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Structure of the caprine kappa casein gene. Exons are depicted schematically as boxes, white (5' and 3'untranslated regions), dashed (part of exon encoding the signal peptide), and black (part of exons encoding the mature protein). Exon numbers and sizes are indicated above and below the boxes, respectively.
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Polymorphism in the goat kappa casein gene was studied using the base excision sequence scanning (BESS) method and sequencing. Seven polymorphic sites, corresponding to single nucleotide transversions were detected. Three of these were silent mutations while the other four produced amino acid substitutions. The association between these polymorphic...
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... are encoded by four tightly linked and clustered genes, covering an area of approximately 250 Kb genomic DNA fragment (Figure 4). The structure and organization of the casein gene locus have been described in human, mouse, and bovine ( Fujiwara et al., 1997;Rijnkels et al., 1997a,b) and mapped on chromosome 6 in bovine and caprine species (Threadgill and Womack, 1990;. ...
Similar publications
Genetic polymorphism k-casein (CSN3) gene was investigated in lactating Egyptian buffalo using nucleotide sequencing. Primer pairs amplified a 453 nucleotide fragment of CSN3 exon IV with an open reading frame of 421 nucleotides encoding 139 amino acids of the mature peptide and 32 nucleotides 3′UTR. Two SNPs (nt-315 C/T and nt-319 C/T) occurred in...
Citations
... Casein single nucleotide polymorphisms (SNPs) act as genetic units that are closely linked through epistatic relationships (8). These markers are transmitted as haplotypes (9). The genetic polymorphism of the casein complex (αS1, β, αS2, and κ-casein genes), either in the form of SNPs, haplotypes, or haplogroups, associates with specific productive traits (milk yield, components, and lactation curve parameters) of interest from an economic and research point of view (10,11). ...
Genomic tools have shown promising results in maximizing breeding outcomes, but their impact has not yet been explored. This study aimed to outline the effect of the individual haplotypes of each component of the casein complex (αS1, β, αS2, and κ-casein) on zoometric/linear appraisal breeding values. A discriminant canonical analysis was performed to study the relationship between the predicted breeding value for 17 zoometric/linear appraisal traits and the aforementioned casein gene haplotypic sequences. The analysis considered a total of 41,323 zoometric/linear appraisal records from 22,727 primiparous does, 17,111 multiparous does, and 1,485 bucks registered in the Murciano-Grandina goat breed herdbook. Results suggest that, although a lack of significant differences (p > 0.05) was reported across the predictive breeding values of zoometric/linear appraisal traits for αS1, αS2, and κ casein, significant differences were found for β casein (p < 0.05). The presence of β casein haplotypic sequences GAGACCCC, GGAACCCC, GGAACCTC, GGAATCTC, GGGACCCC, GGGATCTC, and GGGGCCCC, linked to differential combinations of increased quantities of higher quality milk in terms of its composition, may also be connected to increased zoometric/linear appraisal predicted breeding values. Selection must be performed carefully, given the fact that the consideration of apparently desirable animals that present the haplotypic sequence GGGATCCC in the β casein gene, due to their positive predicted breeding values for certain zoometric/linear appraisal traits such as rear insertion height, bone quality, anterior insertion, udder depth, rear legs side view, and rear legs rear view, may lead to an indirect selection against the other zoometric/linear appraisal traits and in turn lead to an inefficient selection toward an optimal dairy morphological type in Murciano-Granadina goats. Contrastingly, the consideration of animals presenting the GGAACCCC haplotypic sequence involves also considering animals that increase the genetic potential for all zoometric/linear appraisal traits, thus making them recommendable as breeding animals. The relevance of this study relies on the fact that the information derived from these analyses will enhance the selection of breeding individuals, in which a desirable dairy type is indirectly sought, through the haplotypic sequences in the β casein locus, which is not currently routinely considered in the Murciano-Granadina goat breeding program.
... In this review we follow the new nomenclatures of the k-casein variants recently described by Gautam et al. (2019). The DNA (NC_030813, goat genome reference version LWLT01 (Bickhart et al., 2017)) and protein reference sequences of CSN3 (NP_001272516, NCBI database) represent the protein variant CSN3*B as the reference (Yahyaoui et al., 2001;Jann et al., 2004). We supplement the information with nucleotide positions in the coding sequence that is given in the reference X60763 (NCBI database) (Supplementary Table S5) (Coll et al., 1993) to facilitate the comparison between the position in the new goat reference genome of k-casein variants with previous studies that used the position in the coding sequence to name variants. ...
... The difference between CSN3*A and CSN3*B is the amino acid substitution Ile 119 to Val 119 which is the result of the transition of A to G at CHR6:86209184 in exon 4 (Coll et al., 1993;Yahyaoui et al., 2001). CSN3*A occurs also at a frequency ≥0.7 in Ionica and Montefalcone from Italy, Bunte and Weise Deutsche Edelziege, and Thueringer Waldziege from Germany as well as Ardi and Syrian goats from Saudi Arabia (Supplementary Table S6) (Caroli et al., 2001;Angiolillo et al., 2002;Kumar et al., 2009;El-Shazly et al., 2017). ...
... CSN3*C differs from the reference variant CSN3*B in the three amino acid substitutions Val 65 to Ile 65 , Ala 156 to Val 156 , and Ser 159 to Pro 159 (Yahyaoui et al., 2001). The amino acid substitutions occurred as a result of a G to A, C to T, and T to C transitions at position CHR6:86209022, CHR6:86209296, and CHR6:86209304 in exon 4 (Yahyaoui et al., 2001), respectively. ...
The milk casein genes in goats, are highly polymorphic genes with numerous synonymous and non-synonymous mutations. So far, 20 protein variants have been reported in goats for alpha-S1-casein, eight for beta-casein, 14 for alpha-S2-casein, and 24 for kappa-casein. This review provides a comprehensive overview on identified milk casein protein variants in goat and non-coding DNA sequence variants with some affecting the expression of the casein genes. The high frequency of some casein protein variants in different goat breeds and geographical regions might reflect specific breeding goals with respect to milk processing characteristics, properties for human nutrition and health, or adaptation to the environment. Because protein names, alongside the discovery of protein variants, go through a historical process, we linked old protein names with new ones that reveal more genetic variability. The haplotypes across the cluster of the four genetically linked casein genes are recommended as a valuable genetic tool for discrimination between breeds, managing genetic diversity within and between goat populations, and breeding strategies. The enormous variation in the casein proteins and genes is crucial for producing milk and dairy products with different properties for human health and nutrition, and for genetic improvement depending on local breeding goals.
... In this review we follow the new nomenclatures of the k-casein variants recently described by Gautam et al. (2019). The DNA (NC_030813, goat genome reference version LWLT01 (Bickhart et al., 2017)) and protein reference sequences of CSN3 (NP_001272516, NCBI database) represent the protein variant CSN3*B as the reference (Yahyaoui et al., 2001;Jann et al., 2004). We supplement the information with nucleotide positions in the coding sequence that is given in the reference X60763 (NCBI database) (Supplementary Table S5) (Coll et al., 1993) to facilitate the comparison between the position in the new goat reference genome of k-casein variants with previous studies that used the position in the coding sequence to name variants. ...
... The difference between CSN3*A and CSN3*B is the amino acid substitution Ile 119 to Val 119 which is the result of the transition of A to G at CHR6:86209184 in exon 4 (Coll et al., 1993;Yahyaoui et al., 2001). CSN3*A occurs also at a frequency ≥0.7 in Ionica and Montefalcone from Italy, Bunte and Weise Deutsche Edelziege, and Thueringer Waldziege from Germany as well as Ardi and Syrian goats from Saudi Arabia (Supplementary Table S6) (Caroli et al., 2001;Angiolillo et al., 2002;Kumar et al., 2009;El-Shazly et al., 2017). ...
... CSN3*C differs from the reference variant CSN3*B in the three amino acid substitutions Val 65 to Ile 65 , Ala 156 to Val 156 , and Ser 159 to Pro 159 (Yahyaoui et al., 2001). The amino acid substitutions occurred as a result of a G to A, C to T, and T to C transitions at position CHR6:86209022, CHR6:86209296, and CHR6:86209304 in exon 4 (Yahyaoui et al., 2001), respectively. ...
The milk casein genes in goats, are highly polymorphic genes with numerous synonymous and non-synonymous mutations. So far, 20 protein variants have been reported in goats for alpha-S1-casein, eight for beta-casein, 14 for alpha-S2-casein, and 24 for kappa-casein. This review provides a comprehensive overview on identified milk casein protein variants in goat and non-coding DNA sequence variants with some affecting the expression of the casein genes. The high frequency of some casein protein variants in different goat breeds and geographical regions might reflect specific breeding goals with respect to milk processing characteristics, properties for human nutrition and health, or adaptation to the environment. Because protein names, alongside the discovery of protein variants, go through a historical process, we linked old protein names with new ones that reveal more genetic variability. The haplotypes across the cluster of the four genetically linked casein genes are recommended as a valuable genetic tool for discrimination between breeds, managing genetic diversity within and between goat populations, and breeding strategies. The enormous variation in the casein proteins and genes is crucial for producing milk and dairy products with different properties for human health and nutrition, and for genetic improvement depending on local breeding goals.
... Alpha S1 casein gene (CSN1S1) encodes the milk protein αS1-CN is closely linked to the genes CSN1S2, CSN2, and CSN3, which are responsible for the expression of proteins from other casein fractions, and together form the casein locus. The genetic structure of this locus is well described in humans, mice, cattle, and goats (Yahyaoui et al. 2001). In sheep, based on non-isotopic hybridization, the casein locus is mapped on chromosome 6 of the genome of the species Ovis aries and covers an area of about 250 kb in the length of genomic DNA (Amigo et al. 2000). ...
Gencheva, D., Pamukova, D., Naydenova, N., Veleva, P. & Tzanova, M. (2022). Alpha S1-casein genetic variations in Bulgarian sheep breeds and significance on milk casein fractions. Bulg.J. Agric. Sci., 28 (3), 526-533 Single nucleotide polymorphism (SNP) of the exon III at CSN1S1 gene encoding alpha S1-casein (αS1-CN) was investigated by means of the PCR-RFLP analysis in two sheep breeds-Bulgarian Dairy Synthetic Population (BDSP, n = 89) and Pleven Blackhead sheep (PLBH, n = 38) with an aim to establish the possible effect of a particular genotype on the casein content and distribution of milk fractions. The homozygous CC genotype was observed in 63.2% of the studied ewes, while the homozygous AA genotype was established in 4.5 % of the individuals. The calculated mean values of observed (Hо = 0.323) and expected (He = 0.321) heterozygosity at CSN1S1 locus indicated a moderate degree of genetic variability in the examined sheep populations. The estimated negative values of the coefficient (Fis =-0.001 ÷-0.006) showed a low level of inbreeding. The results of the associative analysis indicated that CSN1S1 genotypes were significantly associated with the milk αS1-CN in the BDSP 2 population (P < 0.05). The highest casein percentage in this population (35.24 ± 3.96) was associated with ewes carrying the heterozygous AC genotype. No significant differences (P > 0.05) were established for CSN1S1 genotypes in terms of casein content in the studied PLBH sheep population.
... The geographical location of the Sudanese goat samples included in this study is shown in Supplementary Figure 1. Boulanger et al., 1984;Grosclaude et al., 1987;Brignon et al., 1989Brignon et al., , 1990; Mahé and Grosclaude, 1989;Leroux et al., 1990Leroux et al., , 1992Jansàpérez et al., 1994;Martin and Leroux, 1994;Chianese et al., 1997;Grosclaude and Martin, 1997;Martin et al., 1999;Ramunno et al., 2000Ramunno et al., , 2004Ramunno et al., , 2005Bevilacqua et al., 2002;Cosenza et al., 2003Cosenza et al., , 2008Mestawet et al., 2013 β-CN CSN2 A, B, C, D, E, 0, 0 , another unnamed variant Mahé and Grosclaude, 1993;Rando et al., 1996;Rando, 1998;Persuy et al., 1999;Neveu et al., 2002;Galliano et al., 2004;Chessa et al., 2005;Caroli et al., 2006;Chianese et al., 2007 α s2 -CN CSN1S2 A, B, C, D, E, F, G, 0, truncated sub-variants A and E Boulanger et al., 1984;Bouniol, 1993;Bouniol et al., 1994;Veltri et al., 2000;Lagonigro et al., 2001;Ramunno et al., 2001a,b;Erhardt et al., 2002;Cunsolo et al., 2006 κ-CN CSN3 A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W Coll et al., 1993;Caroli et al., 2001;Yahyaoui et al., 2001Yahyaoui et al., , 2003Angiolillo et al., 2002;Jann et al., 2004;Prinzenberg et al., 2005;Kiplagat et al., 2010;Gautam et al., 2019 Known variants for casein mature proteins published in recent literature. ...
Genetic variations in the four casein genes CSN1S1, CSN2, CSN1S2, and CSN3 have obtained substantial attention since they affect the milk protein yield, milk composition, cheese processing properties, and digestibility as well as tolerance in human nutrition. Furthermore, milk protein variants are used for breed characterization, biodiversity, and phylogenetic studies. The current study aimed at the identification of casein protein variants in five domestic goat breeds from Sudan (Nubian, Desert, Nilotic, Taggar, and Saanen) and three wild goat species [Capra aegagrus aegagrus (Bezoar ibex), Capra nubiana (Nubian ibex), and Capra ibex (Alpine ibex)]. High-density capture sequencing of 33 goats identified in total 22 non-synonymous and 13 synonymous single nucleotide polymorphisms (SNPs), of which nine non-synonymous and seven synonymous SNPs are new. In the CSN1S1 gene, the new non-synonymous SNP ss7213522403 segregated in Alpine ibex. In the CSN2 gene, the new non-synonymous SNPs ss7213522526, ss7213522558, and ss7213522487 were found exclusively in Nubian and Alpine ibex. In the CSN1S2 gene, the new non-synonymous SNPs ss7213522477, ss7213522549, and ss7213522575 were found in Nubian ibex only. In the CSN3 gene, the non-synonymous SNPs ss7213522604 and ss7213522610 were found in Alpine ibex. The identified DNA sequence variants led to the detection of nine new casein protein variants. New variants were detected for alpha S1 casein in Saanen goats (CSN1S1∗C1), Bezoar ibex (CSN1S1∗J), and Alpine ibex (CSN1S1∗K), for beta and kappa caseins in Alpine ibex (CSN2∗F and CSN3∗X), and for alpha S2 casein in all domesticated and wild goats (CSN1S2∗H), in Nubian and Desert goats (CSN1S2∗I), or in Nubian ibex only (CSN1S2∗J and CSN1S2∗K). The results show that most novel SNPs and protein variants occur in the critically endangered Nubian ibex. This highlights the importance of the preservation of this endangered breed. Furthermore, we suggest validating and further characterizing the new casein protein variants.
... The κ-casein gene (CSN3) located on caprine chromosome 6 contains five exons, and most of the coding sequences of the mature protein (162 aa) are present in exon 4 (YAhYAOUI et al. 2001;. (Gene ID:100861231). ...
... The polymorphism of the caprine CSN3 gene that substitutes Val119 to Ile119 was first reported by MERCIER et al. (1976). The gene was extremely polymorphic with 21 identified alleles (A, B, B′, B″, C, C′, D, E, F, G, h, I, J, k, L, M, N, O, P, Q, and R;PRINzENBERG et al., 1999 andCAROLI et al., 2001;YAhYAOUI et al., 2001;JANN et al., 2004;GUPTA et al., 2009). All these variants are separated into two groups; AIEF (A, B, B', B", C, C', F, G, h, I, J, L) and BIEF (D, E, k, M, N, O, P, Q, R) according to isoelectric points (PRINzENBERG et al., 2005). ...
... Vet. arhiv 91 (1), 19-30, 2021 27 CSN3 and AGPAT6 genes. The A and B alleles of the CSN3 gene have been studied in various goat breeds, including Saanen goats (YAhYAOUI et al., 2001(YAhYAOUI et al., /2003PRINzENBERG et al., 2005;kUMAR et al., 2009;ChIATTI et al., 2007;CARAVACA et al. 2009;SzTANkóOVá et al., 2009;GUPTA et al., 2009;CAROLI et al., 2001 andSTRzELEC andNIżNIkOwSkI, 2011;ChESSA et al., 2003). The frequencies of the M and F alleles of the CSN3 gene were investigated in the current study, and the results showed that the genotype frequencies were 99.20% for FF and 0.80% for MF in the Saanen breed. ...
This study was designed to determine the effect of some environmental factors on milk yield and composition in Saanen goats and the effect of CSN3 and AGPAT6 gene polymorphisms on milk production traits. Saanen goats were genotyped for milk traits, and the samples were collected during the lactation, and the milk yield/compositions of each goat were specified. In terms of the CSN3 and AGPAT6 genes, the genotypes were defined by PCR-RFLP. The milk yield (MY), lactation length (LL), protein, fat, total solid (TS), solid not fat (SNF), casein, lactose rates and yields were as follows; 388.9 ± 17.5 kg, 243 ± 5.81 days, 3.29 ± 0.05%, 3.59 ± 0.07%, 11.60 ± 0.13%, 8.43 ± 0.06%, 2.57 ± 0.04%, 4.31 ± 0.03%, 11.21 ± 0.47 kg, 12.79 ± 0.64 kg, 40.95 ± 1.82 kg, 29.53 ± 1.31 kg, 8.82 ± 0.37 kg, 15.40 ± 0.74 kg respectively. The determined genotype and allele frequencies of CSN3 and AGPAT6 gene were as follows; FF (%99.20), MF (%0.80), F (0.996), M (0.004); GG (%12), GC (%43.20), CC (%44.80), G (0.336), C (0.664). The impacts of lactation length on all milk yield parameters (protein, fat, TS, SNF, casein, lactose, MY) (P<0.001); the age on all milk yield parameters (P<0.001) and the protein, fat, SNF, casein rates (P<0.05), the TS rate and LL (P<0.01) were found to be significant. The birth type was not found to significantly affect any milk yield parameters. Although Saanen goats showed the variation for the AGPAT6 gene (g.9263C>G), the herd was found to be monomorphic (FF) for the CSN3 gene. The effect of the AGPAT6 gene on milk traits in Saanen goats was determined not to be statistically significant. Environmental factors, such as maternal age and lactation length, were found to significantly affect some milk traits in Saanen goats. So consideration of factors such as maternal age or lactation length could be useful for improving breeding strategies for dairy goats.
... The genes comprising the casein complex are located within a 250-kb segment on chromosome 6 in the goat [4]. Concretely, SNPs have been reported to act as genetic units, which are closely bonded through epistatic relationships [5] and transmitted as haplotypes [6]. It is the relationship among the genetic polymorphisms of the casein complex (αS1, β, αS2, and κ-casein genes) with the aforementioned characteristics of productive interest that shapes one of the most interesting complexes to study from an economic perspective [7]. ...
Considering casein haplotype variants rather than SNPs may maximize the understanding
of heritable mechanisms and their implication on the expression of functional traits related to milk production. Effects of casein complex haplotypes on milk yield, milk composition, and curve shape parameters were used using a Bayesian inference for ANOVA. We identified 48 single nucleotide polymorphisms (SNPs) present in the casein complex of 159 unrelated individuals of diverse ancestry, which were organized into 86 haplotypes. The Ali and Schaeffer model was chosen as the best fitting model for milk yield (Kg), protein, fat, dry matter, and lactose (%), while parabolic yield-density was
chosen as the best fitting model for somatic cells count (SCC × 103 sc/mL). Peak and persistence for all traits were computed respectively. Statistically significant differences (p < 0.05) were found for milk yield and components. However, no significant difference was found for any curve shape parameter except for protein percentage peak. Those haplotypes for which higher milk yields were reported were the ones that had higher percentages for protein, fat, dry matter, and lactose, while the opposite trend was described by somatic cells counts. Conclusively, casein complex haplotypes can be considered in selection strategies for economically important traits in dairy goats.
... Zhang et al. 8 indicated that an 11-bp indel mutation was significantly associated with the FPD and acidity of Guanzhong dairy goat milk. The CSN3 gene is another member of a casein gene family that most of the coding sequences of the mature protein (162 aa) are presented in exon 4 (Gene ID:100861231) 9 . Similarly, the CSN3 gene was described considerably polymorphic, has 21 alleles (A, B, B′, B″, C, C′, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, and R) have been defined so far [9][10] . ...
... The CSN3 gene is another member of a casein gene family that most of the coding sequences of the mature protein (162 aa) are presented in exon 4 (Gene ID:100861231) 9 . Similarly, the CSN3 gene was described considerably polymorphic, has 21 alleles (A, B, B′, B″, C, C′, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, and R) have been defined so far [9][10] . The genes encoding caseins such as CSN1S1 or CSN3 are strong candidates to clarify the variation between the protein contents of milk, moreover the rheological parameters and cheese yield in general 10 . ...
The physiochemical properties of milk are important factors in terms of the process of dairy production, quality, and profitability. However, the knowledge about the effect of genetic factors such as CSN1S1, CSN3, and AGPAT6 genes on these traits is insufficient. The objective of this study was to determine the effect of these genes and lactation rank (LR) on total acidity, citric acid, density (density), free fatty acid (FFA), freezing point degree (FPD) and urea parameters. A total of fifty (n=50) Saanen goats, which is known as the highest milk-producing breed within the goats were genotyped using polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) methods. For genetic analysis, the blood samples were taken from the jugu-lar vein by aseptic conditions. The DNA isolations were performed by the phenol-chloroform method from blood samples. Milk samples were collected during the lactation and evaluated by Fourier transform infrared (FTIR) spectroscopy for the physico-chemical properties of Saanen goat milk. The statistical analysis was carried out using the least-squares of the GLM procedures. The results indicated that no significant differences were confirmed between the investigated genes with the physicochemical properties of goat milk. However, the effect of the AGPAT6 gene on density and the effect of LR on citric acid composition was found tended to be significant. Moreover, we determined the significant correlations between the physicochemical properties in the present study. According to the results, acidity was correlated with the citric acid (-0.304), density (0.641), FFA (-0.332) significantly. Other significant correlations were observed between the citric acid and FPD (0.275), LR (-0.313); the density and FFA (-0.315), FPD (0.436); the urea and LR (-0.369). These results and novel correlations may be useful for future studies on evaluating the potential impact of AGPAT6 gene on these traits to achieve breeding and commercial goals in the goat production and dairy industry. KEY WORDS Goat milk, physicochemical properties, CSN1S1, CSN3, AGPAT6.
... Initially, the structural analysis of goat κ-CN locus (CSN3) indicated the presence of a biallelic polymorphism with A and B variants [11]. Up to date, within CSN3, about 16 genetic variants were identified and characterized [12][13][14][15][16]. Thirteen alleles (A, B, C, D, E, F, G, H, I, J, K, L, M) of them are protein variants, while only three (Bʹ, Bʺ and Cʹ) showed silent mutations without protein expression. ...
The present study aimed to identify the genetic polymorphism of kappa casein gene (exon 4) among Sudanese desert goat in South Darfur State. DNA was extracted from blood samples obtained from unrelated goats (n = 68) from different herds. Forward (5'-tcccaatgttgtactttcttaacatc-3') and reverse (5'-gcgttgtcctctttgatgtctccttag-3') primer pair was designed to amplify the whole exon 4 of CSN3 in addition to partial promoter intronic regions. Successful amplicons revealed band of about 700 bp, which was subjected to digestion with restriction endonuclease HaeIII. Two electrophoresis patterns representing the homozygous (AA) with two bands of 450 and 250 bp, and the heterozygous (AB) with three bands of 700, 450 and 250 bp were observed. The genotypic frequencies for AA and AB were 66.20 and 33.80%, respectively. While the allelic frequencies were 83.10 and 16.90% for A and B alleles, respectively. The chi-square test (χ 2 = 2.81, P > 0.05) confirmed the validity of Hardy-Weinberg equilibrium for the population. It could be concluded that, because of the association between the polymorphism of kappa casein gene and milk production traits and cheese making, studies and research works are needed to improve the selection criteria.
... κ-casein is one of the most important proteins joined physically to the functional role in micelle formation and stabilization, determined by its size and function (Rijnkels et al. 2003). In addition, κ-casein is dierent to other caseins due to its solubility in a wide interval of concentration of calcium ions which contain a c-terminal hydrophilic region (Yahyaoui et al. 2001 celles, which are smaller, which has an impact on the coagulation features of the milk, reected in a stronger curd and retention of a major amount of substances increasing cheese yield (Ahmed 2011). ...
... A total of 14 genetic variants have been identied in the κ-casein (CSN3) gene in dierent breeds of domestic goats (Jann et al. 2004, Prinzenberg et al. 2005; furthermore, other studies have shown that the number of alleles identied in the domestic goat is actually 16 (Yahyaoui et al. 2001, Angiolillo et al. 2002, Yahyaoui et al. 2003, Jann et al. 2004. ...
... In a study conducted by Caravaca et al. (2009) which could be segregating this allele to the new generations. Regarding the C allele its incidence in this study was low (0.13), which is similar to that reported by Yahyaoui et al. (2001Yahyaoui et al. ( , 2003 in the Murciano, Granadina, Canaria, French Saanen and Italian Teramana breeds, among others. Landi et al. (2011) mentioned that in future generations this mutation could disappear because it is found in very low frequencies. ...
K-casein (CSN3) gene is of particular interest in goat production due to the effect of its polymorphisms on milk quality and composition. The objective of this study was to assess the genotypic and allelic frequencies in CSN3 gene in the Saanen goat breed and its effect on milk production and some of its compositional traits. Allelic discrimination assays were designed to determine the variants (A, B or C) using qPCR and allelic discrimination method. Allelic frequencies for A, B and C were 0.23, 0.64 and 0.13, respectively. Association analysis indicated that the CSN3 was significantly associated only with protein percentage (p = 0.006). Results indicated that animals with AC, BB and CC genotypes showed higher milk protein percentage than those with genotype AB. This evidence suggests that genotypes favorable to this associated trait could be included into Saanen goat breeding strategies.
