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1.

001-es BibID:BIBFORM096013
035-os BibID:(WoS)000613886100001 (Scopus)85100173315
Első szerző:Miklós Máté (biológus)
Cím:Phenotypic plasticity rather than genotype drives reproductive choices in Hydra populations / Máté Miklós, Levente Laczkó, Gábor Sramkó, Flóra Sebestyén, Zoltán Barta, Jácint Tökölyi
Dátum:2021
ISSN:0962-1083
Megjegyzések:Facultative clonality is associated with complex life cycles where sexual and asexual forms can be exposed to contrasting selection pressures. Facultatively clonal animals often have distinct developmental capabilities that depend on reproductive mode (e.g., negligible senescence and exceptional regeneration ability in asexual individuals, which are lacking in sexual individuals). Understanding how these differences in life history strategies evolved is hampered by limited knowledge of the population structure underlying sexual and asexual forms in nature. Here we studied genetic differentiation of coexisting sexual and asexual Hydra oligactis polyps, a freshwater cnidarian where reproductive mode-dependent life history patterns are observed. We collected asexual and sexual polyps from 13 Central European water bodies and used restriction-site associated DNA sequencing to infer population structure. We detected high relatedness among populations and signs that hydras might spread with resting eggs through zoochory. We found no genetic structure with respect to mode of reproduction (asexual vs. sexual). On the other hand, clear evidence was found for phenotypic plasticity in mode of reproduction, as polyps inferred to be clones differed in reproductive mode. Moreover, we detected two cases of apparent sex change (males and females found within the same clonal lineages) in this species with supposedly stable sexes. Our study describes population genetic structure in Hydra for the first time, highlights the role of phenotypic plasticity in generating patterns of life history variation, and contributes to understanding the evolution of reproductive mode-dependent life history variation in coexisting asexual and sexual forms.
Tárgyszavak:Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
clonal reproduction
eco-evo- devo
phenotypic plasticity
population genomics
RAD-seq
sex change
Megjelenés:Molecular Ecology. - 30 : 5 (2021), p. 1206-1222. -
További szerzők:Laczkó Levente (1992-) (biológus) Sramkó Gábor (1981-) (biológus) Sebestyén Flóra (1993-) (biológus) Barta Zoltán (1967-) (biológus, zoológus) Tökölyi Jácint (1984-) (biológus)
Pályázati támogatás:NKFIH FK 124164
Egyéb
ÚNKP-19- 3
Egyéb
ÚNKP-19- 4
Egyéb
János Bolyai Research Scholarship of the Hungarian Academy of Sciences
Egyéb
Higher Education Institutional Excellence Program of the Ministry of Human Capacities in Hungary, FIK-Lendület Behavioral Ecology Research Group
Egyéb
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2.

001-es BibID:BIBFORM096002
035-os BibID:(WoS)000574813200005 (Scopus)85087742888
Első szerző:Sebestyén Flóra (biológus)
Cím:Age-dependent plasticity in reproductive investment, regeneration capacity and survival in a partially clonal animal (Hydra oligactis) / Flóra Sebestyén, Máté Miklós, Katalin Iván, Jácint Tökölyi
Dátum:2020
ISSN:0021-8790
Megjegyzések:1. Asexual reproduction diversifies life-history priorities and is associated with unusual reproduction and somatic maintenance patterns, such as constant fertility with age, extensive regeneration ability and negligible senescence. While agedependent plasticity in relative allocation to sexual versus asexual reproductive modes is relatively well studied, the modulation of somatic maintenance traits in parallel with age-dependent reproduction is much less well understood in clonal or partially clonal animals. 2. Here, we asked how age-dependent investment into sexual and asexual reproduction co-varies with somatic maintenance such as regeneration in a partially clonal freshwater cnidarian Hydra oligactis, a species with remarkable regeneration abilities and experimentally inducible sex. 3. We induced gametogenesis by lowering temperature at two ages, 1 or 4 weeks after detachment from an asexual parent, in animals of a male and a female clone.Then we measured phenotypically asexual and sexual reproductive traits (budding rate, start day and number of sexual organs) together with head regeneration rate, survival and the cellular background of these traits (number of reproductive and interstitial stem cells) for 2 or 5 months. 4. Younger animals had higher asexual reproduction while individuals in the older group had more intensive gametogenesis and reproductive cell production. In parallel with these age-dependent reproductive differences, somatic maintenance of older individuals was also impacted: head regeneration, survival and interstitial stem cell numbers were reduced compared to younger polyps. Some of the traits investigated showed an ontogenetic effect, suggesting that age-dependent plasticity and a fixed ontogenetic response might both contribute to differences between age groups. 5. We show that in H. oligactis asexual reproduction coupled with higher somatic maintenance is prioritized earlier in life, while sexual reproduction with higher maintenance costs occurs later if sex is induced. These findings confirm generallife-history theory predictions on resource allocation between somatic maintenance and sexual reproduction applying in a partially clonal species. At the same time, our study also highlights the age-dependent integration of these resource allocation decisions with sexual/asexual strategies. Accounting for age-related differences might enhance repeatability of research done with clonal individuals derived from mass cultures.
Tárgyszavak:Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
eco-evo-devo
partial clonality
phenotypic plasticity
regeneration
resource allocation
senescence
sexual investment
stem cells
Megjelenés:Journal Of Animal Ecology. - 89 : 10 (2020), p. 2246-2257. -
További szerzők:Miklós Máté (1994-) (biológus) Iván Katalin Tökölyi Jácint (1984-) (biológus)
Pályázati támogatás:NKFIH FK 124164
Egyéb
ÚNKP-18- 3
Egyéb
ÚNKP-19-3
Egyéb
ÚNKP-19-4
Egyéb
János Bolyai Research Scholarship of the Hungarian Academy of Sciences
Egyéb
EFOP-3.6.1-16-2016-00022
EFOP
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3.

001-es BibID:BIBFORM078530
035-os BibID:(WoS)000449861000003 (Scopus)85052627265
Első szerző:Sebestyén Flóra (biológus)
Cím:Reproductive mode, stem cells and regeneration in a freshwater cnidarian with postreproductive senescence / Flóra Sebestyén, Zoltán Barta, Jácint Tökölyi
Dátum:2018
ISSN:0269-8463 1365-2435
Megjegyzések:In many basal metazoans, both somatic and reproductive functions are performed by cellular derivatives of a single multipotent stem cell population. Reproduction can drain these stem cell pools, imposing a physiological cost with subsequent negative effects on somatic maintenance functions. In the freshwater cnidarian Hydra oligactis, both asexual (budding) and sexual reproductive modes (production of resting eggs) are present, and both of these are dependent on a common pool of interstitial stem cells. Resting eggs tolerate harsh abiotic conditions which neither the parental animals, nor asexual offspring can survive (e.g., freezing). Therefore, when facing unfavourable conditions and increased mortality risk, hydra polyps are expected to show higher level of differentiation of interstitial stem cells into germ cells (i.e., sexual reproduction) than other cell types needed for self?maintenance or asexual reproduction. Here, by comparing sexually and asexually reproducing individuals to nonreproductives, we studied the physiological costs of reproduction (size of interstitial stem cell pools, their somatic derivatives and regeneration rate, which is dependent on these cell types) in H. oligactis polyps from a free?living Hungarian population prior to the onset of winter. Sexual individuals were characterized by significantly smaller interstitial stem cell pools, fewer nematoblasts involved in food capture and lower regeneration ability compared to nonreproductives, but asexuals did not differ from nonreproductive animals. We also found a negative correlation between germ cell counts and stem cell numbers in males (but not in females). We suggest that the lower numbers of these cell types and lower regenerative ability in sexual individuals reflect a somatic cost of sexual reproduction. Our results also suggest that increased differentiation of stem cells into gametes might limit investment into somatic functions in hydra polyps. Exhaustion of cellular resources (stem cells) could be a major mechanism behind the extreme postreproductive senescence observed in this species.
Tárgyszavak:Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
cost of reproduction
Evo-Devo
Hydra
interstitial cells
life-history trade-offs
semelparity
Megjelenés:Functional Ecology. - 32 : 11 (2018), p. 2497-2508. -
További szerzők:Barta Zoltán (1967-) (biológus, zoológus) Tökölyi Jácint (1984-) (biológus)
Pályázati támogatás:EFOP-3.6.1
EFOP
NKFIH FK 124164
egyéb
NKFIH K 112527
egyéb
ÚNKP-17- 4
egyéb
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4.

001-es BibID:BIBFORM073444
035-os BibID:(Scopus)85026906262 (WOS)000406789200009
Első szerző:Sebestyén Flóra (biológus)
Cím:Insulin/IGF Signaling and Life History Traits in Response to Food Availability and Perceived Density in the Cnidarian Hydra vulgaris / Sebestyén Flóra, Póliska Szilárd, Rácz Rita, Bereczki Judit, Lénárt Kinga, Barta Zoltán, Lendvai Z. Ádám, Tökölyi Jácint
Dátum:2017
ISSN:0289-0003
Megjegyzések:Insulin/insulin-like growth factor signaling (IIS) is thought to be a central mediator of life history traits, but the generality of its role is not clear. Here, we investigated mRNA expression levels of three insulin-like peptide genes, the insulin-like receptor htk7, as well as several antioxidant genes, and the heat-shock protein hsp70 in the freshwater cnidarian Hydra vulgaris. Hydra polyps were exposed to a combination of different levels of food and perceived population density to manipulate life history traits (asexual reproduction and oxidative stress tolerance). We found that stress tolerance and the rate of asexual reproduction increased with food, and that these two effects were in significant interaction. Exposing animals to high perceived density resulted in increased stress tolerance or reduced reproduction only on lower food levels, but not on high food. The insulin-like receptor htk7 and the antioxidant gene catalase were significantly upregulated in the high density treatments. However, the expression level of insulin-like peptide genes, most antioxidant genes, and hsp70 were not affected by the experimental treatments. The higher expression level of htk7 may suggest that animals maintain a higher level of preparedness for insulin-like ligands at high population densities. However, the lack of difference between food levels suggests that IIS is not involved in regulating asexual reproduction and stress tolerance in hydra, or that its role is more subtle than a simple model of life history regulation would suggest.
Tárgyszavak:Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Insulin signaling, Hydra vulgaris
Megjelenés:Zoological Science. - 34 : 4 (2017), p. 318-325. -
További szerzők:Póliska Szilárd (1978-) (biológus) Rácz Rita (1989-) (biológus) Bereczki Judit (1979-) (biológus) Lénárt Kinga (1994-) (biológus) Barta Zoltán (1967-) (biológus, zoológus) Lendvai Ádám Zoltán (1977-) (biológus) Tökölyi Jácint (1984-) (biológus)
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5.

001-es BibID:BIBFORM096003
035-os BibID:(Scopus)84999027902 (WOS)000396964700012
Első szerző:Tökölyi Jácint (biológus)
Cím:Resource allocation and post-reproductive degeneration in the freshwater cnidarian Hydra oligactis (Pallas, 1766) / Tökölyi Jácint, Ősz Zsófia, Sebestyén Flóra, Barta Zoltán
Dátum:2017
ISSN:0944-2006
Megjegyzések:Freshwater hydra are among the few animal groups that show negligible senescence and can maintain high survival and reproduction rates when kept under stable conditions in the laboratory. Yet, one species of Hydra (H. oligactis) undergoes a senescence-like process in which polyps degenerate and die after sexual reproduction. The ultimate factors responsible for this phenomenon are unclear. High mortality in reproducing animals could be the consequence of increased allocation of resources to reproduction at the expense of somatic maintenance. This hypothesis predicts that patterns of reproduction and survival are influenced by resource availability. To test this prediction we investigated survival and reproduction at different levels of food availability in 10 lineages of H. oligactis derived from a single Hungarian population. Sexual reproduction was accompanied by reduced survival, but a substantial proportion of animals regenerated after sexual reproduction and continued reproducing asexually. Polyps belonging to different lineages showed differences in their propensity to initiate sexual reproduction, gonad number and survival rate. Food availability significantly affected fecundity (number of eggs or testes produced), with the largest number of gonads being produced by animals kept on a high food regime. On the other hand, survival rate was not affected by the amount of food. These results show that survival is conserved at the expense of reproduction in this population when food is low. It remains a question still to be answered why survival is prioritized over reproduction in this population.
Tárgyszavak:Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
folyóiratcikk
Cnidaria
Food availability
Life history
Senescence
Survival/reproduction trade-offs
Megjelenés:Zoology. - 120 (2017), p. 110-116. -
További szerzők:Ősz Zsófia Sebestyén Flóra (1993-) (biológus) Barta Zoltán (1967-) (biológus, zoológus)
Pályázati támogatás:NTP-EFÖ-P-15
Egyéb
János Bolyai Research Scholarship of the Hungarian Academy of Sciences
Egyéb
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6.

001-es BibID:BIBFORM079655
Első szerző:Tökölyi Jácint (biológus)
Cím:Life history traits and previous exposure predict resistance to UV irradiation in the freshwater cnidarian / Tökölyi Jácint, Kozma Beatrix, Sebestyén Flóra, Miklós Máté, Barta Zoltán
Dátum:2017
ISSN:1077-8306 1077-8306
Megjegyzések:Abiotic stress is an important source of mortality for cnidarians and is likely to be a major factor shaping their life histories. In freshwater hydra, the ability to withstand exogenous sources of stress varies between species and populations, but little is known about the factors responsible for this variation. Here, we investigated resistance to UV irradiation in Hydra oligactis, a common temperate freshwater cnidarian. We collected polyps from 12 populations and propagated these asexually under standard conditions in the laboratory to obtain 69 laboratory clonal lines with a total of 324 polyps of different age. We measured the size of polyps and recorded their budding rate. In addition, a subset of animals was exposed to hormetic treatment, where experimental animals received a short, sublethal irradiation 2 d before testing their resistance to a higher dose. We investigated how life history traits (age, size, and budding rate), hormetic treatment, and the interaction between life history traits and hormetic treatment relate to the ability of hydra polyps to tolerate high doses of UV irradiation. In multivariate models controlling for the effect of other variables, stress tolerance was positively related to age (lower tolerance in freshly detached buds compared to adult hydra) and size (higher tolerance in polyps with a large body column). Budding rate was negatively associated with stress tolerance. Hormetic treatment increased resistance to UV irradiation, but we found no evidence for an interaction between hormetic response and any of the life history traits, suggesting that the ability to upregulate physiological defense mechanisms after exposure to mild stress does not depend on the life history background of the individuals.
Tárgyszavak:Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
abiotic stress
Cnidaria
hormesis
resource allocation
somatic maintenance
Megjelenés:Invertebrate Biology. - 136 : 2 (2017), p. 217-227. -
További szerzők:Kozma Beatrix Sebestyén Flóra (1993-) (biológus) Miklós Máté (1994-) (biológus) Barta Zoltán (1967-) (biológus, zoológus)
Pályázati támogatás:NTP-EFO-P-15
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7.

001-es BibID:BIBFORM078527
Első szerző:Tökölyi Jácint (biológus)
Cím:Öregedés és öregedés nélküli életciklus egy édesvízi csalánzónál : párhuzamos életrajzok / Tökölyi Jácint, Sebestyén Flóra, Miklós Máté, Iván Katalin
Dátum:2018
ISSN:0013-6077 1418-1665
Megjegyzések:Abraham Trembley svájci magántanár tanítványaival különleges élőlényt fedezett fel egy kerti patakban 1740 nyarán. A lényről, amely zöld színű volt mint a növények, de mozgásra és helyváltoztatásra volt képes, mint az állatok, elsőre nem tudta eldönteni, hogy növény vagy állat, ezért részletes megfigyeléseket végzett rajta. Része volt vizsgálódásainak az is, hogy kettévágta őket - feltételezte ugyanis, hogy egy növény képes lenne túlélni, ha kettévágják, állat viszont nem. Meglepetésére a lény nemcsak túlélt, de a kettévágott felek néhány nap alatt teljesen újranövesztették elveszett testrészeiket. Trembley elnevezte a lényt hidrának, utalva a görög mitológiai szörnyre, melynek minden levágott feje helyett kettő nő vissza.
Tárgyszavak:Természettudományok Biológiai tudományok magyar nyelvű folyóiratközlemény hazai lapban
Megjelenés:Élet és Tudomány. - 73 : 23 (2018), p. 710-712. -
További szerzők:Sebestyén Flóra (1993-) (biológus) Miklós Máté (1994-) (biológus) Iván Katalin
Pályázati támogatás:ÚNKP-17-4
Egyéb
Fk124164
Egyéb
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8.

001-es BibID:BIBFORM066149
035-os BibID:(Scopus)84952637768 (WoS)000367196900009
Első szerző:Tökölyi Jácint (biológus)
Cím:Effects of food availability on asexual reproduction and stress tolerance along the fast-slow life history continuum in freshwater hydra (Cnidaria: Hydrozoa) / Jácint Tökölyi, Flóra Bradács, Nikolett Hóka, Noémi Kozma, Máté Miklós, Orsolya Mucza, Kinga Lénárt, Zsófia Ősz, Flóra Sebestyén, Zoltán Barta
Dátum:2015
ISSN:0018-8158
Megjegyzések:Life history theory predicts that reproduction and somatic maintenance are negatively related, but the strength of this relationship is expected to depend on food availability. In this study, we investigated asexual reproduction (budding rate) and oxidative stress tolerance as two opposing facets of life history trade-offs in 17 strains of five freshwater hydra species under experimentally simulated low, medium, and high food availability. Stress tolerance was quantified by exposing animals to exogenous H2O2, which mimics reactive oxygen species arising in vivo. The five species differed in life history traits (low budding rate and high stress tolerance in Hydra vulgaris and H. circumcincta and the opposite in H. oligactis and H. viridissima; low budding rate combined with relatively low stress tolerance in H. oxycnida). Stress tolerance and asexual reproduction increased with food, but there were clear interspecific differences in this relationship. Across all strains, stress tolerance and budding rate were significantly negatively related on the low and medium, but not the high food level. These results suggest that resource allocation trade-offs are involved in determining life history traits in hydra; populations/species can be broadly positioned on a fast-slow life history continuum, and response to variation in food varies along this continuum.
Tárgyszavak:Természettudományok Biológiai tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Dietary restriction
Food variability
Hydra
Life history evolution
Resource allocation trade-offs
Megjelenés:Hydrobiologia. - 766 : 1 (2015), p. 121-133. -
További szerzők:Bradács Flóra Hóka Nikolett Kozma Noémi Miklós Máté (1994-) (biológus) Mucza Orsolya Lénárt Kinga (1994-) (biológus) Ősz Zsófia Sebestyén Flóra (1993-) (biológus) Barta Zoltán (1967-) (biológus, zoológus)
Pályázati támogatás:SROP-4.2.2.B-15/1/KONV-2015-0001
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