Polytene Chromosomes of Zaprionus vittiger Coquillett

The karyotype of Zaprionus vittiger consists of six chromosomes, five of which are banded polytene arms extending from a chromocentre in squashed preparations of the salivary glands. The sixth appears as a heterochromatic protusion. The chromosomes are acrocentric and joint together at heterochromatin around the centromere to form a chromocenter which is easily broken. Zaprionus vittiger Coquillett were trapped in the university of Lagos Botanical Garden. Salivary glands chromosomes of Zaprionus vittiger Coquillett third instar larvae were prepared and examined under the microscope. The examination focused on the structure and characteristics of the terminal ends of different chromosomes which can be used to identify them in Zaprionus vittiger salivary glands chromosomes preparations. The five polytene chromosomes were designated A-E and various features which can be used to identify each of them were described. The dot chromosome was designated chromosome F. The chromosomes are also relatively fragile and undergo extensively twisting and coiling.