Future Fates Research Articles

Molecular live cell bioimaging in stem cell research

Functional heterogeneity within stem and progenitor cells has been shown to influence cell fate decisions. Similarly, intracellular signaling activated by external stimuli is highly heterogeneous and its spatiotemporal activity is linked to future cell behavior. To quantify these heterogeneous states and link them to future cell fates, it is important to observe cell populations continuously with single cell resolution. Live cell imaging in combination with fluorescent biosensors for signaling activity serves as a powerful tool to study cellular and molecular heterogeneity and the long-term biological effects of signaling. Here, we describe these methodologies, their advantages over classical approaches, and we illustrate how they could be applied to improve our understanding of the importance of heterogeneous cellular and molecular responses to external signaling cues.

RNA granules: post-transcriptional and epigenetic modulators of gene expression

The composition of cytoplasmic messenger ribonucleoproteins (mRNPs) is determined by their nuclear and cytoplasmic histories and reflects past functions and future fates. The protein components of selected mRNP complexes promote their assembly into microscopically visible cytoplasmic RNA granules, including stress granules, processing bodies and germ cell (or polar) granules. We propose that RNA granules can be both a cause and a consequence of altered mRNA translation, decay or editing. In this capacity, RNA granules serve as key modulators of post-transcriptional and epigenetic gene expression.

Climatic change, refugia, and biodiversity: where do we go from here? An editorial comment

Climate change in the coming century will affect biodiversity at many biological levels, ranging from ecosystems to genes. Forecasting the effects of these changes, especially in the context of which species will be restricted to refugia and/or prone to extinction, is taking on increasing importance. Enhanced integration of phylogeography with phylochronology, paleontological and geological data, and climate science (especially taking into account scales of climate change other than orbitally-induced glacial–interglacial cycles) is needed to more fully appreciate the genetic effects of past climate changes, and to help predict future fates of species.

Centaurs - can they enrich the halley type comets population ?

2060 Chiron (95P/Chiron) is the first known object of the entire class called Centaurs. Since the day of the discovery many papers have discussed its past and future fates. Up to now, Centaurs were perceived as a evolutionary stage between Kuiper Belt Objects and the Jupiter Family comets. Other types of dynamical evolution were not widely discussed in previous works. This paper shows there is a possibility that Chiron's and other Centaurs present orbits can evolve into Halley Type comets orbits and this type of dynamical evolution is significant.

Regulation of dorsal-ventral patterning: the ventralizing effects of the novel Xenopus homeobox gene Vox.

The formation of the dorsal-ventral axis in Xenopus laevis is elicited by a signaling cascade on the dorsal side of the embryo initiated by cortical rotation. These early developmental events impart an initial axial polarity to the embryo. By the time gastrulation occurs, the embryo has established opposing dorsal and ventral regulatory regions. Through a dynamic process, the embryo acquires a definitive pattern that reflects the distribution of future cell fates. Here we present a novel homeobox gene, Vox, whose expression reflects this dynamic process. Vox is first expressed throughout the embryo and subsequently eliminated from the notochord and neural plate. Ectopic expression of Vox demonstrates that the normal function of this gene may be to suppress dorsal genes such as Xnot and chordin, and induce ventral and paraxial genes such as Bmp-4 and MyoD. Ectopic expression of BMP-4 ventralizes embryos and positively regulates the expression of Vox, suggesting that these genes are components of a reciprocal regulatory network.

Cell movements and cell fate during zebrafish gastrulation

The early lineages of the zebrafish are indeterminate and a single cell labeled before the late blastula period will contribute progeny to a variety of tissues. Therefore, early cell lineages in the zebrafish do not establish future cell fates and early blastomeres must necessarily remain pluripotent. Eventually, after a period of random cell mixing, individual cells do become tissue restricted according to their later position within the blastoderm. The elucidation of a fate map for the zebrafish gastrula (Kimmel et al., 1990), has made it possible to study the processes by which cellular identity is conferred and maintained in the zebrafish. In this chapter, I describe single cell transplantation experiments designed to test for the irreversible restriction or 'commitment' of embryonic blastomeres in the zebrafish embryo. These experiments support the hypothesis that cell fate in the vertebrate embryo is determined by cell position. Work on the spadetail mutation will also be reviewed; this mutation causes a subset of mesodermal precursors to mismigrate during gastrulation thereby leading to a change in their eventual cell identity.

Defective ommatidial cell assembly leads to defective morphogenesis: a phenotypic analysis of the E(spl) D mutation of Drosophila melanogaster.

The spl mutation of the N gene causes, among other phenotypic traits, the lack of a few ommatidia, roughness and a general reduction in the size of the compound eye; these defects are drastically enhanced by the dominant mutation E(spl) D. We have studied cellular and developmental aspects of the phenotypic interaction between spl and E(spl) D. We found that the initial clustering of photoreceptor cells is affected in eye imaginal discs of spl larvae causing the defects visible in the adult eye. The degree of disorganization of the spl/Y; E(spl) D/ + eye disc is much higher, only a few photoreceptor cells are able to group with representatives of the other cell types and differentiate normally. BrdU incorporation shows that the proliferation pattern of the spl/Y; E(spl) D/ + disc cells during the third instar is normal. Abundant cell death occurs posteriorly in the mutant discs, which accounts for their small size. Finally, we found that in the eye imaginal disc the transcription of m8, the E(spl) gene, responsible for the enhancement of the spl phenotype caused by the E(spl) D mutation, is restricted to the morphogenetic furrow, where the ommatidial cells start grouping with each other to take on their future developmental fates; the m8 transcription rate is highly increased in E(spl) D eye discs. All these observations indicate that the assembly of the ommatidial cells is affected in the spl/Y; E(spl) D/ + disc and that the other abnormalities are morphogenetic consequences of the defective cell grouping.

Carbon balance of Alaskan tundra and taiga ecosystems: past, present and future

During the Holocene, a great amount of carbon has been stored in the peaty soils beneath the wet coastal tundra at Barrow, Alaska, and in the wet peatlands of the bottomland taiga near Fairbanks, Alaska. On the basis of fossil pollen, plant macrofossil spectra, and present vegetation, an attempt is made to estimate rough carbon budgets for the present and during the last 5000 years at these sites. Carbon capture and carbon accumulation rates have varied cyclically in the past at both sites. However, both tundra and taiga have remained sinks for atmospheric CO 2 through this time. In view of the probable warming of these climates due to increasing atmospheric CO 2 concentrations, future fates of this carbon, now stored in permafrost, are in doubt. Future carbon balances may be quite different from those that have prevailed during the Holocene and at present. These ecosystems may well become carbon sources rather than remain carbon sinks. The use of field and phytotron simulation experiments is suggested as well as the use of mathematical models in attempting to predict the future of these carbon-rich ecosystems in the 21st and 22nd centuries.

The Determination of the Neural Plate in Urodeles

Previous articleNext article No AccessThe Determination of the Neural Plate in UrodelesFrancis G. GilchristFrancis G. Gilchrist Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by The Quarterly Review of Biology Volume 4, Number 4Dec., 1929 Published in association with Stony Brook University Article DOIhttps://doi.org/10.1086/394346 Citations: 7Citations are reported from Crossref PDF download Crossref reports the following articles citing this article:Mabel C. Paterson Animal-vegetal balance in amphibian development, Journal of Experimental Zoology 134, no.11 (Feb 1957): 183–205.https://doi.org/10.1002/jez.1401340110K. R. PORTER DIPLOID AND ANDROGENETIC HAPLOID HYBRIDIZATION BETWEEN TWO FORMS OF RANA PIPIENS, SCHREBER, The Biological Bulletin 80, no.22 (Sep 2016): 238–264.https://doi.org/10.2307/1537601A. Mandel Schbchtman Relation between the grey crescent and the organizer center of a urodele egg (Triturus torosus), Wilhelm Roux' Archiv f�r Entwicklungsmechanik der Organismen 134, no.11 (Jan 1936): 207–208.https://doi.org/10.1007/BF00573471Francis G. Gilchrist The time relations of determinations in early amphibian development, Journal of Experimental Zoology 66, no.11 (Aug 1933): 15–51.https://doi.org/10.1002/jez.1400660103 Kathryn F. Stein The Location and Differentiation of the Presumptive Ectoderm of the Forebrain and Hypophysis as Shown by Chorio-Allantoic Grafts, Physiological Zoology 6, no.22 (Sep 2015): 205–235.https://doi.org/10.1086/physzool.6.2.30151197Walter Altekr�ger �ber den Einfluss experimentell erzeugter Form�nderungen auf die Induktionsf�higkeit von Organisatoren, Wilhelm Roux' Archiv f�r Entwicklungsmechanik der Organismen 126, no.11 (Jan 1932): 1–18.https://doi.org/10.1007/BF00586373Gerhard Fankhauser Die Entwicklungspotenzen diploidkerniger H�lften des ungefurchten Tritoneies, Wilhelm Roux' Archiv f�r Entwicklungsmechanik der Organismen 122, no.44 (Jan 1930): 671–735.https://doi.org/10.1007/BF00575208