The heat stress effect on pollen development and germination

Povišena temperatura ima značajan učinak na sve biljne organe i sve razvojne faze u životu biljke. Osobito je važan učinak na razvoj peluda i ženskih reproduktivnih organa, klijanje peludne mješinice i uspješnost stvaranja ploda. U biljaka izloženih toplotnom stresu mijenjaju se metabolički procesi, usporava sinteza normalnih staničnih proteina, neki se proteini degradiraju, a svi ti procesi događaju se u svrhu uspostavljanja termotolerancije. Posebna karakteristika metabolizma u uvjetima toplotnog stresa je sinteza čitavog seta proteina induciranih stresom, koji omogućavaju funkcioniranje stanice u uvjetima visokih temperatura. Pelud je osjetljiv na povišene temperature, iako ima karakterističnu strukturu koja ga štiti od brojnih okolišnih utjecaja. Peludno zrno razvija peludnu mješinicu koja kroz tučak klije prema sjemenom zametku vršnim rastom i pomoću vrlo složene stanične regulacije. Razlog nemogućnosti oplodnje često je abnormalnost klijanja peludne mješinice ili neuspješnost klijanja peluda na tučku. Zato je nužno istraživati utjecaj vanjskih faktora kao što je temperatura na fiziologiju, dinamiku i molekularne mehanizme klijanja peluda. Rezultati studija pokazali su da se proces klijanja peluda mijenja u trenutku povišenja temperature iznad optimalne, nakon čega se smanjuje brzina rasta, vijabilnost ili postotak uspješne oplodnje. Zanimljivo je da toplotni stres različito djeluje na muške i ženske reproduktivne organe. Postoje podaci da od svih biljnih tkiva toplotni stres ne utječe na ekspresiju HSP jedino u peludi. Međutim, u literaturi se o toj temi nalaze kontradiktorni podaci pa se negdje navodi i postojanje ekspresije HSP u peludi. O konkretnom problemu malo je dostupnih podataka, pa bi se u tom području trebalo provesti više istraživanja koja bi integrirala molekularne mehanizme klijanja, fiziološki odgovor peludi na toplotni stres i ekspresiju određenih staničnih i proteina toplotnog stresa.Increased temperature is an important factor that has impact on the living world. In plants, temperatures can affect pollen and female reproductive organs development, pollen tube growth and fruit ripening. Plants adjust their metabolic processes, decrease the rate of normal cellular proteins’ synthesis, degrade some proteins in order to be more termotolerant to heat stress. Synthesising the set of heat shock proteins is a special plants characteristic, which allows normal cell functions in high temperatures conditions. Pollen is heat-sensitive, although it has a specific structure that protects it from harmful environment conditions. Pollen grain grows into pollen tube allowing tip growth and complex cellular regulations all the way to embrio sac. The reason for unsuccessful pollination is often abnormality of the pollen tube or failure in pollen germination on stigma. The aim of this work was to determine influence of high temperature on physiology, dynamics and molecular mechanisms of pollen germination and growth. Results of recent studies showed that percentage of pollen germination, pollen tube growth rate and successful pollination rate are decreasing under influence of increased temperature. Heat stress differently affects male and female reproductive organs. The only plant organ that does not synthesise heat shock proteins under heat stress is pollen, although there are contradictory data in the literature. There is little information available about this problem, so there should be more scientific studies which would integrate data about pollen tube germination and its molecular mechanisms, physiological responses to heat stress and expression of certain cellular and heat shock proteins

The heat stress effect on pollen development and germination

Povišena temperatura ima značajan učinak na sve biljne organe i sve razvojne faze u životu biljke. Osobito je važan učinak na razvoj peluda i ženskih reproduktivnih organa, klijanje peludne mješinice i uspješnost stvaranja ploda. U biljaka izloženih toplotnom stresu mijenjaju se metabolički procesi, usporava sinteza normalnih staničnih proteina, neki se proteini degradiraju, a svi ti procesi događaju se u svrhu uspostavljanja termotolerancije. Posebna karakteristika metabolizma u uvjetima toplotnog stresa je sinteza čitavog seta proteina induciranih stresom, koji omogućavaju funkcioniranje stanice u uvjetima visokih temperatura. Pelud je osjetljiv na povišene temperature, iako ima karakterističnu strukturu koja ga štiti od brojnih okolišnih utjecaja. Peludno zrno razvija peludnu mješinicu koja kroz tučak klije prema sjemenom zametku vršnim rastom i pomoću vrlo složene stanične regulacije. Razlog nemogućnosti oplodnje često je abnormalnost klijanja peludne mješinice ili neuspješnost klijanja peluda na tučku. Zato je nužno istraživati utjecaj vanjskih faktora kao što je temperatura na fiziologiju, dinamiku i molekularne mehanizme klijanja peluda. Rezultati studija pokazali su da se proces klijanja peluda mijenja u trenutku povišenja temperature iznad optimalne, nakon čega se smanjuje brzina rasta, vijabilnost ili postotak uspješne oplodnje. Zanimljivo je da toplotni stres različito djeluje na muške i ženske reproduktivne organe. Postoje podaci da od svih biljnih tkiva toplotni stres ne utječe na ekspresiju HSP jedino u peludi. Međutim, u literaturi se o toj temi nalaze kontradiktorni podaci pa se negdje navodi i postojanje ekspresije HSP u peludi. O konkretnom problemu malo je dostupnih podataka, pa bi se u tom području trebalo provesti više istraživanja koja bi integrirala molekularne mehanizme klijanja, fiziološki odgovor peludi na toplotni stres i ekspresiju određenih staničnih i proteina toplotnog stresa.Increased temperature is an important factor that has impact on the living world. In plants, temperatures can affect pollen and female reproductive organs development, pollen tube growth and fruit ripening. Plants adjust their metabolic processes, decrease the rate of normal cellular proteins’ synthesis, degrade some proteins in order to be more termotolerant to heat stress. Synthesising the set of heat shock proteins is a special plants characteristic, which allows normal cell functions in high temperatures conditions. Pollen is heat-sensitive, although it has a specific structure that protects it from harmful environment conditions. Pollen grain grows into pollen tube allowing tip growth and complex cellular regulations all the way to embrio sac. The reason for unsuccessful pollination is often abnormality of the pollen tube or failure in pollen germination on stigma. The aim of this work was to determine influence of high temperature on physiology, dynamics and molecular mechanisms of pollen germination and growth. Results of recent studies showed that percentage of pollen germination, pollen tube growth rate and successful pollination rate are decreasing under influence of increased temperature. Heat stress differently affects male and female reproductive organs. The only plant organ that does not synthesise heat shock proteins under heat stress is pollen, although there are contradictory data in the literature. There is little information available about this problem, so there should be more scientific studies which would integrate data about pollen tube germination and its molecular mechanisms, physiological responses to heat stress and expression of certain cellular and heat shock proteins

“How not to judge a deer by its cover”: A personality assessment study on captive adult red deer males (Cervus elaphus)

Personality is not a uniquely human characteristic and it has been documented in a wide range of organisms, from mammals to birds, reptiles, fish, and invertebrates. However, personality is still poorly understood in Cervids. Therefore, our study aimed to fill this gap by i) investigating personality and ii) exploring its links to dominance hierarchy, assessed by behavioral observations in 11 captive and tame male red deer (Cervus elaphus). Using questionnaires to assess personality, three trained volunteers rated these animals in 15 behaviorally composed adjectives with detailed descriptions, based on their overall impression at the end of the observation period. Behavioral data from animals were collected across three different situations, namely “feeding” (i.e., high competition for a scarce resource), “normal” (i.e., no external stimuli) in a group setting, and “handling” (i.e., stressful situation due to human manipulation) in an individual setting. We estimated dominance hierarchies between the individuals based on situations of average and high competition (i.e., “normal” and “feeding”) via the Clutton-Brock Index (CBI). Using Fleiss’ Kappa for inter-rater reliability, only five of our 15 behavioral adjectives showed acceptable reliability. Using principal component analysis, four of these adjectives formed one personality component labelled “Confidence/Aggressiveness”. We found that although “Confidence/Aggressiveness” did not correlate with CBI, ratings of two adjectives loading onto this component, namely “Confident” and “Submissive”, significantly correlated with the CBI, indicating that the questionnaire ratings reflect real behavioral variation in red deer males. Our study provides the first assessment of personality in male red deer and adds to the growing literature on Cervid personality, offering the basis for future personality research in ungulates.</p

The Evolution of Primate Short-Term Memory.

Short-term memory is implicated in a range of cognitive abilities and is critical for understanding primate cognitive evolution. To investigate the effects of phylogeny, ecology and sociality on short-term memory, we tested the largest and most diverse primate sample to date (421 non-human primates across 41 species) in an experimental delayed-response task. Our results confirm previous findings that longer delays decrease memory performance across species and taxa. Our analyses demonstrate a considerable contribution of phylogeny over ecological and social factors on the distribution of short-term memory performance in primates; closely related species had more similar short-term memory abilities. Overall, individuals in the branch of Hominoidea performed better compared to Cercopithecoidea, who in turn performed above Platyrrhini and Strepsirrhini. Interdependencies between phylogeny and socioecology of a given species presented an obstacle to disentangling the effects of each of these factors on the evolution of short-term memory capacity. However, this study offers an important step forward in understanding the interspecies and individual variation in short-term memory ability by providing the first phylogenetic reconstruction of this trait’s evolutionary history. The dataset constitutes a unique resource for studying the evolution of primate cognition and the role of short-term memory in other cognitive abilities.info:eu-repo/semantics/publishedVersio

The Evolution of Primate Short-Term Memory

Short-term memory is implicated in a range of cognitive abilities and is critical for understanding primate cognitive evolution. To investigate the effects of phylogeny, ecology and sociality on short-term memory, we tested the largest and most diverse primate sample to date (421 non-human primates across 41 species) in an experimental delayed-response task. Our results confirm previous findings that longer delays decrease memory performance across species and taxa. Our analyses demonstrate a considerable contribution of phylogeny over ecological and social factors on the distribution of short-term memory performance in primates; closely related species had more similar short-term memory abilities. Overall, individuals in the branch of Hominoidea performed better compared to Cercopithecoidea, who in turn performed above Platyrrhini and Strepsirrhini. Interdependencies between phylogeny and socioecology of a given species presented an obstacle to disentangling the effects of each of these factors on the evolution of short-term memory capacity. However, this study offers an important step forward in understanding the interspecies and individual variation in short-term memory ability by providing the first phylogenetic reconstruction of this trait’s evolutionary history. The dataset constitutes a unique resource for studying the evolution of primate cognition and the role of short-term memory in other cognitive abilities

Personality traits in common marmosets (Callithrix jacchus, L.)

Osobnosti (engl. personalities) u životinja su definirane kao stalne individualne razlike u skupu koreliranih ponašanja u istome kontekstu ili situaciji, ili u različitim kontekstima ili situacijama. Iako postoji duga povijest istraživanja osobnosti u ljudi, osobnosti u životinja su tek relativno nedavno dobile znatni interes znanstvene zajednice, posebice u različitim disciplinama biologije (od ponašanja životinja i ekologije, preko razvojne biologije i neuroendokrinologije, do genetike i evolucije) te su proučavane u raznim vrstama. Štoviše, smatra se da bi neka ponašanja, korelirana u određenim situacijama ili kontekstima, mogla dijeliti iste fiziološke mehanizme te, umjesto da se razviju neovisno jedno o drugome, razviju zajedno. Ovaj koncept bi tako mogao imati važnih implikacija za naše razumijevanje evolucijskih procesa, posebice mehanizama kao što su prirodna selekcija i održavanje jedinstvenih osobnosti u populacijama i vrstama. Isto tako, ovaj koncept bi nam mogao dati uvid u jedno od pitanja koje zanima ljude od davnina: Zašto svatko od nas ima jedinstvene reakcije na isti podražaj, odnosno jedinstvenu osobnost.Animal personalities are defined as consistent individual differences in sets of correlated behaviours across the same or different contexts or situations. Although personalities have a long history of research in humans, the topic of personalities in animals has in recent years received considerable scientific interest from a wide range of disciplines in biology: animal behaviour, ecology, development, neuroendocrinology, genetics and evolution, and has been studied in a variety of species. This interest may be attributed to a notion that different behaviours, when correlated, might share a common proximate mechanism, so they might not evolve independently from each other, but instead evolve together. Thus, this concept could have major implications on our understanding of the evolutionary processes, specifically its ultimate mechanisms, such as natural selection and the maintenance of unique personalities in populations and species. Also, this concept could give us insight into why each and every one of us has individual reactions to the same stimuli, and a unique personality

An observational investigation of behavioural contagion in common marmosets (Callithrix jacchus): indications for contagious scent-marking.

Behavioural contagion is suggested to promote group coordination that may facilitate activity transitions, increased vigilance and state matching. Apart from contagious yawning, however, very little attention has been given to this phenomenon, and studies on contagious yawning in primates have so far only focused on Old World monkeys and apes. Here we studied behavioural contagion in common marmosets, a species for which group coordination and vigilance are paramount. In particular, we investigated the contagiousness of yawning, stretching, scratching, tongue protrusion, gnawing and scent-marking. We coded these behaviours from 14 adult marmosets, from two different social groups. During testing sessions, animals were separated into groups of four individuals for 20-minute observation periods, across three distinct diurnal time points (morning, midday and afternoon) to test for circadian patterns. We observed almost no yawning (0.12 yawns / hour) and very little stretching behaviour. For all other behaviours, which were more common, we found several temporal and inter-individual differences (i.e., sex, age, dominance status) predictive of these responses. Moreover, we found that gnawing and scent-marking, that almost always co-occurred as a fixed-action pattern, were highly temporally clustered within observation sessions. We discuss the relative absence of yawning in marmosets as well as the possible function of contagious scent-marking, and provide suggestions for future research into the proximate and ultimate functions of these behaviours in marmosets

Personality and social environment predict cognitive performance in common marmosets (Callithrix jacchus)

Consistent inter-individual variation in cognition has been increasingly explored in recent years in terms of its patterns, causes and consequences. One of its possible causes are consistent inter-individual differences in behaviour, also referred to as animal personalities, which are shaped by both the physical and the social environment. The latter is particularly relevant for group-living species like common marmosets (Callithrix jacchus), apt learners that display substantial variation in both their personality and cognitive performance, yet no study to date has interlinked these with marmosets' social environment. Here we investigated (i) consistency of learning speed, and (ii) whether the PCA-derived personality traits Exploration-Avoidance and Boldness-Shyness as well as the social environment (i.e., family group membership) are linked with marmosets' speed of learning. We tested 22 individuals in series of personality and learning-focused cognitive tests, including simple motor tasks and discrimination learning tasks. We found that these marmosets showed significant inter-individual consistency in learning across the different tasks, and that females learned faster than males. Further, bolder individuals, and particularly those belonging to certain family groups, learned faster. These findings indicate that both personality and social environment affect learning speed in marmosets and could be important factors driving individual variation in cognition