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1000
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Abstract/Summary
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BACKGROUND:
The silver homologue(SILV) gene plays a major role in melanosome development. SILV is a target for studies concerning melanoma diagnostics and therapy in humans as well as on skin and coat color pigmentation in many species ranging from zebra fish to mammals. However, the precise functional cellular mechanisms, in which SILVis involved, are still not completely understood. While there are many studies addressing SILV function upon a eumelaneic pigment background, there is a substantial lack of in
formation regarding the further relevance of SILV, e.g.
for phaeomelanosome development.
RESULTS:
In contrast to previous results in other species reporting SILV expression exclusively in pigmented tissues, our experiments provide evidence that the bovine SILV gene is expressed in a variety of tissues independent of pigmentation. Our data show that the bovine SILV gene generates an unexpectedly large number of different transcripts occurring in skin as well as in non-pigmented tissues, e.g. liver or mammary gland. The alternative splice sites are generated by internal splicing and primarily remove complete exons. Alternative splicing predominantly affects the repeat domain of the protein, which has a functional key role in fibril formation during eumelanosome
development.
CONCLUSION:
The expression of the bovine SILV gene independent of pigmentation suggests SILV functions exceeding melanosome development in cattle. This hypothesis is further supported by transcript variants lacking functional key elements of the SILV
protein relevant for eumelanosome
development. Thus, the bovine
SILV
gene can serve as a model for the investigation of the putative
additional functions of
SILV
. Furthermore, the splice variants of the bovine
SILV
gene represent a
comprehensive natural model to
refine the knowledge about f
unctional domains in the SILV
protein. Our study exemplifies that the extent of
alternative splicing is
presumably much higher
than previously estimated and that alternativ
ely spliced transcripts presumably can generate
molecules of deviating function compar
ed to their constitutive counterpart.
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