Chromatin structures of goat and sheep beta-lactoglobulin gene differ.
Different levels of the major milk protein beta-lactoglobulin are found in evolutionarily related ruminant species: with sheep milk containing as much as three times the concentration in goat milk. In an attempt to understand why these differences exist, we have characterised, using DNaseI as a probe of structure, the chromatin surrounding the goat beta-lactoglobulin promoter and compared it to that of the sheep homologue. The goat gene displays a mammary-specific chromatin pattern, which is reformed on expressing goat beta-lactoglobulin transgenes. This implies that this chromatin structure is sequence dependent and suggests that it plays a role in regulating beta-lactoglobulin gene expression. This pattern differs from that seen on the ovine beta-lactoglobulin gene in lactating sheep mammary chromatin. Thus, even between highly related species, the transcriptional mechanisms regulating activity of a gene can differ.
Pena
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RN
Unitat de Genètica i Millora, Departament de Patologia i Producció Animals, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra, 08193, Spain. romi@guara.uab.es
Folch
J M
JM
Sánchez
A
A
Whitelaw
C B
CB
D000818:Animals; D002460:Cell Line; D002843:Chromatin / Q000737:chemistry / Q000648:ultrastructure*; D016172:DNA Fingerprinting; D005260:Female; D006041:Goats / Q000235:genetics*; D007782:Lactoglobulins / Q000235:genetics*; D008099:Liver / Q000737:chemistry; D008321:Mammary Glands, Animal / Q000737:chemistry; D051379:Mice; D008822:Mice, Transgenic; D012756:Sheep / Q000235:genetics*; D013045:Species Specificity
D002843:Chromatin; D007782:Lactoglobulins