De Novo Centromere Formation and Centromeric Sequence Expansion in Wheat and its Wide Hybrids

Abstract Background Individuals with rare cytogenetic variants have contributed to our understanding of the genetics of sex chromosome and its disorders. Here, we report on a 23 years old man with a de novo 47,XX,+mar.ish der(Y)neo(Y)(pter-->p11.2::q11.23-->neo-->q11.23-->qter)(DYZ3-,SRY+,WCPY+) chromosome complement, accompanying with azoospermia and some of other clinical features suggestive of Klinefelter's Syndrome. The constitution of the patient was verified by GTG-banding, QFQ-banding, Fluorescence in Situ Hybridization and Polymerase Chain Reaction. Accordingly, we report the finding of a structurally abnormal chromosome Y with no detectable DYZ3 centromeric sequence and with no detection of AZF a, AZF b and AZF c, with clinical features suggestive of Klinefelter's Syndrome. This is the first reported case of Klinefelter's Syndrome involving a neocentromic Y among previously described cases with a neocentromere. Case presentation we report on a 23 years old man with a de novo 47,XX,+mar.ish der(Y)neo(Y)(pter-->p11.2::q11.23-->neo-->q11.23-->qter)(DYZ3-,SRY+,WCPY+) chromosome complement, accompanying with azoospermia and some of other clinical features suggestive of Klinefelter's Syndrome. The constitution of the patient was verified by GTG-banding, QFQ-banding, Fluorescence in Situ Hybridization FISH and Polymerase Chain Reaction PCR. Conclusions It can be inferred that a neocentromic Y is formed by identification of FISH, PCR and the fact that this markerof Y chromosome is present in 100% of peripheral blood cells and has been efficiently retained through cell divisions despite the absence of the endogenous centromere region. To our knowledge, this is the first reported case of Klinefelter's Syndrome involving a neocentromic Y among previously described cases with a neocentromere, which adds to the catalog of chromosomal aberrations. The present study not only improves the understanding of karyotype/phenotype relationships between neocentric marker Y chromosomes and KFS male infertility, but also supports the hypothesis that the combined application of molecular cytogenetic analysis might help to identify breakpoints, origins, and the constitution of the marker chromosomes.

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The Morphology of the Rat Kidney Following Folic Acid Administration

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100067996 ◽

1970 ◽

Vol 28 ◽

pp. 200-201

Author(s):

Aline Byrnes ◽

Elsa E. Ramos ◽

Minoru Suzuki ◽

E.D. Mayfield

Keyword(s):

Folic Acid ◽

De Novo ◽

Specific Activity ◽

Rat Kidney ◽

Present Report ◽

Intracellular Localization ◽

Male Rats ◽

Renal Hypertrophy ◽

Electron Microscopic ◽

Biochemical Alterations

Renal hypertrophy was induced in 100 g male rats by the injection of 250 mg folic acid (FA) dissolved in 0.3 M NaHCO3/kg body weight (i.v.). Preliminary studies of the biochemical alterations in ribonucleic acid (RNA) metabolism of the renal tissue have been reported recently (1). They are: RNA content and concentration, orotic acid-c14 incorporation into RNA and acid soluble nucleotide pool, intracellular localization of the newly synthesized RNA, and the specific activity of enzymes of the de novo pyrimidine biosynthesis pathway. The present report describes the light and electron microscopic observations in these animals. For light microscopy, kidney slices were fixed in formalin, embedded, sectioned, and stained with H & E and PAS.

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Early ossicle growth in the regenerating disc of a brittle star

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100169559 ◽

1994 ◽

Vol 52 ◽

pp. 364-365

Author(s):

M. Shlepr ◽

R. L. Turner

Keyword(s):

Cell Membrane ◽

Light Microscopy ◽

De Novo ◽

Current Model ◽

Syncytium Formation ◽

Brittle Star ◽

Intracellular Location ◽

Limited Volume ◽

Tissue Calcification

Calcification in the echinoderms occurs within a limited-volume cavity enclosed by cytoplasmic extensions of the mineral depositing cells, the sclerocytes. The current model of this process maintains that the sheath formed from these cytoplasmic extensions is syncytial. Prior studies indicate that syncytium formation might be dependent on sclerocyte density and not required for calcification. This model further envisions that ossicles formed de novo nucleate and grow intracellularly until the ossicle effectively outgrows the vacuole. Continued ossicle growth occurs within the sheath but external to the cell membrane. The initial intracellular location has been confirmed only for elements of the echinoid tooth.The regenerating aboral disc integument of ophiophragmus filograneus was used to test the current echinoderm calcification model. This tissue is free of calcite fragments, thus avoiding questions of cellular engulfment, and ossicles are formed de novo. The tissue calcification pattern was followed by light microscopy in both living and fixed preparations.

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Arabidopsis 4-COUMAROYL-COA LIGASE 8 contributes to the biosynthesis of the benzenoid ring of coenzyme Q in peroxisomes

Biochemical Journal ◽

10.1042/bcj20190688 ◽

2019 ◽

Vol 476 (22) ◽

pp. 3521-3532

Author(s):

Eric Soubeyrand ◽

Megan Kelly ◽

Shea A. Keene ◽

Ann C. Bernert ◽

Scott Latimer ◽

...

Keyword(s):

Oxidative Metabolism ◽

Time Course ◽

Reverse Genetics ◽

De Novo ◽

Coenzyme Q ◽

Control Level ◽

Wild Type ◽

Fluorescent Reporters ◽

Coa Ligase ◽

Peroxisomal Targeting

Plants have evolved the ability to derive the benzenoid moiety of the respiratory cofactor and antioxidant, ubiquinone (coenzyme Q), either from the β-oxidative metabolism of p-coumarate or from the peroxidative cleavage of kaempferol. Here, isotopic feeding assays, gene co-expression analysis and reverse genetics identified Arabidopsis 4-COUMARATE-COA LIGASE 8 (4-CL8; At5g38120) as a contributor to the β-oxidation of p-coumarate for ubiquinone biosynthesis. The enzyme is part of the same clade (V) of acyl-activating enzymes than At4g19010, a p-coumarate CoA ligase known to play a central role in the conversion of p-coumarate into 4-hydroxybenzoate. A 4-cl8 T-DNA knockout displayed a 20% decrease in ubiquinone content compared with wild-type plants, while 4-CL8 overexpression boosted ubiquinone content up to 150% of the control level. Similarly, the isotopic enrichment of ubiquinone's ring was decreased by 28% in the 4-cl8 knockout as compared with wild-type controls when Phe-[Ring-13C6] was fed to the plants. This metabolic blockage could be bypassed via the exogenous supply of 4-hydroxybenzoate, the product of p-coumarate β-oxidation. Arabidopsis 4-CL8 displays a canonical peroxisomal targeting sequence type 1, and confocal microscopy experiments using fused fluorescent reporters demonstrated that this enzyme is imported into peroxisomes. Time course feeding assays using Phe-[Ring-13C6] in a series of Arabidopsis single and double knockouts blocked in the β-oxidative metabolism of p-coumarate (4-cl8; at4g19010; at4g19010 × 4-cl8), flavonol biosynthesis (flavanone-3-hydroxylase), or both (at4g19010 × flavanone-3-hydroxylase) indicated that continuous high light treatments (500 µE m−2 s−1; 24 h) markedly stimulated the de novo biosynthesis of ubiquinone independently of kaempferol catabolism.

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