The dietary habits of fruit flies profoundly influence their fitness, morphology, and physiology yet the mechanisms underlying these effects remain incompletely understood. To address this gap, the relationship between dietary regimens and the composition and function of adult Drosophila melanogaster microbiota was investigated in the present study. The adult fly microbiota communities that were reared for long time on five different diets were characterized by means of 16S rRNA sequencing. Obtained results revealed distinct community structures associated with each dietary regimen, which was additionally corroborated through machine learning-based analysis. In general, sugar-rich diets correlate with microbial ecosystems of higher richness/diversity. Dominance of the phyla Proteobacteria and Firmicutes in the microbiota was confirmed irrespective of diet, with the varying proportions of the most abundant families: Acetobacteraceae, Lactobacillaceae, Moraxellaceae, Bradyrhizobiaceae, and Leucostonocaceae. Bacterial families of lower abundance also emerged as differentially present among the studied fly groups. Additionally, functional prediction provided initial clues into how nutrient availability might modulate the metabolic traits of adult fly microbiota in a sex-specific manner to meet host metabolic needs. Overall, the presented findings highlight the intricate interplay between diet, microbiota composition, and host phenotype in fruit flies, underscoring the importance of diet as a determinant of host-microbiota interactions.

Fragile X syndrome (FXS) is a global neurodevelopmental disorder caused by the expansion of CGG trinucleotide repeats (≥200) in the Fragile X Messenger Ribonucleoprotein 1 (FMR1) gene. FXS is the hallmark of Fragile X-associated disorders (FXD) and the most common monogenic cause of inherited intellectual disability and autism spectrum disorder. There are several animal models used to study FXS. In the FXS model of Drosophila, the only ortholog of FMR1, dfmr1, is mutated so that its protein is missing. This model has several relevant phenotypes, including defects in the circadian output pathway, sleep problems, memory deficits in the conditioned courtship and olfactory conditioning paradigms, deficits in social interaction, and deficits in neuronal development. In addition to FXS, a model of another FXD, Fragile X-associated tremor/ataxia syndrome (FXTAS), has also been established in Drosophila. This review summarizes many years of research on FXD in Drosophila models.

Although morphological variation may have an effect on behaviour, there are only a few studies on julid millipedes in which the influence of the variability of some morphological traits on mating success has been explored. Hence, objectives of this study were to investigate mating behaviour in laboratory conditions and identify traits that could possibly be the target of pre-copulatory selection in the julid species Megaphyllum unilineatum. Behavioural sequences were quantified in three types of tests: a mating arena test, a female choice test, and a male choice test. Although the number of contacts with the first chosen partner (from the mating arena test) was greater than with newly offered individuals in choice tests, values of the sexual selection coefficient did not statistically confirm this preference. In addition, analyses of linear measurements (trunk height and width, length of the whole body, antennae, walking legs, and gonopod flagella) in individuals of different mating status were also conducted, as well as geometric morphometric analyses of size and shape of the antennae, heads, walking legs, and gonopod promeres and opisthomeres in such individuals. Antennal length and shape, head shape, and the walking legs shape, differed significantly, depending on the mating status of females. In males of different mating status, statistical significance was established only in the promere centroid size. The differences in certain behavioural sequences in M. unilineatum are similar to those previously reported in M. bosniense, while such similarity is not detected with respect to morphological variation in the mentioned species.

In the world of complex smells in natural environment, feeding and mating represent two important olfactory-guided behaviors in Drosophila melanogaster (Diptera: Drosophilidae). Diet affects the chemoprofile composition of the individuals, which, indirectly, may significantly affect their mating success. In this study, chemoprofiles of recently mated flies belonging to four D. melanogaster strains, which were fed for many generations on different substrates (standard cornmeal-S strain; banana-B strain; carrot-C strain; tomato-T strain) were identified and quantified. In total, 67 chemical compounds were identified: 48 compounds were extracted from males maintained on banana and carrot, and 47 compounds from males maintained on cornmeal and tomato substrates, while total of 60 compounds were identified in females from all strains. The strains and the sexes significantly differed in qualitative nature of their chemoprofiles after mating. Significant differences in the relative amount of three major male pheromones (cis-vaccenyl acetate-cVA, (Z)-7-pentacosene, and (Z)-7-tricosene) and in female pheromone (Z,Z)-7,11-nonacosadiene among strains were also recorded. Furthermore, multivariate analysis of variance (MANOVA) pointed to significant differences between virgin and mated individuals of all strains and within both sexes. Differences in some of the well known sex pheromones were also identified when comparing their relative amount before and after mating. The presence of typical male pheromones in females, and vice versa may indicate their bidirectional transfer during copulation. Our results confirm significant effect of mating status on cuticular hydrocarbon (CHC) phenotypes in differently fed D. melanogaster flies.

Courtship in Drosophila involves exchange of chemosensory, auditory, tactile and visual signals. Differences in courtship signals are strongly influenced by environmental factors, among which nutrition plays one of the more important roles. Through influence on development, morphology, physiology and behaviour, nutrition may affect both sexual selection and isolation. However, the impact of specific nutritive regimes on male mating success has not been extensively studied. Therefore, the aim of this study was to explore how diets affect male attractiveness via changes in wing morphology during long-term rearing of flies on different diets. Through a series of female choice tests, we investigated the mating success of males reared on five different diets for more than 350 generations. Further, we analysed wing size and wing shape of mated and unmated males to link wing morphology with mating success. The results demonstrate significant differences in male mating success between strains. We also found significant differences in wing size between the strains and established that female choice is positively correlated with male wing size, that is, females of all strains preferred males with larger wings. In addition, we noted a significant difference in wing shape between the strains, as well as between mated and unmated males. Our results indicated that among strains, males with elongated wings were more successful in mating than males with rounded wings. Within strains, mated males had more elongated wings than unmated ones, which had more rounded wings. Our results support the hypothesis that nutrition represents an important environmental factor that may affect male attractiveness via changes in wing morphology, thereby playing an important role in sexual selection of Drosophila melanogaster. (C) 2020 The Association for the Study of Animal Behaviour. Published by Elsevier Ltd. All rights reserved.

Covariation of multiple morphological traits and modularity have been widely studied in the field of evolutionary developmental biology. Subunits of a morphological structure can evolve separately from each other in a modular fashion. The aims of our study therefore were: i) to test the hypothesis of modularity in the dorsal part of the head capsule and the gnathochilarium separately during late postembryogenesis in the julidan millipede Megaphyllum unilineatum (C. L. Koch, 1838) using geometric morphometrics; and ii) to investigate the influence of allometry on overall morphological integration in the dorsal part of the head capsule and the gnathochilarium in the mentioned species. Individuals from different ontogenetic stadia (stadium VI - stadium XI) were included in the analyses. Significant influence of fluctuating asymmetry on the dorsal part of the head capsule shape was detected by Procrustes ANOVA. Regressions were significant for the symmetric component of both analysed morphological traits, while non-significant regression was detected for the asymmetric component of the head capsule's dorsal part. Hypotheses of modularity for the dorsal part of the head capsule and the gnathochilarium are rejected because our results indicate that a small proportion of alternate partitions has higher covariation between subsets of structure than between the hypothesized modules. Contrary to our expectations, results of the present study show that allometry does not increase the level of morphological integration in the dorsal part of the head capsule and the gnathochilarium in M. unilineatum. Based on the obtained results, we conclude that the dorsal part of the head capsule and the gnathochilarium are not composed of independent modules and that in the case of the capsule's dorsal part, developmental processes affect morphological integration in different ways at different levels of shape variation.

: Covariation of multiple parts of morphological traits (referred as morphological integration) in combination with investigation about the presence of subunites (modules), and level of integration both within and between themselves (referred as modularity), have been studied in great number of animals. The presence of modularity may have an impact on both development and evolution of the species, because separate module may develop and evolve in a separate and different way. The aim of our study was to test the hypothesis that the distal region of the head capsule is a module in millipede Megaphyllum bosniense (Verhoeff, 1897) using geometric morphometrics. Millipede samples were collected from population inhabiting Mt. Avala (near Belgrade, Serbia). Several different programs were used: MakeFan, TpsDig, CoordGen, MorphoJ, and R program. Allometry was significant for the asymmetric component (FA), so further analyses were conducted on residual values of FA. Modularity hypothesis is accepted, because our results indicated that covariance coefficients (RV) for FA had lower values than 92.86% of other RV coefficients obtained by a random contiguous partition of dorsal part of the head capsule. The scaled variance of the eigenvalues of the FA (EV) was significantly lower after than before allometry removal. Considering obtained results, distal and proximal regions of the head capsule develop and function as separate modules, which indicate that mentioned structures have different developmental pathways and functions in this julidan species.

Foraging behavior in animals is based on the interaction among different factors, such as their nutritional requirements, satiety, reproductive state, food composition and presence of various chemicals in the immediate environment. Food preference depends on complex interactions between environmental and physiological cues, and is affected by sensory experience and metabolism during lifespan. In fruit flies, olfaction is considered as one of the main mechanisms used in detection of environmental cues and further behavior adjustment, including food choice. In this work, preference for a particular food in Drosophila melanogaster reared on standard cornmeal substrate was investigated. Virgin males and females were tested individually and in the groups, separated by sex, for food choice. Starving flies had the opportunity to choose between standard cornmeal, tomato, banana, carrot and apple substrates, for one hour. Food choice was monitored in transparent plastic boxes (dimensions: 220 × 140 × 90 mm), containing five Petri dishes (30 mm in diameter), filled with five above mentioned substrates. Males and females did not significantly differ in food choice, both when tested individually or in groups. However, flies chose standard cornmeal, tomato and banana substrates significantly more often than carrot and apple substrates. We previously determined that apple substrate had the lowest quality. Since flies live, eat, mate and lay eggs on fruits and vegetables, avoiding low-quality food has certain advantages in fitness components.

Until now, morphological trait variation has been investigated in several millipede species using geometric morphometrics. The present study is the first attempt to explore sexual shape and size dimorphism (SShD and SSD) of morphological structures in Polydesmida. We here analyse antennal, head, and leg SShD and SSD in Brachydesmus troglobius Daday, 1889. Our results show that SSD exists in all of the analysed structures, while SShD is present only in the legs. In comparison with females, males possess longer and wider legs, as well as longer antennae and a shorter head. Contrary to previous findings in some Julida, in B. troglobiusSSD of the antennae and legs varies more than SShD in these morphological structures.

Sexual size and shape dimorphism (SSD and SShD) are understudied phenomena in millipedes. In the present study, we investigated both kinds of sexual dimorphism in some morphological traits, as well as whether shape of the morphological traits varied more than their size. Three julidan species, viz., Pachyiulus hungaricus (Karsch, 1881), Megaphyllum unilineatum (C.L. Koch, 1838), and M. bosniense (Verhoeff, 1897), were used for these purposes. By means of traditional and geometric morphometrics, we found that SSD exists in linear measurements of the tested morphological traits, as well as SShD of the legs in all analysed species. Also, SSD of antennal centroid size was detected in P. hungaricus and M. unilineatum , in addition to SShD of antennae in P. hungaricus and M. bosniense . Our results indicate that morphological intersexual differences are species-specific and that the shape of some morphological traits varies more than the size of centroids of the same structures.

It is now widely accepted that bioactive compounds of fruits and vegetables reduce oxidative stress, thus having the beneficial effect of decreasing the risk of many human diseases. The aim of this in vivo study was to evaluate the possible protective effects of Aronia melanocarpa (Michx) Elliott fruit extract using Drosophila melanogaster Meigen, 1830 larvae. Study was done in the year 2016, in Department of Genetics of Populations and Ecogenotoxicology at the Institute for Biological Research, University of Belgrade. Simultaneously with treatments, co-treatments with the same concentrations of black chokeberry fruit extract mixed with a methyl methanesulfonate (MMS) were performed. Fitness traits and morphological characters were monitored. Flies fed on undiluted fruit extract, on MMS + undiluted fruit extract and on MMS, exhibited a prolonged developmental time, lower viability and negatively-impacted wing development. Positive biological effects were observed in flies that developed on substrates with 2 and 25% A. melanocarpa extract. Only a mixture of MMS + 25% fruit extract showed positive effects on both fitness components and wing development in comparison with other MMS co-treatments, indicating the ability of this concentration to protect the cells from MMS-induced damage.

Sexual selection can be a major driving force that favours morphological evolution at the intraspecific level. According to the sexual selection theory, morphological variation may accompany non-random mating or fertilization. Here both variation of linear measurements and variation in the shape of certain structures can significantly influence mate choice in different organisms. In the present work, we quantified sexual behaviour of the millipede Megaphyllum bosniense (Verhoeff, 1897) as characterized by several sequences. These are: mating latency, duration of copulation, contact to copulation time, duration of contact without copulation, time from entrance (time-point when individuals were placed in boxes in which tests occurred) to contact with copulation, and time from entrance to contact without copulation. Further, we analysed the influence of morphological variation (both variation of linear measurements and variation in the shape of several structures) on mating success. Variation of body length, antennal length, length of the walking legs, trunk width, and trunk height was analysed by traditional morphometrics, while variation in size and shape of the antennae, walking legs, head, and gonopods (promeres, opisthomeres) was analysed using geometric morphometrics. More than half of all physical contacts detected among the millipedes resulted in copulation. Based on the value of sexual selection coefficients, preferences toward the previous partner were found to be prevalent in both female and male choice tests. Individuals with different mating status significantly differed in some morphological traits (body mass, head centroid size, head shape, and promere shape). Our study yielded new information about the sexual behaviour of millipedes and variation of morphological traits as a potential basis for mate preferences.

In recent years, it is widely accepted that bioactive compounds of fruits and vegetables are related to reduction of oxidative stress, thus having the beneficial effect of decreasing the risk of many human diseases. The aim of the present study was to evaluate the possible protective effects of Aronia melanocarpa fruit extract. This in vivo study was conducted using fruit fly (Drosphila melanogaster) larvae. Simultaneously with treatments, co-treatments with the same concentrations of aronia fruit extract mixed with a strong mutagen, methyl methanesulphonate (MMS), were performed. Fitness traits and morphological characters were monitored. Positive biological effects were observed in flies that developed on substrates with 2% and 25% A. melanocarpa extract. Only a mixture of MMS+25% fruit extract showed preferable effects both on fitness components and on wing development in comparison with other MMS co-treatments, indicating the ability of this concentration to protect the cells from MMS-induced damage.

We interviewed more than 400 primary school pupils from 5th to the 8th grade (aged 11 to 14 years) from the primary school in Belgrade (Serbia) about their habits concerning nutrition, beverage consumption, and time spend in front of a computer, tablet, playing games on consoles, or using a mobile phone. According to the study, a high percentage of students showed a well-established habit of eating breakfast. Also, the overall water consumption prevailed in all grades, since the school ensures students access to safe and free drinking water, as a healthy alternative to consumption of sugar-sweetened beverages. However, we found increasing food consumption from bakery and consumption of carbonated drinks both in boys and girls from senior grades (7th and 8th). Also, they spent considerably more time with a computer, tablet, or mobile phone than the pupils from lower grades. About one-third of all surveyed students have been watching television or using a computer more than 3 hours during the day. We found a significant increase of BMI, as an indicator of the increasing risk of weight gain and obesity both in boys and girls in senior grades. In the current curriculum of Biology, the topic of human health is studied in the 7th grade, but presented results show that one-year education in health topics is not sufficient. It suggests the necessity of introducing the topic of health in all grades of elementary school, starting from the lowest age.

Although millipedes (Diplopoda) represent one of the most diverse classes of arthropods, data concerning details of their mating behaviour are very scarce. In this work, we explored mating behaviour of the European millipede Pachyiulus hungaricus under laboratory conditions, and its relationship with the size and shape of certain morphological traits. We conducted 3 types of behavioural tests: a mating arena test, a female choice test, and a male choice test. Premating behaviour was "sequenced" in 5 behavioural steps and, together with the duration of copulation, scored in all mating assays. Males were the more active sex in searching for mates, while females were the "choosier" sex. Furthermore, in the choice tests, previous mating partners had significantly more copulations than new ones, thus raising questions about postcopulatory sexual selection in this species. On the other hand, our results indicate that size and/or shape of the tested morphological traits, except for the shape of the male walking legs, were not subject to precopulatory sexual selection. Other sensory domains known to influence courtship behaviour need to be investigated in this regard in P. hungaricus.

In Serbia, Branchipus Schaeffer, 1766 is especially common in the Pannonian lowlands, where Branchipus schaefferi and Branchipus serbicus were previously reported. In the southern parts of the country, at the foothills of the Stara Planina Mountains, a Branchipus intermedius population is reported to occur. We used multivariate analysis to assess the degree of morphological variability between Branchipus populations currently ascribed to different species. Morphometric characters contributed the most to the morphological differentiation. Populations were better defined on the basis of male morphometric characters. Our results indicate that individuals from the southeastern, mountainous part of the country had the highest level of differentiation. We confirmed that this population belongs to B. intermedius. The individuals of the presumed species B. serbicus exhibited a fairly lower level of morphological differentiation in the present study, and grouped together with other lowland Serbian populations ascribed to B. schaefferi. According to this study, B. serbicus is a junior synonym of B. schaefferi.

Male genital morphology of six populations of Branchipus schaefferi from different locations in Serbia is described. Both qualitative and quantitative morphological traits were taken into consideration. The majority of males from lowland parts of the country (Pannonian Plane) had a long sickle-curved or arched spine situated on the basal part of the penis. Males sampled in the south-eastern part of the country (the region of Stara Planina Mountains) possessed short, straight or slightly bowed basal spine. A distal penile part appeared as a more stable character than the proximal one. Males from one of the examined populations possessed roundish and spineless penile tip, a feature heretofore not described in B. schaefferi.

Evolution of reproductive isolation may be a consequence of a variety of signals used in courtship and mate preferences. Pheromones play an important role in both sexual selection and sexual isolation. The abundance of pheromones in Drosophila melanogaster may depend on different environmental factors, including diet. The aim of this study was to ascertain to which degree principal pheromones affect sexual selection in D. melanogaster. We used D. melanogaster strains reared for 14 years on four substrates: standard cornmeal substrate and those containing tomato, banana and carrot. We have previously determined that long-term maintaining of these dietary strains resulted in differences in their cuticular hydrocarbons profile (CHs). In this work, we have tested the level of sexual selection and sexual isolation between aforementioned strains. We found that the high levels of cis-vaccenyl acetate, 7-pentacosene and 7,11-nonacosadiene in the strain reared on a substrate containing carrot affected the individual attractiveness and influenced sexual isolation between flies of this strain and flies reared on a substrate containing banana. Based on these results, long-term different diets, may contribute, to sexual behaviour of D. melanogaster via the effects of principal pheromones.