cADPR is a gene dosage-sensitive biomarker of SARM1 activity in healthy, compromised, and degenerating axons

Abstract Polymorphisms within the Rh blood group system have been defined by serologic agglutination methods, but have not yet been defined at the DNA level. Two closely related genes associated with the Rh D antigen and with the Rh C/c and E/e antigens have been cloned. We used a Southern analysis incorporating probes to the 5′ and 3′ regions of the Rh C, E gene and D gene to identify polymorphisms associated with Rh C/c and E/e antigens, respectively. The D gene dosage could be determined by comparing the relative intensities of the D bands with bands from the 5′ and 3′ region of the Rh C, E gene. The concordance between restriction fragment length polymorphism (RFLP) patterns and serologic phenotypes for 102 randomly selected blood donors was 100% for C, e, and D, 94.8% for c, and 94.3% for E. The data are consistent with the sequences encoding the C/c epitopes residing on the 5′ side of those for the E/e epitopes. All samples discordant for the 3′ probe and E had the cE (r″) serotype. These data show that the gene coding for the cE serotype is different in Rh-positive and -negative individuals. The study demonstrates that Rh DNA typing, including D gene dosage measurements and Rh gene haplotyping, may supplement traditional serotyping methods in transfusion medicine.

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Characterization of Caenorhabditis elegans Homologs of the Down Syndrome Candidate Gene DYRK1A

Genetics ◽

10.1093/genetics/163.2.571 ◽

2003 ◽

Vol 163 (2) ◽

pp. 571-580 ◽

Cited By ~ 1

Author(s):

William B Raich ◽

Celine Moorman ◽

Clay O Lacefield ◽

Jonah Lehrer ◽

Dusan Bartsch ◽

...

Keyword(s):

Down Syndrome ◽

Caenorhabditis Elegans ◽

Trisomy 21 ◽

Gene Dosage ◽

Inducible Promoters ◽

C Elegans ◽

Dual Specificity ◽

Specificity Protein

Abstract The pathology of trisomy 21/Down syndrome includes cognitive and memory deficits. Increased expression of the dual-specificity protein kinase DYRK1A kinase (DYRK1A) appears to play a significant role in the neuropathology of Down syndrome. To shed light on the cellular role of DYRK1A and related genes we identified three DYRK/minibrain-like genes in the genome sequence of Caenorhabditis elegans, termed mbk-1, mbk-2, and hpk-1. We found these genes to be widely expressed and to localize to distinct subcellular compartments. We isolated deletion alleles in all three genes and show that loss of mbk-1, the gene most closely related to DYRK1A, causes no obvious defects, while another gene, mbk-2, is essential for viability. The overexpression of DYRK1A in Down syndrome led us to examine the effects of overexpression of its C. elegans ortholog mbk-1. We found that animals containing additional copies of the mbk-1 gene display behavioral defects in chemotaxis toward volatile chemoattractants and that the extent of these defects correlates with mbk-1 gene dosage. Using tissue-specific and inducible promoters, we show that additional copies of mbk-1 can impair olfaction cell-autonomously in mature, fully differentiated neurons and that this impairment is reversible. Our results suggest that increased gene dosage of human DYRK1A in trisomy 21 may disrupt the function of fully differentiated neurons and that this disruption is reversible.

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A Haplolethal Locus Uncovered by Deletions in the Mouse t Complex

Genetics ◽

10.1093/genetics/160.2.675 ◽

2002 ◽

Vol 160 (2) ◽

pp. 675-682

Author(s):

Victoria L Browning ◽

Rebecca A Bergstrom ◽

Sandra Daigle ◽

John C Schimenti

Keyword(s):

Gene Dosage ◽

Es Cells ◽

Embryonic Stem ◽

Chromosome 17 ◽

Mammalian Development ◽

T Complex ◽

Segmental Aneuploidy ◽

Systematic Exploration ◽

Radiation Induced ◽

Altered Gene

Abstract Proper levels of gene expression are important for normal mammalian development. Typically, altered gene dosage caused by karyotypic abnormalities results in embryonic lethality or birth defects. Segmental aneuploidy can be compatible with life but often results in contiguous gene syndromes. The ability to manipulate the mouse genome allows the systematic exploration of regions that are affected by alterations in gene dosage. To explore the effects of segmental haploidy in the mouse t complex on chromosome 17, radiation-induced deletion complexes centered at the Sod2 and D17Leh94 loci were generated in embryonic stem (ES) cells. A small interval was identified that, when hemizygous, caused specific embryonic lethal phenotypes (exencephaly and edema) in most fetuses. The penetrance of these phenotypes was background dependent. Additionally, evidence for parent-of-origin effects was observed. This genetic approach should be useful for identifying genes that are imprinted or whose dosage is critical for normal embryonic development.

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cot1: A Regulator of Arabidopsis Trichome Initiation

Genetics ◽

10.1093/genetics/149.2.565 ◽

1998 ◽

Vol 149 (2) ◽

pp. 565-577

Author(s):

Daniel B Szymanski ◽

Daniel A Klis ◽

John C Larkin ◽

M David Marks

Keyword(s):

Cell Fate ◽

Gene Dosage ◽

Signal Transduction Pathway ◽

Spatial Arrangement ◽

Complex Signal ◽

Chromosome 2 ◽

Wild Type ◽

Trichome Formation ◽

In The Wild ◽

Leaf Trichome

Abstract In Arabidopsis, the timing and spatial arrangement of trichome initiation is tightly regulated and requires the activity of the GLABROUS1 (GL1) gene. The COTYLEDON TRICHOME 1 (COT1) gene affects trichome initiation during late stages of leaf development and is described in this article. In the wild-type background, cot1 has no observable effect on trichome initiation. GL1 overexpression in wild-type plants leads to a modest number of ectopic trichomes and to a decrease in trichome number on the adaxial leaf surface. The cot1 mutation enhances GL1-overexpression-dependent ectopic trichome formation and also induces increased leaf trichome initiation. The expressivity of the cot1 phenotype is sensitive to cot1 and 35S::GL1 gene dosage, and the most severe phenotypes are observed when cot1 and 35S::GL1 are homozygous. The COT1 locus is located on chromosome 2 15.3 cM north of er. Analysis of the interaction between cot1, try, and 35S::GL1 suggests that COT1 is part of a complex signal transduction pathway that regulates GL1-dependent adoption of the trichome cell fate.

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Nuclear Gene Dosage Effects Upon the Expression of Maize Mitochondrial Genes

Genetics ◽

10.1093/genetics/157.4.1711 ◽

2001 ◽

Vol 157 (4) ◽

pp. 1711-1721

Author(s):

Donald L Auger ◽

Kathleen J Newton ◽

James A Birchler

Keyword(s):

Cytochrome C ◽

Cytochrome C Oxidase ◽

Gene Dosage ◽

Nuclear Gene ◽

Eukaryotic Cell ◽

Mitochondrial Genes ◽

Northern Analysis ◽

Α Subunit ◽

Dosage Effects ◽

A Genome

Abstract Each mitochondrion possesses a genome that encodes some of its own components. The nucleus encodes most of the mitochondrial proteins, including the polymerases and factors that regulate the expression of mitochondrial genes. Little is known about the number or location of these nuclear factors. B-A translocations were used to create dosage series for 14 different chromosome arms in maize plants with normal cytoplasm. The presence of one or more regulatory factors on a chromosome arm was indicated when variation of its dosage resulted in the alteration in the amount of a mitochondrial transcript. We used quantitative Northern analysis to assay the transcript levels of three mitochondrially encoded components of the cytochrome c oxidase complex (cox1, cox2, and cox3). Data for a nuclearly encoded component (cox5b) and for two mitochondrial genes that are unrelated to cytochrome c oxidase, ATP synthase α-subunit and 18S rRNA, were also determined. Two tissues, embryo and endosperm, were compared and most effects were found to be tissue specific. Significantly, the array of dosage effects upon mitochondrial genes was similar to what had been previously found for nuclear genes. These results support the concept that although mitochondrial genes are prokaryotic in origin, their regulation has been extensively integrated into the eukaryotic cell.

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