Diversifying selection signatures among divergently selected subpopulations of Polish Red cattle

Artur Gurgul,T. Szmatoła,I. Jasielczuk,M. Bugno-Poniewierska,E. Sosin-Bzducha,A. Majewska,E. Semik-Gurgul

doi:10.1007/s13353-019-00484-0

Abstract

Polish Red cattle is one of the few indigenous breeds of European red cattle which is characterized by several desired features, such as high disease resistance, good health, longevity, good fertility, and high nutritional value of milk. Currently, Polish Red cattle population is a subject of two independent breeding programs: (i) improvement program and (ii) genetic resources conservation program. The aim of the improvement program is the genetic progress in terms of milk production and body conformation traits, while the conservation program mainly focuses on protection of the genetic resources of Polish Red cattle and preservation of the existing, original gene pool. By the analysis of FST genetic distances across genome-wide SNP panel, we detected diversifying selection signatures among these two subpopulations and indicated (among others) the significance of DGAT1 and FGF2 genes for milk production traits in these cattle. We also found that among genes being presumably under selection in terms of milk production, there are genes responsible, for example, for mammary gland development (e.g., SOSTDC1, PYGO2, MED1, and CCND1) and immune system response (e.g., IL10RA, IL12B, and IL21). The most important finding of this study is that the most pronounced genetic differences between the analyzed populations were associated with β-defensin genes (e.g., DEFB1, DEFB4A, DEFB5, DEFB7, DEFB10, DEFB13, EBD, BNBD-6, and LAP) located within so-called bovine cluster D on BTA27. The β-defensins are expressed mainly in the mammary gland and are antimicrobial peptides against the Gram-negative and Gram-positive bacteria, viruses, and other unicellular parasites. This suggests that antimicrobial resistance of mammary gland is of high importance during selection towards increased milk production and that genes responsible for this process are selected together with increasing levels of productivity.

Highlights

Polish Red cattle is one of the few indigenous breeds of European red cattle
The aim of the improvement program is the genetic progress in terms of milk production and body conformation traits, while the conservation program mainly focuses on protection of the genetic resources of Polish Red cattle and preservation of the existing, original gene pool
We found that among genes being presumably under selection in terms of milk production, there are genes responsible, for example, for mammary gland development (e.g., SOSTDC1, PYGO2, MED1, and CCND1) and immune system response (e.g., IL10RA, IL12B, and IL21)

Summary

Introduction

Polish Red cattle is one of the few indigenous breeds of European red cattle. It is characterized by several features typical for primitive populations, such as high disease resistance, good health, longevity, very good fertility, easy births, ease of calf rearing, and high biological value of milk. The Polish Red cattle is characterized by a good adaptation to harsh environmental conditions, which is especially visible in the ability to limit the efficiency (enabling survival of seasonal feed deficiencies), as well as the relatively quick regeneration after condition loss. These features make the cattle of this breed well adapted to mountainous and submountainous living and production conditions (Szarek et al 2004). The aim of the improvement program is the genetic progress in terms of milk production and body conformation traits, leading to the refinement of the economic aspects of breeding and preservation of the existing beneficial functional features. Maintaining the largely primitive character of this breed is one of the major breeding goals for this part of the population (Adamczyk et al 2008)

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Conclusion