The rationale of this work is based on recent evidences suggesting that: i) both qualitative and quantitative -lactoglobulin (-LG) polymorphism may be found in bovine milk; ii) quantitative polymorphisms are often the result of expression gradients in multiple copies of a gene; iii) the -LG gene is duplicated in the dog and bovine genome; iv) mammary genes are highly con-served across Mammalia. Thus, an investigation was conducted on ovine -LG polymorphism checking phenotypic evidence for copy-number variants of -LG in sheep. To the purpose, 206 milk samples were collected, during a small-scale survey within sheep farms breeding Southern Italian breeds. PAGIF screening of the samples revealed that approximately 50% individuals exhibited -LG polymorphism and 4 different quantitative patterns, which were characterized in detail by a proteomic approach relying on combined chromatographic and mass spectrometric techniques. The expected figures based on the expression gradient models were compared with well-established -globin gene arrangements in sheep. The different phenotypes suggest the presence of both duplicate and triplicate BLG haplotypes. The occurrence of a triplicate haplotype was supported by population data. The current study supports the helpfulness of up-to-date proteomics for inferring copy number polymorphisms through the characterization of the phenotypic expression.
A proteomic approach to investigate the qualitative and quantitative polymorphism of -Lactoglobulin in ovine milk: inference on gene copy-number variations
PIERAGOSTINI, Elisa
2012-01-01
Abstract
The rationale of this work is based on recent evidences suggesting that: i) both qualitative and quantitative -lactoglobulin (-LG) polymorphism may be found in bovine milk; ii) quantitative polymorphisms are often the result of expression gradients in multiple copies of a gene; iii) the -LG gene is duplicated in the dog and bovine genome; iv) mammary genes are highly con-served across Mammalia. Thus, an investigation was conducted on ovine -LG polymorphism checking phenotypic evidence for copy-number variants of -LG in sheep. To the purpose, 206 milk samples were collected, during a small-scale survey within sheep farms breeding Southern Italian breeds. PAGIF screening of the samples revealed that approximately 50% individuals exhibited -LG polymorphism and 4 different quantitative patterns, which were characterized in detail by a proteomic approach relying on combined chromatographic and mass spectrometric techniques. The expected figures based on the expression gradient models were compared with well-established -globin gene arrangements in sheep. The different phenotypes suggest the presence of both duplicate and triplicate BLG haplotypes. The occurrence of a triplicate haplotype was supported by population data. The current study supports the helpfulness of up-to-date proteomics for inferring copy number polymorphisms through the characterization of the phenotypic expression.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
