Use of Anthropogenic Nest Materials by Black-crested Titmice Along an Urban Gradient

Numerous avian species use anthropogenic materials in constructing nests, particularly in urbanized environments. Anthropogenic materials, including plastics, have been demonstrated to have both beneficial and harmful effects on survival and reproduction. During the spring of 2018, we collected 45 Black-crested Titmouse Baeolophus atricristatus nests in San Marcos, TX, U.S. with two objectives: 1) assess and compare the mass and proportion of nest materials along an urban gradient, and 2) examine the relationship between nest materials, clutch size, and hatching success. We categorized each nest based on collection location as either urban, residential, park or rural and separated nest materials into six categories: leaves, snakeskin, twigs, moss, plastic, and non-plastic artificial materials. We then compared raw mass and proportion of mass of each nest material among urbanization categories. Nests in the urban category were 1.6-1.9 times lighter in mass than nests in other locations along the urban gradient (p = 0.01) and contained 4-5 times greater proportion, but not mass, of plastic compared to nests in all other locations. Nests in residential areas contained the greatest mass of combined anthropogenic materials. Neither clutch size nor hatching success differed based on urbanization category, nest mass, or proportions of anthropogenic or natural nest materials. The differences in mass of nests and increased proportion of plastics could have been due to a lack of natural nesting materials however, we did not estimate availability of nesting materials at any location. Results add to the growing literature that the use of anthropogenic materials in nests varies across an urban gradient, and the effect of anthropogenic materials on nesting parameters varies among species.

Reciprocal altruism may have evolved by accident

The most accepted explanation for the evolution of reciprocal altruism is based on cooperative reciprocators engaged in intertemporal choice. Here, we parsimoniously dismiss this narrative and suggest a new hypothesis based on random encounters of selfish individuals that result in theft. Theft can coexist with passive reactions on the victims, as it does not jeopardize survival and reproduction in times of abundance. As a result, offspring with psychological adaptations of not reacting to theft can become reliable reciprocators amid scarcity.

Astroglial CD38 regulates social memory and synapse formation through SPARCL1 in the medial prefrontal cortex

Social behavior is essential for the health, survival and reproduction of animals, yet the role of astrocytes in social behavior is largely unknown. CD38 is critical for social behaviors by regulating oxytocin release from hypothalamic neurons. On the other hand, CD38 is most abundantly expressed in astrocytes especially in the postnatal cortex, and is important for astroglial development. Here, we demonstrate that astroglial CD38 plays a pivotal role in the social behavior. Selective deletion of CD38 in postnatal astrocytes, but not in adult astrocytes, specifically impaired social memory without any other behavioral abnormalities. Morphological analysis revealed reductions in spine numbers, mature spines and excitatory synapse numbers in the pyramidal neurons of the medial prefrontal cortex (mPFC) due to deletion of astroglial CD38 in the postnatal brain. Astrocyte-conditioned medium (ACM) of CD38 KO astrocytes reduced synaptogenesis of cortical neurons by reducing extracellular SPARCL1, a synaptogenic protein. Finally, the release of SPARCL1 from astrocytes is regulated by CD38/cADPR/calcium signaling. Our data indicate that astroglial CD38 developmentally regulates social memory and neural circuit formation in the developing brain by promoting synaptogenesis through SPARCL1.

Pollinators: Their Relevance in Conservation and Sustainable Agro-Ecosystem

Survival and reproduction of several wild plants and crops is mostly by insects pollinator, their recognition and importance have been increased in this climatic changing scenario, which affects the various aspects of their life cycle. According to an estimate, approximately 30,000 species of bees are known in entomology, and about 190 species of bees have been reported to be associated with pollination. There can be an established link between seed production and pollinator diversity, for the plants with a generalist pollination system. The increasing of human habitation affects insect pollinators in various ways, i.e. of habitat destruction, results in low availability of food sources, nesting, oviposition, resting, and mating sites. Pollinator availability restraints the geographical distribution of plant species, i.e. to develop an ecological niche of certain plant species. Failure of pollinator- plant interaction mutualism results in lower seed production and sometimes extirpation of plant population has been recorded. The declining pollinators’ population strengthens existing plant-pollinator interaction or allows new pant pollinator interaction to form. Maintaining the commercial and wild pollinator populations and preventing future shortages of pollination services, therefore, is extremely significant.

Blame It on Sex

This chapter addresses the ultimate driver of competition—sexual selection, the root biological force generating inequality. Like other animals, humans must solve the ecological problems necessary for survival and reproduction. Everyone exists only because their ancestors were successful in doing just that. They were the most successfully competitive in using the resources available in their environments to survive and reproduce. As humans have culturally evolved, what has enabled humans to stand out in their competition for mates has varied according to the prevailing politically determined social institutions. These institutions set the incentive structure, providing guidance as to what kinds of behavior gain high status. High status is sexually attractive. Over history, the sources of status have varied. Individuals have achieved high status by being the best hunters and gatherers, the best warriors, the most cooperative, the most generous, and, since the rise of the state, the wealthiest and most politically powerful.

Drosophila Lysophospholipase Gene swiss cheese Is Required for Survival and Reproduction

Drosophila melanogaster is one of the most famous insects in biological research. It is widely used to analyse functions of different genes. The phosphatidylcholine lysophospholipase gene swiss cheese was initially shown to be important in the fruit fly nervous system. However, the role of this gene in non-nervous cell types has not been elucidated yet, and the evolutional explanation for the conservation of its function remains elusive. In this study, we analyse expression pattern and some aspects of the role of the swiss cheese gene in the fitness of Drosophila melanogaster. We describe the spatiotemporal expression of swiss cheese throughout the fly development and analyse the survival and productivity of swiss cheese mutants. We found swiss cheese to be expressed in salivary glands, midgut, Malpighian tubes, adipocytes, and male reproductive system. Dysfunction of swiss cheese results in severe pupae and imago lethality and decline of fertility, which is impressive in males. The latter is accompanied with abnormalities of male locomotor activity and courtship behaviour, accumulation of lipid droplets in testis cyst cells and decrease in spermatozoa motility. These results suggest that normal swiss cheese is important for Drosophila melanogaster fitness due to its necessity for both specimen survival and their reproductive success.

Drosulfakinin signaling modulates female sexual receptivity in Drosophila

Female sexual behavior as an innate behavior is of prominent biological importance for survival and reproduction. However, molecular and circuit mechanisms underlying female sexual behavior is not well understood. Here, we identify the Cholecystokinin-like peptide Drosulfakinin (DSK) promotes female sexual behavior in Drosophila. Manipulation both Dsk and DSK neuronal activity impact female sexual receptivity. In addition, we reveal that Dsk-expressing neurons receive input signal from R71G01GAL4 neurons to promote female sexual receptivity. Based on intersectional technique, we further found the regulation of female sexual behavior relies mainly on medial DSK neurons rather than lateral DSK neurons, and medial DSK neurons modulate female sexual behavior by acting on its receptor CCKLR-17D3. Thus, we characterized DSK/CCKLR-17D3 as R71G01GAL4 neurons downstream signaling to regulate female sexual behavior.

The UV RESISTANCE LOCUS 8-Mediated UV-B Response Is Required Alongside CRYPTOCHROME1 For Plant Survival Under Sunlight In The Field

As sessile organisms, plants are subjected to fluctuating sunlight including potentially detrimental ultraviolet-B radiation (UV-B). In Arabidopsis thaliana, experiments under controlled conditions have shown that UV RESISTANCE LOCUS 8 (UVR8) controls photomorphogenic responses for acclimation and tolerance to UV-B; however, its long-term impacts on plant performance remain poorly understood in naturally fluctuating environments. Here we quantified the survival and reproduction of different Arabidopsis mutant genotypes in diverse field and laboratory conditions. We found that uvr8 mutants produced more fruits than wild type in growth chambers with artificial low UV-B conditions but not in natural field conditions. Importantly, independent double mutants of UVR8 and the blue-light photoreceptor gene CRYPTOCHROME 1 (CRY1) in two genetic backgrounds showed a drastic reduction in fitness in the field. UV-B attenuation experiments in field conditions and supplemental UV-B in growth chambers demonstrated that UV-B caused the conditional cry1 uvr8 lethality phenotype. RNA sequencing in different conditions revealed a large number of genes with statistical interaction of UVR8 and CRY1 mutations in the presence of UV-B in the field. Among them, Gene Ontology analysis identified enrichment of categories related to UV-B response, oxidative stress, photoprotection and DNA damage repair. Our study demonstrates the functional importance of the UVR8-mediated response across life stages in natura, which is partially redundant with CRY1, and provides an integral picture of gene expression associated with plant environmental responses under diverse environmental conditions.

The cost of a meal: factors influencing prey profitability in Australian fur seals

Knowledge of the factors shaping the foraging behaviour of species is central to understanding their ecosystem role and predicting their response to environmental variability. To maximise survival and reproduction, foraging strategies must balance the costs and benefits related to energy needed to pursue, manipulate, and consume prey with the nutritional reward obtained. While such information is vital for understanding how changes in prey assemblages may affect predators, determining these components is inherently difficult in cryptic predators. The present study used animal-borne video data loggers to investigate the costs and benefits related to different prey types for female Australian fur seals (Arctocephalus pusillus doriferus), a primarily benthic foraging species in the low productivity Bass Strait, south-eastern Australia. A total of 1,263 prey captures, resulting from 2,027 prey detections, were observed in 84.5 h of video recordings from 23 individuals. Substantial differences in prey pursuit and handling times, gross energy gain and total energy expenditure were observed between prey types. Importantly, the profitability of prey was not significantly different between prey types, with the exception of elasmobranchs. This study highlights the benefit of animal-borne video data loggers for understanding the factors that influence foraging decisions in predators. Further studies incorporating search times for different prey types would further elucidate how profitability differs with prey type.

Genome-wide SNP analysis reveals patterns of population differentiation and adaptation of red rock lobster Jasus edwardsii

<p>Declines in global marine finfish catches, which accounts for ~15% of the animal protein consumed by humans, has caused a 6-fold increase in total reported catch of invertebrates since 1950. This has led to the over-exploitation and decline of many marine invertebrate fisheries. The red rock lobster (Jasus edwardsii) fishery is New Zealand’s most economically valuable inshore fishery. The current management strategy relies on the assumption that the stock is comprised of a single panmictic population. However, more recent studies have challenged the genetic homogeneity of Jasus edwardsii across the Tasman sea and described high levels of self-recruitment in a Stewart Island subpopulation. A disregard for the underlying genetic structure in the management of a fishery can lead to excessive removal of individuals from populations contributing to the overall genetic diversity of the stock and thus reduce the species adaptability. The ability to adapt to new environments is particularly important in the context of global climate change and can significantly affect the long-term sustainability of the stock. Thus, the goal of this study was to identify specific patterns of genetic diversity of Jasus edwardsii population and provide an interpretation and assessment of the impact on the NZ fishery. The first objective was to optimize and validate molecular and bioinformatic protocols of Single Nucleotide Polymorphism (SNP) discovery for the red rock lobster Jasus edwardsii. The double digest restriction-site associated DNA (ddRADseq) protocol was optimized for the relatively large red rock lobster genome, which also has a high paralog content. The impact of bioinformatic processing on the population genetic inferences was then assessed by testing three different SNP discovery pipelines with the Rad-loci pipeline producing the most optimal marker discovery rate with a low level of missing data and a low SNP error rate. An analysis of technical replicates confirmed the reproducibility of both the molecular and bioinformatic protocols and also the validated the data generation process suitable for population genetic analyses. The second objective of my thesis was to investigate the genetic structure and population connectivity of adult red rock lobsters. The SNPs discovered were characterised as selectively neutral or under divergent selection (outlier) and both types of markers were analysed using Bayesian model-based clustering (STRUCTURE), non model-based multivariate analysis (Discriminant Analysis of Principal Components (DAPC)) and F-statistics. A lack of population differentiation using neutral genetic markers indicated a high level of gene flow and connectivity between populations. In contrast, there was evidence for selective pressure as a result of the analysis of outlier markers. Three main regions were identified: North-East NZ, North-West NZ and South NZ sub-populations, as part of a larger NZ metapopulation (FST ranged from 0.025 to 0.049, P < 0.001). The results of this study suggested that high levels of gene flow and connectivity are counteracted to some extent by the local selection that promotes the survival and reproduction of locally adapted genotypes. However, the strength of this selective pressure still permits low levels of survival and reproduction of non-optimal genotypes causing allele frequency homogenisation of the new generation of lobsters. The third objective was to investigate the levels of connectivity and adaptive divergence of the red rock lobster pueruli/juvenile lobsters for comparison with pattern of divergence of adult lobster in order to investigate the mechanisms of population structure formation. A suite of Bayesian clustering, non-model multivariate analysis and F-statistics were employed in the assessment of neutral and outlier markers developed for pueruli/juveniles. Similar to adult lobsters, pueruli/juveniles were characterised by a low level of divergence of the neutral markers indicating effective larvae dispersal. Outlier markers detected population differentiation patterns likely to originate from a phenotype – environment mismatch resulting in post-settlement mortality of non-adapted genotypes. The similarity between patterns of genetic divergence of adult lobsters and late juvenile/early juveniles indicates that post-settlement mortality, driven by local environmental conditions, has most likely occurred on earlier developmental stages of Jasus edwardsii, which were not possible to sample in my study. The final objective was to explore environment–genotype associations of Jasus edwardsii. Biological Environment Stepwise (BEST) analyses, redundancy analyses (RDA) and generalized linear modelling (GLM) consistently indicated a correlation between the annual amplitude of sea surface temperature (SST) and adaptive population divergence. In addition, an influence of spatial distribution on the patterns of adaptive population differentiation was also detected via RDA. From these results I propose a mechanism underlying the patterns of population differentiation discovered in Chapters 3 and 4: a latitudinal gradient of SST appears to be the selective force promoting the adaptive divergence of the lobster populations with local patterns of connectivity distorting the gradient and thus forming three distinct temperature adapted genotypes (North-West, North-East, and South). An environmental association analysis offered 43 candidate loci, which after alignment of transcriptome-mapped reference catalog sequences to annotated protein databases identified a candidate gene for thermal adaptation - UDP-glycosyltransferase (UGT). UGT is a detoxification enzyme involved in the metabolization of a variety of endogenous and environmental compounds and its activity and gene expression patterns have been linked to temperature. This study provides evidence for the local adaptations of the NZ population of Jasus edwardsii to SST, which together with the efficient mechanism of larval dispersal creates a system likely resilient to changes in temperature. This feature is important in the light of climate change-induced range shifts and supports the long-term sustainability of the red rock lobster fishery. The three genetically distinct regions identified coincide with existing boundaries of the management units and therefore do not require an adjustment of the current management regime.</p>