The amino acid Tyrosine synthesizes dopa and dopamine which are then oxidized to form different melanin to produce the pigmentation. In the tan mutation, N-β-alanyl-dopamine hydrolase converts NBAD into dopamine. In a reverse reaction, when dopamine is converted into NBAD through NBAD synthetase, the ebony gene is expressed. A high concentration of NBAD results in a tan gene mutation while an excess of dopamine can produce the ebony mutation (John R. True). Not only does tan affect the body pigmentation, but it also has a role on recycling the histamine neurotransmitter in Drosophila. In the synaptic terminal of a photoreceptor cell, histamine is released and enters the epithelial glia. From there, the ebony gene converts the histamine into carcinine. The protein carcinine is available for re-uptake by the photoreceptor cell where it can be reconverted to histamine by the tan gene. In a mutant tan gene fly, however, the photoreceptors have a decreased amount of histamines to release and low levels of histamines suggest no electroretinogram (ERG) recordings from the fly. A mutant tan fly that is exposed to flashes of light will not produce neural signals. The decrease of histamine as a neurotransmitter will decrease wakefulness and induce a more drowsy state. As a result, the mutant tan fly experiences a delayed reaction when exposed to light (John R. True). A noticeable similarity in amino acid sequence was found between the penicillin produced in fungus Penicillium chrysogenum and the tan gene. The isopenicillin enzyme N-acyltransferase (IAT) is self-activated at the Glycine-Cysteine chain to produce two subunits that interact together; similarly, the tan gene also replicates this method. The last step of IAT involves N-acylation and acyl-CoA to produce the penicillin but tan shows no activity in this process (Silvia
The amino acid Tyrosine synthesizes dopa and dopamine which are then oxidized to form different melanin to produce the pigmentation. In the tan mutation, N-β-alanyl-dopamine hydrolase converts NBAD into dopamine. In a reverse reaction, when dopamine is converted into NBAD through NBAD synthetase, the ebony gene is expressed. A high concentration of NBAD results in a tan gene mutation while an excess of dopamine can produce the ebony mutation (John R. True). Not only does tan affect the body pigmentation, but it also has a role on recycling the histamine neurotransmitter in Drosophila. In the synaptic terminal of a photoreceptor cell, histamine is released and enters the epithelial glia. From there, the ebony gene converts the histamine into carcinine. The protein carcinine is available for re-uptake by the photoreceptor cell where it can be reconverted to histamine by the tan gene. In a mutant tan gene fly, however, the photoreceptors have a decreased amount of histamines to release and low levels of histamines suggest no electroretinogram (ERG) recordings from the fly. A mutant tan fly that is exposed to flashes of light will not produce neural signals. The decrease of histamine as a neurotransmitter will decrease wakefulness and induce a more drowsy state. As a result, the mutant tan fly experiences a delayed reaction when exposed to light (John R. True). A noticeable similarity in amino acid sequence was found between the penicillin produced in fungus Penicillium chrysogenum and the tan gene. The isopenicillin enzyme N-acyltransferase (IAT) is self-activated at the Glycine-Cysteine chain to produce two subunits that interact together; similarly, the tan gene also replicates this method. The last step of IAT involves N-acylation and acyl-CoA to produce the penicillin but tan shows no activity in this process (Silvia