Evolution of major milk proteins in Mus musculus and Mus spretus mouse species: a genoproteomic analysis

BMC Genomics

Research Article

Christian Beauvallet¹  Emmanuelle Rebours¹  Patrice Martin¹  Claudia Bevilacqua¹  Guy Miranda¹  Nisrine Boumahrou¹  Sylvain Bellier²  Sanda Andrei³  Jean-Jacques Panthier⁴ 

[1] INRA, UR1313 Génétique animale et Biologie intégrative UMR 1313, Equipe LGS, F-78350, Jouy-en-Josas, France;INRA, UR1313 Génétique animale et Biologie intégrative UMR 1313, Equipe LGS, F-78350, Jouy-en-Josas, France;INRA, UMR955 Génétique Fonctionnelle et Médicale, F-94704, Maisons-Alfort, France;INRA, UR1313 Génétique animale et Biologie intégrative UMR 1313, Equipe LGS, F-78350, Jouy-en-Josas, France;Universitatea de Stiinte Agricole si Medicina Veterinara Cluj-Napoca, Romania;Institut Pasteur, Génétique Fonctionnelle de la Souris; CNRS URA2578, F-75724, Paris, France;

关键词: Milk Protein;    Whey Acidic Protein;    Protein Polymorphism;    Cryptic Splice Site;    Milk Protein Gene;   

DOI  :  10.1186/1471-2164-12-80

 received in 2010-09-13, accepted in 2011-01-28,  发布年份 2011

来源: Springer

【 摘 要 】

BackgroundDue to their high level of genotypic and phenotypic variability, Mus spretus strains were introduced in laboratories to investigate the genetic determinism of complex phenotypes including quantitative trait loci. Mus spretus diverged from Mus musculus around 2.5 million years ago and exhibits on average a single nucleotide polymorphism (SNP) in every 100 base pairs when compared with any of the classical laboratory strains. A genoproteomic approach was used to assess polymorphism of the major milk proteins between SEG/Pas and C57BL/6J, two inbred strains of mice representative of Mus spretus and Mus musculus species, respectively.ResultsThe milk protein concentration was dramatically reduced in the SEG/Pas strain by comparison with the C57BL/6J strain (34 ± 9 g/L vs. 125 ± 12 g/L, respectively). Nine major proteins were identified in both milks using RP-HPLC, bi-dimensional electrophoresis and MALDI-Tof mass spectrometry. Two caseins (β and αs1) and the whey acidic protein (WAP), showed distinct chromatographic and electrophoresis behaviours. These differences were partly explained by the occurrence of amino acid substitutions and splicing variants revealed by cDNA sequencing. A total of 34 SNPs were identified in the coding and 3'untranslated regions of the SEG/Pas Csn1s1 (11), Csn2 (7) and Wap (8) genes. In addition, a 3 nucleotide deletion leading to the loss of a serine residue at position 93 was found in the SEG/Pas Wap gene.ConclusionSNP frequencies found in three milk protein-encoding genes between Mus spretus and Mus musculus is twice the values previously reported at the whole genome level. However, the protein structure and post-translational modifications seem not to be affected by SNPs characterized in our study. Splicing mechanisms (cryptic splice site usage, exon skipping, error-prone junction sequence), already identified in casein genes from other species, likely explain the existence of multiple αs1-casein isoforms both in SEG/Pas and C57BL/6J strains. Finally, we propose a possible mechanism by which the hallmark tandem duplication of a 18-nt exon (14 copies) may have occurred in the mouse genome.

【 授权许可】

Unknown   
© Boumahrou et al; licensee BioMed Central Ltd. 2011. This article is published under license to 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.