease at 20 h of culture. Both AREG and EREG also increased expression of the expansion-related genes; however, the relative abundance of mRNA for each gene was much lower than in the FSH-stimulated COCs. In contrast to FSH, AREG and EREG neither stimulated expression of CYP11A1 in the COCs nor an increase in progesterone production by cumulus cells. AREG and EREG stimulated maturation of oocytes and expansion of cumulus cells, although the percentage of oocytes that had reached metaphase II was significantly lower when compared to FSH-induced maturation. Nevertheless, significantly more oocytes stimulated with AREG and/or EREG developed to blastocyst stage after parthenogenetic activation when compared to oocytes stimulated with FSH alone or combinations of FSH/LH or pregnant mares serum gonadotrophin/human chorionic gonadotrophin. We conclude that EGF-like peptides do not mimic all effects of FSH on the cultured COCs; nevertheless, they yield oocytes with superior developmental competence.
- MeSH
- buněčná diferenciace účinky léků genetika MeSH
- embryonální vývoj účinky léků genetika MeSH
- epidermální růstový faktor chemie farmakologie MeSH
- folikuly stimulující hormon farmakologie MeSH
- gonadotropiny farmakologie MeSH
- kultivace embrya MeSH
- kultivované buňky MeSH
- kumulární buňky účinky léků metabolismus fyziologie MeSH
- oocyty účinky léků metabolismus fyziologie MeSH
- oogeneze účinky léků genetika MeSH
- partenogeneze účinky léků genetika fyziologie MeSH
- peptidové fragmenty chemie farmakologie MeSH
- prasata genetika metabolismus fyziologie MeSH
- proliferace buněk účinky léků MeSH
- stanovení celkové genové exprese MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- hodnotící studie MeSH
- práce podpořená grantem MeSH
- srovnávací studie MeSH
The nitric oxide donor (+)-S-nitroso-N-acetylpenicillamine (SNAP) is capable of inducing parthenogenetic activation in pig oocytes matured in vitro. However, quite a long exposure to the nitric oxide donor, exceeding 10 h, is necessary for successful oocyte activation. Repeated short-term treatment with 2 mm SNAP significantly increased the activation rates despite the fact that the overall exposure time to the nitric oxide donor did not exceed 4 h. With regard to the activation rate, 12 repeated treatments lasting 10 min each were found to be the most efficient regimen (63.3%). The continuous exposure to the nitric oxide donor for the same overall time induced parthenogenetic activation in 12.5% oocytes (2-h continuous treatment with 2 mm SNAP). The development of parthenogenetic embryos increased after repeated short-term treatment with SNAP. After continuous treatment with 2 mm SNAP for 10 h, only 6.7% of the oocytes cleaved, and none developed beyond the 4-cell stage. Thirty-minute treatment repeated four times with 2 mm SNAP induced cleavage in 37.5% of the oocytes, 18.3% developed to the morula stage, and 6.7% reached the blastocyst stage. Based on the results, it is concluded that pulsatile treatment can significantly improve parthenogenetic activation rate when compared with the continuous treatment using nitric oxide donors.
- MeSH
- donory oxidu dusnatého aplikace a dávkování MeSH
- kultivace embrya veterinární MeSH
- kultivované buňky MeSH
- oocyty účinky léků fyziologie MeSH
- partenogeneze účinky léků fyziologie MeSH
- prasata MeSH
- S-nitroso-N-acetylpenicilamin aplikace a dávkování MeSH
- stadium rýhování vajíčka MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
It has been known for long time that asexual organisms may affect the distribution of sexual taxa. In fact, such phenomenon is inherent in the concept of geographical parthenogenesis. On the other hand, it was generally hypothesized that sperm-dependent asexuals may not exercise the same effect on related sexual population, due to their dependence upon them as sperm-donors. Recently, however, it became clear that sperm-dependent asexuals may directly or indirectly affect the distribution of their sperm-hosts, but rather in a small scale. No study addressed the large-scale biogeographic effect of the coexistence of such asexuals with the sexual species. In our study we were interested in the effect of sexual-asexual coexistence on the speed of spatial expansion of the whole complex. We expand previously published Lotka-Volterra model of the coexistence of sexual and gynogenetic forms of spined loach (Cobitis; Teleostei) hybrid complex by diffusion. We show that presence of sperm-dependent parthenogens is likely to negatively affect the spatial expansion of sexuals, and hence the whole complex, compared to pure sexual population. Given that most of the known sperm-dependent asexual complexes are distributed in areas prone to climate-induced colonization/extinction events, we conclude that such mechanism may be an important agent in determining the biogeography of sexual taxa and therefore requires further attention including empirical tests.
