Bread mould avoids infection by mutating its own DNA

Whilst most organisms try to stop their DNA from mutating, scientists from the UK and China have discovered that a common fungus found on bread actively mutates its own DNA as a way of fighting virus-like infections.

Gene found that causes eyes to wither in cavefish

Mexican cavefish spend their entire lives in the dark. With no need for vision, many of them lost functional eyes. In more than 30 varieties of Mexican cavefish, the eyes stop developing as embryos grow into larvae. Although ...

Taming CRISPR's collateral damage

CRISPR-Cas9 can alter genes at pre-defined sites in specific ways, but it does not always act as planned. An LMU team has now developed a simple method to detect unintended "on-target" events, and shown that they often occur ...

Researchers discover new sex hormone

When University of Ottawa biologists Kim Mitchell and Vance Trudeau began studying the effects of gene mutations in zebrafish, they uncovered new functions that regulate how males and females interact while mating. We sat ...

Scientists shake up balancing act of plant metabolism

Step outside and spring is in full bloom, from red tulips, to pink magnolias to purple lilacs, but how do plants create all that color? The alluring hues that attract pollinators and provide beautiful bouquets begin with ...

Gene switch ENO identified as a tomato fruit regulator

A team of researchers from Spain, Germany and France has identified the gene switch ENO (excessive number of floral organs) as a tomato fruit regulator. In their paper published in Proceedings of the National Academy of Sciences, ...

Study connects specific genes with defective social behavior

Animals rely on group behavior to survive, whether it's fish swimming together to avoid predators or humans sharing knowledge with each other. But despite the importance of such social interactions, scientists do not have ...

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Mutation

In biology, mutations are changes to the nucleotide sequence of the genetic material of an organism. Mutations can be caused by copying errors in the genetic material during cell division, by exposure to ultraviolet or ionizing radiation, chemical mutagens, or viruses, or can be induced by the organism itself, by cellular processes such as hypermutation. In multicellular organisms with dedicated reproductive cells, mutations can be subdivided into germ line mutations, which can be passed on to descendants through the reproductive cells, and somatic mutations, which involve cells outside the dedicated reproductive group and which are not usually transmitted to descendants. If the organism can reproduce asexually through mechanisms such as cuttings or budding the distinction can become blurred. For example, plants can sometimes transmit somatic mutations to their descendants asexually or sexually where flower buds develop in somatically mutated parts of plants. A new mutation that was not inherited from either parent is called a de novo mutation. The source of the mutation is unrelated to the consequence, although the consequences are related to which cells were mutated.

Mutations create variation within the gene pool. Less favorable (or deleterious) mutations can be reduced in frequency in the gene pool by natural selection, while more favorable (beneficial or advantageous) mutations may accumulate and result in adaptive evolutionary changes. For example, a butterfly may produce offspring with new mutations. The majority of these mutations will have no effect; but one might change the color of one of the butterfly's offspring, making it harder (or easier) for predators to see. If this color change is advantageous, the chance of this butterfly surviving and producing its own offspring are a little better, and over time the number of butterflies with this mutation may form a larger percentage of the population.

Neutral mutations are defined as mutations whose effects do not influence the fitness of an individual. These can accumulate over time due to genetic drift. It is believed that the overwhelming majority of mutations have no significant effect on an organism's fitness. Also, DNA repair mechanisms are able to mend most changes before they become permanent mutations, and many organisms have mechanisms for eliminating otherwise permanently mutated somatic cells.

Mutation is generally accepted by the scientific community as the mechanism upon which natural selection acts, providing the advantageous new traits that survive and multiply in offspring or disadvantageous traits that die out with weaker organisms.

This text uses material from Wikipedia, licensed under CC BY-SA