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Updated: May 29, 2026
Dissection of Drosophila Ovaries
Published on: October 19, 2006
The Drosophila CPEB protein Orb2 has a novel expression pattern and is important for asymmetric cell division and
Nathaniel Hafer1, Shuwa Xu, Krishna Moorthi Bhat
1Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA.
Abstract:
Cytoplasmic polyadenylation element binding (CPEB) proteins bind mRNAs to regulate their localization and translation. While the first CPEBs discovered were germline specific, subsequent studies indicate that CPEBs also function in many somatic tissues including the nervous system. Drosophila has two CPEB family members. One of these, orb, plays a key role in the establishment of polarity axes in the developing egg and early embryo, but has no known somatic functions or expression outside of the germline. Here we characterize the other Drosophila CPEB, orb2. Unlike orb, orb2 mRNA and protein are found throughout development in many different somatic tissues. While orb2 mRNA and protein of maternal origin are distributed uniformly in early embryos, this pattern changes as development proceeds and by midembryogenesis the highest levels are found in the CNS and PNS. In the embryonic CNS, Orb2 appears to be concentrated in cell bodies and mostly absent from the longitudinal and commissural axon tracts. In contrast, in the adult brain, the protein is seen in axonal and dendritic terminals. Lethal effects are observed for both RNAi knockdowns and orb2 mutant alleles while surviving adults display locomotion and behavioral defects. We also show that orb2 funtions in asymmetric division of stem cells and precursor cells during the development of the embryonic nervous system and mesoderm.
Insights
The Drosophila orb2 gene is crucial for nervous system development, regulating stem cell division and adult behavior. Its disruption leads to lethal effects and locomotion defects, highlighting its somatic functions.
Area of Science:
- Developmental Biology
- Molecular Biology
- Neuroscience
Background:
- Cytoplasmic polyadenylation element binding (CPEB) proteins regulate mRNA localization and translation.
- While some CPEBs are germline-specific, others function in somatic tissues, including the nervous system.
- Drosophila has two CPEB family members: orb and orb2.
Purpose of the Study:
- To characterize the function and expression of the Drosophila CPEB family member, orb2.
- To investigate orb2's role in somatic tissues, particularly the nervous system.
- To determine the effects of orb2 disruption on development and behavior.
Main Methods:
- Analysis of orb2 mRNA and protein expression patterns throughout Drosophila development.
- Investigation of orb2 function using RNAi knockdowns and mutant alleles.
- Examination of orb2's role in asymmetric cell division in the embryonic nervous system and mesoderm.
Main Results:
- orb2 mRNA and protein are expressed in various somatic tissues throughout development, with high levels in the embryonic CNS and PNS.
- Orb2 protein localization shifts from uniform maternal distribution in early embryos to concentration in cell bodies (embryonic CNS) and terminals (adult brain).
- orb2 disruption causes lethal effects, locomotion defects, and behavioral abnormalities, and orb2 is essential for asymmetric stem and precursor cell division.
Conclusions:
- orb2 is a key regulator of somatic development in Drosophila, with critical roles in the nervous system.
- orb2's distinct expression and localization patterns suggest diverse regulatory functions.
- Disruption of orb2 impacts fundamental developmental processes, including cell division and organismal behavior.
