scholarly journals The role of lateral and vertical herkogamy in the divergence of the blue- and red-flowered lineages of Lysimachia arvensis

2020 ◽  
Vol 125 (7) ◽  
pp. 1127-1135 ◽  
Author(s):  
F J Jiménez-López ◽  
P L Ortiz ◽  
M Talavera ◽  
J R Pannell ◽  
M Arista
Keyword(s):  
Pollen Limitation ◽  
Flower Colour ◽  
Reproductive Interference ◽  
Pollen Deposition ◽  
Potential Mechanism ◽  
Reproductive Assurance ◽  
Self Fertilization ◽  
Annual Herb ◽  
Mixed Populations

Abstract Background and Aims Herkogamy, or anther–stigma separation, is known to reduce self-pollen deposition, but little is known about the relative efficacy of different modes or conformations of herkogamy. We assessed the effectiveness of vertical versus lateral herkogamy in preventing or promoting self-pollen deposition in the annual herb Lysimachia arvensis, a plant with lineages that differ in flower colour, and in which flowers first display lateral and then vertical herkogamy. Because mating between the two lineages compromises fitness through the production of low-quality hybrid offspring, we tested the prediction that individuals sampled from sites occupied by both lineages should have flowers that promote autonomous self-pollen deposition and self-fertilization as a result of selection to reduce deleterious reproductive interference. Methods We characterized variation in herkogamy within and among 25 pure and mixed populations of L. arvensis in its European range and assessed the effectiveness of lateral versus vertical herkogamy in avoiding self-pollen deposition. Results Lateral herkogamy was more effective than vertical herkogamy in limiting self-pollen deposition. In the case of vertical herkogamy, only approach herkogamy was effective. Lineages showed consistent differences in herkogamy traits. In general, angles were smaller for blue than red flowers in most populations, and blue flowers showed approach herkogamy, while red flowers showed predominantly reverse herkogamy. In sympatry, the red lineage showed a reduction of both herkogamy traits while for the blue lineage only lateral herkogamy was reduced. Conclusions Our results demonstrate that pollen deposition is affected not only by the degree but also the spatial conformation of herkogamy. They also highlight reduced herkogamy as a potential mechanism for promoting reproductive assurance under pollen limitation, as well as for avoiding reproductive interference between genetically divergent lineages.

scholarly journals The demography and population genomics of evolutionary transitions to self-fertilization in plants

2014 ◽  
Vol 369 (1648) ◽  
pp. 20130344 ◽  
Author(s):  
Spencer C. H. Barrett ◽  
Ramesh Arunkumar ◽  
Stephen I. Wright
Keyword(s):  
Mating System ◽  
Population Genomics ◽  
Molecular Data ◽  
Reproductive Assurance ◽  
Evolutionary Transitions ◽  
Cast Doubt ◽  
Self Fertilization ◽  
Loss Of Diversity ◽  
Linked Selection

The evolution of self-fertilization from outcrossing has occurred on numerous occasions in flowering plants. This shift in mating system profoundly influences the morphology, ecology, genetics and evolution of selfing lineages. As a result, there has been sustained interest in understanding the mechanisms driving the evolution of selfing and its environmental context. Recently, patterns of molecular variation have been used to make inferences about the selective mechanisms associated with mating system transitions. However, these inferences can be complicated by the action of linked selection following the transition. Here, using multilocus simulations and comparative molecular data from related selfers and outcrossers, we demonstrate that there is little evidence for strong bottlenecks associated with initial transitions to selfing, and our simulation results cast doubt on whether it is possible to infer the role of bottlenecks associated with reproductive assurance in the evolution of selfing. They indicate that the effects of background selection on the loss of diversity and efficacy of selection occur rapidly following the shift to high selfing. Future comparative studies that integrate explicit ecological and genomic details are necessary for quantifying the independent and joint effects of selection and demography on transitions to selfing and the loss of genetic diversity.

Insects facilitate wind pollination in pollen-limited Crateva adansonii (Capparaceae)

2011 ◽  
Vol 59 (1) ◽  
pp. 61 ◽  
Author(s):  
Yash Mangla ◽  
Rajesh Tandon
Keyword(s):  
Fruit Set ◽  
Pollen Limitation ◽  
Airborne Pollen ◽  
Pollen Dispersal ◽  
Natural Populations ◽  
Pollen Grains ◽  
Floral Biology ◽  
Wind Pollination ◽  
Reproductive Assurance

Low fruit-set in obligately outbreeding plant species is attributed to a variety of reasons that can be ascertained from reproductive studies. In the present work, the causes of poor natural fruit-set in Crateva adansonii DC. were investigated. Floral biology, the role of wind and insects in pollination and the breeding system of the species were studied in two natural populations for three consecutive seasons (2006–08). The flowers exhibited traits conducive to a mixture of wind and insect pollination (ambophily). Although a variety of insects visited the flowers, they were ineffective in pollinating. Nevertheless, active foraging by the honeybees (Apis dorsata, A. mellifera and A. cerana indica) facilitated enhanced pollen dispersal in the air and resulted in indirect pollination by wind. Airborne pollen grains pollinated the plants only up to 10 m. Fruit-set from open pollination was comparable to wind-pollinated flowers. Supplemental pollination treatments established the occurrence of strong self-incompatibility (SI) (index of SI = 0.14). Spontaneous autogamy was prevented by pronounced herkogamy. Low natural fecundity in C. adansonii is due to pollination failure, pollen limitation (pollen limitation index = 0.98) and the sparse distribution of the conspecifics; partial SI may partly ensure reproductive assurance through geitonogamy. In the absence of a pollinator wind appears to act as a secondary mode of pollination.

scholarly journals Acupuncture for Primary Dysmenorrhea: A Potential Mechanism from an Anti-Inflammatory Perspective

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Wen-Yan Yu ◽  
Liang-Xiao Ma ◽  
Zhou Zhang ◽  
Jie-Dan Mu ◽  
Tian-Yi Sun ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Animal Studies ◽  
Visceral Pain ◽  
Self Healing ◽  
Primary Dysmenorrhea ◽  
Potential Mechanism ◽  
Future Studies ◽  
Anti Inflammatory ◽  
Proinflammatory Factors

The low adverse effects of acupuncture for primary dysmenorrhea (PD), known as one of the most commonly reported gynecological debilitating conditions affecting women’s overall health, have been thus far confirmed. Moreover, it has been increasingly recognized that inflammation is involved in such menstrual cramps, and recent studies have further shown that the anti-inflammatory effects of acupuncture are helpful in its control. This review portrays the role of inflammation in PD pathophysiology, provides evidence from clinical and animal studies on acupuncture for inflammation-induced visceral pain, and reflects on acupuncture-related therapies for dysmenorrhea with regard to their anti-inflammatory characteristics. Further research accordingly needs to be carried out to clarify the effects of acupuncture on proinflammatory factors in PD, particularly chemokines and leukocytes. Future studies on this condition from an anti-inflammatory perspective should be also performed in line with the notion of emphasizing stimulation modes to optimize the clinical modalities of acupuncture. Additionally, the effects and mechanism of more convenient self-healing approaches such as TENS/TEAS for PD should be investigated.

scholarly journals A Triple Threat? The Role of Diet, Nutrition, and the Microbiota in T1D Pathogenesis

2021 ◽  
Vol 8 ◽  
Author(s):  
Emma E. Hamilton-Williams ◽  
Graciela L. Lorca ◽  
Jill M. Norris ◽  
Jessica L. Dunne
Keyword(s):  
Beta Cell ◽  
Intestinal Microbiota ◽  
Beta Cell Function ◽  
Cell Function ◽  
The Body ◽  
Islet Autoimmunity ◽  
Potential Mechanism ◽  
Modifiable Factors ◽  
And Function

In recent years the role of the intestinal microbiota in health and disease has come to the forefront of medical research. Alterations in the intestinal microbiota and several of its features have been linked to numerous diseases, including type 1 diabetes (T1D). To date, studies in animal models of T1D, as well as studies in human subjects, have linked several intestinal microbiota alterations with T1D pathogenesis. Features that are most often linked with T1D pathogenesis include decreased microbial diversity, the relative abundance of specific strains of individual microbes, and altered metabolite production. Alterations in these features as well as others have provided insight into T1D pathogenesis and shed light on the potential mechanism by which the microbiota plays a role in T1D pathogenesis, yet the underlying factors leading to these alterations remains unknown. One potential mechanism for alteration of the microbiota is through diet and nutrition. Previous studies have shown associations of diet with islet autoimmunity, but a direct contributing factor has yet to be identified. Diet, through introduction of antigens and alteration of the composition and function of the microbiota, may elicit the immune system to produce autoreactive responses that result in the destruction of the beta cells. Here, we review the evidence associating diet induced changes in the intestinal microbiota and their contribution to T1D pathogenesis. We further provide a roadmap for determining the effect of diet and other modifiable factors on the entire microbiota ecosystem, including its impact on both immune and beta cell function, as it relates to T1D. A greater understanding of the complex interactions between the intestinal microbiota and several interacting systems in the body (immune, intestinal integrity and function, metabolism, beta cell function, etc.) may provide scientifically rational approaches to prevent development of T1D and other childhood immune and allergic diseases and biomarkers to evaluate the efficacy of interventions.

ALLEE EFFECT AND SELF-FERTILIZATION IN HERMAPHRODITES: REPRODUCTIVE ASSURANCE IN A STRUCTURED METAPOPULATION

Evolution ◽  
2008 ◽  
Vol 62 (10) ◽  
pp. 2558-2569 ◽  
Author(s):  
Antoine Dornier ◽  
François Munoz ◽  
Pierre-Olivier Cheptou
Keyword(s):  
Allee Effect ◽  
Reproductive Assurance ◽  
Self Fertilization ◽  
Structured Metapopulation

The role of oxidative stress in the cardiovascular actions of particulate air pollution

2014 ◽  
Vol 42 (4) ◽  
pp. 1006-1011 ◽  
Author(s):  
Mark R. Miller
Keyword(s):  
Oxidative Stress ◽  
Air Pollution ◽  
Diesel Exhaust ◽  
Vascular Function ◽  
Cardiovascular Effects ◽  
Increase Blood Pressure ◽  
Potential Mechanism ◽  
Particulate Air Pollution ◽  
Cardiovascular Actions

Air pollution has been estimated to be responsible for several millions of deaths worldwide per year, the majority of which have been attributed to cardiovascular causes. The particulate matter in air pollution has been shown impair vascular function, increase blood pressure, promote thrombosis and impair fibrinolysis, accelerate the development of atherosclerosis, increase the extent of myocardial ischaemia, and increase susceptibility to myocardial infarction. The pathways underlying these effects are complex and poorly understood; however, particulate-induced oxidative stress repeatedly emerges as a potential mechanism in all of these detrimental cardiovascular actions. The present mini-review will use diesel exhaust as an example of a pollutant rich in combustion-derived nanoparticles, to describe the potential by which oxidative stress could drive the cardiovascular effects of air pollution.

scholarly journals AP-1 elements and TCL1 protein regulate expression of the gene encoding protein tyrosine phosphatase PTPROt in leukemia

Blood ◽  
2011 ◽  
Vol 118 (23) ◽  
pp. 6132-6140 ◽  
Author(s):  
Tasneem Motiwala ◽  
Nicola Zanesi ◽  
Jharna Datta ◽  
Satavisha Roy ◽  
Huban Kutay ◽  
...  
Keyword(s):  
Protein Tyrosine Phosphatase ◽  
Tyrosine Phosphatase ◽  
Lymphocytic Leukemia ◽  
Potential Mechanism ◽  
Wild Type ◽  
Truncated Form ◽  
Gene Encoding ◽  
Protein Tyrosine ◽  
Encoding Protein

Abstract We previously demonstrated that the gene encoding PTPROt, the truncated form of protein tyrosine phosphatase receptor type O expressed predominantly in hematopoietic cells, is a candidate tumor suppressor and is down-regulated in chronic lymphocytic leukemia (CLL). Here, we show that PTPROt expression is significantly reduced in CD19+ spleen B cells from Eμ-T cell leukemia 1 (TCL1) transgenic mice relative to the wild-type mice. Strikingly, as much as a 60% decrease in PTPROt expression occurs at 7 weeks independently of promoter methylation. To elucidate the potential mechanism for this early suppression of PTPROt in these mice, we explored the role of activating protein-1 (AP-1) in its expression. We first demonstrate that AP-1 activation by 12-O-tetradecanoylphorbol-13-acetate induces PTPROt expression with concurrent recruitment of c-fos and c-jun to its promoter. The PTPROt promoter is also responsive to over- and underexpression of AP-1, confirming the role of AP-1 in PTPROt expression. Next, we demonstrate that TCL1 can repress the PTPROt promoter by altering c-fos expression and c-jun activation state. Finally, using primary CLL cells we have shown an inverse relationship between TCL1 and PTPROt expression. These findings further substantiate the role of TCL1 in PTPROt suppression and its importance in the pathogenesis of CLL.

scholarly journals Garcinoic Acid Improves Cardiac Function and Enhances Angiogenesis Following Myocardial Infarction

2021 ◽  
Author(s):  
Hongyao Hu ◽  
Wei Li ◽  
Yanzhao Wei ◽  
Hui Zhao ◽  
Zhenzhong Wu ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Cardiac Function ◽  
Ventricular Remodeling ◽  
Vehicle Group ◽  
Potential Mechanism ◽  
Garcinia Kola ◽  
Angiogenic Proteins

Abstract Cardiac ischemia impairs angiogenesis in response to hypoxia, resulting in ventricular remodeling. Garcinoic acid (GA), the extraction from the plant garcinia kola, is validated to attenuate inflammatory response. However, the role of GA in heart failure (HF) and neovascularization after myocardial infarction (MI) is incompletely understood. The present study is striving to explore the role of GA and the potential mechanism of which in cardiac function after MI. SD rats were randomized into sham group, MI+vehicle group, and MI+GA group in vivo. Human umbilical endothelial cells (HUVECs) were cultured in vehicle or GA, and then additionally exposed to 2% hypoxia environment in vitro. MI rats displayed a dramatically reduced myocardial injury, cardiac function and vessel density in the peri-infarcted areas. GA delivery markedly improved cardiac performance and promoted angiogenesis. In addition, GA significantly enhanced tube formation in HUVECs under hypoxia condition. Furthermore, the expressions of pro-angiogenic factors HIF-1α, VEGF-A and bFGF, and pro-angiogenic proteins phospho-VEGFR2Tyr1175 and VEGFR2, as well as phosphorylation levels of Akt and eNOS were increased by GA treatment. In conclusion, GA preserved cardiac function after MI probably via promoting neovascularization. And the potential mechanism may be partially through upregulating the expressions of HIF-1α, VEGF-A, bFGF, phospho-VEGFR2Tyr1175 and VEGFR2 and activating the phosphorylations of Akt and eNOS.

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