The objective of the present study was to identify the Prolactin Receptor (PRLR) gene polymorphism related to litter size traits. The study included 101 Topigs 20 line of sows with 426 litters. The traits studied were: Total Number of Born (TNB), Number of Born Alive (NBA), Number of Still Born (NSB), and Number of MUMmified (NMUM) piglets. Polymorphism was identified with the polymerase chain reaction-restriction fragment length polymorphism method. Allelic and genotype frequencies and deviation from Hardy-Weinberg equilibrium were verified with the chi-square test. Analysis of litter size traits was performed using the General Linear Model, which included the potential environmental effects. Additive and dominant allele variances were observed by the regression procedure. In the studied population of sows, the frequency of heterozygotes (0.5149) for PRLR gene exceeded the total number of AA (0.0198) and BB (0.4653) homozygotes, which resulted in a high proportion of B allele (0.7228). The results for PRLR showed statistically significant (P<0.05) differences in first parity sows between BB and AB genotypes for TNB and NBA. Significant differences (P<0.05) were recorded in third parity sows between BB and AB genotypes for NBA, and in AA genotype versus AB and BB genotypes for NMUM. The fourth and subsequent parity sows of AA genotype had a significantly higher (P<0.05) rate of NBA as compared with those of AB and BB genotypes. In all parities analysed, the difference between the BB and AB genotypes for NBA was statistically significant (P<0.05). Interpretation of the results at the levels of phenotypes and either additive or dominant variance was quite difficult due to the small number of AA homozygous sows. The calculation model yielded a significant effect (P<0.05) as well as tendency (P<0.1) for the mentioned effects except for age at first farrowing.
If the inline PDF is not rendering correctly, you can download the PDF file here.
1. Kováč G Tóthova CS Nagy O Seidel H: Acute phase proteins during the reproductive cycle of sows. Acta Vet (Beograd) 2008 58:459-466.
2. Omelka R Martiniaková M Peškovičová D Bauerová M: Associations between Alu I polymorphism in the prolactin receptor gene and reproductive traits of Slovak Large White White Meaty and Landrace pigs. Asian-Aust J Anim Sci 2008 21:484-488.
3. Spötter A Distl O: Genetic approaches to the improvement of fertility traits in the pig. Vet J 2006 172:234-247.
4. Bidanel JP: Biology and genetics of reproduction. In: The genetics of the pig. Cambridge United Kingdom: CAB International; 2011 218-241.
5. Korwin-Kossakowska A Kamyczek M Cieślak D Pierzchala M Kuryl J: Candidate gene markers for reproductive traits in Polish 990 pig line. J Anim Breed Genet 2003 120:181-191.
6. Campbell EM Nonneman D Rohrer GA: Fine mapping a quantitative trait locus affecting ovulation rate in swine on chromosome 8. J Anim Sci 2003 81:1706-1714.
7. Menčik S Balenović T Lulić S Modrić M Ostović M Sušić V Štoković I Ekert Kabalin A: Analysis of estrogen receptor polymorphism and litter size traits in primiparous sows: preliminary results. Krmiva 2012 54:75-80.
8. Šamac H Sladojević Ž Vujanac I Prodanović R Kirovski Dodovski P Kirovski D: Relationship between growth of nursuring pigs and composition of sow colostrum milk from anterior and posterior mammary glands. Acta Vet (Beograd) 2013 63:537-548.
9. Ormandy CJ Camus A Barra J Damotte D Lucas B Buteau H Edery M Brousse N Babinet C Binart N Kelly PA: Null mutation of the prolactin receptor gene produces multiple reproductive defects in the mouse. Genes Dev 1997 11:167-178.
10. Van Rens BTTM Evans GJ Van der Lende T: Components of litter size in gilts with different prolactin receptor genotypes. Theriogenology 2003 59:915-926.
11. Sakai S Katoh M Berthon P Kelly AP: Characterization of prolactin receptors in pig mammary gland. Biochem J 1984 224:911-922.
12. Terman A: Effect of the polymorphism of prolactin receptor (PRLR) and leptin (LEP) genes on litter size in Polish pigs. J Anim Breed Genet 2005 122:400-404.
13. Vincent AL Wang L Tuggle CK Robic A Rothschild MF: Prolactin receptor maps to pig chromosome 16. Mamm Genome 1997 8:793-794.
14. Bole-Feysot C Goffin V Edery M Binart N Kelly PA: Prolactin (PRL) and its receptor: actions signal transduction pathways and phenotypes observed in PRL receptor knockout mice. Endocrinol Rev 1998 19:225-268.
15. Freeman M Kanyicska EB Lerant A Nagy G: Prolactin: structure function and regulation of secretion. Physiol Rev 2000 80:1523-1631.
16. Li XP Shi QS Liu XC Tang F Zhang DJ: The effect of PRLR gene to litter size in Large White and Landrace pigs. 2005. Swine production. [http://en.cnki.com.cn/Journal_en/D-D050-YZZZ-2005-06.htm]
17. Barreras Serrano A Herrera Haro JG Hori-Oshima S Gutierrez Espinosa A Ortega Cerilla ME Perez Perez J Lemus Flores C Kinejara Espinosa AL Gonzales Arangure A Soto Avila JG: Prolactin receptor (PRLR) gen polymorphism and associations with reproductive traits in pigs. J Anim Vet Advan 2009 8:469-475.
18. Kmieć M Terman A: Polymorphism in the PRLR/AluI gene and its effect on litter size in Large White sows. Anim Sci Pap Rep 2004 22:523-527.
19. Drogemuller C Hamann H Distl O: Candidate gene markers for litter size in different German pig lines. J Anim Sci 2001 79:2565-2570.
20. Borges VF Bernardi ML Bortolozzo FP Wentz I: Risk factors for stillbirth and foetal mummification in four Brazilian swine herds. Prev Vet Med 2005 70:165-176.
21. SAS: Statistical Analysis Systems user’s guide: Version 9.3. North Carolina USA: SAS Institute Inc.; 2010.
22. Rodriguez ST Gaun TR Day INM: Hardy-Weinberg equilibrium testing of biological ascertainment for Mendelian randomization studies. Am J Epidemiol 2009 169:505-514.
23. Liu BH: Statistical genomics: linkage mapping and QTL analysis. Boca Raton London New York Washington D. C.: CRC Press LLC; 1998.
24. Vincent AL Evans G Short TH Southwood OI Plastow GS Tuggle CK Rothschild MF: The prolactin receptor gene is associated with increased litter size in pigs. Proceedings of the 6th World Congress on Genetics Applied Livestock Production 11-16 January Armidale NSW Australia; 1998 15-18.
25. Thuy NTD Thuy NT Cuong NV: Genetic polymorphism of prolactin receptor gene in Mong Cai pig. Proceedings of International Workshop on Biotechnology in Agriculture 20-21 October Ho Chi Minh City Thailand; 2006 40-42.
26. Hernández López SH Lemus Flores C Morales RA Herrera Haro JG: Effect of candidate genes on reproductive traits of sows. Rev Científica 2006 16:648-654.
27. Wang XP Wang LX Luo Reng ZM Sun SD: Analysis of PRLR and BF genotypes associated with litter size in Beijing Black pig population. Agri Sci China 2008 7:1374-1378.
28. Ciobanu DC Day AE Nagy A Wales R Rothschild MF Plastow GS: Genetic variation in two conserved local Romanian pig breeds using type 1 DNA markers. Genet Sel Evol 2001 33:417-432.
29. Lin CG Zhu ZM Li SL Chen H Zheng NZ Miao ZW Sun SK Liu YX Ye XH: Relationship between AluI polymorphism of PRLR gene and reproduction trait of swine. Fuj J Agri Sci 2008 23:137-140.
30. Tempfli K Farkas G Simon Z Bali Papp A: Effects of prolactin receptor genotype on the litter size of Mangalica. Acta Vet Hung 2011 59:269-277.
31. Kovacs K Fesus L Zsolnai A Nyiri A Anton I: Porcine prolactin receptor genotypes and production and reproduction traits in Hungarian Large White and Landrace sows. Arch Tierz 2010 53:497-499.
32. Xu NY Zhang SQ Peng SH: Investigation on the distribution and their effects on reproduction traits of three major gene in Jinhua pigs. Acta Genet Sin 2003 30:1090-1096.
33. Van Rens BTTM Van der Lende T: Litter size and piglet traits of gilts with different prolactin receptor genotypes. Theriogenology 2002 57:883-893.
34. Kmieć M Dybus A Terman A: Prolactin receptor gene polymorphism and its association with litter size in Polish Landrace. Arch Tierz Dumm 2001 44:547-551.
35. Kernerova N Matoušek V Čermáková A Forbelská M: Role of genetic markers in the prediction of classification of Czech Large White gilts to a hyperprolific line. Arch Tierz 2009 52:40-50.
36. Ziółkowska A Bogdzińska M Biegniewski J: Polymorphism of prolactin receptor gene (PRLR) in the Polish Landrace and Polish Large White swine population and reproductive traits. J Cent Eur Agric 2010 11:443-448.
37. Shi QS Liu XC Liu ZW Li XP Li YH Tang F: Effect of five genetic loci related to pig litter size. Hereditas 2006 28:652-658.
38. Kalashnikova LA Lalomova EV: Reproductive traits of pigs with different prolactin receptor genotypes. Rus Agric Sci 2008 34:267-269.
39. Ramos AM Mestre MR Gouveia S Evans G Zhang Y Cardoso A Rothschild MF Plastow G Rangel-Figueiredo T: Use of type I DNA markers for initial genetic characterization of two Portuguese swine breeds. Arch Zootec 2003 52:255-264.
40. Rothschild MF Vincent AL Tuggle K Evans G Short TH Southwood OI Wales R Plastow GS: A mutation in the prolactin receptor gene is associated with increased litter size in pigs. Anim Genet 1998 29:69.
41. Košorok S Kastelic M: Systematic use of P. G. 600® on primiparous sows on a well managed farm. Acta Vet (Beograd) 2011 61:642-652.