Zygote arrest 1 gene in pig, cattle and human: evidence of different transcript variants in male and female germ cells

Uzbekova Svetlana, Roy-Sabau Monica, Dalbiès-Tran Rozenn, Perreau Christine, Papillier Pascal, Mompart Florence, Thelie Aurore, Pennetier Sophie, Cognie Juliette, Cadoret Veronique, Royere Dominique, Philippe Monget, Mermillod Pascal

Description

Zygote arrest 1 (ZAR1) is one of the few known oocyte-specific maternal-effect genes essential for the beginning of embryo development discovered in mice. This gene is evolutionary conserved in vertebrates and ZAR1 protein is characterized by the presence of atypical plant homeobox zing finger domain, suggesting its role in transcription regulation. This work was aimed at the study of this gene, which could be one of the key regulators of successful preimplantation development of domestic animals, in pig and cattle, as compared with human. Methods Screenings of somatic cell hybrid panels and in silico research were performed to characterize ZAR1 chromosome localization and sequences. Rapid amplification of cDNA ends was used to obtain full-length cDNAs. Spatio-temporal mRNA expression patterns were studied using Northern blot, reverse transcription coupled to polymerase chain reaction and in situ hybridization. Results We demonstrated that ZAR1 is a single copy gene, positioned on chromosome 8 in pig and 6 in cattle, and several variants of correspondent cDNA were cloned from oocytes. Sequence analysis of ZAR1 cDNAs evidenced numerous short inverted repeats within the coding sequences and putative Pumilio-binding and embryo-deadenylation elements within the 3'-untranslated regions, indicating the potential regulation ways. We showed that ZAR1 expressed exclusively in oocytes in pig ovary, persisted during first cleavages in embryos developed in vivo and declined sharply in morulae and blastocysts. ZAR1 mRNA was also detected in testis, and, at lower level, in hypothalamus and pituitary in both species. For the first time, ZAR1 was localized in testicular germ cells, notably in round spermatids. In addition, in pig, cattle and human only shorter ZAR1 transcript variants resulting from alternative splicing were found in testis as compared to oocyte. Conclusion Our data suggest that in addition to its role in early embryo development highlighted by expression pattern of full-length transcript in oocytes and early embryos, ZAR1 could also be implicated in the regulation of meiosis and post meiotic differentiation of male and female germ cells through expression of shorter splicing variants. Species conservation of ZAR1 expression and regulation underlines the central role of this gene in early reproductive processes.

Informations

• Publié par: biomed
• Publié le: 01 janvier 2006
• Nombre de lectures: 23
• Langue: English

Extrait

Reproductive Biology and Endocrinology

BioMedCentral

Open Access Research Zygote arrest 1 gene in pig, cattle and human: evidence of different transcript variants in male and female germ cells 1 1 1 Svetlana Uzbekova* , Monica RoySabau , Rozenn DalbièsTran , 1 1 3 1 Christine Perreau , Pascal Papillier , Florence Mompart , Aurore Thelie , 1 1 1,2 Sophie Pennetier , Juliette Cognie , Veronique Cadoret , 2 1 1 Dominique Royere , Philippe Monget and Pascal Mermillod

1 Address: Physiologie de la Reproduction et des Comportements, UMR 6175 Institut National de la Recherche Agronomique/Centre National de 2 la Recherche Scientifique, Université François Rabelais de Tours, Haras Nationaux, 37380 Nouzilly, France, Service de Médecine et Biologie de la 3 Reproduction, UMR 6175, Centre Hospitalier Universitaire Bretonneau, 37044 Tours, France and Laboratoire de Génétique Cellulaire, INRA, Chemin de BordeRouge – Auzeville, BP 52627 31326 CastanetTolosan Cedex, France

Email: Svetlana Uzbekova*  [e-mail]; Monica RoySabau  [e-mail]; Rozenn Dalbiès Tran  [e-mail]; Christine Perreau  [e-mail]; Pascal Papillier  [e-mail]; Florence Mompart  [e-mail]; Aurore Thelie  [e-mail]; Sophie Pennetier  [e-mail]; Juliette Cognie  [e-mail]; Veronique Cadoret  [e-mail]; Dominique Royere  [e-mail]tours.fr; Philippe Monget  [e-mail]; Pascal Mermillod  [e-mail] * Corresponding author

Published: 21 March 2006 Received: 06 December 2005 Accepted: 21 March 2006 Reproductive Biology and Endocrinology2006,4:12 doi:10.1186/14777827412 This article is available from: http://www.rbej.com/content/4/1/12 © 2006Uzbekova et al; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract Background:Zygote arrest 1 (ZAR1) is one of the few known oocytespecific maternaleffect genes essential for the beginning of embryo development discovered in mice. This gene is evolutionary conserved in vertebrates and ZAR1 protein is characterized by the presence of atypical plant homeobox zing finger domain, suggesting its role in transcription regulation. This work was aimed at the study of this gene, which could be one of the key regulators of successful preimplantation development of domestic animals, in pig and cattle, as compared with human.

Methods:Screenings of somatic cell hybrid panels and in silico research were performed to characterize ZAR1 chromosome localization and sequences. Rapid amplification of cDNA ends was used to obtain fulllength cDNAs. Spatiotemporal mRNA expression patterns were studied using Northern blot, reverse transcription coupled to polymerase chain reaction and in situ hybridization.

Results:We demonstrated that ZAR1 is a single copy gene, positioned on chromosome 8 in pig and 6 in cattle, and several variants of correspondent cDNA were cloned from oocytes. Sequence analysis of ZAR1 cDNAs evidenced numerous short inverted repeats within the coding sequences and putative Pumiliobinding and embryodeadenylation elements within the 3'untranslated regions, indicating the potential regulation ways. We showed that ZAR1 expressed exclusively in oocytes in pig ovary, persisted during first cleavages in embryos developed in vivo and declined sharply in morulae and blastocysts. ZAR1 mRNA was also detected in testis, and, at lower level, in hypothalamus and pituitary in both species. For the first time, ZAR1 was localized in testicular germ cells, notably in round spermatids. In addition, in pig, cattle and human only shorter ZAR1 transcript variants resulting from alternative splicing were found in testis as compared to oocyte.

Page 1 of 14 (page number not for citation purposes)