Basking Activity is Modulated by Health State but is Constrained by Conspicuousness to Predators in Male Spanish Terrapins

Aerial basking may have several benefits for freshwater turtles in addition to thermoregulation such as removing parasites from the skin, which would improve health state. However, basking outside of water may be risky because it may expose freshwater turtles to terrestrial predators. Here, we monitored the basking activity of male Spanish terrapins (Mauremys leprosa) in a wild population of the south‐western of the Iberian Peninsula. We also measured body size, health state parameters, parasite prevalence, and limb coloration of these individuals. We aimed to examine whether basking may improve health state of turtles. The results showed that male turtles with higher basking activity were those parasitized by Hepatozoon and that had lower total white blood cell (WBC). This might indicate that turtles in worse health condition increase their time spent basking to improve their immune system. In addition, because basking might be risky, we also expected that turtles with more conspicuous coloration should reduce their basking activity to avoid being detected by potential predators. We found that infected turtles, but not uninfected ones, that spent more time basking also had less bright coloration in limb stripes. Our study provides evidence that basking activity may improve health state of terrapins, but that color conspicuity may increase costs of basking, especially for parasitized individuals. Understanding the balance between the benefits and the costs of basking might be essential for the conservation of freshwater turtle populations.     

Genome‐wide association and genome partitioning reveal novel genomic regions underlying variation in gastrointestinal nematode burden in a wild bird

Identifying the genetic architecture underlying complex phenotypes is a notoriously difficult problem that often impedes progress in understanding adaptive eco‐evolutionary processes in natural populations. Host–parasite interactions are fundamentally important drivers of evolutionary processes, but a lack of understanding of the genes involved in the host's response to chronic parasite insult makes it particularly difficult to understand the mechanisms of host life history trade‐offs and the adaptive dynamics involved. Here, we examine the genetic basis of gastrointestinal nematode (Trichostrongylus tenuis) burden in 695 red grouse (Lagopus lagopus scotica) individuals genotyped at 384 genome‐wide SNPs. We first use genome‐wide association to identify individual SNPs associated with nematode burden. We then partition genome‐wide heritability to identify chromosomes with greater heritability than expected from gene content, due to harbouring a multitude of additive SNPs with individually undetectable effects. We identified five SNPs on five chromosomes that accounted for differences of up to 556 worms per bird, but together explained at best 4.9% of the phenotypic variance. These SNPs were closely linked to genes representing a range of physiological processes including the immune system, protein degradation and energy metabolism. Genome partitioning indicated genome‐wide heritability of up to 29% and three chromosomes with excess heritability of up to 4.3% (total 8.9%). These results implicate SNPs and novel genomic regions underlying nematode burden in this system and suggest that this phenotype is somewhere between being based on few large‐effect genes (oligogenic) and based on a large number of genes with small individual but large combined effects (polygenic).     

Host association drives genetic divergence in the bed bug,Cimex lectularius

Genetic differentiation may exist among sympatric populations of a species due to long‐term associations with alternative hosts (i.e. host‐associated differentiation). While host‐associated differentiation has been documented in several phytophagus insects, there are far fewer cases known in animal parasites. The bed bug, Cimex lectularius, a wingless insect, represents a potential model organism for elucidating the processes involved in host‐associated differentiation in animal parasites with relatively limited mobility. In conjunction with the expansion of modern humans from Africa into Eurasia, it has been speculated that bed bugs extended their host range from bats to humans in their shared cave domiciles throughout Eurasia. C. lectularius that associate with humans have a cosmopolitan distribution, whereas those associated with bats occur across Europe, often in human‐built structures. We assessed genetic structure and gene flow within and among populations collected in association with each host using mtDNA, microsatellite loci and knock‐down resistance gene variants. Both nuclear and mitochondrial data support a lack of significant contemporary gene flow between host‐specific populations. Within locations human‐associated bed bug populations exhibit limited genetic diversity and elevated levels of inbreeding, likely due to human‐mediated movement, infrequent additional introduction events per infestation, and pest control. In contrast, populations within bat roosts exhibit higher genetic diversity and lower levels of relatedness, suggesting populations are stable with temporal fluctuations due to host dispersal and bug mortality. In concert with previously published evidence of morphological and behavioural differentiation, the genetic data presented here suggest C. lectularius is currently undergoing lineage divergence through host association.     

Sensation‐seeking genes and physical activity in youth

Many studies examining genetic influences on physical activity (PA) have evaluated the impact of single nucleotide polymorphisms (SNPs) related to the development of lifestyle‐related chronic diseases, under the hypothesis that they would be associated with PA. However, PA is a multidetermined behavior and associated with a multitude of health consequences. Thus, examining a broader range of candidate genes associated with a broader range of PA correlates may provide new insights into the genetic underpinnings of PA. In this study, we focus on one such correlate – sensation‐seeking behavior. Participants (N = 1130 Mexican origin youth) provided a saliva sample and data on PA and sensation‐seeking tendencies in 2008–2009. Participants were genotyped for 630 functional and tagging variants in the dopamine, serotonin and cannabinoid pathways. Overall 30% of participants (males – 37.6% and females – 22.0%) reported ≥60 min of PA on 5 of 7 days. After adjusting for gender, age and population stratification, and applying the Bayesian False Discovery Probability approach for assessing noteworthiness, four gene variants were significantly associated with PA. In a multivariable model, being male, having higher sensation‐seeking tendencies and at least one copy of the minor allele for SNPs in angiotensin I‐converting enzyme gene [ACE; rs8066276 odds ratio (OR) = 1.44; P = 0.012] and tryptophan hydroxylase 2 gene (TPH2; rs11615016 OR = 1.73; P = 0.021) were associated with increased likelihood of meeting PA recommendations. Participants with at least one copy of the minor allele for SNPs in synaptosomal‐associated protein 25 gene (SNAP25; rs363035 OR = 0.53; P = 0.005) and cannabinoid receptor 1 gene (CNR1; rs6454672 OR = 0.62; P = 0.022) have decreased likelihood of meeting PA recommendations. Our findings extend current knowledge of the complex relationship between PA and possible genetic underpinnings.     

The Oxidative Chlorination of Pyrimidine and Purine Bases,and Nucleosides Using Acyl Chloride-Dimethyl-Formamide-m-Chloroperbenzoic Acid System1

Abstract

Pyrimidine and purine bases, and nucleosides were chlorinated by the reaction of acyl chloride in DMF with MCPBA under mild conditions in moderate yields.     

Cultivation and Hybridization Alter the Germination Behavior of Native Plants Used in Revegetation and Restoration

Native plants are increasingly used for revegetation and restoration. These plants are cultivated for several generations at plant nurseries and often they are of unknown provenance. Therefore, cultivated plants often differ from their wild progenitors in life‐history traits. Using germination behavior as example, we tested the assumption that cultivated plants have different life‐history traits than their uncultivated progenitors. Cultivated as well as wild individuals of Plantago lanceolata and Lotus corniculatus, two species frequently used in revegetation, were tested in a common garden experiment as well as in incubators for their germination behavior. We observed significantly faster and more abundant germination in cultivated varieties. Using artificial crossings, we found that also hybrids of cultivated varieties and wild relatives germinate faster and more abundant than the wilds. As wild plants acquire their life‐history traits by natural selection, we have to assume that they represent the optimal adaptation to the environmental conditions. If these traits are changed by cultivation or by hybridization between cultivated varieties and local populations, the long‐term survival probabilities of local populations may be altered. Therefore, the use of cultivated varieties of native plants should be avoided in revegetation.