title: Genetic variation underlying protein expression in eggs of the marine mussel Mytilus edulis.
abstract: Study of the genetic basis of gene expression variation is central to attempts to understand the causes of evolutionary change. Although there are many transcriptomics studies estimating genetic variance and heritability in model organisms such as humans there is a lack of equivalent proteomics studies. In the present study, the heritability underlying egg protein expression was estimated in the marine mussel Mytilus. We believe this to be the first such measurement of genetic variation for gene expression in eggs of any organism. The study of eggs is important in evolutionary theory and life history analysis because maternal effects might have profound effects on the rate of evolution of offspring traits. Evidence is presented that the egg proteome varies significantly between individual females and that heritability of protein expression in mussel eggs is moderate to high suggesting abundant genetic variation on which natural selection might act. The study of the mussel egg proteome is also important because of the unusual system of mitochondrial DNA inheritance in mussels whereby different mitochondrial genomes are transmitted independently through female and male lineages (doubly uniparental inheritance). It is likely that the mechanism underlying this system involves the interaction of specific egg factors with sperm mitochondria following fertilization, and its elucidation might be advanced by study of the proteome in females having different progeny sex ratios. Putative identifications are presented here for egg proteins using MS/MS in Mytilus lines differing in sex ratio. Ontology terms relating to stress response and protein folding occur more frequently for proteins showing large expression differences between the lines. The distribution of ontology terms in mussel eggs was compared with those for previous mussel proteomics studies (using other tissues) and with mammal eggs. Significant differences were observed between mussel eggs and mussel tissues but not between the two types of eggs.
authors.affiliation: Institute of Life Sciences, School of Medicine, Swansea University, Swansea SA2 8PP, West Glamorgan, Wales, United Kingdom.
authors.forename: Angel P
authors.initials: AP
authors.lastname: Diz
authors.forename: Edward
authors.initials: E
authors.lastname: Dudley
authors.forename: Barry W
authors.initials: BW
authors.lastname: MacDonald
authors.forename: Benjamin
authors.initials: B
authors.lastname: Piña
authors.forename: Ellen L R
authors.initials: EL
authors.lastname: Kenchington
authors.forename: Eleftherios
authors.initials: E
authors.lastname: Zouros
authors.forename: David O F
authors.initials: DO
authors.lastname: Skibinski
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D016001:Confidence Intervals; D030562:Databases, Protein; D015180:Electrophoresis, Gel, Two-Dimensional; D005260:Female; D014644:Genetic Variation; D013058:Mass Spectrometry; D049880:Mytilus edulis / Q000378:metabolism*; D010063:Ovum / Q000378:metabolism*; D011506:Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism*; D020543:Proteome / Q000032:analysis
chemical_list: D011506:Proteins; D020543:Proteome
references.citation: J Proteome Res. 2005 Sep-Oct;4(5):1619-27
references.pmid: 16212414
references.citation: Brief Bioinform. 2005 Mar;6(1):57-71
references.pmid: 15826357
references.citation: Reprod Biol Endocrinol. 2003 Feb 14;1:27
references.pmid: 12646049
references.citation: Nature. 1994 Apr 28;368(6474):817-8
references.pmid: 8159240
references.citation: Genetics. 1994 Nov;138(3):801-9
references.pmid: 7851776
references.citation: Proteomics. 2004 Feb;4(2):299-302
references.pmid: 14760699
references.citation: Am Nat. 2000 Mar;155(3):301-310
references.pmid: 10718727
references.citation: Proteomics. 2005 Dec;5(18):4958-63
references.pmid: 16267813
references.citation: Int J Parasitol. 2005 Apr 30;35(5):543-53
references.pmid: 15826646
references.citation: Evolution. 1991 Jun;45(4):853-861
references.pmid: 28564058
references.citation: Trends Ecol Evol. 2006 Jan;21(1):29-37
references.pmid: 16701467
references.citation: Mutat Res. 2006 Dec 1;602(1-2):121-34
references.pmid: 17010391
references.citation: Genetics. 2006 Oct;174(2):627-37
references.pmid: 16888332
references.citation: Gene. 2006 Jul 5;376(1):24-36
references.pmid: 16630699
references.citation: J Evol Biol. 2008 Jan;21(1):88-96
references.pmid: 18034804
references.citation: J Chromatogr B Analyt Technol Biomed Life Sci. 2005 Feb 5;815(1-2):261-74
references.pmid: 15652815
references.citation: Nat Genet. 2002 Oct;32(2):261-6
references.pmid: 12219088
references.citation: Mol Biol Evol. 1995 Sep;12(5):735-47
references.pmid: 7476121
references.citation: Nucleic Acids Res. 2007 Jan;35(Database issue):D193-7
references.pmid: 17142230
references.citation: Reprod Biomed Online. 2007 Sep;15(3):346-53
references.pmid: 17854537
references.citation: Gene. 2003 Sep 18;314:29-40
references.pmid: 14527715
references.citation: Mol Biol Evol. 2004 Jul;21(7):1308-17
references.pmid: 15034135
references.citation: Proteomics. 2003 Oct;3(10):1912-9
references.pmid: 14625853
references.citation: Poult Sci. 2005 Aug;84(8):1209-13
references.pmid: 16156204
references.citation: Genes Genet Syst. 2000 Dec;75(6):313-8
references.pmid: 11280005
references.citation: J Proteome Res. 2005 May-Jun;4(3):809-19
references.pmid: 15952727
references.citation: Aquat Toxicol. 2006 Jun 1;78 Suppl 1:S13-24
references.pmid: 16644027
references.citation: Mamm Genome. 2006 Sep;17(9):941-9
references.pmid: 16964442
references.citation: Proc Biol Sci. 2006 Feb 22;273(1585):485-93
references.pmid: 16615217
references.citation: Genetics. 1997 Apr;145(4):1073-82
references.pmid: 9093859
references.citation: Proteomics. 2005 Aug;5(12):3105-15
references.pmid: 16035117
references.citation: Mol Reprod Dev. 2004 Mar;67(3):313-22
references.pmid: 14735493
references.citation: Proc Natl Acad Sci U S A. 2006 Apr 4;103(14):5425-30
references.pmid: 16567645
references.citation: Mol Cell Proteomics. 2006 Jul;5(7):1274-85
references.pmid: 16603574
references.citation: Bioinformatics. 2007 Jan 15;23(2):e237-44
references.pmid: 17237098
references.citation: Curr Opin Biotechnol. 2007 Aug;18(4):371-7
references.pmid: 17693073
references.citation: Proteomics. 2006 Mar;6(6):1712-5
references.pmid: 16429464
references.citation: Proc Natl Acad Sci U S A. 2000 Aug 15;97(17):9390-5
references.pmid: 10920198
references.citation: Bioinformatics. 2004 Dec 12;20(18):3604-12
references.pmid: 15284092
references.citation: Proc Natl Acad Sci U S A. 1994 Aug 2;91(16):7463-7
references.pmid: 8052604
references.citation: Anal Chem. 1996 Mar 1;68(5):850-8
references.pmid: 8779443
references.citation: Trends Biochem Sci. 1999 Jan;24(1):8-11
references.pmid: 10087914
references.citation: Heredity (Edinb). 1987 Oct;59 ( Pt 2):181-97
references.pmid: 3316130
references.citation: Proteomics. 2006 Jul;6(13):3811-20
references.pmid: 16739132
references.citation: J Evol Biol. 2007 Mar;20(2):588-96
references.pmid: 17305825
references.citation: Proteomics. 2007 Jun;7(12):2111-20
references.pmid: 17514682
references.citation: Proteomics. 2004 Dec;4(12):3665-85
references.pmid: 15543535
references.citation: Biol Bull. 2007 Feb;212(1):12-9
references.pmid: 17301327
references.citation: Bioinformatics. 2006 Jul 15;22(14):e220-6
references.pmid: 16873475
references.citation: Genetics. 2004 Feb;166(2):883-94
references.pmid: 15020473
references.citation: PLoS Comput Biol. 2008 Jan;4(1):e20
references.pmid: 18225946
references.citation: Nature. 1994 Apr 28;368(6474):818
references.pmid: 8159241
references.citation: Mol Ecol. 2006 Apr;15(5):1197-211
references.pmid: 16626448
references.citation: Mol Reprod Dev. 2007 May;74(5):608-16
references.pmid: 17044029
references.citation: Trends Genet. 2007 Sep;23(9):465-74
references.pmid: 17681397
references.citation: Biol Bull. 2007 Apr;212(2):143-50
references.pmid: 17438206
references.citation: J Chromatogr A. 2006 Sep 22;1128(1-2):133-7
references.pmid: 16822518
references.citation: Mol Ecol. 2005 Oct;14(12):3623-42
references.pmid: 16202085
references.citation: Proteomics. 2002 Aug;2(8):960-8
references.pmid: 12203891
references.citation: Am Nat. 2004 Sep;164(3):E62-72
references.pmid: 15478083
references.citation: Am J Hum Genet. 2004 Dec;75(6):1094-105
references.pmid: 15514893
references.citation: Proc Natl Acad Sci U S A. 2007 Feb 13;104(7):2313-8
references.pmid: 17277080