Gamma-tubulin is required for the structure and function of the microtubule organizing centre in Drosophila neuroblasts.
We report that in Drosophila, gamma-tubulin is required for the structure as well as the function of microtubule organizing centres (MTOCs). This conclusion is based on the identification and phenotypic characterization of a mutant allele of the gamma-tubulin gene located at region 23C of the polytene chromosome map. This mutation, which we have called gamma-tub23CPl, is caused by the insertion of a P-element within the 5' untranslated leader of the gamma-tubulin transcript. Northern and Western analysis show that gamma-tub23CPl is either a null or a very severe hypomorph as no gamma-tubulin mRNA or protein can be detected in mutant individuals. Visualization of DNA, MTOCs and microtubules by confocal laser scanning microscopy of cells from individuals homozygous for gamma-tub23CPl reveals a series of phenotypic abnormalities. Some of these are similar to those observed after disruption of gamma-tubulin function in other organisms, including mitotic arrest and a dramatic decrease in the number of microtubules, but, in addition, we have observed that mutation in this gene also results in highly abnormal MTOCs which show a variety of shapes and sizes which we never observed in wild type cells. These results show that gamma-tubulin is required for both structural and functional roles in the MTOCs.
Sunkel
C E
CE
Centro de Citologia Experimental, Universidade do Porto, Portugal.
Gomes
R
R
Sampaio
P
P
Perdigão
J
J
González
C
C
D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D018385:Centrosome / Q000473:pathology / Q000502:physiology* / Q000648:ultrastructure; D002874:Chromosome Mapping; D004251:DNA Transposable Elements; D004330:Drosophila / Q000166:cytology* / Q000196:embryology / Q000235:genetics; D007150:Immunohistochemistry; D018613:Microscopy, Confocal; D008938:Mitosis / Q000235:genetics; D008969:Molecular Sequence Data; D009154:Mutation; D009420:Nervous System / Q000166:cytology / Q000196:embryology / Q000648:ultrastructure; D009474:Neurons / Q000166:cytology / Q000502:physiology* / Q000648:ultrastructure; D008941:Spindle Apparatus / Q000473:pathology; D014404:Tubulin / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology*
D004251:DNA Transposable Elements; D014404:Tubulin