Lineages, Lineage Stability and Pattern Formation in Leaves of Variegated Chimeras of Lophostemon confertus (R. Br.) Wilson & Waterhouse and Tristaniopis laurina (Smith) Wilson & Waterhouse (Myrtaceae)

1987 ◽  
Vol 35 (6) ◽  
pp. 701
Author(s):  
DV Beardsell ◽  
JA Considine

Three variegated chimeras of L. confertus and T. laurina arise spontaneously in seedling populations: 1, white margin: green centre, 2, green margin: light green centre and 3, green margin: white centre. Types 1 and 2 are found in T. laurina and types 1 and 3 in L. confertus. We have determined chloroplast distribution in the leaf tissues by fluorescence microscopy to assess the basis for these colour patterns. In L. confertus, a layer of collenchyma underlies the adaxial epidermis, replaces the upper layer of palisade, and does not mask mutant inner tissues, concealed by the adaxial layer of palisade in type 2 leaves of T. laurina. The central colour patterns are explained on the basis of accepted paths of cell lineage in leaf development (protoderm green in all three types; hypodermal derivatives genetically green in 2 and 3; and subhypodermal cells chlorophyll-deficient in types 2 and 3). The cell lineages postulated are similar in both species and we show that the observations can be accounted for only by a shift in lineage path during leaf ontogeny. We conclude that some established concepts of leaf ontogeny require revision.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Xujun Ye ◽  
Fengrui Zhang ◽  
Li Zhou ◽  
Yadong Wei ◽  
Li Zhang ◽  
...  

AbstractSrc homology 2 domain–containing inositol 5-phosphatase 1 (SHIP-1) regulates the intracellular levels of phosphotidylinositol-3, 4, 5-trisphosphate, a phosphoinositide 3–kinase (PI3K) product. Emerging evidence suggests that the PI3K pathway is involved in allergic inflammation in the lung. Germline or induced whole-body deletion of SHIP-1 in mice led to spontaneous type 2-dominated pulmonary inflammation, demonstrating that SHIP-1 is essential for lung homeostasis. However, the mechanisms by which SHIP-1 regulates lung inflammation and the responsible cell types are still unclear. Deletion of SHIP-1 selectively in B cells, T cells, dendritic cells (DC) or macrophages did not lead to spontaneous allergic inflammation in mice, suggesting that innate immune cells, particularly group 2 innate lymphoid cells (ILC2 cells) may play an important role in this process. We tested this idea using mice with deletion of SHIP-1 in the hematopoietic cell lineage and examined the changes in ILC2 cells. Conditional deletion of SHIP-1 in hematopoietic cells in Tek-Cre/SHIP-1 mice resulted in spontaneous pulmonary inflammation with features of type 2 immune responses and airway remodeling like those seen in mice with global deletion of SHIP-1. Furthermore, when compared to wild-type control mice, Tek-Cre/SHIP-1 mice displayed a significant increase in the number of IL-5/IL-13 producing ILC2 cells in the lung at baseline and after stimulation by allergen Papain. These findings provide some hints that PI3K signaling may play a role in ILC2 cell development at baseline and in response to allergen stimulation. SHIP-1 is required for maintaining lung homeostasis potentially by restraining ILC2 cells and type 2 inflammation.


1998 ◽  
Vol 353 (1370) ◽  
pp. 925-933 ◽  
Author(s):  
Nicholas A. Wright

The main pathways of epithelial differentiation in the intestine, Paneth, mucous, endocrine and columnar cell lineages are well recognized. However, in abnormal circumstances, for example in mucosal ulceration, a cell lineage with features distinct from these emerges, which has often been dismissed in the past as ‘pyloric’ metaplasia, because of its morphological resemblance to the pyloric mucosa in the stomach. However, we can conclude that this cell lineage has a defined phenotype unique in gastrointestinal epithelia, has a histogenesis that resembles that of Brunner's glands, but acquires a proliferative organization similar to that of the gastric gland. It expresses several peptides of particular interest, including epidermal growth factor, the trefoil peptides TFF1, TFF2, TFF3, lysozyme and PSTI. The presence of this lineage also appears to cause altered gene expression in adjacent indigenous cell lineages. We propose that this cell lineage is induced in gastrointestinal stem cells as a result of chronic mucosal ulceration, and plays an important part in ulcer healing; it should therefore be added to the repertoire of gastrointestinal stem cells.


Genetics ◽  
1980 ◽  
Vol 96 (2) ◽  
pp. 435-454 ◽  
Author(s):  
H Robert Horvitz ◽  
John E Sulston

ABSTRACT Twenty-four mutants that alter the normally invariant post-embryonic cell lineages of the nematode Caenorhabditis elegans have been isolated and genetically characterized. In some of these mutants, cell divisions fail that occur in wild-type animals; in other mutants, cells divide that do not normally do so. The mutants differ in the specificities of their defects, so that it is possible to identify mutations that affect some cell lineages but not others. These mutants define 14 complementation groups, which have been mapped. The abnormal phenotype of most of the cell-lineage mutants results from a single recessive mutation; however, the excessive cell divisions characteristic of one strain, CB1322, require the presence of two unlinked recessive mutations. All 24 cell-lineage mutants display incomplete penetrance and/or variable expressivity. Three of the mutants are suppressed by pleiotropic suppressors believed to be specific for null alleles, suggesting that their phenotypes result from the complete absence of gene activity.


Development ◽  
1992 ◽  
Vol 116 (4) ◽  
pp. 943-952 ◽  
Author(s):  
X. Cui ◽  
C.Q. Doe

Cell diversity in the Drosophila central nervous system (CNS) is primarily generated by the invariant lineage of neural precursors called neuroblasts. We used an enhancer trap screen to identify the ming gene, which is transiently expressed in a subset of neuroblasts at reproducible points in their cell lineage (i.e. in neuroblast ‘sublineages’), suggesting that neuroblast identity can be altered during its cell lineage. ming encodes a predicted zinc finger protein and loss of ming function results in precise alterations in CNS gene expression, defects in axonogenesis and embryonic lethality. We propose that ming controls cell fate within neuroblast cell lineages.


2020 ◽  
Author(s):  
Liana Fasching ◽  
Yeongjun Jang ◽  
Simone Tomasi ◽  
Jeremy Schreiner ◽  
Livia Tomasini ◽  
...  

AbstractPost-zygotic mosaic mutations can be used to track cell lineages in humans. By using cell cloning and induced pluripotent cell lines, we analyzed early cell lineages in two living individuals (a patient and a control), and a postmortem human specimen. Of ten reconstructed post-zygotic divisions, none resulted in balanced contributions of daughter lineages to tissues. In both living individuals one of two lineages from the first cleavage was dominant across tissues, with 90% frequency in blood. We propose that the efficiency of DNA repair contributes to lineage imbalance. Allocation of lineages in postmortem brain correlated with anterior-posterior axis, associating lineage history with cell fate choices in embryos. Recurrence of germline variants as mosaic suggested that certain loci may be particularly susceptible to mutagenesis. We establish a minimally invasive framework for defining cell lineages in any living individual, which paves the way for studying their relevance in health and disease.


Blood ◽  
1986 ◽  
Vol 67 (5) ◽  
pp. 1240-1243
Author(s):  
M Keinanen ◽  
S Knuutila ◽  
CD Bloomfield ◽  
E Elonen ◽  
A de la Chapelle

To determine the hematopoietic cell lineage of mitotic cells in human bone marrow on direct examination and after 24-hour culture, marrow mitoses from four healthy individuals were studied, using a new technique that allows analysis of karyotypes in cells whose cell membrane and cytoplasm have been preserved. Mitoses were identified as being of erythroid lineage by immunofluorescent staining for surface glycophorin A and as being of granulocytic lineage by cytoplasmic staining for Sudan black B. On direct marrow examination without prior culture, the great majority of mitoses (74% to 90%) were of erythroid lineage; only a few (0% to 10%) were granulocytic. After 24-hour culture, the percentage of erythroid mitoses (15% to 40%) decreased, while the percentage of granulocytic mitoses (58% to 87%) increased strikingly. These data indicate that mitotic cells of different hematopoietic cell lineages predominate in marrow at different culture times and offer a plausible explanation for the high frequency of normal karyotypes in acute myeloid leukemia after direct marrow cytogenetic evaluation.


2005 ◽  
Vol 6 (1) ◽  
pp. 33
Author(s):  
Jayesh B. Samtani ◽  
John B. Masiunas ◽  
James E. Appleby

In the last few decades, white oak in the north central region have developed malformed spring leaves called “leaf tatters.” Symptoms begin with the death of interveinal leaf tissues, eventually leaving only the main leaf veins with little interveinal tissues present. Winter injury, frost, insect attack, and herbicide drift were all thought to be possible causes of leaf tatters. This study indicates that drift of chloroacetamide herbicides from applications onto corn and soybean fields is a possible cause of the leaf tatters syndrome. Accepted for publication 14 February 2005. Published 21 February 2005.


Development ◽  
1996 ◽  
Vol 122 (3) ◽  
pp. 997-1005 ◽  
Author(s):  
J.C. Larkin ◽  
N. Young ◽  
M. Prigge ◽  
M.D. Marks

Arabidopsis trichomes are single-celled epidermal hairs that serve as a useful model for the study of plant cell differentiation. An examination of the distribution of trichomes early in their development revealed that developing trichomes occur adjacent to another trichome much less frequently than would be expected by chance. Clonal analysis of epidermal cell lineages ruled out a role for cell lineage in generating the observed minimum-distance spacing pattern. Taken together, these results are consistent with a role for lateral inhibition in the control of trichome development. We also report the identification of a new locus, Reduced Trichome Number (RTN), which affects the initiation of trichomes. This locus was initially detected by the reduced number of leaf trichomes on Landsberg erecta plants compared to that on Columbia plants. Quantitative Trait Locus mapping revealed that more than 73% of the variation in trichome number was due to a major locus near erecta on chromosome 2. The reduced number of trichomes conditioned by the Landsberg erecta allele of this locus appeared to be due to an early cessation of trichome initiation. The implications of these observations are discussed with regard to previously published models of trichome development.


Development ◽  
1992 ◽  
Vol 116 (4) ◽  
pp. 855-863 ◽  
Author(s):  
C.Q. Doe

The first step in generating cellular diversity in the Drosophila central nervous system is the formation of a segmentally reiterated array of neural precursor cells, called neuroblasts. Subsequently, each neuroblast goes through an invariant cell lineage to generate neurons and/or glia. Using molecular lineage markers, I show that (1) each neuroblast forms at a stereotyped time and position; (2) the neuroblast pattern is indistinguishable between thoracic and abdominal segments; (3) the development of individual neuroblasts can be followed throughout early neurogenesis; (4) gene expression in a neuroblast can be reproducibly modulated during its cell lineage; (5) identified ganglion mother cells form at stereotyped times and positions; and (6) the cell lineage of four well-characterized neurons can be traced back to two identified neuroblasts. These results set the stage for investigating neuroblast specification and the mechanisms controlling neuroblast cell lineages.


2019 ◽  
Vol 53 (1) ◽  
pp. 505-530 ◽  
Author(s):  
Larissa B. Patterson ◽  
David M. Parichy

Vertebrate pigment patterns are diverse and fascinating adult traits that allow animals to recognize conspecifics, attract mates, and avoid predators. Pigment patterns in fish are among the most amenable traits for studying the cellular basis of adult form, as the cells that produce diverse patterns are readily visible in the skin during development. The genetic basis of pigment pattern development has been most studied in the zebrafish, Danio rerio. Zebrafish adults have alternating dark and light horizontal stripes, resulting from the precise arrangement of three main classes of pigment cells: black melanophores, yellow xanthophores, and iridescent iridophores. The coordination of adult pigment cell lineage specification and differentiation with specific cellular interactions and morphogenetic behaviors is necessary for stripe development. Besides providing a nice example of pattern formation responsible for an adult trait of zebrafish, stripe-forming mechanisms also provide a conceptual framework for posing testable hypotheses about pattern diversification more broadly. Here, we summarize what is known about lineages and molecular interactions required for pattern formation in zebrafish, we review some of what is known about pattern diversification in Danio, and we speculate on how patterns in more distant teleosts may have evolved to produce a stunningly diverse array of patterns in nature.


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