Changes In Reproductive Traits Research Articles

Inconsistent reproductive cycles and postnatal growth between captive and wild Chinese pangolins and its conservation implications

Captive breeding and reintroduction are crucial to the conservation of endangered species and restoring their populations in the wild. Previous research has primarily focused on behavioral changes and adaptations in captive-bred animals prior to release; few studies have examined changes in reproductive traits and postnatal development in captivity. The Chinese pangolin, Manis pentadactyla, is Critically Endangered because its population has substantially declined in the wild due to poaching for sale in the traditional medicine and luxury food markets. Nevertheless, success in captive breeding in Taiwan may provide a pathway to the recovery of wild populations. This study combined records on captive individuals and field observations on wild Chinese pangolins over a period from 1997 to 2023 to determine (i) mating season, (ii) birth timing, (iii) body mass and total length of newborns, and (iv) postnatal growth patterns prior to weaning. The present study suggests that mating and birth timings for captive Chinese pangolins are not seasonal, as they are in the wild. Captive-born infants are significantly longer and heavier at birth than wild-born infants. Remarkably, captive-born pangolins also experience more rapid weight gain, nearly doubling in size compared with their wild counterparts by 25 weeks of age, even before they are weaned. This rapid growth is likely attributable to the high nutritional content of captive diets. This study suggests artificial feed formulas should be aligned more closely with wild pangolins’ diets to reduce the risk of obesity. Additionally, reproductive parameters and postnatal growth rates in Chinese pangolins cannot be based on observations of captive individuals alone; wild populations must also be considered. We conclude that Chinese pangolins exhibit physiological flexibility in reproduction and growth in response to environmental changes, providing insights for captive pangolin management and reintroduction programs.

Meta-analyses of reproductive changes in angiosperm populations in response to elevation reveal a lack of global patterns.

Elevation is a major factor shaping plant populations on a global scale. At the same time, reproductive traits play a major role in plant fitness. With increasing altitude and increasingly harsh conditions, decreases in pollinator visitation rates, sexual investment, seed set, and heterozygosity (due to increased selfing) are expected. In response, selection and/or phenotypic plasticity could lead to an increase in plants' floral displays to increase their attractiveness to pollinators and compensates for the negative fitness impacts of reduced pollinator activity. A large body of literature tests these hypotheses at the among-species level, but empirical evidence at the population level (i.e., wihin-species), where adaptive change may occur, is still limited to species-specific studies. Unravelling the global patterns of change in the reproductive traits, flower visitation rates and heterozygosity of plant populations across variable environmental conditions, especially climate can help us to understand how species are able to cope with shifting conditions associated with global change, particularly in mountains. Here, we used meta-analytic approaches to assess the reproductive changes of plant populations in response to elevation on a global scale. We used a data set with 243 paired populations of plants at 'lower' and 'higher' elevations, spanning an elevation range of 0-4380 m asl and taken from 121 angiosperm species and 115 published studies. We analyzed changes in flower number, size and longevity, pollen production, flower visitation rate, seed set and expected heterozygosity.We then tested whether the observed patterns for each trait were dependent upon plant phylogeny and various ecogeographical factors and species traits. We found no evidence of elevation having a global effect on the reproductive traits of angiosperm populations. This null global pattern was not affected by geograph or phylogenetics. Our results suggest that changes in reproductive traits, flower visitation rates, and heterozygosity in plant populations across elevations are specific to each species and ecosystem. Hence, macroevolutionary (across species) and macroecological patterns of elevation of plant reproduction reported previously are apparently not simply the outcome of microevolutionary changes (within species). This apparent specificity of response across plant species poses difficulties in predicting the effects of global changes and, specifically, climatic changes, on the fate of plant species, populations, and communities.

Sexual maturation and allometry of reproductive traits in large- and small-sized male honeybees

The body size of male honeybees (Apis mellifera L.) is a cause of skewed reproductive success. Large males are usually produced in colonies and have advantages in competition for mating and fertilisation. However, distinct small-sized males were produced depending on the colony conditions, particularly under queen-less conditions. Understanding the reproductive traits of small-sized males is currently limited, but it may provide insight into the developmental patterns and reproductive strategies that maximise reproductive success depending on body size and colony conditions. This study evaluated the process of sexual maturation in large- and small-sized males and the allometry between reproductive traits and body size. Changes in reproductive traits, including reproductive organs, number of spermatozoa, and sperm density, occurred earlier in small-sized males than in large-sized males after emergence. These results suggest that small males are precocious. The relatively early development of small-sized males would reflect the low developmental cost, which is likely to allow the production of many males and ensure reproductive success under circumstances in which available resources are limited. Furthermore, reproductive traits were positively correlated with body size, but allometry was different for these traits. Hence, the findings suggest that there is a given investment pattern toward reproductive traits with increasing body size, which would be responsible for high mating and fertilisation success in large males.

The fertilization process in Lithocarpus dealbatus (Fagaceae) and its implication on the sexual reproduction evolution of Fagales.

The pistillate flowers of Lithocarpus dealbatus show two pollen tube (PT) arresting sites (the style-joining and micropyle) within the pistil during the postpollination-prezygotic stage. The PT, arrested at the pre-ovule stage, enhanced PT competition allowing the most compatible PTs to enter the ovary to ensure the highest fertilization success. During the shift from animal pollination to wind pollination, plants require a series of changes in reproductive traits. The mode of pollination is striking labile in Fagaceae. Lithocarpus is insect pollinated and is closely related to wind-pollinated Quercus. Little is known about the sexual reproduction of Lithocarpus. This study aimed to reveal the sexual reproduction of Lithocarpus dealbatus and to explore the evolutionary pattern of the key sexual reproduction traits to better understand their possible role in labile pollination. We found that after pollination, L. dealbatus PTs grew slowly in the style reaching style-joining in mid-January of the second year; then PT growth was arrested at style-joining for four months. Only two to three PTs resumed growth in mid-May to reach the micropyle, where PT growth ceased for one month before one PT resumed growth and passed through the micropyle to the embryo sac. Fagaceae showed a generalized mating system. Vast pollen production, small-sized pollen grains, long stigmatic receptive time, and reduced perianth were compatible with beetle pollination syndrome, representing the plesiomorphic status in Fagaceae. A large stigmatic surface and dry pollen grains linked to wind pollination might be independently derived several times in fagaceous lineages. Beetle pollination syndrome can cope with the uncertainty of pollinators to ensure conspecific pollen capture, which represents pre-adaptation status and has a selective advantage when conditions change, favouring wind pollination. The arrest of the PT at style-joining is a unique mechanism in later derived fagaceous lineages to enhance PT competition and promote outcrossing.

Temporal changes in the dominance of tree functional traits, but no changes in species diversity during woody plant encroachment in a Brazilian savanna

AbstractQuestions: Woody encroachment in savannas has been associated with changing taxonomic composition and ecosystem function. Interestingly, there is little understanding of how encroachment impacts plant functional diversity and how those changes relate to plant demography, a crucial mediator between taxonomic composition and ecosystem function.Location: Southeastern Brazil.Methods: Using a landscape scale fire suppression experiment in a diverse Brazilian savanna, we quantify how change in species composition over seven years impacted vegetative and reproductive tree functional diversity as determined by new recruits, dead and surviving trees.Results: Over seven years, tree above‐ground biomass increased by 15%, while total species richness did not change. Despite minor changes, species composition remained overall similar (82%), with few species contributing significantly to plot dissimilarity over time. There were small changes in vegetative traits, where the community‐weighted mean increased in maximum tree height (↑ 2.1%) and specific leaf area (↑ 5.3%), and decreased in wood density (↓ 1.3%) and bark thickness (↓ 9.4%). Changes in reproductive traits were larger than in vegetative traits, with an increase in the prevalence of monoecy (↑ 32.6%), dioecy (↑ 44.2%), large seeds (↑ 20.3%), animal‐mediated seed dispersal (↑ 4.9%) and pollination by very small insects (↑ 45.5%), and a decrease in the prevalence of hermaphroditism (↓ 9%), small seeds (6.8%) and pollination by small insects (12.5%). The overall decrease in bark thickness and increase in monoecy and dioecy were mainly driven by characters of the new recruits, while the overall increase in specific leaf area (SLA) and decrease in small seeds appeared largely determined by the loss of trees possessing those traits.Conclusions: Encroachment leads to changes that are likely increasing ecosystem vulnerability to fire and drought. Further, the compositional changes observed appear to drive marked change in reproductive traits, indicating increasing dependence on animals for dispersal and reproduction. Understanding post‐hoc encroachment impacts in an era of widespread pervasive encroachment is fundamental to reconciling ecosystem functions such as nutrient cycling and pollination services as there is a loss of species with open ecosystem life‐history strategies. Among savannas, there remains an urgent need to understand relationships between woody cover and ecosystem function to determine thresholds in woody cover promoting resilient savanna ecosystems.

Seasonal gonadal changes in adult male lizards of Liolaemus cuyanus (Iguania: Liolaemidae) from the Monte desert, Argentina

Male reproductive cycles in lizards can be continuous or seasonal depending on the environmental conditions and female availability. The aim of this study is to investigate whether adult males of the psammophilus lizard Liolaemus cuyanus present seasonal changes of reproductive traits throughout the reproductive cycle. In order to carry out this task, sampling of specimens (N = 27) was carried out monthly from October to March in Valle de Matagusanos, Ullúm, San Juan, Argentina (31°06′46.08′’ S, 68°38′03.84′’ W; altitude: 945 m), a semi-arid zone. The animals captured in different months were grouped based on reproductive criteria according to three relevant periods: pre-reproductive (PrR), reproductive (R) and post-reproductive (PsR). In order to identify and characterize these periods, several male reproductive traits were obtained, like morphometric parameters (body mass, snout-vent length, testes and abdominal fat body mass), tubular surface and estimation of the interstitial tissue coverage, combined with histological and cell seminiferous tubule observations (germ cells types, histological and ultrastructural details) and presence of sperm in the cauda epididymis. During the PrR period, which occurred during spring, well-developed testes with free tubular sperm cells were present, but these were less frequent than during the R period. On the other hand, luminal sperm cells were evident at the seminiferous tubules from the beginning of the R period, in conjunction with the maximum testes mass and seminiferous tubular surfaces. This was also coincident with a higher abundance of sperm cells in the cauda epididymal lumen. At the end of this period, the initial regression of the seminiferous epithelium was corroborated by organelle regression which was observed in the ultrastructure of spermatogenic cells. At the beginning of the PsR period, before autumn, a marked decrease in male reproductive traits above described was detected. Instead, an increase in abdominal fat body mass could be observed indicating the onset of the lethargy period. The results obtained suggest that this population of L. cuyanus has a seasonal reproductive cycle, with its reproductive activity occurring during the spring-summer months (PrR-R periods) and finishing in late summer (PsR).

Effects of Rederivation by Embryo Vitrification on Performance in a Rabbit Paternal Line

Embryo cryopreservation is a valuable tool for maintaining genetic variability and preserving breeds and lines, allowing to assess the response to selection and enabling genetic diffusion. This study aimed to evaluate the impact of rederivation by embryo vitrification and transfer procedures on the growth and reproductive traits in a paternal rabbit line selected for average daily gain from weaning (28 days old) to fattening (63 days old). The rederived population was bred over two generations at the same time as a control population of this paternal line and, growth trait parameters (weights at weaning, end of the fattening period, and average daily gain) and reproductive performance (kindling rate, litter size at birth and at weaning) were compared with three filial generations. Moreover, fetal growth and litter size components were assessed for the second generation by ultrasonography and laparoscopy. Differences in postnatal growth traits (end of fattening weight and average daily gain) were observed in the three generations assessed. However, fetal growth, litter size components, and reproductive traits did not show significant differences. In conclusion, cryopreservation and embryo transfer processes cause changes in growth traits of reconstituted populations that influence the following generations, without changes in reproductive traits in a paternal line of rabbits.

Intra‐population variation in reproductive timing covaries with thermal plasticity of offspring performance in perch Percafluviatilis

Life history theory posits that organisms should time their reproduction to coincide with environmental conditions that maximize their fitness. Population-level comparisons have contributed important insights on the adaptive value of reproductive timing and its association to environmental variation. Yet, despite its central role to ecology and evolution, the causes and consequences of variation in reproductive timing among individuals within populations are poorly understood in vertebrates other than birds. Using a combination of observational field studies and a split-brood experiment, we investigated whether differences in breeding time were associated with changes in hatching success, reproductive allocation and reaction norms linking offspring performance to temperature within an anadromous Baltic Sea population of perch Perca fluviatilis. Field observations revealed substantial variation in reproductive timing, with the breeding period lasting almost 2months and occurring in temperatures ranging from 10 to 21℃. The hatching success of perch decreased as the reproductive season progressed. At the same time, the reproductive allocation strategy changed over the season, late breeders (the offspring of which were introduced into a high resource environment and increased predation pressure) produced more and smaller eggs that resulted in smaller larvae, compared with early breeders. The split-brood experiment in which eggs were incubated in different temperatures (10, 12, 15, 18°C) showed that differences in reproductive timing were associated with a change in the shape of the reaction norm linking offspring performance to water temperature indicative of adaptive phenotypic plasticity, with the offspring of early breeders performing best in low temperatures and the offspring of late breeders performing best in high temperatures. The seasonal changes in reproductive traits and the shape of the thermal performance suggest time-dependent adaptive differences among individuals within the population. Management actions aimed at preserving and restoring variation in the timing of reproductive events will thus likely also influence variation in associated life history traits and thermal performance curves, which could safeguard populations against environmental challenges and changes associated with exploitation and global warming.

The interplay between hunting rate, hunting selectivity, and reproductive strategies shapes population dynamics of a large carnivore.

Harvest, through its intensity and regulation, often results in selection on female reproductive traits. Changes in female traits can have demographic consequences, as they are fundamental in shaping population dynamics. It is thus imperative to understand and quantify the demographic consequences of changes in female reproductive traits to better understand and anticipate population trajectories under different harvest intensities and regulations. Here, using a dynamic, frequency‐dependent, population model of the intensively hunted brown bear (Ursus arctos) population in Sweden, we quantify and compare population responses to changes in four reproductive traits susceptible to harvest‐induced selection: litter size, weaning age, age at first reproduction, and annual probability to reproduce. We did so for different hunting quotas and under four possible hunting regulations: (i) no individuals are protected, (ii) mothers but not dependent offspring are protected, (iii) mothers and dependent offspring of the year (cubs) are protected, and (iv) entire family groups are protected (i.e., mothers and dependent offspring of any age). We found that population growth rate declines sharply with increasing hunting quotas. Increases in litter size and the probability to reproduce have the greatest potential to affect population growth rate. Population growth rate increases the most when mothers are protected. Adding protection on offspring (of any age), however, reduces the availability of bears for hunting, which feeds back to increase hunting pressure on the nonprotected categories of individuals, leading to reduced population growth. Finally, we found that changes in reproductive traits can dampen population declines at very high hunting quotas, but only when protecting mothers. Our results illustrate that changes in female reproductive traits may have context‐dependent consequences for demography. Thus, to predict population consequences of harvest‐induced selection in wild populations, it is critical to integrate both hunting intensity and regulation, especially if hunting selectivity targets female reproductive strategies.

Changes in Reproductive Traits in Physalis philadelphica; An Unexpected Shift Toward Self-Incompatibility in a Domesticated Annual Fruit Crop.

Domestication is an evolutionary process with an impact on plant reproduction. Many domesticated plants are self-compatible (i.e., they lack mechanisms to reject their own pollen), but few domesticated plants are fully or partially self-incompatible. We used the husk tomato, Physalis philadelphica, as a study model to investigate changes in the reproductive strategy of an annual partially self-incompatible plant during the process of domestication. Wild and cultivated populations of this species coexist in close proximity. These different populations present a high level of morphological and genetic variation associated with different degrees of domestication. We hypothesized that artificial selection favors self-compatibility in cultivated plants through changes in their reproductive strategy and some reproductive parameters associated with domestication. To test this hypothesis, we characterized the floral morphology and some reproductive parameters of weedy plants (wild plants), landraces (semi-domesticated plant), and commercial plants (domesticated plants). We conducted an artificial crossing experiment, germinated the seeds, and recorded seedling growth. Commercial plants had the largest flowers and the highest number of ovules. Yet, they did not differ in other reproductive parameters (e.g., herkogamy, size of pollen grains, stigmatic area, and pollen:ovule ratio) from landraces and weedy plants. Physalis philadelphica produced fruits by autonomous autogamy in the artificial crossing experiment. These fruits were the smallest and lightest fruits at all degrees of domestication; however, fruit set of autonomous autogamy was higher in weedy plants. In addition, fruit production was higher when weedy plants donated pollen to commercial plants. Although seeds produced by autonomous autogamy of weedy plants had a low germination percentage, their cotyledons and the embryonic foliage leaves appeared earlier than in landraces and commercial plants. In conclusion, the domestication syndrome in this plant was manifested as increments in flower size and ovule production. Contrary to expectations, there was higher fruit production by autonomous autogamy in weedy plants than in cultivated plants. It seems that artificial selection in P. philadelphica favors self-incompatibility in cultivated plants. Nonetheless, spontaneous self-pollination seems to be advantageous in weedy populations because they produced viable seeds from which cotyledons and the embryonic foliage leaves emerged earlier than in cultivated plants.

Standard and biochemical toxicological effects of zinc pyrithione in Daphnia magna and Daphnia longispina

Chemical toxicity in the environment may be the consequence of exposure of living organisms to multiple substances, with distinct putative effects. Among this mulytiplicity of chemicals that occur in the wild, pharmaceutical drugs and antifoulers are prone to exert toxic effects on non-target organisms. To characterize the toxicity elicited by a compound of this specific class, the present study used standard and biochemical-based tools to quantify the toxic response of the antifouler and antidandruff zinc pyrithione in Daphnia magna and Daphnia longispina. The analised parameters were immobility, reproduction, behavioral alteration (swimming patterns), anti-oxidant defense (catalase activity), metabolism (GSTs activities), and neurotoxicity (ChE activity) after exposure to sublethal concentrations of this drug. Exposure to zinc pyrithione has been shown to have neurotoxic and oxidative effects, with changes in swimming behavior. There were no changes in reproductive traits of exposed individuals, from both species. The obtained data demonstrate that ecologically relevant levels of zinc pyrithione can deleteriously alter critical parameters in two distinct freshwater microcrustacean species, although with distinct toxicity patterns and outcomes.

Shifts in Reproductive Investment in Response to Competitors Lower Male Reproductive Success.

AbstractIn many species, males exhibit phenotypic plasticity in sexually selected traits when exposed to social cues about the intensity of sexual competition. To date, however, few studies have tested how this plasticity affects male reproductive success. We initially tested whether male mosquitofish, Gambusia holbrooki (Poeciliidae), change their investment in traits under pre- and postcopulatory sexual selection depending on the social environment. For a full spermatogenesis cycle, focal males were exposed to visual and chemical cues of rivals that were either present (competitive treatment) or absent (control). Males from the competitive treatment had significantly slower-swimming sperm but did not differ in sperm count from control males. When two males competed for a female, competitive treatment males also made significantly fewer copulation attempts and courtship displays than control males. Further, paternity analysis of 708 offspring from 148 potential sires, testing whether these changes in reproductive traits affected male reproductive success, showed that males previously exposed to cues about the presence of rivals sired significantly fewer offspring when competing with a control male. We discuss several possible explanations for these unusual findings.

NRDR inhibits estradiol synthesis and is associated with changes in reproductive traits in pigs.

Cumulus cells secreting steroid hormones have important functions in oocyte development. Several members of the short‐chain dehydrogenase/reductase (SDR) family are critical to the biosynthesis of steroid hormones. NADPH‐dependent retinol dehydrogenase/reductase ( NRDR), a member of the SDR superfamily, is overexpressed in pig breeds that also show high levels of androstenone. However, the potential functions and regulatory mechanisms of NRDR in pig ovaries have not been reported to date. The present study demonstrated that NRDR is highly expressed in pig ovaries and is specifically located in cumulus granulosa cells. Functional studies showed that NRDR inhibition increased estradiol synthesis. Both pregnant mare serum gonadotropin and human chorionic gonadotropin downregulated the expression of NRDR in pig cumulus granulosa cells. When the relationship between reproductive traits and single‐nucleotide polymorphisms (SNPs) of the NRDR gene was examined, we found that two SNPs affected reproductive traits. SNP rs701332503 was significantly associated with a decrease in the total number of piglets born during multiparity, and rs326982309 was significantly associated with an increase in the average birth weight during primiparity. Thus, NRDR has an important role in steroid hormone biosynthesis in cumulus granulosa cells, and NRDR SNPs are associated with changes in porcine reproduction traits.

Competitive ability of Capsella species with different mating systems and ploidy levels.

Capsella is a model genus for studying the transition from outcrossing to selfing, with or without change in ploidy levels. The genomic consequences and changes in reproductive traits (selfing syndrome) associated with these shifts have been studied in depth. However, potential ecological divergence among species of the genus has not been determined. Among ecological traits, competitive ability could be relevant for selfing evolution, as selfing has been shown to be statistically associated with reduced competitiveness in a recent meta-analysis. We assessed the effect of competition on three Capsella species differing in their mating system and ploidy level. We used an experimental design where fitness related traits were measured in focal individuals with and without competitors. The diploid selfer (C. rubella) was most sensitive to competition, whereas the tetraploid selfer (C. bursa-pastoris) performed the best, with the diploid outcrosser (C. grandiflora) being intermediate. These results add to the detailed characterization of Capsella species and highlight the possible roles of ecological context and ploidy in the evolutionary trajectories of selfing species.

Seasonal changes in reproductive traits and paternity in the Japanese pygmy squid Idiosepius paradoxus

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 582:121-131 (2017) - DOI: https://doi.org/10.3354/meps12338 Seasonal changes in reproductive traits and paternity in the Japanese pygmy squid Idiosepius paradoxus Noriyosi Sato1,2,* 1Graduate School of Fisheries Science and Environmental Studies, Nagasaki University, Nagasaki, Japan 2Present address: Oki Marine Biological Station, Shimane University, Shimane, Japan *Corresponding author: norico3000@gmail.com ABSTRACT: Sperm production in males and sperm storage in females can change over an individual’s reproductive timespan. This implies that the strength of sperm competition may also change with time. The seasonal pattern of reproductive traits and paternity in the Japanese pygmy squid, which has 2 life-history types (large and small types having long and short reproductive periods, respectively), were compared among 3 reproductive periods: early and late reproductive period of the large type and middle reproductive period of the small type. Although the gonad somatic index (GSI) decreased during one of the reproductive periods in males, the number of spermatophores and the spermatophoric complex somatic index (SCSI) increased. The GSI was higher in large-type males, whereas the SCSI was higher in the small type. Multiple paternity was detected in all egg masses, and on average about 10 males were estimated to be sires in a single egg mass. Paternity numbers differed significantly between life-history types, whereas there were no significant differences between the early and late reproductive periods in the large type. These results imply that the Japanese pygmy squid is polyandrous and exposed to a very high level of sperm competition risk. Paternity numbers did not change during reproductive periods even when the reproductive traits changed between these periods. Seasonal changes in reproductive traits may have a minor effect on paternity in promiscuous animals. However, 2 life-history strategies were observed: large-type males, invested in transferring more sperm to one female, and small-type males that stored more spermatophores to copulate with many females. KEY WORDS: Cephalopod · Microsatellites · Parentage · Multiple paternity · Seasonal change Full text in pdf format PreviousNextCite this article as: Sato N (2017) Seasonal changes in reproductive traits and paternity in the Japanese pygmy squid Idiosepius paradoxus. Mar Ecol Prog Ser 582:121-131. https://doi.org/10.3354/meps12338 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 582. Online publication date: November 06, 2017 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2017 Inter-Research.

Reproductive traits and evolutionary divergence between Mediterranean crops and their wild relatives.

Changes in reproductive traits associated with domestication critically determine the evolutionary divergence between crops and their wild relatives, as well as the potential of crop plants to become feral. In this review, we examine the genetic mechanisms of plant domestication and the different types of selection involved, and describe the particularities of domestication of Mediterranean field crops with regard to their reproductive traits, showing illustrative examples. We also explore gene flow patterns between Mediterranean field crops and their wild relatives, along with their ecological, evolutionary and economic implications. Domestication entails multiple selective processes, including direct selection, environmental adaptation and developmental constraints. In contrast to clonal propagation in perennials, sexual reproduction and seed propagation in annuals and biennials have led to a distinct pathway of evolution of reproductive traits. Thus, the initial domestication and further breeding of Mediterranean field crops has brought about changes in reproductive traits, such as higher mean values and variance of seed and fruit sizes, reduced fruit and seed toxicity, non-shattering seeds and loss of seed dormancy. Evolution under domestication is not a linear process, and bi-directional gene flow between wild and crop taxa is a frequent phenomenon. Thus, hybridisation and introgression have played a very important role in determining the genetics of current cultivars. In turn, gene flow from crops to wild relatives can lead to introgression of crop genes into wild populations and potentially alter the characteristics of natural communities. In conclusion, plant evolution under domestication has not only changed the reproductive biology of cultivated taxa, its effects are multifaceted and have implications beyond agriculture.

Expression of Melatonin Receptor Subtype Genes and its Impact on Reproductive Traits in Japanese Quail in Different Lighting Systems

Melatonin receptors are G-protein coupled receptors which mediate the action of melatonin hormone. In this study, we investigated the effects of two different lighting systems, 23 h L: 1 h D (group I) and 12 h L: 12 h D (group II), on reproductive traits in Japanese Quail ( Coturnix coturnix japonica). As well as the expression pattern of three melatonin receptor subtypes, mRNA in ovaries and testes were analysed using quantitative real time PCR. The results revealed the expression of all three subtypes of melatonin receptors (MNTR1A, MNTR1B and MNTR1C) in ovaries and MNTR1B, MNTR1C in testes in both groups. Further, the expression of melatonin receptors was significantly higher in group II relative to group I. The fold change level of MNTR1C was 6.7 in ovaries and 3.1 in testes in short day light. Altered expression pattern of these genes associated with changes in Japanese Quail reproductive traits, while, Japanese Quail exposed to long day light started egg laying earlier than those in short day light. Egg weight and egg percentage increased significantly in group I compared to group II. The average of relative ovary and testis weight at six weeks of age were declined by 1.72 and 1.64 g, respectively, in group II. It was concluded that, different lighting system induced different expression levels of melatonin receptor genes accompanied with changes in reproductive traits in both sex of Japanese Quail.

Invasion Fosters Change: Independent Evolutionary Shifts in Reproductive Traits after Oxalis pes-caprae L. Introduction.

Biological invasions offer optimal scenarios to study evolutionary changes under contemporary timescales. After long-distance dispersal, exotic species have to cope with strong mate limitation, and shifts toward uniparental reproduction have been hypothesized to be selectively advantageous. Oxalis pes-caprae is a clonal tristylous species native to South Africa, and invasive in Mediterranean regions worldwide. It reproduces sexually and asexually but the importance of each strategy differs between ranges. Native populations reproduce mostly sexually while in invasive ones asexual reproduction is the prevailing strategy due to the dominance of pentaploid monomorphic populations. Nevertheless, two contrasting scenarios have been observed after introduction: transition toward clonality, and re-acquisition of sexuality fueled by multiple introductions of compatible mates. Here, we aimed to assess evolutionary changes of reproductive traits in O. pes-caprae invasive populations and evaluate whether these traits could be related with invasion success and prevalence of certain forms in the western Mediterranean basin. Sexual and asexual reproduction traits were quantified under optimal conditions in a common garden experiment including native and invasive sexual, predominately asexual, and obligated asexual individuals. Different reproductive, ecological, and genetic constraints created by long-distance dispersal seem to have generated different selective pressures in sexual and asexual traits, with our results supporting evolutionary changes in invasive populations of O. pes-caprae. Native plants had higher sexual fitness, while a transition toward clonality was clear for invasive forms, supporting clonal reproduction as a major trait driving invasion. Differences were also observed among invasive plants, with sexual forms having increased dispersal potential; thus, they are expected to be in advantage in comparison with predominantly asexual and obligated asexual plants, and may become widespread in the future. Historical processes, like the initial introduction of predominantly asexual forms followed by sexual forms more recently, could be in the origin of current distribution patterns of O. pes-caprae in the western Mediterranean. This study shows that invasion processes are very dynamic and that ecological and genetic constraints determined by the invasion process may originate different reproductive strategies that are likely to determine invasion success.

Functional diversity of reproductive traits increases across succession in the Atlantic forest

Abstract Niche and neutral processes shape community assembly with a possible shift of niche and neutral importance in communities undergoing temporal changes during succession. Functional diversity helps to discriminate assembly processes since trait distribution is dependent on those processes. We evaluated the changes in reproductive traits related to pollination and seed dispersal in a successional gradient in an Atlantic Forest area, Southern Brazil. We surveyed forests undergoing regeneration varying in age from 2 to 80 years after pasture abandonment. We expected an increase in functional diversity of reproductive traits and a greater role of limiting similarity across succession. Abiotic and mixed pollination systems, dioecious sexual system, biotic dispersed, many-seeded and small-seeded species decreased as the forest got older. Conversely, bee-pollinated, bell-shaped, small and androgynous flowers increased across forest succession as well biotic dispersed and large-seeded species. Functional richness and functional dispersion were higher in older forests. Changes in functional diversity were positively related to species richness, indicating that species enrichment in older forests added new sets of reproductive traits. These changes in trait distribution and functional diversity across succession in the Atlantic Forest suggest an increased role of biotic interactions and limiting similarity process structuring plant assemblages of second-growth tropical forests.

Reproductive performance of Ile de France ewes under dietary supplementation before and during the breeding season

The aim of this study was to evaluate the reproductive performance of Ile de France ewes undergoing dietary supplementation before and during the breeding season, with and without association with management conditions (pre-mating shearing). Thirty-six ewes with an average body weight of 66 kg were used in the experiment. Treatments involved ewes receiving or not receiving concentrate supplementation (flushing), with groups subdivided according to the management condition to which animals were subjected: shearing or lack of it. Thus, ewes were divided into four treatments: flushed and shorn; flushed and unshorn; unflushed and shorn; and unflushed and unshorn. Flushing increased weight gain and body condition score, and when associated with shearing, it promoted anticipation of estrus. Fertility rate (86.05%), calving rate (77.77%), birth rate (113.83%), and type of birth (single: 82.29% and twin: 17.71%) were not influenced. Birth weight (3.96 kg) and prolificacy (1.25%) also were not affected. Despite the lack of changes in reproductive traits, flushing adopted during the breeding season associated with shearing anticipated estrus in ewes.