Development of the Drosophila mushroom bodies: sequential generation of three distinct types of neurons from a neuroblast

Development ◽  
1999 ◽  
Vol 126 (18) ◽  
pp. 4065-4076 ◽  
Author(s):  
T. Lee ◽  
A. Lee ◽  
L. Luo
Keyword(s):  
Single Cell ◽  
Larval Stage ◽  
Mushroom Body ◽  
Molecular Mechanisms ◽  
Developmental Stages ◽  
Mushroom Bodies ◽  
After Puparium Formation ◽  
Body Development ◽  
Drosophila Brain ◽  
Puparium Formation

The mushroom bodies (MBs) are prominent structures in the Drosophila brain that are essential for olfactory learning and memory. Characterization of the development and projection patterns of individual MB neurons will be important for elucidating their functions. Using mosaic analysis with a repressible cell marker (Lee, T. and Luo, L. (1999) Neuron 22, 451–461), we have positively marked the axons and dendrites of multicellular and single-cell mushroom body clones at specific developmental stages. Systematic clonal analysis demonstrates that a single mushroom body neuroblast sequentially generates at least three types of morphologically distinct neurons. Neurons projecting into the (gamma) lobe of the adult MB are born first, prior to the mid-3rd instar larval stage. Neurons projecting into the alpha' and beta' lobes are born between the mid-3rd instar larval stage and puparium formation. Finally, neurons projecting into the alpha and beta lobes are born after puparium formation. Visualization of individual MB neurons has also revealed how different neurons acquire their characteristic axon projections. During the larval stage, axons of all MB neurons bifurcate into both the dorsal and medial lobes. Shortly after puparium formation, larval MB neurons are selectively pruned according to birthdays. Degeneration of axon branches makes early-born gamma neurons retain only their main processes in the peduncle, which then project into the adult gamma lobe without bifurcation. In contrast, the basic axon projections of the later-born (alpha'/beta') larval neurons are preserved during metamorphosis. This study illustrates the cellular organization of mushroom bodies and the development of different MB neurons at the single cell level. It allows for future studies on the molecular mechanisms of mushroom body development.

The retinal determination gene, dachshund, is required for mushroom body cell differentiation

Development ◽  
2000 ◽  
Vol 127 (12) ◽  
pp. 2663-2672 ◽  
Author(s):  
S.R. Martini ◽  
G. Roman ◽  
S. Meuser ◽  
G. Mardon ◽  
R.L. Davis
Keyword(s):  
Mushroom Body ◽  
Transcriptional Regulator ◽  
Mushroom Bodies ◽  
Normal Brain ◽  
Wild Type ◽  
Brain Areas ◽  
Body Development ◽  
Retinal Determination ◽  
Leg Development ◽  
Normal Brain Development

The dachshund gene of Drosophila encodes a putative transcriptional regulator required for eye and leg development. We show here that dachshund is also required for normal brain development. The mushroom bodies of dachshund mutants exhibit a marked reduction in the number of (α) lobe axons, a disorganization of axons extending into horizontal lobes, and aberrant projections into brain areas normally unoccupied by mushroom body processes. The phenotypes become pronounced during pupariation, suggesting that dachshund function is required during this period. GAL4-mediated expression of dachshund in the mushroom bodies rescues the mushroom body phenotypes. Moreover, dachshund mutant mushroom body clones in an otherwise wild-type brain exhibit the phenotypes, indicating an autonomous role for dachshund. Although eyeless, like dachshund, is preferentially expressed in the mushroom body and is genetically upstream of dachshund for eye development, no interaction of these genes was detected for mushroom body development. Thus, dachshund functions in the developing mushroom body neurons to ensure their proper differentiation.

scholarly journals Single-cell analysis of early chick hypothalamic development reveals that hypothalamic cells are induced from prethalamic-like progenitors.

2021 ◽  
Author(s):  
Dong Won Kim ◽  
Elsie Place ◽  
Kavitha Chinnaiya ◽  
Elizabeth Manning ◽  
Changyu Sun ◽  
...  
Keyword(s):  
Single Cell ◽  
Molecular Mechanisms ◽  
Developmental Stages ◽  
Single Cell Analysis ◽  
Cell Analysis ◽  
Proof Of Concept ◽  
Rna Seq ◽  
Neuroepithelial Cells ◽  
Hypothalamic Cells ◽  
Innate Behaviors

The hypothalamus is an evolutionarily ancient brain region that regulates many innate behaviors, but its development is still poorly understood. To identify molecular mechanisms controlling hypothalamic specification and patterning, we used single-cell RNA-Seq to profile multiple stages of early hypothalamic development in the chick. We observe that hypothalamic neuroepithelial cells are initially induced from prethalamic-like cells. Two distinct hypothalamic progenitor populations emerge later, which give rise to paraventricular/mammillary and tuberal hypothalamus, respectively. At later developmental stages, the regional organization of the chick and mouse hypothalamus closely resembles one another. This study identifies selective markers for major subdivisions of the developing chick hypothalamus and many uncharacterized candidate regulators of hypothalamic patterning and neurogenesis. As proof of concept for the utility of the dataset, we demonstrate that prethalamic progenitor-derived follistatin inhibits hypothalamic induction. This study both clarifies the organization of the early developing hypothalamus and identifies novel molecular mechanisms controlling hypothalamic induction, regionalization, and neurogenesis.

scholarly journals The development of the bristles in normal and some mutant types of Drosophila melanogaster

1942 ◽  
Vol 131 (862) ◽  
pp. 87-110 ◽  
Keyword(s):  
Drosophila Melanogaster ◽  
Single Cell ◽  
Epidermal Cells ◽  
After Puparium Formation ◽  
Puparium Formation ◽  
Tormogen Cell

This paper describes the development of the normal macro- and micro-chaetae of Drosophila , together with that of twelve mutant types. The phenotypes of twenty combinations of these genes have been studied. Each normal bristle is secreted by a single cell, the trichogen, which lies beneath a tormogen cell which secretes a socket. These bristle cells are first distinguishable in the epidermis at about 15 hr. after puparium formation, when they have already divided to form a pair, and are slightly larger than the normal epidermal cells. The secretion of the bristle proceeds most rapidly between 30 and 55 hr., during which time the bristle cells are very large and obviously highly polyploid. The socket, apparently, does not completely enclose the base of the bristle in the earliest stages. The development of the microchaetae is essentially similar to that of the macrochaetae. The actions of the twelve genes can be summarized as follows: Scute causes a primary absence of certain bristle cells, and extra-bristle-complex -41 e and hairy the presence of supernumerary groups. Split frequently causes an extra division, so that a group of four cells is formed; these may be arranged as two trichogens and two tormogens, or one trichogen and three tormogens; or the whole group may fail to reach the surface of the epithelium, when no bristle or socket is formed. Dichaete may produce an effect similar to the last-described of split , and it may also cause an extra division of the trichogen, producing a double bristle in a single socket. Hairless causes the trichogens of some bristle groups to lie level with the tormogens, and to develop like them into sockets. In Stubble the tormogens are shifted rather to one side of the trichogens, so that the bristle is less closely invested by the socket, and becomes thicker and shorter. In shaven-naked the trichogen is irregularly displaced, becoming more or less converted into a tormogen; the small bristle which may be secreted is often peculiarly fanned out at the tip, suggesting an effect of the gene on the nature of the material secreted. Spineless and morula slow down the growth of the bristle cells. Singed, forked and Bristle all affect the nature of the bristle secretion, there being some reason to suggest that the effects of Bristle and singed may be similar and different to that of forked.

Dissecting primate early post-implantation development using long-term in vitro embryo culture

Science ◽  
2019 ◽  
Vol 366 (6467) ◽  
pp. eaaw5754 ◽  
Author(s):  
Yuyu Niu ◽  
Nianqin Sun ◽  
Chang Li ◽  
Ying Lei ◽  
Zhihao Huang ◽  
...  
Keyword(s):  
Single Cell ◽  
Molecular Mechanisms ◽  
Developmental Stages ◽  
Primordial Germ Cell ◽  
Chromatin Accessibility ◽  
Sequencing Analysis ◽  
Ethical Challenges ◽  
Development Trajectories

The transition from peri-implantation to gastrulation in mammals entails the specification and organization of the lineage progenitors into a body plan. Technical and ethical challenges have limited understanding of the cellular and molecular mechanisms that underlie this transition. We established a culture system that enabled the development of cynomolgus monkey embryos in vitro for up to 20 days. Cultured embryos underwent key primate developmental stages, including lineage segregation, bilaminar disc formation, amniotic and yolk sac cavitation, and primordial germ cell–like cell (PGCLC) differentiation. Single-cell RNA-sequencing analysis revealed development trajectories of primitive endoderm, trophectoderm, epiblast lineages, and PGCLCs. Analysis of single-cell chromatin accessibility identified transcription factors specifying each cell type. Our results reveal critical developmental events and complex molecular mechanisms underlying nonhuman primate embryogenesis in the early postimplantation period, with possible relevance to human development.

scholarly journals Early Development of Mushroom Bodies in the Brain of the Honeybee Apis mellifera as Revealed by BrdU Incorporation and Ablation Experiments

1998 ◽  
Vol 5 (1) ◽  
pp. 90-101 ◽  
Author(s):  
Dagmar Malun
Keyword(s):  
Stem Cells ◽  
Larval Stage ◽  
Mushroom Body ◽  
Brdu Incorporation ◽  
Homogeneous Distribution ◽  
Mushroom Bodies ◽  
Kenyon Cell ◽  
Cell Clusters ◽  
Stage 1 ◽  
The Brain

In the honeybee the mushroom bodies are prominent neuropil structures arranged as pairs in the dorsal protocerebrum of the brain. Each mushroom body is composed of a medial and a lateral subunit. To understand their development, the proliferation pattern of mushroom body intrinsic cells, the Kenyon cells, were examined during larval and pupal stages using the bromodeoxyuridine (BrdU) technique and chemical ablation with hydroxyurea.By larval stage 1, ∼40 neuroblasts are located in the periphery of the protocerebrum. Many of these stem cells divide asymmetrically to produce a chain of ganglion mother cells. Kenyon cell precursors underly a different proliferation pattern. With the beginning of larval stage 3, they are arranged in two large distinct cell clusters in each side of the brain. BrdU incorporation into newly synthesized DNA and its immunohistochemical detection show high mitotic activity in these cell clusters that lasts until mid-pupal stages. The uniform diameter of cells, the homogeneous distribution of BrdU-labeled nuclei, and the presence of equally dividing cells in these clusters indicate symmetrical cell divisions of Kenyon cell precursors.Hydroxyurea applied to stage 1 larvae caused the selective ablation of mushroom bodies. Within these animals a variety of defects were observed. In the majority of brains exhibiting mushroom body defects, either one mushroom body subunit on one or on both sides, or three or four subunits (e.g., complete mushroom body ablation) were missing. In contrast, partial ablation of mushroom body subunits resulting in small Kenyon cell clusters and peduncles was observed very rarely. These findings indicate that hydroxyurea applied during larval stage 1 selectively deletes Kenyon stem cells. The results also show that each mushroom body subunit originates from a very small number of stem cells and develops independently of its neighboring subunit.

scholarly journals Single cell transcriptome atlas of mouse mammary epithelial cells across development

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Bhupinder Pal ◽  
Yunshun Chen ◽  
Michael J. G. Milevskiy ◽  
François Vaillant ◽  
Lexie Prokopuk ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Single Cell ◽  
Developmental Stages ◽  
Mammary Epithelial Cells ◽  
Expression Profiles ◽  
Single Cells ◽  
Chromatin Accessibility ◽  
Mammary Epithelial ◽  
Cell Transcriptome ◽  
Single Cell Transcriptome

Abstract Background Heterogeneity within the mouse mammary epithelium and potential lineage relationships have been recently explored by single-cell RNA profiling. To further understand how cellular diversity changes during mammary ontogeny, we profiled single cells from nine different developmental stages spanning late embryogenesis, early postnatal, prepuberty, adult, mid-pregnancy, late-pregnancy, and post-involution, as well as the transcriptomes of micro-dissected terminal end buds (TEBs) and subtending ducts during puberty. Methods The single cell transcriptomes of 132,599 mammary epithelial cells from 9 different developmental stages were determined on the 10x Genomics Chromium platform, and integrative analyses were performed to compare specific time points. Results The mammary rudiment at E18.5 closely aligned with the basal lineage, while prepubertal epithelial cells exhibited lineage segregation but to a less differentiated state than their adult counterparts. Comparison of micro-dissected TEBs versus ducts showed that luminal cells within TEBs harbored intermediate expression profiles. Ductal basal cells exhibited increased chromatin accessibility of luminal genes compared to their TEB counterparts suggesting that lineage-specific chromatin is established within the subtending ducts during puberty. An integrative analysis of five stages spanning the pregnancy cycle revealed distinct stage-specific profiles and the presence of cycling basal, mixed-lineage, and 'late' alveolar intermediates in pregnancy. Moreover, a number of intermediates were uncovered along the basal-luminal progenitor cell axis, suggesting a continuum of alveolar-restricted progenitor states. Conclusions This extended single cell transcriptome atlas of mouse mammary epithelial cells provides the most complete coverage for mammary epithelial cells during morphogenesis to date. Together with chromatin accessibility analysis of TEB structures, it represents a valuable framework for understanding developmental decisions within the mouse mammary gland.

scholarly journals Integrated transcriptomic and proteomic analysis reveals the complex molecular mechanisms underlying stone cell formation in Korla pear

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Aisajan Mamat ◽  
Kuerban Tusong ◽  
Juan Xu ◽  
Peng Yan ◽  
Chuang Mei ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Proteomic Analysis ◽  
Molecular Mechanisms ◽  
Developmental Stages ◽  
Cell Formation ◽  
Parenchyma Cell ◽  
Lignin Biosynthesis ◽  
Cell Content ◽  
Stone Cell ◽  
Fruit Samples

AbstractKorla pear (Pyrus sinkiangensis Yü) is a landrace selected from a hybrid pear species in the Xinjiang Autonomous Region in China. In recent years, pericarp roughening has been one of the major factors that adversely affects fruit quality. Compared with regular fruits, rough-skin fruits have a greater stone cell content. Stone cells compose sclerenchyma tissue that is formed by secondary thickening of parenchyma cell walls. In this work, we determined the main components of stone cells by isolating them from the pulp of rough-skin fruits at the ripening stage. Stone cell staining and apoptosis detection were then performed on fruit samples that were collected at three different developmental stages (20, 50 and 80 days after flowering (DAF)) representing the prime, late and stationary stages of stone cell differentiation, respectively. The same batches of samples were used for parallel transcriptomic and proteomic analysis to identify candidate genes and proteins that are related to SCW biogenesis in Korla pear fruits. The results showed that stone cells are mainly composed of cellulose (52%), hemicellulose (23%), lignin (20%) and a small amount of polysaccharides (3%). The periods of stone cell differentiation and cell apoptosis were synchronous and primarily occurred from 0 to 50 DAF. The stone cell components increased abundantly at 20 DAF but then decreased gradually. A total of 24,268 differentially expressed genes (DEGs) and 1011 differentially accumulated proteins (DAPs) were identified from the transcriptomic and proteomic data, respectively. We screened the DEGs and DAPs that were enriched in SCW-related pathways, including those associated with lignin biosynthesis (94 DEGs and 31 DAPs), cellulose and xylan biosynthesis (46 DEGs and 18 DAPs), S-adenosylmethionine (SAM) metabolic processes (10 DEGs and 3 DAPs), apoplastic ROS production (16 DEGs and 2 DAPs), and cell death (14 DEGs and 6 DAPs). Among the identified DEGs and DAPs, 63 significantly changed at both the transcript and protein levels during the experimental periods. In addition, the majority of these identified genes and proteins were expressed the most at the prime stage of stone cell differentiation, but their levels gradually decreased at the later stages.

scholarly journals Integrative Modelling of Gene Expression and Digital Phenotypes to Describe Senescence in Wheat

Genes ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 909
Author(s):  
Anyela Valentina Camargo Rodriguez
Keyword(s):  
Gene Expression ◽  
Regulatory Networks ◽  
Molecular Mechanisms ◽  
Developmental Stages ◽  
Computational Modelling ◽  
Plant Morphology ◽  
Reproductive Organs ◽  
Biological Trait ◽  
Cereal Grain ◽  
Plant Level

Senescence is the final stage of leaf development and is critical for plants’ fitness as nutrient relocation from leaves to reproductive organs takes place. Although senescence is key in nutrient relocation and yield determination in cereal grain production, there is limited understanding of the genetic and molecular mechanisms that control it in major staple crops such as wheat. Senescence is a highly orchestrated continuum of interacting pathways throughout the lifecycle of a plant. Levels of gene expression, morphogenesis, and phenotypic development all play key roles. Yet, most studies focus on a short window immediately after anthesis. This approach clearly leaves out key components controlling the activation, development, and modulation of the senescence pathway before anthesis, as well as during the later developmental stages, during which grain development continues. Here, a computational multiscale modelling approach integrates multi-omics developmental data to attempt to simulate senescence at the molecular and plant level. To recreate the senescence process in wheat, core principles were borrowed from Arabidopsis Thaliana, a more widely researched plant model. The resulted model describes temporal gene regulatory networks and their effect on plant morphology leading to senescence. Digital phenotypes generated from images using a phenomics platform were used to capture the dynamics of plant development. This work provides the basis for the application of computational modelling to advance understanding of the complex biological trait senescence. This supports the development of a predictive framework enabling its prediction in changing or extreme environmental conditions, with a view to targeted selection for optimal lifecycle duration for improving resilience to climate change.

scholarly journals Combining QTL Mapping and Gene Expression Analysis to Elucidate the Genetic Control of ‘Crumbly’ Fruit in Red Raspberry (Rubus idaeus L.)

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 794
Author(s):  
Luca M. Scolari ◽  
Robert D. Hancock ◽  
Pete E. Hedley ◽  
Jenny Morris ◽  
Kay Smith ◽  
...  
Keyword(s):  
Genetic Control ◽  
Developmental Disorder ◽  
Molecular Mechanisms ◽  
Developmental Stages ◽  
Microarray Experiment ◽  
Rubus Idaeus ◽  
Red Raspberry ◽  
Genotype By Sequencing ◽  
First Time ◽  
Selection Of

‘Crumbly’ fruit is a developmental disorder in raspberry that results in malformed and unsaleable fruits. For the first time, we define two distinct crumbly phenotypes as part of this work. A consistent crumbly fruit phenotype affecting the majority of fruits every season, which we refer to as crumbly fruit disorder (CFD) and a second phenotype where symptoms vary across seasons as malformed fruit disorder (MFD). Here, segregation of crumbly fruit of the MFD phenotype was examined in a full-sib family and three QTL (Quantitative Trait Loci) were identified on a high density GbS (Genotype by Sequencing) linkage map. This included a new QTL and more accurate location of two previously identified QTLs. A microarray experiment using normal and crumbly fruit at three different developmental stages identified several genes that were differentially expressed between the crumbly and non-crumbly phenotypes within the three QTL. Analysis of gene function highlighted the importance of processes that compromise ovule fertilization as triggers of crumbly fruit. These candidate genes provided insights regarding the molecular mechanisms involved in the genetic control of crumbly fruit in red raspberry. This study will contribute to new breeding strategies and diagnostics through the selection of molecular markers associated with the crumbly trait.

scholarly journals Tumor to normal single-cell mRNA comparisons reveal a pan-neuroblastoma cancer cell

2021 ◽  
Vol 7 (6) ◽  
pp. eabd3311
Author(s):  
Gerda Kildisiute ◽  
Waleed M. Kholosy ◽  
Matthew D. Young ◽  
Kenny Roberts ◽  
Rasa Elmentaite ◽  
...  
Keyword(s):  
Childhood Cancer ◽  
Single Cell ◽  
Cancer Cells ◽  
Cancer Cell ◽  
Developmental Stages ◽  
Neuroblastoma Cells ◽  
Cell Type ◽  
Adrenal Cell ◽  
Universal Feature ◽  
Principal Finding

Neuroblastoma is a childhood cancer that resembles developmental stages of the neural crest. It is not established what developmental processes neuroblastoma cancer cells represent. Here, we sought to reveal the phenotype of neuroblastoma cancer cells by comparing cancer (n = 19,723) with normal fetal adrenal single-cell transcriptomes (n = 57,972). Our principal finding was that the neuroblastoma cancer cell resembled fetal sympathoblasts, but no other fetal adrenal cell type. The sympathoblastic state was a universal feature of neuroblastoma cells, transcending cell cluster diversity, individual patients, and clinical phenotypes. We substantiated our findings in 650 neuroblastoma bulk transcriptomes and by integrating canonical features of the neuroblastoma genome with transcriptional signals. Overall, our observations indicate that a pan-neuroblastoma cancer cell state exists, which may be attractive for novel immunotherapeutic and targeted avenues.

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