An intron is any nucleotide sequence within a gene that is not expressed or operative in the final RNA product. The word intron is derived from the term intragenic region, i.e., a region inside a gene. The term intron refers to both the DNA sequence within a gene and the corresponding RNA sequence in RNA transcripts. The non-intron sequences that become joined by this RNA processing to form the mature RNA are called exons.
Self-pollination is a form of pollination in which pollen from the same plant arrives at the stigma of a flower or at the ovule. There are two types of self-pollination: in autogamy, pollen is transferred to the stigma of the same flower; in geitonogamy, pollen is transferred from the anther of one flower to the stigma of another flower on the same flowering plant, or from microsporangium to ovule within a single (monoecious) gymnosperm. Some plants have mechanisms that ensure autogamy, such as flowers that do not open (cleistogamy), or stamens that move to come into contact with the stigma. The term selfing that is often used as a synonym, is not limited to self-pollination, but also applies to other type of self-fertilization.
Verbascum is a genus of over 450 species of flowering plants, common name mullein, in the figwort family Scrophulariaceae. They are native to Europe and Asia, with the highest species diversity in the Mediterranean.
The rangeomorphs are a form taxon of frondose Ediacaran fossils that are united by a similarity to Rangea. Some researchers, such as Pflug and Narbonne, suggest that a natural taxon Rangeomorpha may include all similar-looking fossils. Rangeomorphs appear to have had an effective reproductive strategy, based on analysis of the distribution pattern of Fractofusus misrai, which consisted of sending out a waterborne asexual propagule to a distant area, and then spreading rapidly from there, just as plants today spread by stolons or runners.
Capsella is a genus of herbaceous plant and biennial plants in the family Brassicaceae. It is a close relative of Arabidopsis, Neslia, and Halimolobos.
Self-incompatibility (SI) is a general name for several genetic mechanisms that prevent self-fertilization in sexually reproducing organisms, and thus encourage outcrossing and allogamy. It is contrasted with separation of sexes among individuals (dioecy), and their various modes of spatial (herkogamy) and temporal (dichogamy) separation.
Viridiplantae constitute a clade of eukaryotic organisms that comprises approximately 450,000–500,000 species that play important roles in both terrestrial and aquatic ecosystems. They include the green algae, which are primarily aquatic, and the land plants (embryophytes), which emerged from within them. Green algae traditionally excludes the land plants, rendering them a paraphyletic group. However it is accurate to think of land plants as a kind of alga. Since the realization that the embryophytes emerged from within the green algae, some authors are starting to include them. They have cells with cellulose in their cell walls, and primary chloroplasts derived from endosymbiosis with cyanobacteria that contain chlorophylls a and b and lack phycobilins. Corroborating this, a basal phagotroph archaeplastida group has been found in the Rhodelphydia.
The Rafflesiaceae are a family of rare parasitic plants comprising 36 species in 3 genera found in the tropical forests of east and southeast Asia, including Rafflesia arnoldii, which has the largest flowers of all plants. The plants are endoparasites of vines in the genus Tetrastigma (Vitaceae) and lack stems, leaves, roots, and any photosynthetic tissue. They rely entirely on their host plants for both water and nutrients, and only then emerge as flowers from the roots or lower stems of the host plants.
Epitherians comprise all the placental mammals except the Xenarthra. They are primarily characterized by having a stirrup-shaped stapes in the middle ear, which allows for passage of a blood vessel. This is in contrast to the column-shaped stapes found in marsupials, monotremes, and xenarthrans. They are also characterized by having a shorter fibula relative to the tibia.
New World crops are those crops, food and otherwise, that are native to the New World and were not found in the Old World before 1492 AD. Many of these crops are now grown around the world and have often become an integral part of the cuisine of various cultures in the Old World. Notable among them are the "Three Sisters": maize, winter squash, and climbing beans.
An ecological network is a representation of the biotic interactions in an ecosystem, in which species (nodes) are connected by pairwise interactions (links). These interactions can be trophic or symbiotic. Ecological networks are used to describe and compare the structures of real ecosystems, while network models are used to investigate the effects of network structure on properties such as ecosystem stability.
Peptide signaling plays a significant role in various aspects of plant growth and development and specific receptors for various peptides have been identified as being membrane-localized receptor kinases, the largest family of receptor-like molecules in plants. Signaling peptides include members of the following protein families.
Hans Joachim "John" Schellnhuber is a German atmospheric physicist, climatologist and founding director of the Potsdam Institute for Climate Impact Research (PIK) and former chair of the German Advisory Council on Global Change (WBGU). Since 1 December 2023, Schellnhuber is the Director General of IIASA.
Sanjiv Sam Gambhir was an American physician–scientist. He was the Virginia and D.K. Ludwig Professor in Cancer Research, Chairman of the Department of Radiology at Stanford University School of Medicine, and a professor by courtesy in the departments of Bioengineering and Materials Science and Engineering at Stanford University. Additionally, he served as the Director of the Molecular Imaging Program at Stanford (MIPS), Canary Center at Stanford for Cancer Early Detection and the Precision Health and Integrated Diagnostics Center (PHIND). He authored 680 publications and had over 40 patents pending or granted. His work was featured on the cover of over 25 journals including the Nature Series, Science, and Science Translational Medicine. He was on the editorial board of several journals including Nano Letters, Nature Clinical Practice Oncology, and Science Translational Medicine. He was founder/co-founder of several biotechnology companies and also served on the scientific advisory board of multiple companies. He mentored over 150 post-doctoral fellows and graduate students from over a dozen disciplines. He was known for his work in molecular imaging of living subjects and early cancer detection.
Neorites is a monotypic genus of plants in the family Proteaceae. The sole species Neorites kevedianus, commonly called fishtail oak or fishtail silky oak, is a tall tree endemic to the wet tropics rainforests of north eastern Queensland, Australia.
Capsella rubella, the pink shepherd's-purse, is a plant species in the genus Capsella, a very close relative of Arabidopsis thaliana and a member of the mustard family, Brassicaceae. It has a very similar appearance to Capsella bursa-pastoris, but C. rubella has a diploid genome, whereas C. bursa-pastoris is tetraploid. Capsella rubella is used as a model plant to study the evolution of self-incompatibility into self-compatibility in plant reproduction. The species is found mostly in Mediterranean region. Separation of this species from its closest ancestor is predicted to have happened around 30,000 to 50,000 years ago.
Raymond Ethan Goldstein FRS FInstP is the Alan Turing Professor of Complex Physical Systems in the Department of Applied Mathematics and Theoretical Physics (DAMTP) at the University of Cambridge and a Fellow of Churchill College, Cambridge.
Eukaryote hybrid genomes result from interspecific hybridization, where closely related species mate and produce offspring with admixed genomes. The advent of large-scale genomic sequencing has shown that hybridization is common, and that it may represent an important source of novel variation. Although most interspecific hybrids are sterile or less fit than their parents, some may survive and reproduce, enabling the transfer of adaptive variants across the species boundary, and even result in the formation of novel evolutionary lineages. There are two main variants of hybrid species genomes: allopolyploid, which have one full chromosome set from each parent species, and homoploid, which are a mosaic of the parent species genomes with no increase in chromosome number.
Selfing syndrome refers to plants that are autogamous and display a complex of characteristics associated with self-pollination. The term was first coined by Adrien Sicard and Michael Lenhard in 2011, but was first described in detail by Charles Darwin in his book “The Effects of Cross and Self Fertilisation in the Vegetable Kingdom” (1876), making note that the flowers of self-fertilizing plants are typically smaller and have little distance between reproductive organs.
June Nasrallah is Barbara McClintock Professor in the Plant Biology Section of the School of Integrative Plant Science at Cornell University. Her research focuses on plant reproductive biology and the cell-cell interactions that underlie self-incompatibility in plants belonging to the mustard (Brassicaceae) family. She was elected to the US National Academy of Sciences in 2003 for this work and her contributions generally to our understanding of receptor-based signaling in plants.
