Self-experimentation Research Articles

Pollination efficiency and pollen limitation in bistaminate vs tetrastaminate Lamiaceae

AbstractThe evolution of bilabiate flowers in Lamiaceae has several times led to a reduction in stamen number. It is generally assumed that stamen reduction goes along with decreasing pollen production. One should, therefore, expect that bistaminate flowers have either a more efficient pollen transfer mechanism or a higher selfíng rate than tetrastaminate species to adapt to the stamen reduction. We tested this hypothesis in a community of Lamiaceae including three bistaminate and three tetrastaminate species. The results of selfing experiments, extra‐pollination, counting pollen number, and stigmatic pollen load analysis were used to calculate the autonomous selfing index, the pollen limitation index, and the pollination efficiency index. The results indicate a significantly lower pollen number in bistaminate flowers than in tetrastaminate flowers of similar anther size. Bistaminate species shared a higher selfing rate which was related to their structural adaptation to delayed selfing. In Ziziphora clinopodioides, the delayed selfing was accompanied by low pollination efficiency, and plants suffered from pollen limitation at the location studied. However, in Salvia sclarea and Salvia hypoleuca, which benefited from a relatively high pollination efficiency, no pollen limitation was observed. Our results reveal a close association between adaptive mechanisms such as increasing precision of pollen transfer and evolution of delayed selfing with stamen reduction in bistaminate Lamiaceae.

Fertility investigation in F1 hybrid and karyotype analysis of backcross progeny from Misgurnus anguillicaudatus and Paramisgurnus dabryanus

Dojo loach (Misgurnus anguillicaudatus) (DD, 2n = 50) and large-scale loach (Paramisgurnus dabryanus) (PP, 2n = 48) are freshwater fish species widely distributed across East Asia. Hybrids of these two loach species have disrupted gonadal development, but few studies have reported the actual fertility and chromosome number in gametes of reciprocal hybrid loaches (DD × PP and PP × DD, assigned as DP and PD, 2n = 49). In this study, selfing and backcrossing experiments between M. anguilicaudatus and P. dabryanus were conducted. The fertilization, hatching, deformity, and survival rates were examined along with the embryonic development and growth performance to analyze the actual fertility of the hybrid loach. The karyotypes of viable backcross offspring were studied to indirectly assess the chromosome number in eggs of DP and PD hybrids. The failure in fertilization among crosses using male hybrid proved that the male hybrid was sterile. The moderate fertilization rates (11.49%‐–49.16%), high hatching rates (82.78%–86.31%), high survival rates (78.67%–81.33%), and the normal embryonic development among crosses using female hybrid revealed that the female hybrid was fertile, albeit with relatively high deformity rates (12.68%–27.45%). The karyotype analysis of viable backcross offspring showed 49 chromosomes for DP × DD (assigned as DPD) and PD × DD (assigned as PDD) hybrids, and 48 chromosomes for DP × PP (assigned as DPP) and PD × PP (assigned as PDP) hybrids. This indicated that fertile gametes produced by female hybrid loach contained 24 chromosomes. This study provides valuable information for loach hybrid breeding and in-depth research on the precise mechanism of meiosis in these hybrid loach.

Investigating the potential of novel non-woven fabrics for efficient pollination control in plant breeding.

Plant breeding is achieved through the controlled self- or cross-pollination of individuals and typically involves isolation of floral parts from selected parental plants. Paper, cellulose or synthetic materials are used to avoid self pollination or cross contamination. Low seed set limits the rate of breeding progress and increases costs. We hypothesized that a novel ‘non-woven’ fabric optimal for both pollination and seed set in multiple plant species could be developed. After determining the baseline pollen characteristics and usage requirements we established iterative three phase development and biological testing. This determined (1) that white fabric gave superior seed return and informed the (2) development of three non-woven materials using different fibre and layering techniques. We tested their performance in selfing and hybridisation experiments recording differences in performance by material type within species. Finally we (3) developed further advanced fabrics with increased air permeability and tested biological performance. An interaction between material type and species was observed and environmental decoupling investigated, showing that the non-woven fabrics had superior water vapour transmission and temperature regulation compared to controls. Overall, non-woven fabrics outperformed existing materials for both pollination and seed set and we found that different materials can optimize species-specific, rather than species-generic performance.

Self-Experiments with Psychoactive Substances: A Historical Perspective.

The purpose of this chapter is to highlight the rich tradition of self-experiments (SEs) with psychoactive substances carried out by scientists and therapists for more than a century. Scientifically inspired controlled SEs dominated until the end of the twentieth century, when ethical requirements minimized controlled SEs and "wild" SEs expanded particularly with the emergence of new psychoactive substances. The review focuses on laughing gas (nitrous oxide), cannabis, cocaine, hallucinogens, entactogens, and dissociative hallucinogens. This is due to the fact that substances that induce "complex" effects such as alteration of space/time experience, ego dissolution, and increased feelings and insights (e.g., hallucinogens, entactogens) represent by far the majority of SEs, whereas SEs with substances inducing "simple" effects such as euphoria, anxiolysis, dissociation, or emotional blunting (e.g., cocaine, opioids) are much rarer or even absent (e.g., benzodiazepines). Complex drug effects are much harder to describe, thus allowing SEs to fulfill a more important function.SEs with psychoactive drugs appeared to emerge in the mid-eighteenth century, which triggered a long-standing tradition throughout the nineteenth and early twentieth century. SEs have been de facto performed for a variety of reasons, ranging from establishing scientific knowledge and gaining philosophical insights to compensating for personal deficits. Self-experimenters can be divided into two general types. Besides their scientific intentions, "exploratory" self-experimenters intend to expand awareness and insight, whereas "compensatory" self-experimenters might aim for coping with psychiatric symptoms or personality deficits. Scientific limitations of SEs are obvious when compared to double-blind, randomized, placebo-controlled trials. Whereas the former might lead to more "realistic" detailed description of subjective effects, the latter lead to more solid results in respect to objectively measurable "average" effects. Possible adverse effects of SEs were identified that resulted in loss of scientific objectivity and decreased control over substance use and addiction, development of isolation, problematic group dynamics, and "social autism."

Theatre: The needle in Newton's eye

A play about Isaac Newton's self-experimentation illuminates scientific rivalry, finds Alla Katsnelson

Physicians’ Role in Research Including Self-Experimentation

Physicians’ Role in Research Including Self-Experimentation

Evolution towards self‐compatibility when mates are limited

Theory of plant mating system evolution predicts the spread of self-compatibility (SC) in a predominantly self-incompatible population when inbreeding depression (ID; the decline in fitness because of selfing) is small and when compatible mates are limited. I tested these two predictions by measuring the occurrence of SC in 13 natural populations of Ranunculus reptans L. that varied in ID and frequency of cross-incompatible mates. Enforced selfing experiments were conducted in 2 years. In the first year, self-pollination was applied at two flower ages to investigate the occurrence of delayed SC. I found that SC was not uncommon across all populations, but self-compatible plants usually produced few seeds. There was no evidence for delayed SC. The occurrence of SC was not associated with population-level ID, but populations with more limited availability of compatible mates had a significantly higher frequency of plants that were at least partially self-compatible. The results indicate that, in R. reptans, a shortage of available mates in small populations may cause the evolution of partial SC and mixed mating.

Scaled-up self-experimentation proposed

Scaled-up self-experimentation proposed

Self-Experimentation and Web Trials

Self-Experimentation and Web Trials

The Courageous — and Weird — Tradition of Self-Experimentation

The Courageous — and Weird — Tradition of Self-Experimentation

George Ralph Mines: victim of self-experimentation?

George Ralph Mines: victim of self-experimentation?

Comment: Lessons from Self-Experimentation: Counting for Content, Inspecting for Insight

Comment: Lessons from Self-Experimentation: Counting for Content, Inspecting for Insight

Hybridization in larch-alternating Melampsora epitea (M. larici-epitea)

Crossing and selfing experiments were carried out with six field collections and five isolates belonging to three formae speciales, larici-epitea typica (LET), larici-daphnoides (LD), and larici-retusae (LR), of willow rust, Melampsora epitea . European larch ( Larix decidua ) was inoculated with basidiospores produced on overwintered telial leaves and the resulting spermagonial lesions on larch needles subsequently paired in vitro . In two crosses between LR and LD involving a total of 439 lesion pairs, only two cultures obtained were identified as hybrids. These two cultures were non-pathogenic to the maternal host Salix burjatica cv. Korso and weakly pathogenic to the paternal host S. daphnoides cv. Meikle. No identifiable hybrids were obtained from 56 lesion pairs between LET and LD. In a cross between LET as receptor and LD as donor, one-third of the lesions formed aecia. In the reciprocal combination, however, less than 1% developed aecia. All F 1 cultures between LET and LR were weakly pathogenic to the parental hosts S. viminalis cv. Mullatin and S. burjatica cv. Korso. When three of the F 1 cultures were used to produce telia, only one developed mature teliospores. Subsequent selfing experiments showed that this culture was predominantly self-sterile, with only 1 % of lesions producing aecia. In selfing and crossing two pathotypes within the same f. spp. , 20–40 % of needles produced aecia and the rate of aecial formation was similar in both directions. The results obtained suggest that M. epitea is heterothallic and the sexual compatibility is controlled by a pair of alleles at a locus. It is concluded that the three f. spp. are genetically different populations and ecologically fit new pathotypes cannot arise easily as a result of hybridization between them. Within a f. sp. , however, many pathotypes exist or will occur due to exchange of genes for virulence during the sexual life-cycle.

Self-Experimentation

Self-Experimentation

The Ideology of Self-Knowledge and the Practice of Self-Experimentation

Etude de la situation precaire et previlegiee du sujet dans l'ideologie scientique et romantique de la connaissance de la nature et de la connaissance de soi en Allemagne au XVIII e siecle. Examinant l'histoire de la subjectivite moderne au regard de l'instant critique de la transformation structurelle de la sphere publique, l'A. mesure le role du soi dans la construction d'une nouvelle conception de l'individualite, a travers l'utilisation du corps comme instrument d'experimentation, comme source de connaissance et comme embleme de son individualite, par le savant J. W. Ritter (1776-1810)

Inferring deleterious-mutation parameters in natural daphnia populations

Deng and Lynch (1, 2) proposed to characterize deleterious genomic mutations from changes in the mean and genetic variance of fitness traits upon selfing in outcrossing populations. Such observations can be readily acquired in cyclical parthenogens. Selfing and life-table experiments were performed for two such Daphnia populations. A significant inbreeding depression and an increase of genetic variance for all traits analyzed were observed. Deng and Lynch's (2) procedures were employed to estimate the genomic mutation rate (U), mean dominance coefficient (), mean selection coefficient (), and scaled genomic mutational variance (). On average, , , and (^ indicates an estimate) are 0.84, 0.30, 0.14 and 4.6E-4 respectively. For the true values, the and are lower bounds, and and upper bounds.

Inbreeding depression and inferred deleterious-mutation parameters in Daphnia.

DENG and LYNCH recently proposed a method for estimating deleterious genomic mutation parameters from changes in the mean and genetic variance of fitness traits upon inbreeding in outcrossing populations. Such observations are readily acquired in cyclical parthenogens. Selfing and life-table experiments were performed for two such Daphnia populations. We observed a significant inbreeding depression and an increase of genetic variance for all traits analyzed. DENG and LYNCH's original procedures were extended to estimate genomic mutation rate (U), mean dominance coefficient (h), mean selection coefficient (s), and scaled genomic mutational variance (Vm/Ve). On average, U, h, s and Vm/Ve (indicates an estimate) are 0.84 [corrected], 0.30, 0.14 and 4.6E-4, respectively. For the true values, the U and h are lower bounds, and s and Vm/Ve upper bounds. The present U, h and Vm/Ve are in general concordance with earlier results. The discrepancy between the present s and that from mutation-accumulation experiments in Drosophila (approximately 0.04) is discussed. It is shown that different reproductive modes do not affect gene frequency at mutation-selection equilibrium if mutational effects on fitness are multiplicative and not completely recessive.

Book ReviewWho Goes First? The story of self-experimentation in medicine

Book ReviewWho Goes First? The story of self-experimentation in medicine

Self experimentation in medicine

Self experimentation in medicine

Who Goes First?: The Story of Self-Experimentation in Medicine.

Who Goes First?: The Story of Self-Experimentation in Medicine.