scholarly journals Polymorphisms of the PRLR Gene and Their Association with Milk Production Traits in Egyptian Buffaloes

Animals ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1237
Author(s):  
Mohammed A. El-Magd ◽  
Aziza Fathy ◽  
Khaled A. Kahilo ◽  
Ayman A. Saleh ◽  
Ahmed I. El Sheikh ◽  
...  

Prolactin (PRL) and its receptor (PRLR) were considered as potential genetic markers for milk production and quality traits in cattle. However, little information is available regarding PRLR genetic diversity and association studies with milk traits in Egyptian water buffaloes. Therefore, the present study was conducted to search for mutations in PRLR and determine their associations with milk performance in these animals. Exon3 (E3) and E10 of PRLR were screened for polymorphisms using single strand conformation polymorphism (SSCP) and sequencing in 400 buffaloes. The associations between haplotypes and milk production (fat%, protein%, lactose%, and solid%) traits as well as mRNA and protein levels of PRL and PRLR were studied. Two single nucleotide polymorphisms (SNPs) in E10 were detected: g.11685G>A (p.Ala494Thr) and g.11773T>C (p.Val523Aal). The G and T alleles were wild (ancestral) alleles, while the A and C alleles were mutant alleles. These SNPs resulted in four haplotypes; AC, AT, GC, and GT. Buffaloes with wild GT haplotypes showed significantly higher milk yield, fat% and protein%, mRNA and protein levels of PRL and PRLR in milk somatic cells than other animals. Animals carrying mutant AC haplotype had inferior milk traits and lowest levels of associated mRNAs and proteins. With these results, we could conclude that the selection of buffaloes with wild GT haplotypes for g.11685G>A and g.11773T>C SNPs of the PRLR gene might improve the milk production traits of Egyptian water buffaloes.

2020 ◽  
Vol 52 (1) ◽  
Author(s):  
Thierry Tribout ◽  
Pascal Croiseau ◽  
Rachel Lefebvre ◽  
Anne Barbat ◽  
Mekki Boussaha ◽  
...  

Abstract Background Over the last years, genome-wide association studies (GWAS) based on imputed whole-genome sequences (WGS) have been used to detect quantitative trait loci (QTL) and highlight candidate genes for important traits. However, in general this approach does not allow to validate the effects of candidate mutations or determine if they are truly causative for the trait(s) in question. To address these questions, we applied a two-step, within-breed GWAS approach on 15 traits (5 linked with milk production, 2 with udder health, and 8 with udder morphology) in Montbéliarde (MON), Normande (NOR), and Holstein (HOL) cattle. We detected the most-promising candidate variants (CV) using imputed WGS of 2515 MON, 2203 NOR, and 6321 HOL bulls, and validated their effects in three younger populations of 23,926 MON, 9400 NOR, and 51,977 HOL cows. Results Bull sequence-based GWAS detected 84 QTL: 13, 10, and 30 for milk production traits; 3, 0, and 2 for somatic cell score (SCS); and 8, 2 and 16 for udder morphology traits, in MON, NOR, and HOL respectively. Five genomic regions with effects on milk production traits were shared among the three breeds whereas six (2 for production and 4 for udder morphology and health traits) had effects in two breeds. In 80 of these QTL, 855 CV were highlighted based on the significance of their effects and functional annotation. The subsequent GWAS on MON, NOR, and HOL cows validated 8, 9, and 23 QTL for production traits; 0, 0, and 1 for SCS; and 4, 1, and 8 for udder morphology traits, respectively. In 47 of the 54 confirmed QTL, the CV identified in bulls had more significant effects than single nucleotide polymorphisms (SNPs) from the standard 50K chip. The best CV for each validated QTL was located in a gene that was functionally related to production (36 QTL) or udder (9 QTL) traits. Conclusions Using this two-step GWAS approach, we identified and validated 54 QTL that included CV mostly located within functional candidate genes and explained up to 6.3% (udder traits) and 37% (production traits) of the genetic variance of economically important dairy traits. These CV are now included in the chip used to evaluate French dairy cattle and can be integrated into routine genomic evaluation.


2009 ◽  
Vol 77 (1) ◽  
pp. 37-42 ◽  
Author(s):  
Emilia Bagnicka ◽  
Eulalia Siadkowska ◽  
Nina Strzałkowska ◽  
Beata Żelazowska ◽  
Krzysztof Flisikowski ◽  
...  

Insulin-like growth factor 2 (IGF2) is considered to be a regulator of post-natal growth and differentiation of the mammary gland. In the present work, associations of two single nucleotide polymorphisms in the bovine IGF2 gene with milk production traits were studied in dairy Holstein-Friesian cows: the already described g.8656C>T transition in exon 2 (RFLP-BsrI) and the newly found g.24507G>T transversion in exon 10 (RFLP-HaeIII), found by sequencing 273-bp exon 10 of the IGF2 gene in six individuals. Associations were analysed individually and in combination with the multi-trait repeatability test-day animal model. The CT/GT haplotype appeared to be associated with most of the milk traits studied (differences were significant at P⩽0·001). The most frequent CT/GG haplotype seemed inferior to others in fat and protein content and daily yield of fat and protein but superior (together with the TT/GG genotype) when the daily milk yield is considered.


2010 ◽  
Vol 55 (No. 11) ◽  
pp. 463-467 ◽  
Author(s):  
H. Kulig ◽  
I. Kowalewska-Łuczak ◽  
M. Kmieć ◽  
K. Wojdak-Maksymiec C

Milk components originating from blood plasma substrates are synthesized in epithelial cells of the mammary gland. Milk lipids are synthesized from fatty acids which bind to specific proteins – FABPs (fatty acid binding proteins). FABPs are a family of small cytoplasmic proteins; nine members of the family have been identified so far (FABP1–FABP9) (Chmurzyńska et al., 2006). Their main roles include fatty acid uptake, transport and metabolism. FABPs can modulate the fatty acid concentration in cells and therefore they affect different cellular processes, especially lipid metabolism. FABP3 and FABP4 are present in tissues with a high demand for fatty acids, such as heart muscle, skeletal muscles, lactating mammary gland, liver or adipose tissue (Roy et al., 2003). FABP3 gene was mapped to bovine chromosome 2 (Calvo et al., 2004), where QTLs affecting milk fat yield and content were described (Khatkar et al., 2004). FABP4 gene was mapped to BTA14 (Michal et al., 2006), which is very rich in QTLs for milk production traits (Khatkar et al., 2004). Fatty acid transport is assisted by the specific proteins called FATPs (fatty acid transport proteins). This protein group includes SLC27A3 (solute carrier family 27, member 3). It belongs to the family of proteins that facilitate long-chain fatty acid transport across the cytoplasmic membrane. Another protein with similar functions is ANXA9 (annexin A9), the member of Ca2+ and phospholipid-binding protein family (Calvo et al., 2006b). Genes encoding SLC27A3 and ANXA9 were mapped to chromosome 3, within the region where QTLs for milk fat content and the other milk traits have been mapped. Both of the above-mentioned genes are expressed in the mammary gland (Calvo et al., 2006b). The polymorphic sites (SNPs – single nucleotide polymorphisms) within the bovine FABP3, FABP4, SLC27A3 and ANXA9 genes were identified (Wu et al., 2005; Calvo et al., 2006b; Michal et al., 2006; Cho et al., 2008). Associations between SNPs in these genes and milk production traits in cattle have not been reported so far. However, polymorphism in the FABP4 gene has been significantly associated with carcass traits in cattle (Michal et al., 2006; Cho et al., 2008). Due to their expression sites, physiological properties and chromosomal localisation, the described genes might be considered as candidate genes for milk production traits. The aim of this study was to determine allele and genotype frequencies and to establish possible associations between the ANXA9, SLC27A3, FABP3 and FABP4 SNPs, and selected milk traits in Jersey cows.


2010 ◽  
Vol 53 (5) ◽  
pp. 501-509
Author(s):  
M. Muszyńska ◽  
I. Szatkowska ◽  
W. Grzesiak ◽  
A. Dybus ◽  
D. Zaborski

Abstract. Associations between two polymorphisms localized in the seventh exon of the butyrophilin gene (BTN/HaeIII and BTN/SchI) and milk production traits of Jersey cattle were analysed. A total of 171 cows were included in the study. PCR-RFLP method was used. In both polymorphisms three genotypes were identified. Statistically significant differences between polymorphic variants and milk production traits of Jersey cows were observed. Those differences concerned the percentage fat content in milk in the case of both polymorphisms and additionally the yield of milk and protein in the case of BTN/HaeIII polymorphism. The influence of the combined genotypes (BTN/HaeIII/SchI) on the examined traits was also analysed. GGHaeIII/AGSchI combined genotype was characterized by a significantly lower percentage fat content in comparison to other combinations. Moreover, incomplete linkage between the studied polymorphic sites was observed, despite relatively small distance between them.


2010 ◽  
Vol 55 (No. 1) ◽  
pp. 463-467 ◽  
Author(s):  
H. Kulig ◽  
I. Kowalewska-Łuczak ◽  
M. Kmieć ◽  
K. Wojdak-Maksymiec

Milk components originating from blood plasma substrates are synthesized in epithelial cells of the mammary gland. Milk lipids are synthesized from fatty acids which bind to specific proteins – FABPs (fatty acid binding proteins). FABPs are a family of small cytoplasmic proteins; nine members of the family have been identified so far (FABP1–FABP9) (Chmurzyńska et al., 2006). Their main roles include fatty acid uptake, transport and metabolism. FABPs can modulate the fatty acid concentration in cells and therefore they affect different cellular processes, especially lipid metabolism. FABP3 and FABP4 are present in tissues with a high demand for fatty acids, such as heart muscle, skeletal muscles, lactating mammary gland, liver or adipose tissue (Roy et al., 2003). FABP3 gene was mapped to bovine chromosome 2 (Calvo et al., 2004), where QTLs affecting milk fat yield and content were described (Khatkar et al., 2004). FABP4 gene was mapped to BTA14 (Michal et al., 2006), which is very rich in QTLs for milk production traits (Khatkar et al., 2004). Fatty acid transport is assisted by the specific proteins called FATPs (fatty acid transport proteins). This protein group includes SLC27A3 (solute carrier family 27, member 3). It belongs to the family of proteins that facilitate long-chain fatty acid transport across the cytoplasmic membrane. Another protein with similar functions is ANXA9 (annexin A9), the member of Ca2+ and phospholipid-binding protein family (Calvo et al., 2006b). Genes encoding SLC27A3 and ANXA9 were mapped to chromosome 3, within the region where QTLs for milk fat content and the other milk traits have been mapped. Both of the above-mentioned genes are expressed in the mammary gland (Calvo et al., 2006b). The polymorphic sites (SNPs – single nucleotide polymorphisms) within the bovine FABP3, FABP4, SLC27A3 and ANXA9 genes were identified (Wu et al., 2005; Calvo et al., 2006b; Michal et al., 2006; Cho et al., 2008). Associations between SNPs in these genes and milk production traits in cattle have not been reported so far. However, polymorphism in the FABP4 gene has been significantly associated with carcass traits in cattle (Michal et al., 2006; Cho et al., 2008). Due to their expression sites, physiological properties and chromosomal localisation, the described genes might be considered as candidate genes for milk production traits. The aim of this study was to determine allele and genotype frequencies and to establish possible associations between the ANXA9, SLC27A3, FABP3 and FABP4 SNPs, and selected milk traits in Jersey cows.


Genetics ◽  
1996 ◽  
Vol 144 (4) ◽  
pp. 1809-1816 ◽  
Author(s):  
Jianbo Yao ◽  
Samuel E Aggrey ◽  
David Zadworny ◽  
J Flan Hayes ◽  
Urs Kühnlein

Sequence variations in the bovine growth hormone (GH) gene were investigated by single strand conformation polymorphism (SSCP) analysis of seven amplified fragments covering almost the entire gene (2.7 kb). SSCPs were detected in four of these fragments and a total of six polymorphisms were found in a sample of 128 Holstein bulls. Two polymorphisms, a T→C transition in the third intron (designated GH4.1) and an A→C transversion in the fifth exon (designated GH6.2), were shown to be associated with milk production traits. GH4.1c/GH4.1c bulls had higher milk yield than GH4.1c/GH4.1t (P ≤ 0.005) and GH4.1t/GH4.1t (P ≤ 0.0022) bulls. GH4.1c/GH4.1c bulls had higher kg fat (P ≤ 0.0076) and protein (P ≤ 0.0018) than GH4.1c/GH4.1t bulls. Similar effects on milk production traits with the GH6.2 polymorphism were observed with the GH6.2a allele being the favorable allele. The average effects of the gene substitution for GH4.1 and GH6.2 are similar, with ±300 kg for milk yield, ±8 kg for fat content and ±7 kg for protein content per lactation. The positive association of GH4.1c and GH6.2a with milk production traits may be useful for improving milk performance in dairy cattle.


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