Can interaction specificity in the fungus-farming termite symbiosis be explained by nutritional requirements of the fungal crop?

<p>Fungus-growing termites are associated with genus-specific fungal symbionts, which they acquire via horizontal transmission. Selection of specific symbionts may be explained by the provisioning of specific, optimal cultivar growth substrates by termite farmers. We tested whether differences in in vitro performance of Termitomyces cultivars from nests of three termite species on various substrates are correlated with the interaction specificity of their hosts. We performed single-factor growth assays (varying carbon sources), and a two-factor geometric framework experiment (simultaneously varying carbohydrate and protein availability). Although we did not find qualitative differences between Termitomyces strains in carbon-source use, there were quantitative differences, which we analysed using principal component analysis. This showed that growth of Termitomyces on different carbon sources was correlated with termite host genus, rather than host species, while growth on different ratios and concentrations of protein and carbohydrate was correlated with termite host species. Our findings corroborate the interaction specificity between fungus-growing termites and Termitomyces cultivars and indicate that specificity between termite hosts and fungi is reflected both nutritionally and physiologically. However, it remains to be demonstrated whether those differences contribute to selection of specific fungal cultivars by termites at the onset of colony foundation.</p

Phylogenetic analyses of diverse <i>Podaxis</i> specimens from Southern Africa reveal hidden diversity and new insights into associations with termites

<p>Although frequently found on mounds of the grass-cutting termite genus . Trinervitermes, virtually nothing is known about the natural history of the fungal genus . Podaxis (Agaricaceae) nor why it associates with termite mounds. More than 40 species of this secotioid genus have been described since Linnaeus characterised the first species in 1771. However, taxonomic confusion arose when most of these species were reduced to synonymy with . Podaxis pistillaris in 1933. Although a few more species have since been described, the vast majority of specimens worldwide are still treated as . P. pistillaris. Using 45 fresh and herbarium specimens from Southern Africa, four from North America and one each from Ethiopia, and Kenya, we constructed the first comprehensive phylogeny of the genus. Four of the genotyped specimens were more than 100 y old. With the exception of the type specimen of . Podaxis rugospora, all herbarium specimens were labelled as . P. pistillaris or . Podaxis sp. However, our data shows that the genus contains at least five well-supported clades with significant inter-clade differences in spore length, width and wall thickness, and fruiting body length, supporting that clades likely represent distinct . Podaxis species. Certain clades consistently associate with termites while others appear entirely free-living.</p

Asexual and sexual reproduction are two separate developmental pathways in a <i>Termitomyces</i> species

Although mutualistic symbioses per definition are beneficial for interacting species, conflict may arise if partners reproduce independently. We address how this reproductive conflict is regulated in the obligate mutualistic symbiosis between fungus-growing termites and Termitomyces fungi. Even though the termites and their fungal symbiont disperse independently to establish new colonies, dispersal is correlated in time. The fungal symbiont typically forms mushrooms a few weeks after the colony has produced dispersing alates. It is thought that this timing is due to a trade-off between alate and worker production; alate production reduces resources available for worker production. As workers consume the fungus, reduced numbers of workers will allow mushrooms to 'escape' from the host colony. Here, we test a specific version of this hypothesis: the typical asexual structures found in all species of Termitomyces-nodules-are immature stages of mushrooms that are normally harvested by the termites at a primordial stage. We refute this hypothesis by showing that nodules and mushroom primordia are macro- and microscopically different structures and by showing that in the absence of workers, primordia do, and nodules do not grow out into mushrooms. It remains to be tested whether termite control of primordia formation or of primordia outgrowth mitigates the reproductive conflict.</p

Disease-free monoculture farming by fungus-growing termites

Fungus-growing termites engage in an obligate mutualistic relationship with Termitomyces fungi, which they maintain in monocultures on specialised fungus comb structures, without apparent problems with infectious diseases. While other fungi have been reported in the symbiosis, detailed comb fungal community analyses have been lacking. Here we use culture-dependent and -independent methods to characterise fungus comb mycobiotas from three fungus-growing termite species (two genera). Internal Transcribed Spacer (ITS) gene analyses using 454 pyrosequencing and Illumina MiSeq showed that non-Termitomyces fungi were essentially absent in fungus combs, and that Termitomyces fungal crops are maintained in monocultures as heterokaryons with two or three abundant ITS variants in a single fungal strain. To explore whether the essential absence of other fungi within fungus combs is potentially due to the production of antifungal metabolites by Termitomyces or comb bacteria, we performed in vitro assays and found that both Termitomyces and chemical extracts of fungus comb material can inhibit potential fungal antagonists. Chemical analyses of fungus comb material point to a highly complex metabolome, including compounds with the potential to play roles in mediating these contaminant-free farming conditions in the termite symbiosis

EuroScitizen Working Group 2 I Identifying needs and opportunities to improve the contribution of formal education to public literacy on evolution

EuroScitizen is a COST Action and involves a research network whose aim is to identify strategies to raise levels of scientific literacy about evolution in Europe. EuroScitizen comprises five working groups (WG) and this poster summarizes the current achievements of WG2 on formal education. WG2 aims to identify the needs and opportunities to improve the teaching of evolution since the first school years in distinct countries and enhance the contribution of formal education to European public scientific literacy on this important topic. To achieve these objectives we are studying: i) the school curricula and ii) textbooks of the participating countries; iii) teachers’ content knowledge, pedagogical content knowledge, attitudes and beliefs about teaching evolution and effective methodologies and strategies to empower teachers about evolution education; and iv) strategies to promote evolution understanding in elementary school students. This poster presents some of the current achievements of WG2, such as: i) publication of a paper about the development and validation of a framework for the assessment of school curricula on the presence of evolutionary concepts (FACE); ii) comparison of the content of most adopted textbooks in the schools of 8 countries, from the 1st to the 9th grade, about the presence of evolution Big Ideas; iii) identification of teachers’ best practices in evolution education and teacher’ training actions about evolution education; and iv) the publication of a study about the evolutionary concepts that elementary school students most often used after a pedagogical intervention. The next steps of the WG2 are also presented.info:eu-repo/semantics/publishedVersio

Ancestral predisposition toward a domesticated lifestyle in the termite-cultivated fungus Termitomyces

The ancestor of termites relied on gut symbionts for degradation of plant material, an association that persists in all termite families. However, the single-lineage Macrotermitinae has additionally acquired a fungal symbiont that complements digestion of food outside the termite gut. Phylogenetic analysis has shown that fungi grown by these termites forma clade—the genus Termitomyces—but the events leading toward domestication remain unclear. To address this, we reconstructed the lifestyle of the common ancestor of Termitomyces using a combination of ecological data with a phylogenomic analysis of 21 related non-domesticated species and 25 species of Termitomyces. We show that the closely related genera Blastosporella and Arthromyces also contain insect-associated species. Furthermore, the genus Arthromyces produces asexual spores on the mycelium, which may facilitate insect dispersal when growing on aggregated subterranean fecal pellets of a plant-feeding insect. The sister-group relationship between Arthromyces and Termitomyces implies that insect association and asexual sporulation, present in both genera, preceded the domestication of Termitomyces and did not follow domestication as has been proposed previously. Specialization of the common ancestor of these two genera on an insect-fecal substrate is further supported by similar carbohydrate-degrading profiles between Arthromyces and Termitomyces. We describe a set of traits that may have predisposed the ancestor of Termitomyces toward domestication, with each trait found scattered in related taxa outside of the termite-domesticated clade. This pattern indicates that the origin of the termite-fungus symbiosis may not have required large-scale changes of the fungal partner.http://www.cell.com/current-biology/homeam2022BiochemistryForestry and Agricultural Biotechnology Institute (FABI)GeneticsMicrobiology and Plant Patholog

Dwelling as the life basis of Ukrainians

На прикладі містечок Батурина, Глухова, Борзни та Кролевця у статті розглядається інтер’єр жител населення Чернігово-Сіверщини (друга половина ХVІІІ – середина ХІХ ст.). На основі значного описового матеріалу, стосовно звичаїв і побуту українців, який накопичився в середині і особливо в другій половині ХІХ ст. можна зробити науково-вивірені узагальнення з приводу порівняльної характеристики українців і росіян. Дослідженням цієї теми займалися М. Маркевич, І. Срезнєвський, П. Куліш та ін. Значний внесок до вивчення даної проблематики належить історику М. Костомарову, який виокремив український культурний і традиційно-буттєвий комплекс із загальноросійського, що утрадиційнилось як спільне за понад сторіччя співжиття в рамках однієї імперії. Також у даній статті характеризується поділ оселі на умовні частини та визначаються основні сакральні центри хати. Автор наголошує на глибокому символічному обрядово-ритуальному значенні, яке українці надавали всім предметам хатнього інтер’єру та наголошує на ліричній прив’язаності їх до місця свого проживання.На примере городков Батурина, Глухова, Борзны и Кролевца в статье рассматривается интерьер жилищ населения Чернигово-Северщины во второй половине XVIII – середине XIX вв. На основе материалов, описывающих украинские обычаи и быт, накопившихся в средине, а особенно во второй половине XIX в., можно сделать обобщения по поводу сравнительной характеристики украинцев и русских. Исследованием этой темы занимались Н. Маркевич, И. Срезневский, П. Кулиш и другие ученые. Значительный вклад в изучение данной проблематики принадлежит историку Н. Костомарову, который выделил украинский культурный и традиционно- бытейный комплекс из общероссийского, которые сосуществовали более столетия в границах одной империи. Также в данной статье характеризируется разделение жилища на условные части и определяются основные сакральные центры дома (хаты). Автор отмечает глубокое символическое ритуально-обрядовое значение, которое украинцы придавали всем предметам домашнего интерьера, а также подчеркивает лирическую привязанность населения к месту его проживания.Article deals with the interior of dwellings in Chernihiv-Siverskyi region (in the 2nd half of the ХVІІІ – 1st half of the ХІХ cent.). On the example of towns Baturyn, Glukhiv, Borzna and Krolevets the article deals with the house interiors of the population of Chernihovo-Sivershchyna (the second half of the XVIII – mid. XIX cent.). The analysis is based on considerable descriptive material concerning Ukrainian customs and way of life that has accumulated in the middle and especially in the second half of the XIX cent. and led to scientific adjusted conclusion about the comparative characteristics of Ukrainians and Russians. This topic was researched by M. Markevych, I. Sreznevskyi, P. Kulish and others. A significant contribution to the study of this subject belongs to historian M. Kostomarov, who singled Ukrainian cultural and traditional existential complex out of all-Russian complex, that was considered unified for more than three centuries of coexistence within a single empire. Also, this article characterizes the division of the house on special parts and identifies the main sacred centres of the house. The attention is given to the fact that the Ukrainian housing is associated with many beliefs and rituals. It indicates that the dwelling-house reflects not only people’s ideological and artistic heritage, but also a pragmatic idea. After all, the house seemed a model of nature and the universe, which protected both physically and spiritually. We know that house was not only a place where the family spent most of its life, but it was the family hearth around which ancient and beautiful traditions were preserved. The author emphasizes the deep symbolic ritual value that Ukrainians gave to all subjects of domestic interior and the lyrical attachment to their place of residence. After all, the house had a kind of sacred meaning for its tenants, that is why, to the house and all domestic things people gave some philosophical content. Complexity of representations of the world for humans began from the dwelling and was a dominant through all life. It is revealed that a Ukrainian house with its aesthetic appearance and its interior in particular, is an important factor in the understanding of the Ukrainian people and makes the character unique, and one that is very different from the characteristics of other nations. The author concluded that this topic needs a further study

Single nucleus genome sequencing reveals high similarity among nuclei of an endomycorrhizal fungus

Nuclei of arbuscular endomycorrhizal fungi have been described as highly diverse due to their asexual nature and absence of a single cell stage with only one nucleus. This has raised fundamental questions concerning speciation, selection and transmission of the genetic make-up to next generations. Although this concept has become textbook knowledge, it is only based on studying a few loci, including 45S rDNA. To provide a more comprehensive insight into the genetic makeup of arbuscular endomycorrhizal fungi, we applied de novo genome sequencing of individual nuclei of Rhizophagus irregularis. This revealed a surprisingly low level of polymorphism between nuclei. In contrast, within a nucleus, the 45S rDNA repeat unit turned out to be highly diverged. This finding demystifies a long-lasting hypothesis on the complex genetic makeup of arbuscular endomycorrhizal fungi. Subsequent genome assembly resulted in the first draft reference genome sequence of an arbuscular endomycorrhizal fungus. Its length is 141 Mbps, representing over 27,000 protein-coding gene models. We used the genomic sequence to reinvestigate the phylogenetic relationships of Rhizophagus irregularis with other fungal phyla. This unambiguously demonstrated that Glomeromycota are more closely related to Mucoromycotina than to its postulated sister Dikarya