title: Molecular and biochemical characterization of Mottled-dappled, an embryonic lethal Menkes disease mouse model.
abstract: Mottled-dappled (Mo-dp) is a mouse model of Menkes disease caused by a large, previously uncharacterized deletion in the 5' region of Atp7a, the mouse ortholog of ATP7A. Affected mutants die in utero at embryonic day 17, and show bending and thickening of the ribs and distortion of the pectoral and pelvic girdles and limbs. To characterize this allele, we designed a custom 4x180K microarray on the mouse X chromosome and performed comparative genomic hybridization using extracted DNA from normal and carrier Mo-dp females, and identified an approximately 9 kb deletion. We used PCR to fine-map the breakpoints and amplify a junction fragment of 630 bp. Sequencing of the junction fragment disclosed the exact breakpoint locations and that the Mo-dp deletion is precisely 8990 bp, including approximately 2 kb in the promoter region of Atp7a. Western blot analysis of Mo-dp heterozygous brains showed diminished amounts of Atp7a protein, consistent with reduced expression due to the promoter region deletion on one allele. In heterozygous females, brain copper levels tended to be lower compared to wild type whereas neurochemical analyses revealed higher dihydroxyphenylacetic acid:dihydroxyphenylglycol (DOPAC:DHPG) and dopamine:norepinephrine (DA:NE) ratios compared to normal (P=0.002 and 0.029, respectively), consistent with partial deficiency of dopamine-beta-hydroxylase, a copper-dependent enzyme. Heterozygous females showed no significant differences in body weight compared to wild type females. Our results delineate the molecular details of the Mo-dp mutation for the first time and define novel biochemical findings in heterozygous female carriers of this allele.
authors.affiliation: Section on Translational Neuroscience, Molecular Medicine Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address: reina.haddad@nih.gov.
authors.forename: Marie Reine
authors.initials: MR
authors.lastname: Haddad
authors.affiliation: Section on Translational Neuroscience, Molecular Medicine Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address: keyur.patel19@gmail.com.
authors.forename: Keyur D
authors.initials: KD
authors.lastname: Patel
authors.affiliation: Clinical Neurocardiology Section, Clinical Neuroscience Program, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address: psullivan1@ninds.nih.gov.
authors.forename: Patricia H
authors.initials: PH
authors.lastname: Sullivan
authors.affiliation: Clinical Neurocardiology Section, Clinical Neuroscience Program, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address: goldsteind@ninds.nih.gov.
authors.forename: David S
authors.initials: DS
authors.lastname: Goldstein
authors.affiliation: Division of Biophysical Toxicology, Joint Pathology Center, Malcolm Grow Medical Clinic, Andrews Air Force Base, Camp Springs, MD 20762, USA. Electronic address: kevin.m.murphy2@navy.mil.
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Murphy
authors.affiliation: Division of Biophysical Toxicology, Joint Pathology Center, Malcolm Grow Medical Clinic, Andrews Air Force Base, Camp Springs, MD 20762, USA. Electronic address: jose.centeno@afncr.af.mil.
authors.forename: Jose A
authors.initials: JA
authors.lastname: Centeno
authors.affiliation: Section on Translational Neuroscience, Molecular Medicine Program, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892, USA. Electronic address: kalers@mail.nih.gov.
authors.forename: Stephen G
authors.initials: SG
authors.lastname: Kaler
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics*; D000483:Alleles; D000818:Animals; D015153:Blotting, Western; D001835:Body Weight; D001921:Brain / Q000378:metabolism; D027682:Cation Transport Proteins / Q000235:genetics*; D055028:Comparative Genomic Hybridization; D003300:Copper / Q000378:metabolism; D000073840:Copper-Transporting ATPases; D004195:Disease Models, Animal; D004299:Dopamine beta-Hydroxylase / Q000378:metabolism; D005260:Female; D006579:Heterozygote; D006801:Humans; D007706:Menkes Kinky Hair Syndrome / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D020411:Oligonucleotide Array Sequence Analysis; D010641:Phenotype; D016133:Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017384:Sequence Deletion; D014960:X Chromosome / Q000235:genetics
chemical_list: C486201:Atp7a protein, mouse; D027682:Cation Transport Proteins; D003300:Copper; D004299:Dopamine beta-Hydroxylase; D000251:Adenosine Triphosphatases; D000073840:Copper-Transporting ATPases
keywords: Atp7a; Copper; Menkes disease; Mottled-dappled