The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Understanding the mechanisms underlying the morphological divergence of species is one of the central goals of evolutionary biology. Here, we analyze the genetic and molecular bases of the divergence of body pigmentation patterns between Drosophila yakuba and its sister species Drosophila santomea. We found that loss of pigmentation in D. santomea involved the selective loss of expression of the tan...
Toward the end of mitosis, neighboring chromosomes gather closely to form a compact cluster. This is important for reassembling the nuclear envelope around the entire chromosome mass but not individual chromosomes. By analyzing mice and cultured cells lacking the expression of chromokinesin Kid/kinesin-10, we show that Kid localizes to the boundaries of anaphase and telophase chromosomes and contributes...
To explore the role of Dicer-dependent control mechanisms in B lymphocyte development, we ablated this enzyme in early B cell progenitors. This resulted in a developmental block at the pro- to pre-B cell transition. Gene-expression profiling revealed a miR-17∼92 signature in the 3′UTRs of genes upregulated in Dicer-deficient pro-B cells; a top miR-17∼92 target, the proapoptotic molecule Bim, was highly...
Complex organisms require tissue-specific transcriptional programs, yet little is known about how these are established. The transcription factor FoxA1 is thought to contribute to gene regulation through its ability to act as a pioneer factor binding to nucleosomal DNA. Through genome-wide positional analyses, we demonstrate that FoxA1 cell type-specific functions rely primarily on differential recruitment...
Insulin/IGF-1-like signaling (IIS) is central to growth and metabolism and has a conserved role in aging. In C. elegans, reductions in IIS increase stress resistance and longevity, effects that require the IIS-inhibited FOXO protein DAF-16. The C. elegans transcription factor SKN-1 also defends against oxidative stress by mobilizing the conserved phase 2 detoxification response. Here we show that...
Trans-acting siRNA form through a refined RNAi mechanism in plants. miRNA-guided cleavage triggers entry of precursor transcripts into an RNA-DEPENDENT RNA POLYMERASE6 pathway, and sets the register for phased tasiRNA formation by DICER-LIKE4. Here, we show that miR390-ARGONAUTE7 complexes function in distinct cleavage or noncleavage modes at two target sites in TAS3a transcripts. The AGO7 cleavage,...
Plants have evolved a tremendous ability to respond to environmental changes by adapting their growth and development. The interaction between hormonal and developmental signals is a critical mechanism in the generation of this enormous plasticity. A good example is the response to the hormone ethylene that depends on tissue type, developmental stage, and environmental conditions. By characterizing...
Plants grown at high densities perceive a decrease in the red to far-red (R:FR) ratio of incoming light, resulting from absorption of red light by canopy leaves and reflection of far-red light from neighboring plants. These changes in light quality trigger a series of responses known collectively as the shade avoidance syndrome. During shade avoidance, stems elongate at the expense of leaf and storage...
To fully understand animal transcription networks, it is essential to accurately measure the spatial and temporal expression patterns of transcription factors and their targets. We describe a registration technique that takes image-based data from hundreds of Drosophila blastoderm embryos, each costained for a reference gene and one of a set of genes of interest, and builds a model VirtualEmbryo....
Canonical Wnt signaling critically regulates cell fate and proliferation in development and disease. Nuclear localization of β-catenin is indispensable for canonical Wnt signaling; however, the mechanisms governing β-catenin nuclear localization are not well understood. Here we demonstrate that nuclear accumulation of β-catenin in response to Wnt requires Rac1 activation. The role of Rac1 depends...
Astrocytes constitute the most abundant cell type in the central nervous system (CNS) and play diverse functional roles, but the ontogenetic origins of this phenotypic diversity are poorly understood. We have investigated whether positional identity, a fundamental organizing principle governing the generation of neuronal subtype diversity, is also relevant to astrocyte diversification. We identified...
Dosage compensation, mediated by the MSL complex, regulates X-chromosomal gene expression in Drosophila. Here we report that the histone H4 lysine 16 (H4K16) specific histone acetyltransferase MOF displays differential binding behavior depending on whether the target gene is located on the X chromosome versus the autosomes. More specifically, on the male X chromosome, where MSL1 and MSL3 are preferentially...
The timing mechanisms responsible for terminating cell proliferation toward the end of development remain unclear. In the Drosophila CNS, individual progenitors called neuroblasts are known to express a series of transcription factors endowing daughter neurons with different temporal identities. Here we show that Castor and Seven-Up, members of this temporal series, regulate key events in many different...
A significant proportion of neurons in the brain undergo programmed cell death. In order to prevent the diffusion of damaging degradation products, dying neurons are quickly digested by microglia. Despite the importance of microglia in several neuronal pathologies, the mechanism underlying their degradation of neurons remains elusive. Here, we exploit a microglial population in the zebrafish to study...
During gastrulation of the amphibian embryo, specification of the three germ layers, endo-, ecto-, and mesoderm, is regulated by maternal and zygotic mechanisms. Although it is known that mesoderm specification requires the cooperation between TGF-β signaling and p53 activity and requires maternal factors, essential zygotic factors have been elusive. Here, we report that the Zn-finger protein XFDL156...
VAP proteins (human VAPB/ALS8, Drosophila VAP33, and C. elegans VPR-1) are homologous proteins with an amino-terminal major sperm protein (MSP) domain and a transmembrane domain. The MSP domain is named for its similarity to the C. elegans MSP protein, a sperm-derived hormone that binds to the Eph receptor and induces oocyte maturation. A point mutation (P56S) in the MSP domain of human VAPB is associated...
Acquisition of planar cell polarity (PCP) in epithelia involves intercellular communication, during which cells align their polarity with that of their neighbors. The transmembrane proteins Frizzled (Fz) and Van Gogh (Vang) are essential components of the intercellular communication mechanism, as loss of either strongly perturbs the polarity of neighboring cells. How Fz and Vang communicate polarity...
Pluripotency is a unique biological state that allows cells to differentiate into any tissue type. Here we describe a candidate pluripotency factor, Ronin, that possesses a THAP domain, which is associated with sequence-specific DNA binding and epigenetic silencing of gene expression. Ronin is expressed primarily during the earliest stages of murine embryonic development, and its deficiency in mice...
The mammalian circadian timing system is composed of a central pacemaker in the suprachiasmatic nucleus of the brain that synchronizes countless subsidiary oscillators in peripheral tissues. The rhythm-generating mechanism is thought to rely on a feedback loop involving positively and negatively acting transcription factors. BMAL1 and CLOCK activate the expression of Period (Per) and Cryptochrome...
The precision with which motor neurons innervate target muscles depends on a regulatory network of Hox transcription factors that translates neuronal identity into patterns of connectivity. We show that a single transcription factor, FoxP1, coordinates motor neuron subtype identity and connectivity through its activity as a Hox accessory factor. FoxP1 is expressed in Hox-sensitive motor columns and...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.