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Mariana Wolfner
Mariana Federica Wolfner is the Goldwin Smith Professor of molecular biology and genetics at Cornell University. Her research investigates sexual conflict in the fruit fly '' Drosophila melanogaster''. She was elected a member of the National Academy of Sciences (NAS) in 2019 in recognition of her distinguished and continuing achievements in original research. Early life and education Wolfner became interested in biology as a child. She decided to study at Cornell University because it was well known for genetics. During her undergraduate degree she worked in Gerald Fink's laboratory, studying the control of amino acids in yeast, and graduated in 1974. She moved to Stanford University for her graduate degree, where she was a doctoral student in the lab of David Hogness. She was one of the first to use recombinant DNA to isolate the genes in '' Drosophila''. Wolfner pioneered the use of cDNA hybridisation to isolate the genes which respond to ecdysone during metamorphosi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cornell University
Cornell University is a private statutory land-grant research university based in Ithaca, New York. It is a member of the Ivy League. Founded in 1865 by Ezra Cornell and Andrew Dickson White, Cornell was founded with the intention to teach and make contributions in all fields of knowledge—from the classics to the sciences, and from the theoretical to the applied. These ideals, unconventional for the time, are captured in Cornell's founding principle, a popular 1868 quotation from founder Ezra Cornell: "I would found an institution where any person can find instruction in any study." Cornell is ranked among the top global universities. The university is organized into seven undergraduate colleges and seven graduate divisions at its main Ithaca campus, with each college and division defining its specific admission standards and academic programs in near autonomy. The university also administers three satellite campuses, two in New York City and one in Educatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amino Acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha amino acids appear in the genetic code. Amino acids can be classified according to the locations of the core structural functional groups, as Alpha and beta carbon, alpha- , beta- , gamma- or delta- amino acids; other categories relate to Chemical polarity, polarity, ionization, and side chain group type (aliphatic, Open-chain compound, acyclic, aromatic, containing hydroxyl or sulfur, etc.). In the form of proteins, amino acid ''residues'' form the second-largest component ( water being the largest) of human muscles and other tissues. Beyond their role as residues in proteins, amino acids participate in a number of processes such as neurotransmitter transport and biosynthesis. It is thought that they played a key role in enabling li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Male Accessory Gland
Male accessory glands (MAG) in humans are the seminal vesicles, prostate gland, and the bulbourethral glands (also called Cowper's glands). In insects, male accessory glands produce products that mix with the sperm to protect and preserve them, including seminal fluid proteins. Some insecticides can induce an increase in the protein content of the male accessory glands of certain types of insects. This has the unintended effect of increasing the number of offspring they produce. These glands secrete fluid for nourishment of sperm. Accessory glands The male accessory glands are the ampullary gland, seminal vesicles, prostate, bulbourethral gland, and urethral glands. The products of these glands serve to nourish and activate the spermatozoa, to clear the urethral tract prior to ejaculation, serve as the vehicle of transport of the spermatozoa in the female tract, and to plug the female tract after placement of spermatozoa to help ensure fertilization. Although the glands ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Ablation
Genetic ablation occurs when a gene is deemed “null” through the homologous genetic recombination of a gene. It is utilized in the selective suppression of a specific cell line or cell type. This genetic engineering technique does not limit growth suppression to just the activity of an individual gene. Specific cell ablation enables the examination of the ''in vivo'' activity of cells. An example of this method in action can be seen through the production of a knockout mouse. This is accomplished through the administration of one or more transgenes into a fertilized mouse oocyte’s pronucleus. Afterwards, it is reimplanted into a host mother, who then births a transgenic mouse. The transgenic mouse carries one copy of the transgene3 out of several hundred. From these mice, a homozygous colony can be created through breeding. Historical development In 1990, the gene knockout technique was just developing. There was a lack of information on the initial events that occur through ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seminal Fluid Protein
Seminal fluid proteins (SFPs) or accessory gland proteins (Acps) are one of the non-sperm components of semen. In many animals with internal fertilization, males transfer a complex cocktail of proteins in their semen to females during copulation. These seminal fluid proteins often have diverse, potent effects on female post-mating phenotypes. SFPs are produced by the male accessory glands. Seminal fluid proteins frequently show evidence of elevated evolutionary rates and are often cited as an example of sexual conflict. Proteomics SFPs are best studied in mammals and insects, especially in the common fruit fly, '' Drosophila melanogaster''. Most species produce a wide variety of proteins that are transferred to females. For example, approximately 150 SFPs have been identified in ''D. melanogaster'', 46 in the mosquito '' Anopheles gambae'', and around 160 in humans. Elevated evolution Even between closely related species, the seminal fluid proteome can vary greatly. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doublesex
''Doublesex'' (''dsx'') is a gene that is involved in the sex determination system of many insects including the fruit fly ''Drosophila melanogaster''. Sex determination The gene is expressed in both male and female flies and is subject to alternative splicing, producing the protein isoforms ''dsxf'' in females and the longer ''dsxm'' in males. The production of ''dsxf'' is caused by the presence of the female-specific version of the ''transformer'' (''tra'') gene. In a sense, the isoform of ''dsx'' informs a cell about the organism's sex; for instance, female genitals only develop if ''dsxf'' is present. In conjunction with the gene ''fruitless'', ''dsx'' also causes differences in the brain structure and behavior of males and females. Lay summary: Although the details of sex determination differ in the various species, there is a gene related to ''dsx'' in vertebrates (DMRT1) and in nematodes ( MAB-3). All of these are transcription factors with a zinc finger DNA-binding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sex-determination System
A sex-determination system is a biological system that determines the development of sexual characteristics in an organism. Most organisms that create their offspring using sexual reproduction have two sexes. In some species there are hermaphrodites. There are also some species that are only one sex due to parthenogenesis, the act of a female reproducing without fertilization. In some species, sex determination is genetic: males and females have different alleles or even different genes that specify their sexual morphology. In animals this is often accompanied by chromosomal differences, generally through combinations of XY, ZW, XO, ZO chromosomes, or haplodiploidy. The sexual differentiation is generally triggered by a main gene (a "sex locus"), with a multitude of other genes following in a domino effect. In other cases, sex of a fetus is determined by environmental variables (such as temperature). The details of some sex-determination systems are not yet fully und ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fellow
A fellow is a concept whose exact meaning depends on context. In learned or professional societies, it refers to a privileged member who is specially elected in recognition of their work and achievements. Within the context of higher educational institutions, a fellow can be a member of a highly ranked group of teachers at a particular college or university or a member of the governing body in some universities (such as the Fellows of Harvard College); it can also be a specially selected postgraduate student who has been appointed to a post (called a fellowship) granting a stipend, research facilities and other privileges for a fixed period (usually one year or more) in order to undertake some advanced study or research, often in return for teaching services. In the context of research and development-intensive large companies or corporations, the title "fellow" is sometimes given to a small number of senior scientists and engineers. In the context of medical education in N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Postdoctoral
A postdoctoral fellow, postdoctoral researcher, or simply postdoc, is a person professionally conducting research after the completion of their doctoral studies (typically a PhD). The ultimate goal of a postdoctoral research position is to pursue additional research, training, or teaching in order to have better skills to pursue a career in academia, research, or any other field. Postdocs often, but not always, have a temporary academic appointment, sometimes in preparation for an academic faculty position. They continue their studies or carry out research and further increase expertise in a specialist subject, including integrating a team and acquiring novel skills and research methods. Postdoctoral research is often considered essential while advancing the scholarly mission of the host institution; it is expected to produce relevant publications in peer-reviewed academic journals or conferences. In some countries, postdoctoral research may lead to further formal qualification ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metamorphosis
Metamorphosis is a biological process by which an animal physically develops including birth or hatching, involving a conspicuous and relatively abrupt change in the animal's body structure through cell growth and differentiation. Some insects, fish, amphibians, mollusks, crustaceans, cnidarians, echinoderms, and tunicates undergo metamorphosis, which is often accompanied by a change of nutrition source or behavior. Animals can be divided into species that undergo complete metamorphosis (" holometaboly"), incomplete metamorphosis (" hemimetaboly"), or no metamorphosis (" ametaboly"). Scientific usage of the term is technically precise, and it is not applied to general aspects of cell growth, including rapid growth spurts. Generally organisms with a larva stage undergo metamorphosis, and during metamorphosis the organism loses larval characteristics. References to "metamorphosis" in mammals are imprecise and only colloquial, but historically idealist ideas of transf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ecdysone
Ecdysone is a prohormone of the major insect molting hormone 20-hydroxyecdysone, which is secreted from the prothoracic glands. It is of steroidal structure. Insect molting hormones (ecdysone and its homologues) are generally called ecdysteroids. Ecdysteroids act as moulting hormones of arthropods but also occur in other related phyla where they can play different roles. In '' Drosophila melanogaster'', an increase in ecdysone concentration induces the expression of genes coding for proteins that the larva requires, and it causes chromosome puffs (sites of high expression) to form in polytene chromosomes. Recent findings in the laboratory of Chris Q. Doe have found a novel role of this hormone in regulating temporal gene transitions within neural stem cells of the fruit fly. Ecdysone and other ecdysteroids also appear in many plants mostly as a protection agent (toxins or antifeedants) against herbivorous insects. These phytoecdysteroids have been reputed to have medici ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CDNA
In genetics, complementary DNA (cDNA) is DNA synthesized from a single-stranded RNA (e.g., messenger RNA (mRNA) or microRNA (miRNA)) template in a reaction catalyzed by the enzyme reverse transcriptase. cDNA is often used to express a specific protein in a cell that does not normally express that protein (i.e., heterologous expression), or to sequence or quantify mRNA molecules using DNA based methods (qPCR, RNA-seq). cDNA that codes for a specific protein can be transferred to a recipient cell for expression, often bacterial or yeast expression systems. cDNA is also generated to analyze transcriptomic profiles in bulk tissue, single cells, or single nuclei in assays such as microarrays, qPCR, and RNA-seq. cDNA is also produced naturally by retroviruses (such as HIV-1, HIV-2, simian immunodeficiency virus, etc.) and then integrated into the host's genome, where it creates a provirus. The term ''cDNA'' is also used, typically in a bioinformatics context, to refer to an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
