Evolution of Pinnipedia lactation strategies: a potential role for alpha-lactalbumin?
Despite the considerable variation in milk composition found among mammals, a constituent common across all groups is lactose, the main sugar and osmole in most eutherians milk. Exceptions to this are the families Otariidae (fur seals and sea lions) and Odobenidae (walruses), where lactose has not been detected. We investigated the molecular basis for this by cloning alpha-lactalbumin, the modifier protein of the lactose synthase complex. A mutation was observed which, in addition to preventing lactose production, may enable otariids to maintain lactation despite the extremely long inter-suckling intervals during the mother's time at sea foraging (more than 23 days in some species).
Reich
Coralie M
CM
CRC for Innovative Dairy Products, Department of Zoology, University of Melbourne, Victoria 3010, Australia.
Arnould
John P Y
JP
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D010872:Caniformia / Q000235:genetics / Q000502:physiology*; D007768:Lactalbumin / Q000235:genetics*; D007774:Lactation; D008969:Molecular Sequence Data
D007768:Lactalbumin
Proteins. 2001 Feb 1;42(2):237-42
11119648
Comp Biochem Physiol B Biochem Mol Biol. 2001 Feb;128(2):307-23
11207444
Cell Mol Life Sci. 2004 Aug;61(15):1867-83
15289930
Biochem Biophys Res Commun. 1972 Apr 28;47(2):393-7
4196975
Biochem J. 1980 Jan 1;185(1):227-37
6769429
Proc Natl Acad Sci U S A. 1994 Jul 5;91(14):6544-8
8022817
Biochem Biophys Res Commun. 2007 Mar 2;354(1):1-7
17223074
Proc Natl Acad Sci U S A. 1995 Aug 15;92(17):8064-8
7644538
Biochim Biophys Acta. 1999 Feb 2;1426(3):439-48
10076060
Biosci Biotechnol Biochem. 2005 Jun;69(6):1082-9
15973038
J Dairy Res. 2005;72 Spec No:81-9
16180725
Mol Phylogenet Evol. 2006 Nov;41(2):345-54
16815048
Biotechniques. 1994 Oct;17(4):692-6
7833030