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SRGAP2C
SLIT-ROBO Rho GTPase activating protein 2C is a protein in humans that is encoded by the SRGAP2C gene. Cortical development gene Slit-Robo Rho GTPase-activating protein 2 (SRGAP2) has been highly conserved over mammalian evolution, and human is the only lineage wherein gene duplications have occurred (three times). The promoter and first nine exons of SRGAP2 duplicated from 1q23.1 ( SRGAP2A) to 1q21.1 ( SRGAP2B) ∼3.4 million years ago (mya). Two larger duplications later copied SRGAP2B to chromosome 1p12 (SRGAP2C) and to proximal 1q21.1 ( SRGAP2D) ∼2.4 and ∼1 mya, respectively. Ancestral SRGAP2A and the derived SRGAP2C copy are fixed at diploid copy number two. In contrast, the SRGAP2B and SRGAP2D are highly copy number polymorphic, with normal individuals identified that completely lack these paralogscopies. SRGAP2C is the most likely duplicate to encode a functional protein and is among the most fixed human-specific duplicate genes. Incomplete duplication created a novel gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SRGAP2
SLIT-ROBO Rho GTPase-activating protein 2 (srGAP2), also known as formin-binding protein 2 (FNBP2), is a mammalian protein that in humans is encoded by the ''SRGAP2'' gene. It is involved in neuronal migration and differentiation and plays a critical role in synaptic development, brain mass and number of cortical neurons. Downregulation of srGAP2 inhibits cell–cell repulsion and enhances cell–cell contact duration. SRGAP2 dimerizes through its F-BAR domain. SRGAP2C, a shortened version found in early hominins and humans that only has the F-BAR domain, antagonizes its action. It slows maturation of some neurons and increases neuronal spine density. Evolution ''SRGAP2'' is one of 23 genes that are known to be duplicated in humans but not other primates. ''SRGAP2'' has been duplicated three times in the human genome in the past 3.4 million years: one duplication 3.4 million years ago (mya) called SRGAP2B, followed by two that copied SRGAP2B 2.4 mya into SRGAP2C and ~1 mya in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Australopithecus
''Australopithecus'' (, ; ) is a genus of early hominins that existed in Africa during the Late Pliocene and Early Pleistocene. The genus ''Homo'' (which includes modern humans) emerged within ''Australopithecus'', as sister to e.g. ''Australopithecus sediba''. Also the genera ''Paranthropus'' and ''Kenyanthropus'' emerged within ''Australopithecus''. ''Australopithecus'' is a member of the subtribe Australopithecina, which sometimes also includes ''Ardipithecus'', though the term "australopithecine" is sometimes used to refer only to members of ''Australopithecus''. Species include ''Australopithecus garhi, A. garhi'', ''Australopithecus africanus, A. africanus'', ''Australopithecus sediba, A. sediba'', ''Australopithecus afarensis, A. afarensis, Australopithecus anamensis, A. anamensis, Australopithecus bahrelghazali, A. bahrelghazali'' and ''Australopithecus deyiremeda, A. deyiremeda''. Debate exists as to whether some ''Australopithecus'' species should be reclassified into ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, responding to stimuli, providing structure to cells and organisms, and transporting molecules from one location to another. Proteins differ from one another primarily in their sequence of amino acids, which is dictated by the nucleotide sequence of their genes, and which usually results in protein folding into a specific 3D structure that determines its activity. A linear chain of amino acid residues is called a polypeptide. A protein contains at least one long polypeptide. Short polypeptides, containing less than 20–30 residues, are rarely considered to be proteins and are commonly called peptides. The individual amino acid residues are bonded together by peptide bonds and adjacent amino acid residues. The sequence of amino acid residue ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene
In biology, the word gene (from , ; "...Wilhelm Johannsen coined the word gene to describe the Mendelian units of heredity..." meaning ''generation'' or ''birth'' or ''gender'') can have several different meanings. The Mendelian gene is a basic unit of heredity and the molecular gene is a sequence of nucleotides in DNA that is transcribed to produce a functional RNA. There are two types of molecular genes: protein-coding genes and noncoding genes. During gene expression, the DNA is first copied into RNA. The RNA can be directly functional or be the intermediate template for a protein that performs a function. The transmission of genes to an organism's offspring is the basis of the inheritance of phenotypic traits. These genes make up different DNA sequences called genotypes. Genotypes along with environmental and developmental factors determine what the phenotypes will be. Most biological traits are under the influence of polygenes (many different genes) as well as gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homo
''Homo'' () is the genus that emerged in the (otherwise extinct) genus ''Australopithecus'' that encompasses the extant species ''Homo sapiens'' ( modern humans), plus several extinct species classified as either ancestral to or closely related to modern humans (depending on the species), most notably ''Homo erectus'' and ''Homo neanderthalensis''. The genus emerged with the appearance of '' Homo habilis'' just over 2 million years ago. ''Homo'', together with the genus '' Paranthropus'', is probably sister to ''Australopithecus africanus'', which itself had previously split from the lineage of '' Pan'', the chimpanzees. ''Homo erectus'' appeared about 2 million years ago and, in several early migrations, spread throughout Africa (where it is dubbed ''Homo ergaster'') and Eurasia. It was likely that the first human species lived in a hunter-gatherer society and was able to control fire. An adaptive and successful species, ''Homo erectus'' persisted for more than a million ye ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neocortex
The neocortex, also called the neopallium, isocortex, or the six-layered cortex, is a set of layers of the mammalian cerebral cortex involved in higher-order brain functions such as sensory perception, cognition, generation of motor commands, spatial reasoning and language. The neocortex is further subdivided into the true isocortex and the proisocortex. In the human brain, the neocortex is the largest part of the cerebral cortex (the outer layer of the cerebrum). The neocortex makes up the largest part of the cerebral cortex, with the allocortex making up the rest. The neocortex is made up of six layers, labelled from the outermost inwards, I to VI. Etymology The term is from ''cortex'', Latin, " bark" or "rind", combined with ''neo-'', Greek, "new". ''Neopallium'' is a similar hybrid, from Latin ''pallium'', "cloak". ''Isocortex'' and ''allocortex'' are hybrids with Greek ''isos'', "same", and ''allos'', "other". Anatomy The neocortex is the most developed in its organisat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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