The Belgian Blue is a breed of beef cattle from Belgium. It may also be known as the Race de la Moyenne et Haute Belgique, or dikbil. Alternative names for this breed include Belgian Blue-White; Belgian White and Blue Pied; Belgian White Blue; Blue; and Blue Belgian. The Belgian Blue's extremely lean, hyper-sculpted, ultra-muscular physique is termed "double-muscling". The double-muscling phenotype is a heritable condition resulting in an increased number of muscle fibres (hyperplasia), instead of the (normal) enlargement of individual muscle fibres (hypertrophy).
Myostatin is a protein that in humans is encoded by the MSTN gene. Myostatin is a myokine that is produced and released by myocytes and acts on muscle cells to inhibit muscle growth. Myostatin is a secreted growth differentiation factor that is a member of the TGF beta protein family.
Human genetic enhancement or human genetic engineering refers to human enhancement by means of a genetic modification. This could be done in order to cure diseases, prevent the possibility of getting a particular disease, to improve athlete performance in sporting events, or to change physical appearance, metabolism, and even improve physical capabilities and mental faculties such as memory and intelligence. These genetic enhancements may or may not be done in such a way that the change is heritable.
Dystrophin is a rod-shaped cytoplasmic protein, and a vital part of a protein complex that connects the cytoskeleton of a muscle fiber to the surrounding extracellular matrix through the cell membrane. This complex is variously known as the costamere or the dystrophin-associated protein complex (DAPC). Many muscle proteins, such as α-dystrobrevin, syncoilin, synemin, sarcoglycan, dystroglycan, and sarcospan, colocalize with dystrophin at the costamere. It has a molecular weight of 427 kDa
Duchenne muscular dystrophy (DMD) is a severe type of muscular dystrophy predominantly affecting boys. The onset of muscle weakness typically begins around age four, with rapid progression. Initially, muscle loss occurs in the thighs and pelvis, extending to the arms, which can lead to difficulties in standing up. By the age of 12, most individuals with Duchenne muscular dystrophy are unable to walk. Affected muscles may appear larger due to an increase in fat content, and scoliosis is common. Some individuals may experience intellectual disability, and females carrying a single copy of the mutated gene may show mild symptoms.
Follistatin, also known as activin-bindings protein, is a protein that in humans is encoded by the FST gene. Follistatin is an autocrine glycoprotein that is expressed in nearly all tissues of higher animals.
Muscle hypertrophy or muscle building involves a hypertrophy or increase in size of skeletal muscle through a growth in size of its component cells. Two factors contribute to hypertrophy: sarcoplasmic hypertrophy, which focuses more on increased muscle glycogen storage; and myofibrillar hypertrophy, which focuses more on increased myofibril size. It is the primary focus of bodybuilding-related activities.
Growth differentiation factor 11 (GDF11), also known as bone morphogenetic protein 11 (BMP-11), is a protein that in humans is encoded by the growth differentiation factor 11 gene. GDF11 is a member of the Transforming growth factor beta family.
Sarcospan is a protein that in humans is encoded by the SSPN gene.
T-box transcription factor TBX5, is a protein that in humans is encoded by the TBX5 gene. Abnormalities in the TBX5 gene can result in altered limb development, Holt-Oram syndrome, Tetra-amelia syndrome, and cardiac and skeletal problems.
Double-muscled cattle are breeds of cattle that carry one of seven known mutations that limits and reduces the activity of the myostatin protein. Normally, myostatin limits the number of muscle fibers present at birth, and interfering with activity of this protein causes animals to be born with higher numbers of muscle fibers, consequently augmenting muscle growth. Additionally, these mutations reduce the superficial and internal fat deposits, causing the meat to be less marbled and lower in fat content. Animals homozygous for myostatin mutation also have improved meat tenderness in some cuts of meat. The enlarged muscles of dam and calf at birth leads to increased difficulty of calving, and in some breeds frequently necessitates birth by cesarean section.
Genetically modified mammals are mammals that have been genetically engineered. They are an important category of genetically modified organisms. The majority of research involving genetically modified mammals involves mice with attempts to produce knockout animals in other mammalian species limited by the inability to derive and stably culture embryonic stem cells.
Genome editing, or genome engineering, or gene editing, is a type of genetic engineering in which DNA is inserted, deleted, modified or replaced in the genome of a living organism. Unlike early genetic engineering techniques that randomly inserts genetic material into a host genome, genome editing targets the insertions to site-specific locations. The basic mechanism involved in genetic manipulations through programmable nucleases is the recognition of target genomic loci and binding of effector DNA-binding domain (DBD), double-strand breaks (DSBs) in target DNA by the restriction endonucleases, and the repair of DSBs through homology-directed recombination (HDR) or non-homologous end joining (NHEJ).
Cas9 is a 160 kilodalton protein which plays a vital role in the immunological defense of certain bacteria against DNA viruses and plasmids, and is heavily utilized in genetic engineering applications. Its main function is to cut DNA and thereby alter a cell's genome. The CRISPR-Cas9 genome editing technique was a significant contributor to the Nobel Prize in Chemistry in 2020 being awarded to Emmanuelle Charpentier and Jennifer Doudna.
Human germline engineering is the process by which the genome of an individual is edited in such a way that the change is heritable. This is achieved by altering the genes of the germ cells, which then mature into genetically modified eggs and sperm. For safety, ethical, and social reasons, there is broad agreement among the scientific community and the public that germline editing for reproduction is a red line that should not be crossed at this point in time. There are differing public sentiments, however, on whether it may be performed in the future depending on whether the intent would be therapeutic or non-therapeutic.
CRISPR activation (CRISPRa) is a gene regulation technique that utilizes an engineered form of the CRISPR-Cas9 system to enhance the expression of specific genes without altering the underlying DNA sequence. Unlike traditional CRISPR-Cas9, which introduces double-strand breaks to edit genes, CRISPRa employs a modified, catalytically inactive Cas9 (dCas9) fused with transcriptional activators to target promoter or enhancer regions, thereby boosting gene transcription. This method allows for precise control of gene expression, making it a valuable tool for studying gene function, creating gene regulatory networks, and developing potential therapeutic interventions for a variety of diseases.
Off-target genome editing refers to nonspecific and unintended genetic modifications that can arise through the use of engineered nuclease technologies such as: clustered, regularly interspaced, short palindromic repeats (CRISPR)-Cas9, transcription activator-like effector nucleases (TALEN), meganucleases, and zinc finger nucleases (ZFN). These tools use different mechanisms to bind a predetermined sequence of DNA (“target”), which they cleave, creating a double-stranded chromosomal break (DSB) that summons the cell's DNA repair mechanisms and leads to site-specific modifications. If these complexes do not bind at the target, often a result of homologous sequences and/or mismatch tolerance, they will cleave off-target DSB and cause non-specific genetic modifications. Specifically, off-target effects consist of unintended point mutations, deletions, insertions inversions, and translocations.
CRISPR gene editing (CRISPR, pronounced "crisper", refers to "clustered regularly interspaced short palindromic repeats") is a genetic engineering technique in molecular biology by which the genomes of living organisms may be modified. It is based on a simplified version of the bacterial CRISPR-Cas9 antiviral defense system. By delivering the Cas9 nuclease complexed with a synthetic guide RNA (gRNA) into a cell, the cell's genome can be cut at a desired location, allowing existing genes to be removed and/or new ones added in vivo.
Genome-wide CRISPR-Cas9 knockout screens aim to elucidate the relationship between genotype and phenotype by ablating gene expression on a genome-wide scale and studying the resulting phenotypic alterations. The approach utilises the CRISPR-Cas9 gene editing system, coupled with libraries of single guide RNAs (sgRNAs), which are designed to target every gene in the genome. Over recent years, the genome-wide CRISPR screen has emerged as a powerful tool for performing large-scale loss-of-function screens, with low noise, high knockout efficiency and minimal off-target effects.
Myostatin inhibitors are a class of drugs that work by blocking the effects of myostatin, which inhibits muscle growth. In animal models and limited human studies, myostatin inhibitors have increased muscle size. They are being developed to treat obesity, sarcopenia, muscular dystrophy, and other illnesses.
