Background: Insulin-like growth factor 2 (IGF2) is a protein hormone known to regulate cell proliferation, growth, migration, differentiation and survival. The gene is parentally imprinted in the sense that transcripts are almost exclusively derived from the paternal allele. Loss of imprinting of the IGF2 gene is a recurrent observation in growth disorders that combine overgrowth with a variety of malignant tumours. Moreover, IGF2 has been proposed to play a role in the development of a variety of seemingly unrelated cancers that play an important role in geriatric medicine, e.g. breast cancer, colon cancer and lung cancer. Finally, IGF2 has been implicated in cardiovascular disease, since, for example, IGF2 has been shown to influence the size of atherosclerotic lesions. Objective: To summarize current knowledge about IGF2, its interactions with binding proteins and receptors and connections with key diseases. Methods: The contents of this paper were based on reviews of existing literature within the field. Results: There is a substantial amount of research linking IGF2 to growth disorders, cancer and to a much lesser degree cardiovascular disease. Some of the studies on IGF2 and tumour growth have yielded conflicting results, for instance regarding its effect on apoptosis. Conclusion: Today, our knowledge on how IGF2 is composed and interacts with receptors has come a long way. However, there is comparatively little information on how IGF2 affects tumour growth and cardiovascular diseases such as atherosclerosis. Thus, further research will be needed to elucidate the impact of IGF2 on key diseases.

Agonistic behavior is a fundamental aspect of ecological theories on resource acquisition and sexual selection. Crustaceans are exemplary models for agonistic behavior within the laboratory, but agonistic behavior in natural habitats is often neglected. Laboratory studies do not achieve the same ecological realism as field studies. In an attempt to connect laboratory results to field data and investigate how habitat structure affects agonistic interactions, the nocturnal behavior of two crayfish species was observed by scuba diving and snorkeling in two northern Michigan lakes. Intraspecific agonistic interactions were analyzed in three habitats: two food resources-macrophytes and detritus-and one sheltered habitat. The overall observations reinforce the concept that resources influence agonistic bouts. Fights in the presence of shelters were longer and more intense, suggesting that shelters have a higher perceived value than food resources. Fights in the presence of detritus patches had higher average intensities and ended with more tailflips away from an opponent, suggesting that detritus was a more valuable food resource than macrophytes. In addition, observations of aggressive behavior within a natural setting can add validity to laboratory studies. When fights in nature are compared with laboratory fights, those in nature are shorter, less intense, and less likely to end with a tailflip, but do show the fundamental fight dynamics associated with laboratory studies. Extrinsic and intrinsic factors affect intraspecific aggression in many ways, and both should always be recognized as having the potential to alter agonistic behavior.

In mammals, cilia are critical for development, sensation, cell signaling, sperm motility, and fluid movement. Defects in cilia are causes of several congenital syndromes, providing additional reasons to identify cilia-related genes. We hypothesized that mRNAs selectively abundant in tissues rich in highly ciliated cells encode cilia proteins. Selective abundance in olfactory epithelium, testes, vomeronasal organ, trachea, and lung proved to be an expression pattern uniquely effective in identifying documented cilia-related genes. Known and suspected cilia-related genes were statistically overrepresented among the 99 genes identified, but the majority encoded proteins of unknown function, thereby predicting new cilia-related proteins. Evidence of expression in a highly ciliated cell, the olfactory sensory neuron, exists for 73 of the genes. In situ hybridization for 17 mRNAs confirmed expression of all 17 in olfactory sensory neurons. Most were also detected in vomeronasal sensory neurons and in neighboring tissues rich in ciliated cells such as respiratory epithelium. Immunoreactivity for one of the proteins identified, Spa17, colocalized with acetylated tubulin in the cilia layer of the olfactory epithelium. In contrast, the ciliary rootlet protein, Crocc, was located in discrete structures whose position was consistent with the dendritic knobs of the olfactory sensory neurons. A compilation of >2,000 mouse genes predicted to encode cilia-related proteins revealed a strong correlation (R = 0.99) between the number of studies predicting a gene's involvement in cilia and documented evidence of such involvement, a fact that simplifies the selection of genes for further study of the physiology of cilia.

Igf2 (insulin-like growth factor 2) and H19 genes are imprinted in mammals; they are expressed unevenly from the two parental alleles. Igf2 is a growth factor expressed in most normal tissues, solely from the paternal allele. H19 gene is transcribed (but not translated to a protein) from the maternal allele. Igf2 protein is a growth factor particularly important during pregnancy, where it promotes both foetal and placental growth and also nutrient transfer from mother to offspring via the placenta. This article reviews epigenetic regulation of the Igf2/H19 gene-cluster that leads to parent-specific expression, with current models including parental allele-specific DNA methylation and chromatin modifications, DNA-binding of insulator proteins (CTCFs) and three-dimensional partitioning of DNA in the nucleus. It is emphasized that key genomic features are conserved among mammals and have been functionally tested in mouse. 'The enhancer competition model', 'the boundary model' and 'the chromatin-loop model' are three models based on differential methylation as the epigenetic mark responsible for the imprinted expression pattern. Pathways are discussed that can account for allelic methylation differences; there is a recent study that contradicts the previously accepted fact that biallelic expression is accompanied with loss of differential methylation pattern.

BackgroundNew field applicable diagnostic tools are needed for highly sensitive detection of residual malaria infections in pre-elimination settings. Field performance of a high throughput DNA extraction system for loop mediated isothermal amplification (HTP-LAMP) was therefore evaluated for detecting malaria parasites among asymptomatic individuals in Zanzibar.MethodsHTP-LAMP performance was evaluated against real-time PCR on 3008 paired blood samples collected on filter papers in a community-based survey in 2015.ResultsThe PCR and HTP-LAMP determined malaria prevalences were 1.6% (95%CI 1.3–2.4) and 0.7% (95%CI 0.4–1.1), respectively. The sensitivity of HTP-LAMP compared to PCR was 40.8% (CI95% 27.0–55.8) and the specificity was 99.9% (CI95% 99.8–100). For the PCR positive samples, there was no statistically significant difference between the geometric mean parasite densities among the HTP-LAMP positive (2.5 p/μL, range 0.2–770) and HTP-LAMP negative (1.4 p/μL, range 0.1–7) samples (p = 0.088). Two lab technicians analysed up to 282 samples per day and the HTP-LAMP method was experienced as user friendly.ConclusionsAlthough field applicable, this high throughput format of LAMP as used here was not sensitive enough to be recommended for detection of asymptomatic low-density infections in areas like Zanzibar, approaching malaria elimination.

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A variety of factors influences the formation of hierarchical structures, and can include an altered aggressive state, an ability to physically dominate, and previous agonistic experience. Using male Orconectes rusticus, we tested the duration of the winner effect by varying the time between a winning encounter and a subsequent encounter by a 20, 40 or 60-minute interval. Varying the time between the two fights significantly altered the probabilities of initiating fight behaviour and of winning a fight. A crayfish with a 20-minute delay between its winning experience and its subsequent fight was significantly less likely to initiate fight behaviour and significantly more likely to win its next fight than was an animal whose next fight was delayed for 40 or 60 minutes. We then investigated whether the dynamics of this winner effect were influenced by perception of odour signals during agonistic interactions by blocking the chemo- and mechanoreceptors on the antennae and antennules to prevent reception of relevant cues communicating social status. Individuals fighting an opponent with this loss of sensory information were significantly more likely to initiate a fight, but then escalated at a slower rate to a higher fight intensity level. In addition, individuals had a decreased chance of winning an agonistic bout against an opponent deprived of sensory input from the antennae and antennules.