tailieunhanh - Báo cáo sinh học: " A specific pattern of splicing for the horse αS1-Casein mRNA and partial genomic characterization of the relevant locus"

Tuyển tập các báo cáo nghiên cứu về sinh học được đăng trên tạp chí sinh học thế giới đề tài: A specific pattern of splicing for the horse αS1-Casein mRNA and partial genomic characterization of the relevant locus | 509 Genet Sei. Evol. 34 2002 509-519 INRA EDP Sciences 2002 DOI gse 2002020 Original article a specific pattern of splicing for the horse aSl-Casein mRNA and partial genomic characterization of the relevant locus Dragan Milenkovic Patrice Martin Gérard Guérin Christine Leroux Institut national de la recherche agronomique Departement de Génétique animale Laboratoire de génétique biochimique et de cytogénétique Centre de recherches de Jouy 78352 Jouy-en-Josas Cedex France Received 7 August 2001 accepted 3 December 2001 Abstract - Mares milk has a composition very different from that of cows milk. It is much more similar to human milk in particular in its casein fraction. This study reports on the sequence of a 994 bp amplified fragment corresponding to a horse aSl-Casein aSl-Cn cDNA and its comparison with its caprine pig rabbit and human counterparts. The alignment of these sequences revealed a specific pattern of splicing for this horse primary transcript. As in humans exons 30 60 and 130 are present whereas exons 5 13 and 14 are absent in this equine mRNA sequence. BAC clones screened from a horse BAC library containing the aSl-Cn gene allowed the mapping of its locus by FISH on equine chromosome which is in agreement with the Zoo-FISH results. Genomic analysis of the aSl-Cn gene showed that the region from the second exon to the last exon is scattered within a nucleotide stretch nearly 15-kb in length which is quite similar in size to its ruminant and rabbit counterparts. The region between aSl- and b-Cn genes suspected to contain cứ-acting elements involved in the expression of all clustered casein genes is similar in size ca. 15-kb to the caprine and mouse intergenic region. horse aSl-Casein cDNA localisation 1. introduction Milk the natural food for new-born mammals obviously contains all of the components necessary for the initial phases of postnatal development. With regards to the protein content of milk marked qualitative and .