Dermal-epidermal interactions and the action of alleles at the agouti locus in the mouse☆

[摘要] Inthemouse,allelesattheagoutilocusdetermineeumelaninorpheomelaninsynthesisbythefollicularmelanocytes.Previousstudieshaveidentifiedthedermisasthesiteofactionofthesealleles.However,arecentinvestigationutilizingtheyellow(Ay)allelesuggestedapossibleroleoftheepidermisintheexpressionofagoutilocusalleles.Usingdermal-epidermalrecombinationsofembryonicskinofvariousagoutigenotypes,thepresentinvestigationsupportstheroleofboththedermisandepidermis.Ifnonagouti(aa)dermisisrecombinedwithagouti(AA)epidermis,theresultinghairsarepigmentedinthenonagoutipattern.Thereciprocalrecombinationofagoutidermisandnonagoutiepidermisresultsinhairspigmentedintheagoutipattern.Therecombinationsofyellow(Aya)dermisandagoutiorextremenonagouti(aeae)epidermisresultinhairscompletelypigmentedintheyellowpattern(pheomelanin).However,whenextremenonagoutioragoutidermisisrecombinedwithyellowepidermis,theresultinghairsarecompletelypigmentedwithpheomelanin.Similarresultsoccurinrecombinationsof“young”yellowepidermis(13days)and“old”dermis(17days)eventhoughdermalpapillaearepresent.Theroleofdermal-epidermalinteractionsintheexpressionofagoutiallelesaswellaspossibleexplanationsfortheuniqueactionoftheyellowallelearediscussed.

[学科分类] 生物科学（综合）