title: Reorganisation of human sperm nuclear architecture during formation of pronuclei in a model system.
abstract: By fertilisation, two terminally differentiated cells, namely the egg and spermatozoon, are combined to create a totipotent zygote. During this process, the inactive sperm nucleus is transformed into a functional male pronucleus. Recent studies demonstrate that human sperm chromatin has an elaborate multilevel organisation, but almost nothing is known about how sperm chromosomes are transformed during fertilisation. Because of ethical reasons and technical complications, experimentation with human embryos is generally unworkable and adequate model systems are necessary to study the formation of male pronuclei. Here, we analyse remodelling of human sperm chromatin and chromosome architecture in Xenopus egg extracts using immunofluorescent localisation of protamines and centromere protein A, as well as fluorescence in situ hybridisation localisation of major alpha-satellite DNA and whole chromosome territory (CT). We demonstrate noticeable relocalisation of centromeres and remodelling of CT during the decondensation-recondensation cycle, mimicking cellular events that occur in the paternal genome in vivo during fertilisation.
authors.affiliation: The Jones Institute for Reproductive Medicine, Eastern Virginia Medical School, Norfolk, VA 23507, USA.
authors.forename: Olga
authors.initials: O
authors.lastname: Mudrak
authors.forename: Rajeev
authors.initials: R
authors.lastname: Chandra
authors.forename: Estella
authors.initials: E
authors.lastname: Jones
authors.forename: Earl
authors.initials: E
authors.lastname: Godfrey
authors.forename: Andrei
authors.initials: A
authors.lastname: Zalensky
mesh_terms: D000818:Animals; D001324:Autoantigens / Q000378:metabolism; D002467:Cell Nucleus / Q000648:ultrastructure*; D002503:Centromere / Q000378:metabolism / Q000648:ultrastructure; D000076247:Centromere Protein A; D002843:Chromatin / Q000648:ultrastructure*; D002868:Chromosomal Proteins, Non-Histone / Q000378:metabolism; D002875:Chromosomes / Q000378:metabolism / Q000648:ultrastructure; D005260:Female; D005306:Fertilization / Q000502:physiology*; D006801:Humans; D008297:Male; D023421:Models, Animal; D008954:Models, Biological; D009865:Oocytes / Q000502:physiology / Q000648:ultrastructure; D011479:Protamines / Q000378:metabolism; D013084:Sperm-Ovum Interactions / Q000502:physiology*; D013094:Spermatozoa / Q000502:physiology / Q000648:ultrastructure*; D014982:Xenopus laevis
chemical_list: D001324:Autoantigens; C000619700:CENPA protein, human; D000076247:Centromere Protein A; D002843:Chromatin; D002868:Chromosomal Proteins, Non-Histone; D011479:Protamines