Swallowtail butterfly tiger swallowtail), Y-linkage determines whether the females are either wild-type (yellow and black) or melanic (dark melanin replaces the yellow background). This genetic difference stems from the fact that melanism is controlled by a single gene, which controls the level of dopamine in the organism. The enzyme BAS, which assists dopamine in producing the yellow pigmentation, normally found on the wings' background, is suppressed. Without the pigmentation, the butterfly appears mostly black (the melanic form) and is a Batesian mimic of "Battus philenor", the pipevine swallowtail. There are also "Papilio glaucus" that are not wholly black; several possess an intermediate
Comma distinguish it from the Arabic diacritic "" (), representing the vowel , which is similarly comma-shaped. In Arabic texts, Western-styled comma () is used as a decimal point. Reversed comma () is used in Sindhi when written in Arabic script. It is different from the standard Arabic comma. Hebrew script is also written from right to left. However, Hebrew punctuation includes only a regular comma (). Dravidian languages such as Tamil, Telugu, Kannada, and Malayalam also use the punctuation mark in similar usage to that of European languages with similar spacing. In the common character encoding systems Unicode and ASCII,