[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Gluten, major histocompatibility complex, and the small intestine: A molecular and immunobiologic approach to the spectrum of gluten sensitivity (‘celiac sprue’)

Insects are the most speciose group of animals, but the phylogenetic relationships of many major lineages remain unresolved. We inferred the phylogeny of insects from 1478 protein-coding genes. Phylogenomic analyses of nucleotide and amino acid sequences, with site-specific nucleotide or domain-specific amino acid substitution models, produced statistically robust and congruent results resolving previously controversial phylogenetic relations hips. We dated the origin of insects to the Early Ordovician [~479 million years ago (Ma)], of insect flight to the Early Devonian (~406 Ma), of major extant lineages to the Mississippian (~345 Ma), and the major diversification of holometabolous insects to the Early Cretaceous. Our phylogenomic study provides a comprehensive reliable scaffold for future comparative analyses of evolutionary innovations among insects.

https://science.sciencemag.org/content/sci/346/6210/763.full.pdf

Phylogenomics resolves the timing and pattern of insect evolution

Host plant quality is a key determinant of the fecundity of herbivorous insects. Components of host plant quality (such as carbon, nitrogen, and defensive metabolites) directly affect potential and achieved herbivore fecundity. The responses of insect herbivores to changes in host plant quality vary within and between feeding guilds. Host plant quality also affects insect reproductive strategies: Egg size and quality, the allocation of resources to eggs, and the choice of oviposition sites may all be influenced by plant quality, as may egg or embryo resorption on poor-quality hosts. Many insect herbivores change the quality of their host plants, affecting both inter- and intraspecific interactions. Higher-trophic level interactions, such as the performance of predators and parasitoids, may also be affected by host plant quality. We conclude that host plant quality affects the fecundity of herbivorous insects at both the individual and the population scale.

Host plant quality and fecundity in herbivorous insects

Insect guts present distinctive environments for microbial colonization, and bacteria in the gut potentially provide many beneficial services to their hosts. Insects display a wide range in degree of dependence on gut bacteria for basic functions. Most insect guts contain relatively few microbial species as compared to mammalian guts, but some insects harbor large gut communities of specialized bacteria. Others are colonized only opportunistically and sparsely by bacteria common in other environments. Insect digestive tracts vary extensively in morphology and physicochemical properties, factors that greatly influence microbial community structure. One obstacle to the evolution of intimate associations with gut microorganisms is the lack of dependable transmission routes between host individuals. Here, social insects, such as termites, ants, and bees, are exceptions: social interactions provide opportunities for transfer of gut bacteria, and some of the most distinctive and consistent gut communities, with specialized beneficial functions in nutrition and protection, have been found in social insect species. Still, gut bacteria of other insects have also been shown to contribute to nutrition, protection from parasites and pathogens, modulation of immune responses, and communication. The extent of these roles is still unclear and awaits further studies.

The gut microbiota of insects - diversity in structure and function.

Williamson MS, Anstead JA, Devine GJ, Devonshire AL, Field LM, Foster SP, Moores GD, Denholm A, (2003), Insecticide resistance: from science to practice, Paper presented at the British Crop Production Council (BCPC) Conference, Glasgow, UK, 10-12 November, 2003, ISBN 1 901396 63 0, published by BCPC

Insecticide resistance: from science to practice.

Identification of mutations in the housefly acetylcholinesterase gene involved in resistance to insecticides

An international team of scientists and veterinarians was assembled in 1999 to develop a monitoring program to determine the susceptibility of cat fleas, Ctenocephalides felis felis (Bouche) (Siphonaptera: Pulicidae), to imidacloprid. Cat flea eggs were collected, shipped to laboratories, and tested for their susceptibility to imidacloprid. Over 3,000 C. felis populations were collected from 2002 to 2017 from 10 different countries. Of these, 66.3% were collected from cats and 33.7% from dogs. C. f. felis populations (n = 2,200) were bioassayed by exposing cat flea eggs and the emerging larvae to a Diagnostic Dose (DD) of 3 ppm imidacloprid in larval rearing medium. Flea eggs hatched and developed in the untreated controls in 1,837 of the isolates (83.5%) bioassayed. Flea isolates (n = 61) that had ≥5% survival at the DD of 3 ppm were retested with a second DD of 3 ppm. None of them had ≥5% survival to the second dose of 3 ppm. Of the 1,837 valid C. felis isolates tested, there has been no evidence of a decreased susceptibility to imidacloprid over the past 17 yr. The methods outlined in this article should provide an acceptable protocol for testing many of the new active ingredients that have been registered for cat flea control.

International Program to Monitor Cat Flea Populations for Susceptibility to Imidacloprid.

Eleftherianos I., Foster S., Williamson M., Denholm A., (2003), Toxicological and molecular characterisation of pyrethroid knockdown resistance (kdr) in the peach-potato aphids, Myzus persicae (sulzer), Paper presented at the 6th International Symposium on Aphids Conference, Rennes, France, September, 2003, ISBN 978-2-7380-1113-8, published by Ecole Nationale Superieure Agronomique de Rennes (ENSAR)

Martin S. Williamson

Papers

Insecticide resistance: from science to practice.

Identification of mutations in the housefly acetylcholinesterase gene involved in resistance to insecticides

International Program to Monitor Cat Flea Populations for Susceptibility to Imidacloprid.

Toxicological and molecular characterisation of pyrethroid knockdown resistance (kdr) in the peach-potato aphids, Myzus persicae (sulzer)

The biochemical and molecular genetics of barley seed proteins.