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The CRCI2NA inaugural symposium, a meeting on tumor and immune ecosystems, took place in the vibrant and picturesque city of Nantes. The meeting gathered world‐renowned experts in cancer biology and immunology. It showcased the most advanced science on mechanisms driving cellular heterogeneity, plasticity, and signaling in normal and cancer cellular ecosystems, which contribute to cancer development, progression, and therapeutic resistance. Recent developments in cancer immunotherapy and anti‐tumor strategies were also discussed to collectively assess new therapeutic vulnerabilities to defeat cancer. [ABSTRACT FROM AUTHOR]

We describe the breeding system of an autotetraploid trioecious cactus, Pachycereus pringlei, provide estimates of the fitnesses of males and females relative to that of hermaphrodites, and discuss the role played by pollinators in the maintenance of three sexual morphs. Relatively high frequencies of females (45%) and males (26%) exist in coastal desert populations around Bahia Kino, Sonora, Mexico. They differ from hermaphrodites in flower size (females only), initiation of the flowering season, number of flowers produced per night and per season, sucrose content of nectar, and, in females, number of fruits produced per season under open pollination and in response to hand-pollination. Major similarities between the sex classes include overall plant size, nectar volume per flower, percent fruit set in open-pollinated flowers of females and hermaphrodites, seed mass and number of seeds per fruit, and pollen mass per flower in males and hermaphrodites. Hermaphrodites are self-compatible, and the selfing rate is high (65%). Levels of inbreeding depression in selfed fruits and seeds appear to be low. Fruit set is strongly pollinator-dependent in females but much less so in hermaphrodites. Relative fitness of males and females, as measured by annual production of pollen or seeds, is at least 1.5 times higher than that of the corresponding sex function in hermaphrodites. Given the high selfing rate and apparent lack of inbreeding depression, these fitness differences are insufficient to explain the occurrence of trioecy in this species.

Premise: Inbreeding depression is traditionally considered a major factor favoring outcrossing in hermaphrodites. Recent experiments have shown that environmental conditions can influence the magnitude of inbreeding depression, but their relevance in natural populations is unclear. To investigate this, we studied the cleistogamous species Lamium amplexicaule, an annual species with individuals experiencing either spring or autumn environmental conditions. In this species, the proportion of cleistogamous/chasmogamous flowers changes according to seasonal cues (e.g., temperature, photoperiod). Our hypothesis was that the plasticity of cleistogamy is an adaptation to seasonal fitness variation in different flower progenies. Methods: To test this hypothesis, we produced the three possible types of progenies through controlled crosses: (1) selfed progeny from cleistogamous flowers; (2) chasmogamous selfed progeny; and (3) chasmogamous outcrossed progeny. Progeny fitness was then measured in a common garden in the two reproduction seasons (autumn and spring). Results: The results showed that season had a major impact on fitness. The fitness of the different progeny types changed across seasons, indicating that the effect of cleistogamy on progeny performance is season‐dependent, consistent with a previous study in a similar environment. Surprisingly, the flower from which the progeny issued (cleistogamous or chasmogamous) had more impact on fitness than the inbred status of the progeny (selfed versus outcrossed), suggesting a potential role of epigenetic processes. Conclusions: The observed patterns of variation were not consistent either with adaptation to environment‐dependent inbreeding depression or to variation in resource availability, but were possibly consistent with adaptation to seasonal pollinator activity. [ABSTRACT FROM AUTHOR]

Gynodioecy is a sexual dimorphism where females coexist with hermaphrodite individuals. In most cases, this dimorphism involves the interaction of cytoplasmicmale sterility (CMS) genes and nuclear restorer genes. Two scenarios can account for how these interactions maintain gynodioecy. Either CMS genes recurrently enter populations at low frequency via mutation or migration and go to fixation unimpeded (successive sweeps), or CMS genes maintain polymorphism over evolutionary time through interactions with a nuclear restorer allele (balanced polymorphism). To distinguish between these scenarios, we used transcriptome sequencing in gynodioecious Thymus vulgaris and surveyed genome-wide diversity in 18 naturally occurring individuals sampled from populations at a local geographic scale. We contrast the amount and patterns of nucleotide diversity in the nuclear and cytoplasmic genome, and find ample diversity at the nuclear level (π=0.019 at synonymous sites) but reduced genetic diversity and an excess of rare polymorphisms in the cytoplasmic genome relative to the nuclear genome. Our finding is incompatible with the maintenance of gynodioecy via scenarios invoking long-term balancing selection, and instead suggests the recent fixation of CMS lineages in the populations studied. [ABSTRACT FROM AUTHOR]

Gynodioecious populations (i.e. populations with female and hermaphrodite individuals) often contain a third phenotype with an intermediate sex expression. In Silene italica, this phenotype is characterized by a mixture of pistillate and perfect flowers and is thus gynomonoecious. To characterize sexual functions of these gynomonoecious individuals and their potential influence in the maintenance of gynodioecy, reproductive characters of the three sexual phenotypes were compared over 2 years in several families of S. italica produced by crossing. We found that gynomonoecious individuals were intermediate for flower production and female fertility characters, although they did not always significantly differ from female individuals. Perfect flowers of gynomonoecious and hermaphrodite plants were similar in size and pollen production. Gynomonoecious individuals were thus intermediate in female and in male functions. Family effects were found for most of the characters. The female advantage (i.e. the fertility of females compared to the female fertility of pollen producing plants) was not dramatically different when gynomonoecious plants were taken into account. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society, 2006, 87, 583–591. [ABSTRACT FROM AUTHOR]

Senecio inaequidens is an invasive plant native from South Africa where it is part of a polyploid complex. We developed nine polymorphic microsatellite markers for tetraploid and diploid plants of the complex. The loci described have between 3 and 28 alleles. They were amplified in both diploid and tetraploid populations with the exception of two loci that were not amplified in one of the diploid population. These markers can be used to clarify relationships within the complex, phylogeography of the invasive plants and diversity in the invaded area. [ABSTRACT FROM AUTHOR]