Hunchback is required for the specification of the early sublineage of neuroblast 7-3 in the Drosophila central nervous system

The Drosophila ventral nerve cord (VNC) derives from neuroblasts (NBs), which mostly divide in a stem cell mode and give rise to defined NB lineages characterized by specific sets of sequentially generated neurons and/or glia cells. To understand how different cell types are generated within a NB lineage, we have focused on the NB7-3 lineage as a model system. This NB gives rise to four individually identifiable neurons and we show that these cells are generated from three different ganglion mother cells (GMCs). The finding that the transcription factor Hunchback (Hb) is expressed in the early sublineage of NB7-3, which consists of the early NB and the first GMC (GMC7-3a) and its progeny (EW1 and GW), prompted us to investigate its possible role in NB7-3 lineage development. Our analysis revealed that loss of hb results in a lack of the normally Hb-positive neurons, while the later-born neurons (designated as EW2 and EW3) are still present. However, overexpression of hb in the whole lineage leads to additional cells with the characteristics of GMC7-3a-derived neurons, at the cost of EW2 and EW3. Thus, hb is an important determinant in specifying early sublineage identity in the NB7-3 lineage. Using Even-skipped (Eve) as a marker, we have additionally shown that hb is also needed for the determination and/or differentiation of several other early-born neurons, indicating that this gene is an important player in sequential cell fate specification within the Drosophila CNS.

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Modifications of cell fate specification in equal-cleaving nemertean embryos: alternate patterns of spiralian development

Development ◽

10.1242/dev.121.10.3175 ◽

1995 ◽

Vol 121 (10) ◽

pp. 3175-3185 ◽

Cited By ~ 1

Author(s):

M.Q. Martindale ◽

J.Q. Henry

Keyword(s):

Cell Fate ◽

Cell Lineage ◽

Cell Types ◽

Embryonic Cell ◽

Specific Cell ◽

Cell Fate Specification ◽

Cell Fates ◽

Developmental Potential ◽

Fate Specification ◽

Symmetry Properties

The nemerteans belong to a phylum of coelomate worms that display a highly conserved pattern of cell divisions referred to as spiral cleavage. It has recently been shown that the fates of the four embryonic cell quadrants in two species of nemerteans are not homologous to those in other spiralian embryos, such as the annelids and molluscs (Henry, J. Q. and Martindale, M. Q. (1994a) Develop. Genetics 15, 64–78). Equal-cleaving molluscs utilize inductive interactions to establish quadrant-specific cell fates and embryonic symmetry properties following fifth cleavage. In order to elucidate the manner in which cell fates are established in nemertean embryos, we have conducted cell isolation and deletion experiments to examine the developmental potential of the early cleavage blastomeres of two equal-cleaving nemerteans, Nemertopsis bivittata and Cerebratulus lacteus. These two species display different modes of development: N. bivittata develops directly via a non-feeding larvae, while C. lacteus develops to form a feeding pilidium larva which undergoes a radical metamorphosis to give rise to the juvenile worm. By examining the development of certain structures and cell types characteristic of quadrant-specific fates for each of these species, we have shown that isolated blastomeres of the indirect-developing nemertean, C. lacteus, are capable of generating cell fates that are not a consequence of that cell's normal developmental program. For instance, dorsal blastomeres can form muscle fibers when cultured in isolation. In contrast, isolated blastomeres of the direct-developing species, N. bivittata do not regulate their development to the same extent. Some cell fates are specified in a precocious manner in this species, such as those that give rise to the eyes. Thus, these findings indicate that equal-cleaving spiralian embryos can utilize different mechanisms of cell fate and axis specification. The implications of these patterns of nemertean development are discussed in relation to experimental work in other spiralian embryos, and a model is presented that accounts for possible evolutionary changes in cell lineage and the process of cell fate specification amongst these protostome phyla.

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Multimodal Long Noncoding RNA Interaction Networks: Control Panels for Cell Fate Specification

Genetics ◽

10.1534/genetics.119.302661 ◽

2019 ◽

Vol 213 (4) ◽

pp. 1093-1110 ◽

Cited By ~ 3

Author(s):

Keriayn N. Smith ◽

Sarah C. Miller ◽

Gabriele Varani ◽

J. Mauro Calabrese ◽

Terry Magnuson

Keyword(s):

Cell Fate ◽

Early Development ◽

Noncoding Rna ◽

Cell Types ◽

Cell Fate Specification ◽

Phenotypic Analysis ◽

Cell Fate Decisions ◽

Fate Specification ◽

Mechanistic Basis ◽

Rna Interaction

Lineage specification in early development is the basis for the exquisitely precise body plan of multicellular organisms. It is therefore critical to understand cell fate decisions in early development. Moreover, for regenerative medicine, the accurate specification of cell types to replace damaged/diseased tissue is strongly dependent on identifying determinants of cell identity. Long noncoding RNAs (lncRNAs) have been shown to regulate cellular plasticity, including pluripotency establishment and maintenance, differentiation and development, yet broad phenotypic analysis and the mechanistic basis of their function remains lacking. As components of molecular condensates, lncRNAs interact with almost all classes of cellular biomolecules, including proteins, DNA, mRNAs, and microRNAs. With functions ranging from controlling alternative splicing of mRNAs, to providing scaffolding upon which chromatin modifiers are assembled, it is clear that at least a subset of lncRNAs are far from the transcriptional noise they were once deemed. This review highlights the diversity of lncRNA interactions in the context of cell fate specification, and provides examples of each type of interaction in relevant developmental contexts. Also highlighted are experimental and computational approaches to study lncRNAs.

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Specification of diverse cell types during early neurogenesis of the mouse cerebellum

eLife ◽

10.7554/elife.42388 ◽

2019 ◽

Vol 8 ◽

Cited By ~ 8

Author(s):

John W Wizeman ◽

Qiuxia Guo ◽

Elliott M Wilion ◽

James YH Li

Keyword(s):

Gene Expression ◽

Cell Fate ◽

Developmental Trajectories ◽

Ventricular Zone ◽

Cell Types ◽

Cell Fate Specification ◽

Fate Specification ◽

Integral Role ◽

Cerebellar Cell ◽

And Function

We applied single-cell RNA sequencing to profile genome-wide gene expression in about 9400 individual cerebellar cells from the mouse embryo at embryonic day 13.5. Reiterative clustering identified the major cerebellar cell types and subpopulations of different lineages. Through pseudotemporal ordering to reconstruct developmental trajectories, we identified novel transcriptional programs controlling cell fate specification of populations arising from the ventricular zone and the rhombic lip, two distinct germinal zones of the embryonic cerebellum. Together, our data revealed cell-specific markers for studying the cerebellum, gene-expression cascades underlying cell fate specification, and a number of previously unknown subpopulations that may play an integral role in the formation and function of the cerebellum. Our findings will facilitate new discovery by providing insights into the molecular and cell type diversity in the developing cerebellum.

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Faculty Opinions recommendation of The expression and function of the achaete-scute genes in Tribolium castaneum reveals conservation and variation in neural pattern formation and cell fate specification.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1016251.200311 ◽

2003 ◽

Author(s):

Patricia Simpson

Keyword(s):

Pattern Formation ◽

Cell Fate ◽

Tribolium Castaneum ◽

Cell Fate Specification ◽

Fate Specification ◽

And Function

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Faculty Opinions recommendation of The WEREWOLF MYB protein directly regulates CAPRICE transcription during cell fate specification in the Arabidopsis root epidermis.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.1028584.342203 ◽

2005 ◽

Author(s):

Liam Dolan

Keyword(s):

Cell Fate ◽

Cell Fate Specification ◽

Arabidopsis Root ◽

Fate Specification ◽

Root Epidermis ◽

Myb Protein

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Faculty Opinions recommendation of Subcellular localization and functional domain studies of DEFECTIVE KERNEL1 in maize and Arabidopsis suggest a model for aleurone cell fate specification involving CRINKLY4 and SUPERNUMERARY ALEURONE LAYER1.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.720401353.793504094 ◽

2015 ◽

Author(s):

David Jackson

Keyword(s):

Subcellular Localization ◽

Cell Fate ◽

Functional Domain ◽

Cell Fate Specification ◽

Aleurone Cell ◽

Fate Specification

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MiR-7 in Cancer Development

Biomedicines ◽

10.3390/biomedicines9030325 ◽

2021 ◽

Vol 9 (3) ◽

pp. 325

Author(s):

Petra Korać ◽

Mariastefania Antica ◽

Maja Matulić

Keyword(s):

Cell Fate ◽

Dominant Role ◽

Tumor Development ◽

Mrna Translation ◽

Cell Types ◽

Fine Tuning ◽

Non Coding Rna ◽

Tumor Types ◽

Different Cell Types ◽

The Brain

MicroRNAs (miRNAs) are short non-coding RNA involved in the regulation of specific mRNA translation. They participate in cellular signaling circuits and can act as oncogenes in tumor development, so-called oncomirs, as well as tumor suppressors. miR-7 is an ancient miRNA involved in the fine-tuning of several signaling pathways, acting mainly as tumor suppressor. Through downregulation of PI3K and MAPK pathways, its dominant role is the suppression of proliferation and survival, stimulation of apoptosis and inhibition of migration. Besides these functions, it has numerous additional roles in the differentiation process of different cell types, protection from stress and chromatin remodulation. One of the most investigated tissues is the brain, where its downregulation is linked with glioblastoma cell proliferation. Its deregulation is found also in other tumor types, such as in liver, lung and pancreas. In some types of lung and oral carcinoma, it can act as oncomir. miR-7 roles in cell fate determination and maintenance of cell homeostasis are still to be discovered, as well as the possibilities of its use as a specific biotherapeutic.

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