Biology Reference
In-Depth Information
CHAPTER THREE
Temporal Patterning of Neural
Progenitors in
Drosophila
Xin Li, Zhenqing Chen, Claude Desplan
1
Department of Biology, New York University, New York, New York, USA
1
Corresponding author: e-mail address: cd38@nyu.edu
Contents
1.
Introduction
70
1.1 Embryonic and larval ventral nerve cord
71
1.2 Olfactory system
72
1.3 Medulla in the optic lobes
72
1.4 Type II NBs in the central brain
73
2. Sequentially Expressed Transcription Factors in NBs Control Birth-
Order-Dependent Neuron Fates
73
2.1 Temporal sequence of transcription factors in Drosophila embryonic
VNC NBs
73
2.2 Similar or different TF sequence in other systems?
75
2.3 Different TF sequence in medulla NBs
76
2.4 Combinatorial temporal patterning of INPs
and type II NBs
77
3. How are Temporal Transitions in NBs Controlled?
78
3.1 Cross-regulations between the TFs play important roles in the transitions
78
3.2 Differential requirements for cell cycle and asymmetric division
80
3.3 Switching factors involved in TF transitions
80
4. Relationship Between Temporal Sequence and NB Competence
81
4.1 Restriction of NB competence
81
4.2 TF sequence and regulation of NB competence
81
4.3 Epigenetic mechanism for loss of NB competence
82
5. Feedforward Loops Downstream of the Temporal Sequence Control
Neuron Fates
84
6. Progression of the TF Sequence Required for the End of Neurogenesis
85
6.1 Apoptosis of abdominal pNBs
85
6.2 Pros-dependent cell-cycle exit of thoracic and central brain pNBs
86
6.3 Studies in other systems about the end of neurogenesis
87
7.
Integration of Temporal and Spatial Information Determines Lineages
87
8.
Integration of Temporal Identity with Binary Fate Choice
88
9. Conclusions and Future Questions
90
References
91
