Prolactin polymorphism effect over production traits types at Transylvanian Merino sheep

Mihail Alexandru Gras, Catalin Mircea Rotar, Rodica Stefania Pelmus, Cristina Lazar, Elena Ghita, Horia Grosu


Worldwide were developed animal selection programs assisted by molecular markers at many local breeds, targeting biodiversity and intrinsic value preservation.

Until now, were considered molecular markers associated with milk (beta-lactoglobulin, caseins) and meat production (calpastatin, miostatin etc.).

Another important marker for milk production is prolactin. Previous studies prove that prolactin depletion is associated with milk secretion decrease, making codifying gene for prolactin a candidate gene for milk production variation.  Correlation of this marker effect with meat quality parameters was not studied yet.

Objective of this study is estimation of prolactin gene polymorphism effect over two traits types (for milk and meat quality) with a view to simultaneous use of both types in selection programs.

Using genomic DNA isolated from blood, we evaluate prolactin genetic polymorphism of 50 Transylvanian Merino sheep through PCR-RFLP method.  The effect of prl polymorphism over production traits was estimated using animal model.

The research results reveal an important effect of prl gene over productive quality traits. The alleles effect is similar between those types; this fact sustain common selection program development in the same population

In conclusion, our study proved that prl gene can be an important marker for selection programs in local sheep breeds.


marker assisted selection, meat traits, milk traits, PCR-RFLP, prolactin

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Carta A, Casu S, Salaris S. Invited review: Current state of genetic improvement in dairy sheep. J Dairy Sci 2009; 92(12):5814-5833.

Pădeanu, I., Producțiile ovinelor și caprinelor, Editura Mirton, Timișoara, 2002

Marshal K, Quiros-Campos C, van der Werf JHJ, and Kinghorn B. Marker-based selection within smallholder production systems in developing countries. Livest Sci 2011; 136(1):45-54.

Orford M, Tzamaloukas O, Papachristoforou C, Miltiadou D. A simplified PCR-based assay for the characterization of two prolactin variants that affect milk traits in sheep breeds. J Dairy Sci 2010; 93(12):5996-9

Staiger EA, Thonney ML, Buchanan JW, Rogers ER, Oltenacu PA, Mateescu RG. Effect of prolactin, β-lactoglobulin, and κ-casein genotype on milk yield in East Friesian sheep. J Dairy Sci 2010; 93(4):1736–1742.

Mateescu RG, Thonney M. Genetic mapping of quantitative trait loci for milk production in sheep. Anim Genet 2010; 41(5):460-6.

Gutierrez-Gil B, El-Zarei MF, Alvarez L, Bayon Y, de la Fuente LF, San Primitivo F et al. Quantitative trait loci underlying milk production traits in sheep. Anim Genet 2009; 40(4):423-34.

Giambra IJ, Erhardt G. Molecular genetic characterization of ovine CSN1S2 variants C and D reveal further important variability within CSN1S2. Animal Genet 2012; 43(5):642-5.

Gao H, Christensen OF, Madsen P, Nielsen US, Zhang Y, Lund MS, Su G. Comparison on genomic predictions using three GBLUP methods and two single-step blending methods in the Nordic Holstein population. Genet Sel Evol 2012; 44(1):8.

Strandén I, Christensen OF. Allele coding in genomic evaluation. Genet Sel Evol 2011; 43:25.

Pelmus RS, Pistol GC, Lazar C, Gras MA, Ghita E. Estimation of genetic parameters for milk traits in Romanian local sheep breed. Rev MVZ Córdoba 2014, 19(1):4033-4040.

Ramos AM, Matos CAP, Russo-Almeida PA, Bettencourt CMV, Matos J, Martins A, et al. Candidate genes for milk production traits in Portuguese dairy sheep. Small Rumin Res 2009; 82(2-3):117–121.


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