title: Comparison of the absolute level of epigenetic marks 5-methylcytosine, 5-hydroxymethylcytosine, and 5-hydroxymethyluracil between human leukocytes and sperm.
abstract: 5-Methylcytosine is one of the most important epigenetic modifications and has a profound impact on embryonic development. After gamete fusion, there is a widespread and rapid active demethylation process of sperm DNA, which suggests that the paternal epigenome has an important role during embryonic development. To better understand the epigenome of sperm DNA and its possible involvement in a developing embryo, we determined epigenetic marks in human sperm DNA and in surrogate somatic tissue leukocytes; the analyzed epigenetic modifications included 5-methyl-2'-deoxycytidine, 5-hydroxymethyl-2'-deoxycytidine, and 5-hydroxymethyl-2'-deoxyuridine. For absolute determination of the modification, we used liquid chromatography with UV detection and tandem mass spectrometry techniques with isotopically labeled internal standards. Our analyses demonstrated, for the first time to date, that absolute global values of 5-methyl-2'-deoxycytidine, 5-hydroxymethyl-2'-deoxycytidine, and 5-hydroxymethyl-2'-deoxyuridine in sperm are highly statistically different from those observed for leukocyte DNA, with respective mean values of 3.815% versus 4.307%, 0.797 versus 2.945 per 10⁴ deoxynucleosides, and 5.209 versus 0.492 per 10⁶ deoxynucleosides. We hypothesize that an exceptionally high value of 5-hydroxymethyluracil in sperm (>10-fold higher than in leukocytes) may play a not yet recognized regulatory role in the paternal genome.
authors: Department of Clinical Biochemistry, Nicolaus Copernicus University in Toruń, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Bydgoszcz, Poland.
authors: Jolanta
authors: J
authors: Guz
authors: Department of Clinical Biochemistry, Nicolaus Copernicus University in Toruń, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Bydgoszcz, Poland.
authors: Daniel
authors: D
authors: Gackowski
authors: Department of Clinical Biochemistry, Nicolaus Copernicus University in Toruń, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Bydgoszcz, Poland.
authors: Marek
authors: M
authors: Foksinski
authors: Department of Clinical Biochemistry, Nicolaus Copernicus University in Toruń, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Bydgoszcz, Poland.
authors: Rafal
authors: R
authors: Rozalski
authors: Department of Clinical Biochemistry, Nicolaus Copernicus University in Toruń, Ludwik Rydygier Collegium Medicum in Bydgoszcz, Bydgoszcz, Poland ryszardo@cm.umk.pl.
authors: Ryszard
authors: R
authors: Olinski
mesh_terms: D044503:5-Methylcytosine / Q000097:blood / Q000378:metabolism* / Q000031:analogs & derivatives; D000328:Adult; D015415:Biomarkers / Q000097:blood / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003596:Cytosine / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D019175:DNA Methylation; D003841:Deoxycytidine / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism; D044127:Epigenesis, Genetic; D006801:Humans; D007962:Leukocytes / Q000378:metabolism; D008297:Male; D010432:Pentoxyl / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism; D011044:Poland; D021241:Spectrometry, Mass, Electrospray Ionization; D013094:Spermatozoa / Q000378:metabolism*; D053719:Tandem Mass Spectrometry; D013936:Thymidine / Q000031:analogs & derivatives / Q000097:blood / Q000378:metabolism; D015854:Up-Regulation
chemical_list: C540838:5-hydroxymethyl-2'-deoxycytidine; D015415:Biomarkers; D003841:Deoxycytidine; C011865:5-hydroxymethylcytosine; C008055:5-hydroxymethyluracil; C018080:5-hydroxymethyl-2'-deoxyuridine; D044503:5-Methylcytosine; D010432:Pentoxyl; D003596:Cytosine; D004247:DNA; C016569:5-methyldeoxycytidine; D013936:Thymidine
keywords: 5-hydroxymethylcytosine; 5-hydroxymethyluracil; 5-methylcytosine; epigenetics; leukocytes; sperm