myb provides an essential function during Drosophila  development

Abstract

Vertebrate c-myb encodes a transcription factor thought to play an important role in the cell cycle. To gain further insight into myb function, we have been studying a related gene in Drosophila. We found that Drosophila myb is abundantly expressed throughout development in all mitotically active tissues, at lower levels in some postmitotic tissues, but not at detectable levels in polyploid larval tissues. We performed genetic screens to isolate recessive lethal mutations in the chromosomal region that includes the myb gene. We obtained two temperature-sensitive alleles of myb, demonstrating that the gene provides an essential function. Examination of the mutant phenotype revealed that Drosophila myb is important for both embryonic and imaginal development and that myb serves a role in the development of many tissues and during oogenesis.

Animal-specific C-terminal domain links myeloblastosis oncoprotein (Myb) to an ancient repressor complex

“…S3). Interestingly, a similar phenotype has been reported in Myb 1 -mutant animals raised at the permissive temperature (18). These results imply that the C terminus can function as a dominant loss-of-function allele at high levels of expression.…”

“…Several temperature-sensitive and null alleles of Drosophila Myb have previously been described (17)(18)(19)(20). However, attempts to isolate additional mutant alleles via traditional chemical mutagenesis were unsuccessful despite the screening of large numbers of mutagenized animals.…”

Epigenetic regulation of olfactory receptor gene expression by the Myb–MuvB/dREAM complex

“…We chose not to analyze myb À clones, since loss of myb during pupal development can cause defects such as incomplete cell division (Katzen and Bishop 1996), which could confound results in mature ORNs. To test the effect of loss of Myb alone on Gr63a expression, we used a temperature-sensitive myb 1 mutant that is viable if raised to adulthood at the permissive temperature (18°C) (Katzen and Bishop 1996). This myb 1 allele has a point mutation in the functionally important C-terminal domain, disrupting protein function at the restrictive temperature (25°C) (Katzen et al 1998).…”

The transcription factor B-Myb is essential for S-phase progression and genomic stability in diploid and polyploid megakaryocytes

“…Dm-Myb has been shown to be essential for development (Katzen and Bishop, 1996;Fitzpatrick et al, 2002;Manak et al, 2002). Studies of Dm-Myb mutants have suggested roles in the transcriptional regulation of cyclin B (Okada et al, 2002) and the regulation of S phase and genomic stability (Beall et al, 2002;Manak et al, 2002;Beall et al, 2004).…”