• In 1944 it was realized that genetic transformation in bacteria was due to DNA and not protein and that DNA was the molecule responsible for heredity in genes and chromosomes [ 8 ]. (biomedcentral.com)
  • Thomas Hunt Morgan, American zoologist and geneticist, famous for his experimental research with the fruit fly (Drosophila) by which he established the chromosome theory of heredity. (papercritters.com)
  • He showed that genes are linked in a series on chromosomes and are â ¦ He was talented enough to have three of his painting exhibited at the Royal Academy by the age of 17 only. (papercritters.com)
  • The stage was set for ideas about the transmutability of species, the heritability of physical traits and Darwin's theory of the origin of species [ 1 ]. (biomedcentral.com)
  • Morgan, Sturtevant, Bridges and Muller constructed the first genetic linkage maps from recombination studies in crosses made in the fruit fly and from cytological preparations of its polytene salivary gland chromosomes [ 4 - 6 ]. (biomedcentral.com)
  • Variations in morphology within species, and to a greater extent between species, led Linnaeus and other taxonomists to classify all organisms in terms of genealogies with species, families and orders depending on their similarities, starting with individuals capable of reproduction that defined a species. (biomedcentral.com)
  • The identification of chromosomes and chromosomal subregions can be a challenging task. (biomedcentral.com)
  • The low rates of chromosomal evolution within the species of the genus Talpa-T. altaica and T. europaea-and the high rates of karyotypic reshuffling within the Asian genera of the tribe were confirmed. (bvsalud.org)
  • Until recently, MCB probes have only been available for human and some murine chromosomes. (biomedcentral.com)
  • Generation of MCB probes for chromosomes of other species, useful and required in many cytogenetics research fields, was limited by technical difficulties. (biomedcentral.com)
  • MCB probes are established by chromosome microdissection followed by whole genomic DNA amplification. (biomedcentral.com)
  • Here we present a complete workflow for MCB probe generation for those cases and species where chromosome morphology is too challenging to recognize target chromosomes by conventional methods and where WCP probes are not available. (biomedcentral.com)
  • The present method can be applied for generation of whole or region-specific DNA probes for species, where karyotyping of G-banded chromosomes is challenging due to similar chromosome morphology and/or chromosome banding patterns. (biomedcentral.com)
  • however, for many species there is a lack of available DNA probes. (biomedcentral.com)
  • Besides whole chromosome painting probes (WCP), partial chromosome painting (PCP) probes can also be extremely helpful for the characterization of chromosomes of closely related species and their evolutionary relations to each other. (biomedcentral.com)
  • However, application of human MCB probes on chromosomes of evolutionarily distant species is challenging, and often not feasible. (biomedcentral.com)
  • This created the necessity of generating MCB probes for the chromosomes of other species, potentially interesting from the cytogenetic point of view. (biomedcentral.com)
  • Here, we used sets of chromosome-specific probes from Tamias sibiricus (Sciuridae), Castor fiber (Castoridae) and humans to study karyotypes of six ground squirrels (genera Marmota and Spermophilus) and one tree squirrel (genus Sciurus), mountain hare (genus Lepus), and rabbit (genus Oryctolagus). (bvsalud.org)
  • Comparison with the recently reported two-superdomain structure of the human inactive X shows that the genomic content of the superdomains differs between species, but part of the boundary region is conserved and located near the Dxz4 / DXZ4 locus. (biomedcentral.com)
  • In mammals, one of the female X chromosomes and all imprinted genes are expressed exclusively from a single allele in somatic cells. (biomedcentral.com)
  • In diploid cells, homologous chromosomes occupy separate territories, but expression from genes located on either the paternal or maternal homolog is usually similar. (biomedcentral.com)
  • In contrast, X-linked genes are subject to silencing by X chromosome inactivation (XCI) on one of the two homologs in female somatic cells [ 2 ], and a subset of autosomal genes are subject to imprinting and expressed from either the paternal or maternal allele [ 3 ]. (biomedcentral.com)
  • Unfortunately, cytogenetic data are not yet available for all species. (bvsalud.org)
  • Through comparative analysis of available Euroscaptor (Euroscaptor parvidens, Euroscaptor klossi, and Euroscaptor malayana) and Oreoscaptor (Oreoscaptor mizura) karyotypes, we found cytogenetic signatures for each of the studied species. (bvsalud.org)
  • Previously proposed protocols suggested G-banding staining or preliminary FISH with whole chromosome paints (WCP) as methods to identify the chromosome of interest. (biomedcentral.com)
  • The workflow was successfully applied for murine chromosomes that are difficult to identify unambiguously. (biomedcentral.com)
  • The absolutely necessary condition for chromosome microdissection is the possibility to identify the target chromosome unambiguously. (biomedcentral.com)
  • Zoo-FISH with sorted chromosomes of the Siberian mole (Talpa altaica) on chromosome sets of the small-toothed mole (E. parvidens), the small Japanese mole (Mogera imaizumii) from the closely related genus, and the Japanese shrew mole (Urotrichus talpoides) from the tribe Urotrichini made it possible to identify syntenic regions between these species. (bvsalud.org)
  • Approaches to visualize the 3D configuration of the whole nucleus and of entire chromosomes include Hi-C, a method to identify chromatin contacts within chromosomes (intrachromosomal) or between chromosomes (interchromosomal). (biomedcentral.com)
  • By applying a novel Hi-C method to map allelic chromatin contacts, we discover a specific bipartite organization of the mouse inactive X chromosome that probably plays an important role in maintenance of gene silencing. (biomedcentral.com)
  • Chromosomes occupy specific territories within the nucleus [ 1 ]. (biomedcentral.com)
  • The heterochromatization of one of the X chromosomes in female somatic cells is initiated by the long non-coding RNA (lncRNA) Xist that coats the Xi in early embryogenesis and silences transcription by recruiting specific proteins that put in place repressive histone modifications such as tri-methylation of histone H3K27, ubiquitination of histone H2AK119, and de-acetylation [ 9 - 12 ]. (biomedcentral.com)
  • The inactive X chromosome (Xi) becomes highly condensed compared with the active X (Xa) and forms the Barr body, often visible as a dense region within the nucleus [ 8 ]. (biomedcentral.com)
  • Our data showed the absence of previously found squirrel associations HSA 1/8 and 2/17 in the Eurasian ground squirrels--sousliks and woodchucks, and disruptions of squirrel HSA 10/13 and HSA 8/4/8/12/22 syntenies in the four Spermophilus species studied here. (bvsalud.org)