Allelic differences in bovine kappa-CN gene which may regulate gene expression.
The most common kappa casein (kappa-CN) variants, kappa-CN A and kappa-CN B, are synthesised differentially in the lactating mammary gland of heterozygous animals (kappa-CN AB). In this study we evaluated several approaches for quantification of allele specific mRNA transcripts. The most consistent results were obtained using allele specific RT-PCR and capillary electrophoresis. On average, 13.4% more allele B specific than A specific transcripts were found. DNA sequencing of the proximal promoter region in several homozygous animals (kappa-CN AA, BB, EE) did not reveal any allele specific polymorphisms. Using the EMSA and DNase I footprinting we confirmed functional binding sites for three transcription factors (AP-2, NF1 and MGF) within the kappa-CN proximal promoter region. Sequence analysis of the 3'-UTR of the kappa-CN gene revealed seven allele specific sites. Two of these allelic differences were close to previously identified 3'-end regulatory sequences. In addition, allele specific differences in length between mRNAs of both variants were found. The two later findings suggest a possible post translational control determining content differences of kappa-CN in milk.
Debeljak
M
M
Department of Animal Science, Biotechnical Faculty, University of Ljubljana, Domzale, Slovenia.
Susnik
S
S
Marinsek-Logar
R
R
Medrano
J F
JF
Dovc
P
P
D020413:3' Untranslated Regions / Q000235:genetics; D000483:Alleles; D000818:Animals; D002364:Caseins / Q000235:genetics*; D002417:Cattle / Q000235:genetics*; D005260:Female; D015870:Gene Expression; D014644:Genetic Variation; D011110:Polymorphism, Genetic / Q000235:genetics; D012333:RNA, Messenger / Q000378:metabolism
D020413:3' Untranslated Regions; D002364:Caseins; D012333:RNA, Messenger