Homework SourseFalse 2 1 In arthropods expression of the distalless gene pr
False
2.
| 1. | In arthropods, expression of the distal-less gene promotes leg development. In a subset of arthropods—the insects—an alanine repeat exists in the Ubx protein and functions by turning on distal-less expression in abdominal segments. | ||||||||||||||
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Solution
1. Answer “True”
Ubx is a gene found in insects, a member of homeobox gene family. It is expressed in the 3rd thoracic (T3) and first abdominal segments (A1). The gene regulates wings and legs formation in the adult flies.
2. a. Answer “A”
Misexpression (mutation) of Ubx gene will lead to transformation of dorsal and ventral appendages of third thoracic segement (T3), which includes the Haltere and third leg formation on the second thoracic segment (T2) and second set of wings
b. Answer “A”
The misexpression of Ubx throughout all of the tissues of the presumptive thorax in transgenic Drosophilo embryos suppresses limb development due to the repression of DIL In contrast, the misexpression of the crustacean Ubx protein in transgenic flies does not interfere with Oil gene expression and the formation of thoracic limbs.
These observations indicate that the Drosophilo Ubx protein is functionally distinct from Ubx in crustaceans. The fly protein represses Dll gene expression, whereas the crustacean Ubx protein does not,
