Details

Autor(en) / Beteiligte

• Delabaere, Laetitia
• Orsi, Guillermo A.
• Sapey-Triomphe, Laure
• Horard, Béatrice
• Couble, Pierre
• Loppin, Benjamin

Titel

The Spartan Ortholog Maternal Haploid Is Required for Paternal Chromosome Integrity in the Drosophila Zygote

Ist Teil von

• Current biology, 2014-10, Vol.24 (19), p.2281-2287

Ort / Verlag

England: Elsevier Inc

Erscheinungsjahr

2014

Quelle

MEDLINE

Beschreibungen/Notizen

• The animal sperm nucleus is characterized by an extremely compacted organization of its DNA after the global replacement of histones with sperm-specific nuclear basic proteins, such as protamines [1, 2]. In the absence of DNA repair activity in the mature gamete, the integrity of the paternal genome is potentially challenged by the unique topological constraints exerted on sperm DNA [3]. In addition, the maintenance of paternal DNA integrity during the rapid remodeling of sperm chromatin at fertilization has long been regarded as a maternal trait [4]. However, little is known about the nature of the egg proteins involved in this essential aspect of zygote formation [5, 6]. We had previously characterized the unique phenotype of the classical Drosophila maternal effect mutant maternal haploid (mh), which specifically affects the integration of paternal chromosomes in the zygote [7]. Here we show that MH is the fly ortholog of the recently identified human DVC1/Spartan protein, a conserved regulator of DNA damage tolerance [8–14]. Like Spartan, MH protein is involved in the resistance to UV radiation and recruits the p97/TER94 segregase to stalled DNA replication forks in somatic cells. In the zygote, we found that the mh phenotype is consistent with perturbed or incomplete paternal DNA replication. Remarkably, however, the specific accumulation of MH in the male pronucleus before the first S phase suggests that this maternal protein is required to maintain paternal DNA integrity during nuclear decondensation or to set the paternal chromatin landscape in preparation of the first zygotic cycle. [Display omitted] •maternal haploid (mh) encodes the Drosophila ortholog of human Spartan/DVC1•Like Spartan, MH is involved in UV resistance in somatic cells•At fertilization, MH localizes in the male nucleus before the first S phase•MH is essential for the integration of paternal chromosomes into the zygote Delabaere et al. show that the Drosophila Spartan ortholog Maternal Haploid is a conserved maternal metalloprotease required in the male pronucleus for the subsequent replication and segregation of paternal chromosomes.