161 research outputs found
A rapid method for detection of Y-chromosomal DNA from dried blood specimens by the polymerase chain reaction
The alphoid satellite family is the only repetitive DNA family showing chromosome specificity. We have developed a simple, rapid, and reliable test for sex diagnosis based on detection of these sequences in undigested genomic DNA using the polymerase chain reaction. In our test, dried blood specimens were the source of DNA. When female DNA was used as a template for the reaction, only the expected 130-bp X-chromosome-specific fragment was detected, while with male DNA both the expected 170-bp Y-chromosome-specific and X-chromosome-specific fragments were detected. The Y-chromosome-specific fragment was further characterized by restriction enzyme analysis. The Y fragment was detectable when DNA obtained from an equivalent of 10 μl of spotted blood was used in the reaction, whereas detection of the X fragment was possible with DNA from an equivalent of 5 μl of blood. Our test may find various applications in newborn screening and in forensic science.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47625/1/439_2004_Article_BF00291168.pd
Erratum
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47629/1/439_2004_Article_BF00194654.pd
Polymerase chain reactions with alphoid-repeat primers in combination with Alu or LINEs primers, generate chromosome-specific DNA fragments
Y alphoid primers in combination with Alu and LINEs primers generated new DNA fragments in polymerase chain reactions (PCR) on DNA from a Y-only somatic cell hybrid but not from X-only, 3-only, or 21-only hybrids. X alphoid primers used in a similar manner generated new DNA fragments from the X-only hybrid, and 1 of the primers (X 2 ) also generated new DNA fragments on 3-only and 21-only hybrids when used in conjunction with Alu or LINEs primers. In all but one case, consensus alphoid primers generated new chromosome-specific fragments in PCR reactions with the Alu or LINEs primers. A search for cryptic Alu- or alphoid-alone PCR products as the source for one Alu -alphoid band (chosen at random) was negative. Partial sequencing of products demonstrated that alphoid and Alu sequences were indeed contiguous in some newly synthesized DNA fragments. While Alu or LINEs primers generate smears of DNA fragments on total human DNA, the alphoid-nonalphoid repeat combinations generated electrophoretically distinguishable bands of DNA when the template was total DNA. While these were distinguishable with different chromosome-specific alphoid primers, the DNA fragments were not of the same sizes as those generated with the chromosome-only hybrids.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66359/1/j.1469-1809.1991.tb00414.x.pd
A genomic clone of Zfy-1 from a YDOM mouse strain detects post-meiotic gene expression of Zfy in testes
In order to obtain a genomic clone of Zfy-1 from a Y chromosome of (YDOM) origin, we cloned size-fractionated SJL/J DNA in EMBL-4 and selected colonies which hybridized to pDP1007, a human zinc finger Y clone. The specificity of the clone in hybridizations to mouse and human DNA and partial sequencing confirmed that the clone (subcloned as pGZfy1D) was of Zfy-1 origin. Studies on the expression during testicular development of mRNAs hybridizing to the clone suggested that the gene is expressed post-meiotically.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27626/1/0000001.pd
Molecular mechanisms of cell death: recommendations of the Nomenclature Committee on Cell Death 2018.
Over the past decade, the Nomenclature Committee on Cell Death (NCCD) has formulated guidelines for the definition and interpretation of cell death from morphological, biochemical, and functional perspectives. Since the field continues to expand and novel mechanisms that orchestrate multiple cell death pathways are unveiled, we propose an updated classification of cell death subroutines focusing on mechanistic and essential (as opposed to correlative and dispensable) aspects of the process. As we provide molecularly oriented definitions of terms including intrinsic apoptosis, extrinsic apoptosis, mitochondrial permeability transition (MPT)-driven necrosis, necroptosis, ferroptosis, pyroptosis, parthanatos, entotic cell death, NETotic cell death, lysosome-dependent cell death, autophagy-dependent cell death, immunogenic cell death, cellular senescence, and mitotic catastrophe, we discuss the utility of neologisms that refer to highly specialized instances of these processes. The mission of the NCCD is to provide a widely accepted nomenclature on cell death in support of the continued development of the field
The genetic architecture of the human cerebral cortex
The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder
Detection and localization of early- and late-stage cancers using platelet RNA
Cancer patients benefit from early tumor detection since treatment outcomes are more favorable for less advanced cancers. Platelets are involved in cancer progression and are considered a promising biosource for cancer detection, as they alter their RNA content upon local and systemic cues. We show that tumor-educated platelet (TEP) RNA-based blood tests enable the detection of 18 cancer types. With 99% specificity in asymptomatic controls, thromboSeq correctly detected the presence of cancer in two-thirds of 1,096 blood samples from stage I–IV cancer patients and in half of 352 stage I–III tumors. Symptomatic controls, including inflammatory and cardiovascular diseases, and benign tumors had increased false-positive test results with an average specificity of 78%. Moreover, thromboSeq determined the tumor site of origin in five different tumor types correctly in over 80% of the cancer patients. These results highlight the potential properties of TEP-derived RNA panels to supplement current approaches for blood-based cancer screening
Thermal Switching of the Reflection in Chiral Nematic Mesoporous Organosilica Films Infiltrated with Liquid Crystals
Materials
that undergo stimulus-induced optical changes are important for many
new technologies. In this paper, we describe a new free-standing silica-based
composite film that exhibits reversible thermochromic reflection,
induced by a liquid crystalline guest in the pores of iridescent mesoporous
films. We demonstrate that selective reflection from the novel mesoporous
organosilica material with chiral nematic organization can be reversibly
switched by thermal cycling of the 8CB guest between its isotropic
and liquid crystalline states, which was proven by solid-state NMR
experiments. The switching of the optical properties of the chiral
solid-state host by stimulus-induced transitions of the guest opens
the possibility of applications for these novel materials in sensors
and displays
A rapid method for detection of Y-chromosomal DNA from dried blood specimens by the polymerase chain reaction
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