scholarly journals Studies on genetic variants of α‐lactalbumin and β‐lactoglobulin from milk of native Portuguese ovine and caprine breeds

1999 ◽  
Vol 34 (3) ◽  
pp. 245-252 ◽  
Author(s):  
Manuela E. Pintado ◽  
F. Xavier Malcata
Keyword(s):  
Genetic Variants ◽  
Β Lactoglobulin

scholarly journals The relevance of milk protein polymorphisms for dairy cattle breeding.

1993 ◽  
Vol 1993 ◽  
pp. 46-46
Author(s):  
Henk Bovenhuis
Keyword(s):  
Genetic Variants ◽  
Milk Protein ◽  
Production Traits ◽  
Milk Production Traits ◽  
Breeding Scheme ◽  
Cattle Breeding ◽  
Dairy Cattle Breeding ◽  
Nucleus Breeding ◽  
Selection For ◽  
Β Lactoglobulin

Several studies have shown milk protein genetic variants to be associated with manufacturing properties of milk. The main findings were that κ-casein genetic variants affect renneting time of milk and βlactoglobulin genetic variants are associated with casein number (reviewed by Grosclaude, 1988). There are reports also of associations between milk protein genetic variants and milk production traits. Results from these studies indicate that κ-casein genotypes are associated with protein content and βlactoglobulin genotypes are related to fat content (reviewed by Bovenhuis et al., 1992). Therefore, κ-casein and βlactoglobulin genotypes might be of value as selection criteria. The aim of the present study was to quantify the potential effects of selection for κ-casein and β-lactoglobulin genotypes by using stochastic simulation of a closed adult MOET nucleus breeding scheme.

Effect of the A and B variants of both αs1- and κ-casein on bovine casein micelle solvation and κ-casein content

1993 ◽  
Vol 60 (4) ◽  
pp. 505-516 ◽  
Author(s):  
Skelte G. Anema ◽  
Lawrence K. Creamer
Keyword(s):  
Genetic Variants ◽  
The Other ◽  
Casein Micelle ◽  
Lactation Period ◽  
Chromosomal Dna ◽  
Electrophoretic Method ◽  
Milk Samples ◽  
Micelle Size ◽  
Centrifugation Technique ◽  
Β Lactoglobulin

SummaryCasein micelle solvation, a micelle characteristic that is sensitive to many factors, has been measured by a centrifugation technique at 30 °C for a series of uncooled fresh skim milks at pH 6·3, 6·6, 6·9 and 7·1. The relative αs-(αs1- plus αs2-), β– and κ-casein contents of all centrifuge pellets and supernatants were determined by a standardized electrophoretic method. The calcium and phosphate contents of a number of the pellets and milk samples were also determined. Solvation of micelles from milks with various genetic variants of β-lactoglobulin (A and B), αs1-casein (A and B) and κ-casein (A and B) was often found to be lower for milks containing either the B variant of αs1-casein or the A variant of κ-casein. It was also found that these two variant caseins were associated with a lower κ-casein content of the milks and the micelles, which is consistent with the lower solvation as κ-casein is associated with smaller micelle size and greater solvation. The solvations also seemed to increase during the lactation period. It is possible that some of the other features of milk and its products that have been ascribed to the differences in functional character between the A and B variants of αs1-casein may be partly caused by the increased level of κ-casein. The reason for the association of the A variant of αs1-casein with higher concentrations of κ-casein (and micelle solvation) is not obvious but possibly the haplotype αs1-casein A, β-casein A1, κ-casein A contains a controlling sequence in the chromosomal DNA that enhances expression of the κ-casein gene.

A rapid microbore HPLC method for determination of primary structure of β-lactoglobulin genetic variants

1990 ◽  
Vol 20 (4) ◽  
pp. 325-333 ◽  
Author(s):  
Bernardine Presnell ◽  
Amedeo Conti ◽  
Georg Erhardt ◽  
Ingolf Krause ◽  
Jasminka Godovac-Zimmermann
Keyword(s):  
Primary Structure ◽  
Genetic Variants ◽  
Hplc Method ◽  
Β Lactoglobulin

Effects of β-lactoglobulin and κ-casein genetic variants and concentrations on syneresis of gels from renneted heated milk

1989 ◽  
Vol 56 (2) ◽  
pp. 297-301 ◽  
Author(s):  
Douglas M. McLean ◽  
Johan Schaar
Keyword(s):  
Genetic Polymorphism ◽  
Complex Formation ◽  
Genetic Variants ◽  
Milk Protein ◽  
Major Influence ◽  
Essential Requirement ◽  
Heated Milk ◽  
Cheese Curd ◽  
Processing Properties ◽  
Β Lactoglobulin

Milk protein genetic polymorphism has a major influence on the composition of milk, and on its processing properties, including yield of cheese (see Schaaret al.1985; McLeanet al.1984, 1987; McLean, 1987). However, there appears to be little information on the effects of milk protein genetic variants on syneresis of cheese curd. The effect of casein composition on syneresis was studied by Pearseet al.(1986), who found that syneresis was affected only by the level of β-casein. Syneresis is an essential requirement in cheese making from renneted or acidified milk, but is undesirable during the storage of products such as yogurt. Milk for yogurt manufacture is preheated to minimize syneresis and to give maximal firmness of the yogurt coagulum (Tamime & Deeth, 1980). Pearseet al.(1985) showed that the reduction of one-third in the extent of syneresis caused by heating artificial micelle milk (AMM) containing βlactoglobulin (β-lg) in natural concentrations was due to sulphydryl-mediated complex formation between β-lg and micellar κ-casein which appeared to interfere with the micelle–micelle interactions responsible for syneresis. The results presented here were part of a study which investigated the effects of κcasein and κ-lg genetic variants and concentrations on syneresis of curd formed from renneted heated AMM.

Antigenic response of whey proteins and genetic variants of β-lactoglobulin — the effect of proteolysis and processing

2000 ◽  
Vol 10 (10) ◽  
pp. 699-711 ◽  
Author(s):  
Cecilie Svenning ◽  
Jorund Brynhildsvold ◽  
Tone Molland ◽  
Thor Langsrud ◽  
Gerd Elisabeth Vegarud
Keyword(s):  
Genetic Variants ◽  
Whey Proteins ◽  
Β Lactoglobulin

Polymorphisms in the goat β-lactoglobulin gene

2005 ◽  
Vol 72 (3) ◽  
pp. 379-384 ◽  
Author(s):  
Maria Ballester ◽  
Armand Sánchez ◽  
Josep M Folch
Keyword(s):  
Genetic Variants ◽  
Promoter Region ◽  
Point Mutations ◽  
Proximal Promoter ◽  
Coding Region ◽  
Nucleotide Substitutions ◽  
Single Nucleotide ◽  
Β Lactoglobulin ◽  
Pyrosequencing Technology ◽  
Frequent Haplotype

β-lactoglobulin polymorphisms have been reported in the milk of different goat breeds, although no genetic variants affecting the protein have been characterized. In the present study, we amplified and sequenced the proximal promoter and the first six exons containing the entire coding region for the β-lactoglobulin gene in eleven goat breeds from Spain, France, Italy, Switzerland, Senegal and Asia to identify genetic variants. Fifteen polymorphisms were detected, nine in the promoter region and six in the exons of the β-lactoglobulin gene. All polymorphisms were single nucleotide substitutions with the exception of one deletion/insertion in the promoter region. The polymorphisms in the coding region did not produce any amino acid change. In addition, pyrosequencing technology was used to genotype four polymorphisms in the promoter region in 200 goats belonging to eleven breeds. Differences in allelic frequencies for these polymorphisms between breeds are described and a specific polymorphism for the Italian populations was identified. Finally, the analysis of association between these four promoter point mutations was investigated resulting in five haplotypes, GCGC being the most frequent haplotype in all breeds analysed.

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