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  • centromere
  • Before this happens, every chromosome is copied once (S phase), and the copy is joined to the original by a centromere, resulting either in an X-shaped structure (pictured to the right) if the centromere is located in the middle of the chromosome or a two-arm structure if the centromere is located near one of the ends. (wikipedia.org)
  • Isochromosome: Formed by the mirror image copy of a chromosome segment including the centromere. (wikipedia.org)
  • Under normal separation of sister chromatids in metaphase, the centromere will divide longitudinally, or parallel to the long axis of the chromosome. (wikipedia.org)
  • An isochromosome is created when the centromere is divided transversely, or perpendicular to the long axis of the chromosome. (wikipedia.org)
  • A double-stranded break in the pericentric region of the chromosome is repaired when the sister chromatids, each containing a centromere, are fused together. (wikipedia.org)
  • Chromosome 17 polysomy may not be present when the centromere is amplified, so it was later discovered that polysomy 17 is rare. (wikipedia.org)
  • organism
  • A chromosome (from ancient Greek: χρωμόσωμα, chromosoma, chroma means color, soma means body) is a DNA molecule with part or all of the genetic material (genome) of an organism. (wikipedia.org)
  • recessive
  • Except for color matching, his performance was similar to blue-cone "monochromacy," an X chromosome-linked recessive retinal dystrophy in which color vision is dichromatic, mediated by the visual pigments of rods and short-wave-sensitive cones. (biomedsearch.com)
  • If the gene is recessive, the feature it determines will not show up in the offspring unless both the parents' chromosomes contain the recessive gene for that characteristic. (encyclopedia.com)
  • Recessive sex-linked traits, such as hemophilia and red-green colour blindness , occur far more frequently in men than in women. (britannica.com)
  • This is because the male who inherits the recessive allele on his X chromosome has no allele on his Y chromosome to counteract its effects. (britannica.com)
  • The female, on the other hand, must inherit the recessive allele on both of her X chromosomes in order to fully display the trait. (britannica.com)
  • A woman who inherits the recessive allele for a sex-linked disorder on one of her X chromosomes may, however, show a limited expression of the trait. (britannica.com)
  • DISORDERS
  • Several disorders are known to be associated with abnormal numbers of sex chromosomes. (britannica.com)
  • These disorders manifest in and are passed on by either sex with equal frequency. (wikipedia.org)
  • Known human disorders include Charcot-Marie-Tooth disease type 1A, which may be caused by duplication of the gene encoding peripheral myelin protein 22 (PMP22) on chromosome 17. (wikipedia.org)
  • An unusual aspect of the disease is that up to two-thirds of affected 46,XY genotypic males display a range of Disorders of Sexual Development (DSD) and genital ambiguities or may even develop as normal phenotypic females as in complete 46 XY sex reversal. (wikipedia.org)
  • deletion
  • Prenatally the deletion of the cri du chat related region in the p arm of chromosome 5 can be detected from amniotic fluid or chorionic villi samples with BACs-on-Beads technology. (wikipedia.org)
  • gene
  • When a dominant gene is passed on to offspring, the feature or trait it determines will appear regardless of the characteristics of the corresponding gene on the chromosome inherited from the other parent. (encyclopedia.com)
  • and Figure 5.3 shows the hereditary hemochromatosis gene located on chromosome 6. (encyclopedia.com)
  • Chromosome mutation was formerly used in a strict sense to mean a change in a chromosomal segment, involving more than one gene. (wikipedia.org)
  • When the SRY gene of the Y chromosome is expressed in human embryos, a cascade of gene interactions controlled by SOX9 begins and ultimately leads to male gender. (wikipedia.org)
  • The SMARCB1 gene (also termed BAF47, INI1, or hSNF5) is located on chromosome 22q11.2 and codes for a member of the SWI/SNF chromatin remodeling complex. (wikipedia.org)
  • In squamous cell carcinoma, a protein from the epidermal growth factor receptor (EGFR) gene is often overexpressed in conjunction with polysomy of chromosome 7, so chromosome 7 can be used to predict the presence of EGFR in squamous cell carcinoma. (wikipedia.org)
  • Overexpression of the HER2/neu gene on chromosome 17 and some type of polysomy has been reported in 8-68% of breast carcinomas. (wikipedia.org)
  • 2005). Sequential strategy to identify a susceptibility gene for schizophrenia: report of potential linkage on chromosome 22q12-q13.1: Part 1. (wikipedia.org)
  • mutations
  • The mutagenic property of mutagens was first demonstrated in 1927, when Hermann Muller discovered that x-rays can cause genetic mutations in fruit flies, producing phenotypic mutants as well as observable changes to the chromosomes, visible due to presence of enlarged 'polytene' chromosomes in fruit fly salivary glands. (wikipedia.org)
  • Any mutation within the coding region of SOX9 can cause campomelic dysplasia and 75% of the reported mutations lead to sex reversal. (wikipedia.org)
  • The lack of correlation between specific genetic mutations and observed phenotype, particularly with regard to sex reversal, give clear evidence of the variable expressivity of the disease. (wikipedia.org)
  • metaphase
  • Chromosomes are normally visible under a light microscope only when the cell is undergoing the metaphase of cell division. (wikipedia.org)
  • During metaphase the X-shape structure is called a metaphase chromosome. (wikipedia.org)
  • All human autosomes have been identified and mapped by extracting the chromosomes from a cell arrested in metaphase or prometaphase and then staining them with some sort of dye (most commonly, Giemsa). (wikipedia.org)
  • Joe Hin Tjio working in Albert Levan's lab was responsible for finding the approach: Using cells in culture Pre-treating cells in a hypotonic solution, which swells them and spreads the chromosomes Arresting mitosis in metaphase by a solution of colchicine Squashing the preparation on the slide forcing the chromosomes into a single plane Cutting up a photomicrograph and arranging the result into an indisputable karyogram. (wikipedia.org)
  • genome
  • Conventional karyotypes can assess the entire genome for changes in chromosome structure and number, but the resolution is relatively coarse, with a detection limit of 5-10Mb. (wikipedia.org)
  • males
  • The female has two X chromosomes, and all female egg cells normally carry a single X. The eggs fertilized by X-bearing sperm become females (XX), whereas those fertilized by Y-bearing sperm become males (XY). (britannica.com)
  • By contrast, the allosome pair consists of two X chromosomes in females or one X and one Y chromosome in males. (wikipedia.org)
  • While the definitive presentation of the disease is a patient having bowed lower limbs and sex reversal in 46,XY males, there are other clinical criteria that can be used, absent these characteristics, to make the diagnosis. (wikipedia.org)
  • 49,XXXXY chromosome polysomy occurs every 1 in 85,000 newborn males. (wikipedia.org)
  • fetus
  • As part of a larger prospective study of the influence of environmental factors on pregnancy, birth and the fetus, chromosome examinations have been made in 34910 newborn children in Århus over a 13-year period. (springer.com)
  • inheritance
  • Aided by the rediscovery at the start of the 1900s of Gregor Mendel's earlier work, Boveri was able to point out the connection between the rules of inheritance and the behaviour of the chromosomes. (wikipedia.org)
  • In his famous textbook The Cell in Development and Heredity, Wilson linked together the independent work of Boveri and Sutton (both around 1902) by naming the chromosome theory of inheritance the Boveri-Sutton chromosome theory (the names are sometimes reversed). (wikipedia.org)
  • McClintock continued her career in cytogenetics studying the mechanics and inheritance of broken and ring (circular) chromosomes of maize. (wikipedia.org)
  • Autopolyploids may show polysomic inheritance of all the linkage groups, and their fertility may be reduced due unbalanced chromosome numbers in the gametes. (wikipedia.org)
  • secondary sex characteris
  • Affected females reach puberty, develop secondary sex characteristics, and menstruate at the usual time. (wikipedia.org)
  • Because of the inability of the streak gonads to produce sex hormones (both estrogens and androgens), most of the secondary sex characteristics do not develop. (wikipedia.org)
  • eukaryotic
  • Most eukaryotic chromosomes include packaging proteins which, aided by chaperone proteins, bind to and condense the DNA molecule to prevent the DNA from becoming an unmanageable tangle. (wikipedia.org)
  • fusions
  • Other possible causes of chromosome loss that could lead to micronuclei formation are defects in kinetochore and microtubule interactions, defects in mitotic spindle assembly, mitosis check point defects, abnormal centrosome amplification, and telomeric end fusions that result in dicentric chromosomes that detach from the spindle during anaphase. (wikipedia.org)
  • Polysomy of chromosome 13 (Polysomy 13) is significant in the development of prostate cancer and is often caused by centric fusions. (wikipedia.org)
  • fragments
  • These full chromosomes or chromatid fragments are eventually enclosed by a nuclear membranes and are structurally similar to conventional nuclei, albeit smaller in size. (wikipedia.org)
  • One way is that disrepair of DNA double-strand breaks can lead to symmetrical or asymmetrical chromatid and chromosome exchanges as well as chromatid and chromosome fragments. (wikipedia.org)
  • Comparative
  • It detects genomic copy number variations at a higher resolution level than conventional karyotyping or chromosome-based comparative genomic hybridization (CGH). (wikipedia.org)
  • male
  • Normal X and Y chromosome profiles were established by analysis with DNA from normal fertile male and female individuals. (bmj.com)
  • The presence of SRY on the X chromosome leads to normal male sexual development with male external genitalia, but hypospadias or cryptorchidism may be seen. (medscape.com)
  • individuals having one X chromosome and one Y chromosome (XY) are male. (britannica.com)
  • 2560 probes in the male specific region of chromosome Y (mLRR-Y) and suggested considerable inter-individual differences regarding the proportion of cells with nullisomy Y. A conservative estimate of the frequency of LOY in the ULSAM cohort at 8.2% (93/1141) was based on the lowest value (-0.139) in a simulated distribution of experimental variation of mLRR-Y ( Fig. 2 ). (pubmedcentralcanada.ca)
  • Associated with a more positive outcome are younger age, female vs. male sex, distal vs. proximal location, smaller tumor size, and negative margins upon tumor resection. (wikipedia.org)
  • gonadal
  • Human rhabdomyosarcoma cells express functional pituitary and gonadal sex hormone receptors: Therapeutic implications. (cancerindex.org)
  • We also report that human RMS cell lines responded both to pituitary and gonadal sex hormone stimulation by enhanced proliferation, chemotaxis, cell adhesion and phosphorylation of MAPKp42/44 and AKT. (cancerindex.org)
  • In contrast XX gonadal dysgenesis has a normal female chromosome situation. (wikipedia.org)
  • hormones
  • Evidence has accumulated that sex hormones play an important role in several types of cancer. (cancerindex.org)
  • In summary, our results indicate that sex hormones are involved in the pathogenesis and progression of RMS, and therefore, their therapeutic application should be avoided in patients that have been diagnosed with RMS. (cancerindex.org)
  • Because of the inability of the streak gonads to produce sex hormones (both estrogens and androgens), most of the secondary sex characteristics do not develop. (wikipedia.org)
  • cell
  • The expression of sex hormone receptors was evaluated by RT-PCR and their functionality by chemotaxis, adhesion and direct cell proliferation assays. (cancerindex.org)
  • Most eukaryotic species are diploid, meaning they have two sets of chromosomes, whereas prokaryotes are haploid, containing a single chromosome in each cell. (wikipedia.org)
  • Micronucleus is the name given to the small nucleus that forms whenever a chromosome or a fragment of a chromosome is not incorporated into one of the daughter nuclei during cell division. (wikipedia.org)
  • distinct
  • Given that biological sex does not always fall into distinct and identifiable categories, it is logical to assume that genders would be just as variable, if not more so. (encyclopedia.com)
  • primarily
  • Hypernasal speech, or "hypernasality", is primarily the result of velopharyngeal insufficiency, a sometimes congenital aberration in which the velopharyngeal sphincter allows too much air into the nasal cavity during speech. (wikipedia.org)
  • Male
  • Although it is agreed that gender is culturally constructed and sex is biologically determined, some scholars consider that the concept of a biological distinction between male and female also has a cultural component that guides the outward expression of biological sex. (encyclopedia.com)
  • Biological sex is determined by two chromosomes, X and Y. Normally, a female has two X chromosomes and a male has an X and a Y chromosome . (encyclopedia.com)
  • Note the bristles on the thorax and the sex comb (dark region on the front pair of legs) in this male. (creation.mobi)
  • Associated with a more positive outcome are younger age, female vs. male sex, distal vs. proximal location, smaller tumor size, and negative margins upon tumor resection. (wikipedia.org)
  • single
  • MethylQTL analysis resulted in significant associations between cg26930596 and two intergenic single nucleotide polymorphisms on chromosome 3, rs4574216 (p? (jove.com)
  • X chromosome polysomies can be inherited from either a single maternal (49, X polysomies) or paternal (48, X polysomies) X chromosome. (wikipedia.org)
  • nuclear
  • Following fusion, nuclear divisions begin, and a break in a chromosome can have drastic effects on the viability of the embryo as development proceeds. (wikipedia.org)
  • result
  • Micronuclei formation may also result from chromosome malsegregation during anaphase. (wikipedia.org)
  • Since assembly of kinetochore proteins at centromeres is affected by the methylation of cytosine and histone proteins, a reduction in heterochromatin integrity as a result of hypomethylation can interfere with microtubule attachment to chromosomes and with the sensing of tension from correct microtubule-kinetochore connections. (wikipedia.org)
  • however
  • For the purposes of this discussion, however, sex will refer to the biological aspects of the body, whereas gender will refer to the expression of the individual culturally. (encyclopedia.com)
  • copy
  • It detects genomic copy number variations at a higher resolution level than conventional karyotyping or chromosome-based comparative genomic hybridization (CGH). (wikipedia.org)
  • large
  • The prevalence of Turner's syndrome at birth has been studied, so far, only in large scale chromosome surveys of children. (bmj.com)
  • Given
  • This attitude seems a bit odd, given that in Western society, and indeed any known society, differentiation between sexes and genders are critical components of social, political, and economic activity and of culture and knowledge. (encyclopedia.com)
  • case
  • In such a case, the biological sex of an individual does not fit within the norm and may not correspond with the expected gender. (encyclopedia.com)