title: Lama glama αS1-casein: Identification of new polymorphisms in the CSN1S1 gene.
abstract: South American camelids have been poorly genetically investigated and little information is available in llamas (Lama glama) regarding the diversity of the caseins at the protein and gene level. Exon skipping and duplication events previously reported in the αS1-casein gene (CSN1S1) led us to investigate the genetic variability at this locus. Seventy-two positive clones for the αS1-casein transcripts were analyzed and randomly sequenced. The comparative analysis of the sequences revealed 2 transitions, c.366A>G and c.690T>C, at the 10th nucleotide of exon 12 and 94 bp of exon 19, respectively. These SNP are responsible for 2 amino acid changes, Ile→Val in position 86 and Tyr→His in position 194 of the mature protein. Both polymorphisms clarify the genetic events behind the protein variants A and B. This result was confirmed by isoelectric focusing analysis of llama milk samples. Quick methods based on PCR-RFLP and allele-specific PCR were set up for allelic discrimination in a population of 128 animals. Based on genotyping results, 4 haplotypes were observed and the estimated frequencies indicated B as the most common haplotype (0.629) in the investigated population. These data add knowledge to the genetic variability of a species little investigated, and open opportunity for new investigation in the field of milk protein for South American camelids, including the possibility, in the future, to select alleles with favorable characteristics.
authors.affiliation: Department of Agricultural, Forest and Food Sciences, University of Turin, 10095, Grugliasco (TO), Italy; Institute for Animal Breeding and Genetics, Justus Liebig University, 35390, Gießen, Germany. Electronic address: alfredo.pauciullo@unito.it.
authors.forename: A
authors.initials: A
authors.lastname: Pauciullo
authors.affiliation: Faculty of Science and Technology, Free University of Bozen, 39100, Bozen, Italy.
authors.forename: M
authors.initials: M
authors.lastname: Gauly
authors.affiliation: Department of Agriculture, University of Naples "Federico II" 80055, Portici (NA), Italy.
authors.forename: G
authors.initials: G
authors.lastname: Cosenza
authors.affiliation: Department of Obstetrics, Gynaecology and Andrology of Large and Small Animals with ambulance, Justus Liebig University, 35392, Gießen, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Wagner
authors.affiliation: Institute for Animal Breeding and Genetics, Justus Liebig University, 35390, Gießen, Germany.
authors.forename: G
authors.initials: G
authors.lastname: Erhardt
mesh_terms: D000818:Animals; D002161:Camelids, New World; D002364:Caseins / Q000235:genetics*; D005838:Genotype; D008892:Milk / Q000737:chemistry
chemical_list: D002364:Caseins
keywords: CSN1S1; Lama glama; haplotype; α(S1)-casein