Polymorphism of κ-Casein in Italian Goat Breeds: A New ACRS-PCR Designed DNA Test for Discrimination of A and B Alleles

Autor: Maria Feligini, Vlatka Cubric-Curik, Pietro Parma, Ino Curik, Gian Franco Greppi, Giuseppe Enne
Jazyk: angličtina
Rok vydání: 2002
Předmět:
Zdroj: Food Technology and Biotechnology
Volume 40
Issue 4
ISSN: 1334-2606
1330-9862
Popis: The objective of this study was to develop a DNA test for rapid characterisation of goat κ-casein (κ-CN) A and B variants and to study this polymorphism in Italian goat breeds. Genetic polymorphism of κ-CN gene was, in addition to isoelectric focusing, analysed according to a new technique designated as amplification created restriction site. Two alleles that differ in one nucleotide mutation (G Ø A) in exon 4 were characterised. The 167-bp PCR product surrounding the nucleotide mutation was amplified from genomic DNA and the PCR product was digested with MaeIII. After digestion the A allele gives three fragments of 77, 65 and 25 bp in comparison with the B allele which gives two fragments of 90 and 77 bp. The analysis of allele frequency distribution at κ-CN locus, based on 401 individual samples, revealed significant differences among three goat breeds from the north of Italy (Nera di Verzasca, Frontalasca and Alpine) with frequency of κ-CN B allele around 0.3, versus two goat breeds from the south of Italy (Maltese and Sarda) with frequency of κ-CN B allele around 0.5. While two goat breeds (Maltese and Nera di Verzasca) did not show significant deviations from the Hardy-Weinberg equilibrium, a highly significant excess of heterozygote genotype (AB) was observed in Alpine, Frontalasca and Sarda goats. Here the developed DNA method and observed relatively high frequency of κ-CN B allele give a prerequisite for the assessment of research related to the simultaneous estimation of the effects of composite αs1/κ-CN genotypes on milk production and cheese-making properties.
Svrha je bila razviti DNA test za brzo određivanje genetičkih varijanti κ-kazeina u talijanskih pasmina koza. Genetički je polimorfizam istraživan izoelektričnim fokusiranjem (IEF) i amplifikacijom nastalim restrikcijskim mjestom na genomu (ACRS). PCR produkt na ekzonu 4, dug 167-bp koji okružuje nukleotidnu mutaciju (G Ø A), amplificiran s genomske DNA i razgrađen je s MaeIII enzimom. Identificirana su dva alela koja se razlikuju u jednoj nukleotidnoj mutaciji (G Ø A). Dobiveni su fragmenti 77 i 65 bp za alel A te 90 i 77 bp za alel B. Signifikantna razlika za frekvenciju alela B ustanovljena je za tri pasmine koza sa sjevera Italije (Nera di Verzasca, Frontalasca i Alpine) s frekvencijom κ-kazeina B oko 0,3, u usporedbi s dvjema pasminama s juga Italije (Maltese i Sarda), s frekvencijom κ-kazeina B otprilike 0,5. Pasmine Maltese i Nera di Verzasca nisu pokazale signifikantno odstupanje od Hardy-Weinbergove ravnoteže, za razliku od pasmina Alpine, Frontalasca i Sarda u kojima je uočeno veliko signifikantno odstupanje. Prikazana DNA metoda i promatrana relativno velika frekvencija κ-kazeina B alela omogućavaju daljnja istraživanja zajedničkog utjecaja αs1-kazeina i κ-kazeina na proizvodnju mlijeka i sira.
Databáze: OpenAIRE
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