title: Genetic determinants of pig birth weight variability.
abstract: BACKGROUND
  Piglet birth weight variability, a trait also known as the within-litter homogeneity of birth weight, reflects the sow's prolificacy, because it is positively genetically correlated with preweaning mortality but negatively correlated with the mean growth of piglets during sucking. In addition, the maternal additive genetic variance and heritability has been found exist for this trait, thus, reduction in the variability of piglet birth weight to improve the sow prolificacy is possible by selective breeding.
  
  
  RESULTS
  We performed a genome wide association study (GWAS) in 82 sows with extreme standard deviation of birth weights within the first parity to identify significant SNPs, and finally 266 genome-wide significant SNPs (p < 0.01) were identified. These SNPs were mainly enriched on chromosome 7, 1, 13, 14, 15 and 18. We further scanned genes of the top 50 SNPs with the lowest p values and found some genes involved in plasma glucose homeostasis (GLP1R) and lipid metabolism as well as maternal-fetal lipid transport (AACS, APOB, OSBPL10 and LRP1B) which may contribute to the birth weight variability trait.
  
  
  CONCLUSIONS
  Birth weight variability trait has a low heritability. It is not easy to get significant signal by GWAS using small sample size. Herein, we identified some candidate chromosome regions especially chromosome 7 and suggested five genes which may provide some information for the further study.
authors.affiliation: Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China. wxmexplorer@163.com.|Institute of Animal Science, Jiangsu Academy of Agricultural Science, Nanjing, 210014, China. wxmexplorer@163.com.
authors.forename: Xuemin
authors.initials: X
authors.lastname: Wang
authors.affiliation: Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China. Xll198708@gmail.com.|Institute for Genomic Diversity, Cornell University, Ithaca, NY, 14853, USA. Xll198708@gmail.com.
authors.forename: Xiaolei
authors.initials: X
authors.lastname: Liu
authors.affiliation: Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China. dadong_deng@163.com.
authors.forename: Dadong
authors.initials: D
authors.lastname: Deng
authors.affiliation: Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China. yumei@mail.hzau.edu.cn.
authors.forename: Mei
authors.initials: M
authors.lastname: Yu
authors.affiliation: Key Laboratory of Agricultural Animal Genetics, Breeding, and Reproduction of Ministry of Education, Huazhong Agricultural University, Wuhan, 430070, China. lixiaoping@mail.hzau.edu.cn.
authors.forename: Xiaoping
authors.initials: X
authors.lastname: Li
mesh_terms: D000818:Animals; D001724:Birth Weight / Q000235:genetics*; D001786:Blood Glucose / Q000235:genetics; D005260:Female; D055106:Genome-Wide Association Study; D050356:Lipid Metabolism / Q000235:genetics; D020641:Polymorphism, Single Nucleotide; D011247:Pregnancy; D034421:Sus scrofa / Q000235:genetics*
chemical_list: D001786:Blood Glucose
references.citation: J Physiol. 2007 Jun 15;581(Pt 3):1323-32
references.pmid: 17430988
references.citation: Biol Reprod. 2013 Jan 31;88(1):24
references.pmid: 23153566
references.citation: Semin Perinatol. 2000 Apr;24(2):94-106
references.pmid: 10805165
references.citation: Genetics. 1998 May;149(1):301-6
references.pmid: 9584104
references.citation: Pharmacol Ther. 2007 Mar;113(3):546-93
references.pmid: 17306374
references.citation: Proc Natl Acad Sci U S A. 1995 Feb 28;92(5):1774-8
references.pmid: 7878058
references.citation: Ann Nutr Metab. 2015;66 Suppl 2:14-20
references.pmid: 26045324
references.citation: J Anim Sci. 1991 Aug;69(8):3177-82
references.pmid: 1894552
references.citation: PLoS One. 2013;8(1):e55345
references.pmid: 23383161
references.citation: Endocrinology. 1992 Sep;131(3):1390-6
references.pmid: 1505469
references.citation: Biochim Biophys Acta. 1985 Apr 26;815(1):44-50
references.pmid: 3986201
references.citation: Am J Physiol Endocrinol Metab. 2012 Mar 1;302(5):E522-31
references.pmid: 22167521
references.citation: Can J Vet Res. 1997 Oct;61(4):312-4
references.pmid: 9342458
references.citation: Bioinformatics. 2012 Sep 15;28(18):2397-9
references.pmid: 22796960
references.citation: Epigenomics. 2015 Oct;7(7):1111-22
references.pmid: 26586120
references.citation: J Physiol. 1993 Apr;463:141-55
references.pmid: 8246179
references.citation: Mamm Genome. 1996 Sep;7(9):698-700
references.pmid: 8703127
references.citation: Exp Cell Res. 1999 Jun 15;249(2):320-6
references.pmid: 10366431
references.citation: J Anim Sci. 2002 Oct;80(10):2540-7
references.pmid: 12413075
references.citation: Int J Mol Sci. 2015 Sep 18;16(9):22692-710
references.pmid: 26393584
references.citation: Mol Genet Metab. 2012 Nov;107(3):553-60
references.pmid: 22985732
references.citation: BMC Evol Biol. 2006 Dec 13;6:108
references.pmid: 17166275
references.citation: BMC Genomics. 2013 Dec 03;14:848
references.pmid: 24299188
references.citation: PLoS One. 2011 Feb 24;6(2):e14726
references.pmid: 21383979
references.citation: J Mol Med (Berl). 2009 Aug;87(8):825-35
references.pmid: 19554302
references.citation: Biochimie. 2015 May;112:121-8
references.pmid: 25765953
references.citation: Reprod Biol Endocrinol. 2003 Nov 10;1:90
references.pmid: 14613534
references.citation: Anim Biotechnol. 2009;20(3):110-23
references.pmid: 19544207
references.citation: Placenta. 1998 Sep;19(7):517-24
references.pmid: 9778125
references.citation: Physiol Rev. 2007 Oct;87(4):1409-39
references.pmid: 17928588
references.citation: Biochem Biophys Res Commun. 2005 Sep 16;335(1):215-9
references.pmid: 16055091
references.citation: J Anim Sci. 2003 Mar;81(3):604-10
references.pmid: 12661639
references.citation: Animal. 2008 Nov;2(11):1559-68
references.pmid: 22444006
references.citation: Hum Genet. 2014 Dec;133(12):1487-95
references.pmid: 25273842
references.citation: PLoS One. 2015 Mar 17;10(3):e0117468
references.pmid: 25781935
references.citation: Diabetes Metab Res Rev. 2000 May-Jun;16(3):202-10
references.pmid: 10867720
references.citation: Placenta. 2011 Mar;32 Suppl 2:S218-21
references.pmid: 21300403
references.citation: J Membr Biol. 1993 Mar;132(2):147-55
references.pmid: 8496946
references.citation: Atherosclerosis. 2011 Jun;216(2):342-7
references.pmid: 21420681
references.citation: J Anim Sci. 2002 Oct;80(10):2548-55
references.pmid: 12413076
references.citation: N Engl J Med. 2008 May 8;358(19):1991-2002
references.pmid: 18463375
references.citation: PLoS One. 2010 Apr 07;5(4):e9960
references.pmid: 20383322
references.citation: PLoS One. 2013 Sep 25;8(9):e76317
references.pmid: 24086726
references.citation: Hepatology. 2010 May;51(5):1584-92
references.pmid: 20225248
references.citation: Biochim Biophys Acta. 2012 Dec;1821(12):1472-84
references.pmid: 22906437
references.citation: Diabetologia. 2012 Jan;55(1):105-13
references.pmid: 21953277
references.citation: PLoS One. 2015 Jun 29;10(6):e0131667
references.pmid: 26121138
references.citation: Cell Metab. 2006 Mar;3(3):153-65
references.pmid: 16517403
references.citation: Am J Hum Genet. 2007 Sep;81(3):559-75
references.pmid: 17701901
references.citation: Placenta. 1996 Mar-Apr;17(2-3):89-96
references.pmid: 8730878
references.citation: Proc Natl Acad Sci U S A. 1998 Jul 21;95(15):8686-91
references.pmid: 9671739
references.citation: J Lipid Res. 1996 Feb;37(2):347-60
references.pmid: 9026532
references.citation: J Biol Chem. 2004 Dec 31;279(53):55271-6
references.pmid: 15504742
references.citation: Hum Reprod Update. 2010 Jan-Feb;16(1):20-38
references.pmid: 19700490
references.citation: J Lipid Res. 1999 Nov;40(11):1967-77
references.pmid: 10553000
references.citation: Int J Mol Sci. 2014 Sep 12;15(9):16153-85
references.pmid: 25222554
references.citation: Hypertens Res. 2010 May;33(5):511-4
references.pmid: 20224571
references.citation: Neuro Endocrinol Lett. 2015;36(2):101-5
references.pmid: 26071574
references.citation: Endocrine. 2002 Oct;19(1):13-22
references.pmid: 12583599
references.citation: PLoS One. 2014 Oct 08;9(10):e109983
references.pmid: 25296178
references.citation: Genet Mol Res. 2015 Dec 02;14(4):15668-82
references.pmid: 26634535
references.citation: Proc Natl Acad Sci U S A. 1986 Nov;83(21):8102-6
references.pmid: 3464945