共查询到20条相似文献,搜索用时 46 毫秒
1.
Over the past 35 years, developmental geneticists have made impressive progress
toward an understanding of how genes specify morphology and function, particularly as
they relate to the specification of each physical component of an organism. In the
last 20 years, male courtship behavior in Drosophila melanogaster
has emerged as a robust model system for the study of genetic specification of
behavior. Courtship behavior is both complex and innate, and a single gene,
fruitless (fru), is both necessary and sufficient for all aspects of the
courtship ritual. Typically, loss of male-specific Fruitless protein function results
in male flies that perform the courtship ritual incorrectly, slowly, or not at all.
Here we describe a novel requirement for fru: we have identified a group of cells in which male Fru
proteins are required to reduce the speed of courtship initiation. In addition, we
have identified a gene, Trapped in endoderm
1 (Tre1), which is required in these cells for normal courtship
and mating behavior. Tre1 encodes a G-protein-coupled receptor required for
establishment of cell polarity and cell migration and has previously not been shown
to be involved in courtship behavior. We describe the results of feminization of the
Tre1-expressing neurons, as well as the effects on courtship
behavior of mutation of Tre1. In addition, we show that Tre1 is expressed in a sexually dimorphic pattern in the
central and peripheral nervous systems and investigate the role of the
Tre1 cells in mate identification. 相似文献
2.
Takashi Okumura Takeshi Sasamura Momoko Inatomi Shunya Hozumi Mitsutoshi Nakamura Ryo Hatori Kiichiro Taniguchi Naotaka Nakazawa Emiko Suzuki Reo Maeda Tomoko Yamakawa Kenji Matsuno 《Genetics》2015,199(4):1183-1199
The class I myosin genes are conserved in diverse organisms, and their gene products are involved in actin dynamics, endocytosis, and signal transduction. Drosophila melanogaster has three class I myosin genes, Myosin 31DF (Myo31DF), Myosin 61F (Myo61F), and Myosin 95E (Myo95E). Myo31DF, Myo61F, and Myo95E belong to the Myosin ID, Myosin IC, and Myosin IB families, respectively. Previous loss-of-function analyses of Myo31DF and Myo61F revealed important roles in left–right (LR) asymmetric development and enterocyte maintenance, respectively. However, it was difficult to elucidate their roles in vivo, because of potential redundant activities. Here we generated class I myosin double and triple mutants to address this issue. We found that the triple mutant was viable and fertile, indicating that all three class I myosins were dispensable for survival. A loss-of-function analysis revealed further that Myo31DF and Myo61F, but not Myo95E, had redundant functions in promoting the dextral LR asymmetric development of the male genitalia. Myo61F overexpression is known to antagonize the dextral activity of Myo31DF in various Drosophila organs. Thus, the LR-reversing activity of overexpressed Myo61F may not reflect its physiological function. The endogenous activity of Myo61F in promoting dextral LR asymmetric development was observed in the male genitalia, but not the embryonic gut, another LR asymmetric organ. Thus, Myo61F and Myo31DF, but not Myo95E, play tissue-specific, redundant roles in LR asymmetric development. Our studies also revealed differential colocalization of the class I myosins with filamentous (F)-actin in the brush border of intestinal enterocytes. 相似文献
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Ginny R. Morriss Carmelita T. Jaramillo Crystal M. Mikolajczak Sandy Duong MaryAnn S. Jaramillo Richard M. Cripps 《Genetics》2013,195(3):927-940
wings apart (wap) is a recessive, semilethal gene located on the X chromosome in Drosophila melanogaster, which is required for normal wing-vein patterning. We show that the wap mutation also results in loss of the adult jump muscle. We use complementation mapping and gene-specific RNA interference to localize the wap locus to the proximal X chromosome. We identify the annotated gene CG14614 as the gene affected by the wap mutation, since one wap allele contains a non-sense mutation in CG14614, and a genomic fragment containing only CG14614 rescues the jump-muscle phenotypes of two wap mutant alleles. The wap gene lies centromere-proximal to touch-insensitive larva B and centromere-distal to CG14619, which is tentatively assigned as the gene affected in introverted mutants. In mutant wap animals, founder cell precursors for the jump muscle are specified early in development, but are later lost. Through tissue-specific knockdowns, we demonstrate that wap function is required in both the musculature and the nervous system for normal jump-muscle formation. wap/CG14614 is homologous to vertebrate wdr68, DDB1 and CUL4 associated factor 7, which also are expressed in neuromuscular tissues. Thus, our findings provide insight into mechanisms of neuromuscular development in higher animals and facilitate the understanding of neuromuscular diseases that may result from mis-expression of muscle-specific or neuron-specific genes. 相似文献
5.
Chromatin remodeling is crucial for gene regulation. Remodeling is often mediated through chemical modifications of the DNA template, DNA-associated proteins, and RNA-mediated processes. Y-linked regulatory variation (YRV) refers to the quantitative effects that polymorphic tracts of Y-linked chromatin exert on gene expression of X-linked and autosomal genes. Here we show that naturally occurring polymorphisms in the Drosophila melanogaster Y chromosome contribute disproportionally to gene expression variation in the testis. The variation is dependent on wild-type expression levels of mod(mdg4) as well as Su(var)205; the latter gene codes for heterochromatin protein 1 (HP1) in Drosophila. Testis-specific YRV is abolished in genotypes with heterozygous loss-of-function mutations for mod(mdg4) and Su(var)205 but not in similar experiments with JIL-1. Furthermore, the Y chromosome differentially regulates several ubiquitously expressed genes. The results highlight the requirement for wild-type dosage of Su(var)205 and mod(mdg4) in enabling naturally occurring Y-linked regulatory variation in the testis. The phenotypes that emerge in the context of wild-type levels of the HP1 and Mod(mdg4) proteins might be part of an adaptive response to the environment. 相似文献
6.
Ibrahim ?mer ?i?ek Samir Karaca Marko Brankatschk Suzanne Eaton Henning Urlaub Halyna R. Shcherbata 《Genetics》2016,202(3):1167-1183
Since the discovery of microRNAs (miRNAs) only two decades ago, they have emerged as an essential component of the gene regulatory machinery. miRNAs have seemingly paradoxical features: a single miRNA is able to simultaneously target hundreds of genes, while its presence is mostly dispensable for animal viability under normal conditions. It is known that miRNAs act as stress response factors; however, it remains challenging to determine their relevant targets and the conditions under which they function. To address this challenge, we propose a new workflow for miRNA function analysis, by which we found that the evolutionarily young miRNA family, the mir-310s (mir-310/mir-311/mir-312/mir-313), are important regulators of Drosophila metabolic status. mir-310s-deficient animals have an abnormal diet-dependent expression profile for numerous diet-sensitive components, accumulate fats, and show various physiological defects. We found that the mir-310s simultaneously repress the production of several regulatory factors (Rab23, DHR96, and Ttk) of the evolutionarily conserved Hedgehog (Hh) pathway to sharpen dietary response. As the mir-310s expression is highly dynamic and nutrition sensitive, this signal relay model helps to explain the molecular mechanism governing quick and robust Hh signaling responses to nutritional changes. Additionally, we discovered a new component of the Hh signaling pathway in Drosophila, Rab23, which cell autonomously regulates Hh ligand trafficking in the germline stem cell niche. How organisms adjust to dietary fluctuations to sustain healthy homeostasis is an intriguing research topic. These data are the first to report that miRNAs can act as executives that transduce nutritional signals to an essential signaling pathway. This suggests miRNAs as plausible therapeutic agents that can be used in combination with low calorie and cholesterol diets to manage quick and precise tissue-specific responses to nutritional changes. 相似文献
7.
Although evolutionary changes must take place in neural connectivity and synaptic architecture as nervous systems become more complex, we lack understanding of the general principles and specific mechanisms by which these changes occur. Previously, we found that morphology of the larval neuromuscular junction (NMJ) varies extensively among different species of Drosophila but is relatively conserved within a species. To identify specific genes as candidates that might underlie phenotypic differences in NMJ morphology among Drosophila species, we performed a genetic analysis on one of two phenotypic variants we found among 20 natural isolates of Drosophila melanogaster. We discovered genetic polymorphisms for both positive and negative regulators of NMJ growth segregating within the variant line. Focusing on one subline, that displayed NMJ overgrowth, we mapped the phenotype to Mob2 [Monopolar spindle (Mps) one binding protein 2)], a gene encoding a Nuclear Dbf2 (Dumbbell formation 2)-Related (NDR) kinase activator. We confirmed this identification by transformation rescue experiments and showed that presynaptic expression of Mob2 is necessary and sufficient to regulate NMJ growth. Mob2 interacts in a dominant, dose-dependent manner with tricornered but not with warts, to cause NMJ overgrowth, suggesting that Mob2 specifically functions in combination with the former NDR kinase to regulate NMJ development. These results demonstrate the feasibility and utility of identifying genetic variants affecting NMJ morphology in natural populations of Drosophila. These variants can lead to discovery of new genes and molecular mechanisms that regulate NMJ development while also providing new information that can advance our understanding of mechanisms that underlie nervous system evolution. 相似文献
8.
Jessica L. Sitnik Carmen Francis Korneel Hens Roger Huybrechts Mariana F. Wolfner Patrick Callaerts 《Genetics》2014,196(3):781-797
Members of the M13 class of metalloproteases have been implicated in diseases and in reproductive fitness. Nevertheless, their physiological role remains poorly understood. To obtain a tractable model with which to analyze this protein family’s function, we characterized the gene family in Drosophila melanogaster and focused on reproductive phenotypes. The D. melanogaster genome contains 24 M13 class protease homologs, some of which are orthologs of human proteases, including neprilysin. Many are expressed in the reproductive tracts of either sex. Using RNAi we individually targeted the five Nep genes most closely related to vertebrate neprilysin, Nep1-5, to investigate their roles in reproduction. A reduction in Nep1, Nep2, or Nep4 expression in females reduced egg laying. Nep1 and Nep2 are required in the CNS and the spermathecae for wild-type fecundity. Females that are null for Nep2 also show defects as hosts of sperm competition as well as an increased rate of depletion for stored sperm. Furthermore, eggs laid by Nep2 mutant females are fertilized normally, but arrest early in embryonic development. In the male, only Nep1 was required to induce normal patterns of female egg laying. Reduction in the expression of Nep2-5 in the male did not cause any dramatic effects on reproductive fitness, which suggests that these genes are either nonessential for male fertility or perform redundant functions. Our results suggest that, consistent with the functions of neprilysins in mammals, these proteins are also required for reproduction in Drosophila, opening up this model system for further functional analysis of this protein class and their substrates. 相似文献
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Francesca Cipressa Sabrina Romano Silvia Centonze Petra I. zur Lage Fiammetta Vernì Patrizio Dimitri Maurizio Gatti Giovanni Cenci 《Genetics》2013,195(1):147-158
Drosophila telomeres are elongated by the transposition of telomere-specific retrotransposons rather than telomerase activity. Proximal to the terminal transposon array, Drosophila chromosomes contain several kilobases of a complex satellite DNA termed telomere-associated sequences (TASs). Reporter genes inserted into or next to the TAS are silenced through a mechanism called telomere position effect (TPE). TPE is reminiscent of the position effect variegation (PEV) induced by Drosophila constitutive heterochromatin. However, most genes that modulate PEV have no effect on TPE, and systematic searches for TPE modifiers have so far identified only a few dominant suppressors. Surprisingly, only a few of the genes required to prevent telomere fusion have been tested for their effect on TPE. Here, we show that with the exception of the effete (eff; also called UbcD1) mutant alleles, none of the tested mutations at the other telomere fusion genes affects TPE. We also found that mutations in eff, which encodes a class I ubiquitin-conjugating enzyme, act as suppressors of PEV. Thus, eff is one of the rare genes that can modulate both TPE and PEV. Immunolocalization experiments showed that Eff is a major constituent of polytene chromosomes. Eff is enriched at several euchromatic bands and interbands, the TAS regions, and the chromocenter. Our results suggest that Eff associates with different types of chromatin affecting their abilities to regulate gene expression. 相似文献
11.
Michael Visser Sofiya N. Parshina Joana I. Alves Diana Z. Sousa Inês A. C. Pereira Gerard Muyzer Jan Kuever Alexander V. Lebedinsky Jasper J. Koehorst Petra Worm Caroline M. Plugge Peter J. Schaap Lynne A. Goodwin Alla Lapidus Nikos C. Kyrpides Janine C. Detter Tanja Woyke Patrick Chain Karen W. Davenport Stefan Spring Manfred Rohde Hans Peter Klenk Alfons J.M. Stams 《Standards in genomic sciences》2014,9(3):655-675
12.
Mohamed Sassi Catherine Robert Didier Raoult Michel Drancourt 《Standards in genomic sciences》2013,8(2):306-317
Mycobacterium simiae is a non-tuberculosis mycobacterium causing pulmonary infections in both immunocompetent and imunocompromized patients. We announce the draft genome sequence of M. simiae DSM 44165T. The 5,782,968-bp long genome with 65.15% GC content (one chromosome, no plasmid) contains 5,727 open reading frames (33% with unknown function and 11 ORFs sizing more than 5000 -bp), three rRNA operons, 52 tRNA, one 66-bp tmRNA matching with tmRNA tags from Mycobacterium avium, Mycobacterium tuberculosis, Mycobacterium bovis, Mycobacterium microti, Mycobacterium marinum, and Mycobacterium africanum and 389 DNA repetitive sequences. Comparing ORFs and size distribution between M. simiae and five other Mycobacterium species M. simiae clustered with M. abscessus and M. smegmatis. A 40-kb prophage was predicted in addition to two prophage-like elements, 7-kb and 18-kb in size, but no mycobacteriophage was seen after the observation of 106
M. simiae cells. Fifteen putative CRISPRs were found. Three genes were predicted to encode resistance to aminoglycosides, betalactams and macrolide-lincosamide-streptogramin B. A total of 163 CAZYmes were annotated. M. simiae contains ESX-1 to ESX-5 genes encoding for a type-VII secretion system. Availability of the genome sequence may help depict the unique properties of this environmental, opportunistic pathogen. 相似文献
13.
Laura Tatjer Almudena Sacristán-Reviriego Carlos Casado Asier González Boris Rodríguez-Porrata Lorena Palacios David Canadell Albert Serra-Cardona Humberto Martín María Molina Joaquín Ari?o 《Genetics》2016,202(1):141-156
The Saccharomyces cerevisiae type 2C protein phosphatase Ptc1 is required for a wide variety of cellular functions, although only a few cellular targets have been identified. A genetic screen in search of mutations in protein kinase–encoding genes able to suppress multiple phenotypic traits caused by the ptc1 deletion yielded a single gene, MKK1, coding for a MAPK kinase (MAPKK) known to activate the cell-wall integrity (CWI) Slt2 MAPK. In contrast, mutation of the MKK1 paralog, MKK2, had a less significant effect. Deletion of MKK1 abolished the increased phosphorylation of Slt2 induced by the absence of Ptc1 both under basal and CWI pathway stimulatory conditions. We demonstrate that Ptc1 acts at the level of the MAPKKs of the CWI pathway, but only the Mkk1 kinase activity is essential for ptc1 mutants to display high Slt2 activation. We also show that Ptc1 is able to dephosphorylate Mkk1
in vitro. Our results reveal the preeminent role of Mkk1 in signaling through the CWI pathway and strongly suggest that hyperactivation of Slt2 caused by upregulation of Mkk1 is at the basis of most of the phenotypic defects associated with lack of Ptc1 function. 相似文献
14.
《Standards in genomic sciences》2013,8(2):228-238
Turneriella parva Levett et al. 2005 is the only species of the genus Turneriella which was established as a result of the reclassification of Leptospira parva Hovind-Hougen et al. 1982. Together with Leptonema and Leptospira, Turneriella constitutes the family Leptospiraceae, within the order Spirochaetales. Here we describe the features of this free-living aerobic spirochete together with the complete genome sequence and annotation. This is the first complete genome sequence of a member of the genus Turneriella and the 13th member of the family Leptospiraceae for which a complete or draft genome sequence is now available. The 4,409,302 bp long genome with its 4,169 protein-coding and 45 RNA genes is part of the Genomic
Encyclopedia of
Bacteria and
Archaea project. 相似文献
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Wanzhong Ge Qiannan Deng Ting Guo Xin Hong Jan-Michael Kugler Xiaohang Yang Stephen M. Cohen 《Genetics》2015,200(1):255-265
Pattern formation during epithelial development requires the coordination of multiple signaling pathways. Here, we investigate the functions of an ovary-enriched miRNA, miR-318, in epithelial development during Drosophila oogenesis. mir-318 maternal loss-of-function mutants were female-sterile and laid eggs with abnormal morphology. Removal of mir-318 disrupted the dorsal–anterior follicle cell patterning, resulting in abnormal dorsal appendages. mir-318 mutant females also produced thin and fragile eggshells due to impaired chorion gene amplification. We provide evidence that the ecdysone signaling pathway activates expression of miR-318 and that miR-318 cooperates with Tramtrack69 to control the switch from endocycling to chorion gene amplification during differentiation of the follicular epithelium. The multiple functions of miR-318 in oogenesis illustrate the importance of miRNAs in maintaining cell fate and in promoting the developmental transition in the female follicular epithelium. 相似文献
17.
PHA-1 encodes a cytoplasmic protein that is required for embryonic morphogenesis and attachment of the foregut (pharynx) to the mouth (buccal capsule). Previous reports have in some cases suggested that PHA-1 is essential for the differentiation of most or all pharyngeal cell types. By performing mosaic analysis with a recently acquired pha-1 null mutation (tm3671), we found that PHA-1 is not required within most or all pharyngeal cells for their proper specification, differentiation, or function. Rather, our evidence suggests that PHA-1 acts in the arcade or anterior epithelial cells of the pharynx to promote attachment of the pharynx to the future buccal capsule. In addition, PHA-1 appears to be required in the epidermis for embryonic morphogenesis, in the excretory system for osmoregulation, and in the somatic gonad for normal ovulation and fertility. PHA-1 activity is also required within at least a subset of intestinal cells for viability. To better understand the role of PHA-1 in the epidermis, we analyzed several apical junction markers in pha-1(tm3671) homozygous embryos. PHA-1 regulates the expression of several components of two apical junction complexes including AJM-1–DLG-1/discs large complex and the classical cadherin–catenin complex, which may account for the role of PHA-1 in embryonic morphogenesis. 相似文献
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Johannes Menzel Mackenzie E. Malo Cynthia Chan Martin Prusinkiewicz Terra G. Arnason Troy A. A. Harkness 《Genetics》2014,196(3):693-709
Genomic stability, stress response, and nutrient signaling all play critical, evolutionarily conserved roles in lifespan determination. However, the molecular mechanisms coordinating these processes with longevity remain unresolved. Here we investigate the involvement of the yeast anaphase promoting complex (APC) in longevity. The APC governs passage through M and G1 via ubiquitin-dependent targeting of substrate proteins and is associated with cancer and premature aging when defective. Our two-hybrid screen utilizing Apc5 as bait recovered the lifespan determinant Fob1 as prey. Fob1 is unstable specifically in G1, cycles throughout the cell cycle in a manner similar to Clb2 (an APC target), and is stabilized in APC (apc5CA) and proteasome (rpn10∆) mutants. Deletion of FOB1 increased replicative lifespan (RLS) in wild type (WT), apc5CA, and apc10∆ cells, and suppressed apc5CA cell cycle progression and rDNA recombination defects. Alternatively, increased FOB1 expression decreased RLS in WT cells, but did not reduce the already short apc5CA RLS, suggesting an epistatic interaction between apc5CA and fob1∆. Mutation to a putative L-Box (Fob1E420V), a Destruction Box-like motif, abolished Fob1 modifications, stabilized the protein, and increased rDNA recombination. Our work provides a mechanistic role played by the APC to promote replicative longevity and genomic stability in yeast. 相似文献
20.
Erica Walkinshaw Yunchao Gai Caitlin Farkas Daniel Richter Eric Nicholas Krystyna Keleman Ronald L. Davis 《Genetics》2015,199(4):1173-1182
Genetic screens in Drosophila melanogaster and other organisms have been pursued to filter the genome for genetic functions important for memory formation. Such screens have employed primarily chemical or transposon-mediated mutagenesis and have identified numerous mutants including classical memory mutants, dunce and rutabaga. Here, we report the results of a large screen using panneuronal RNAi expression to identify additional genes critical for memory formation. We identified >500 genes that compromise memory when inhibited (low hits), either by disrupting the development and normal function of the adult animal or by participating in the neurophysiological mechanisms underlying memory formation. We also identified >40 genes that enhance memory when inhibited (high hits). The dunce gene was identified as one of the low hits and further experiments were performed to map the effects of the dunce RNAi to the α/β and γ mushroom body neurons. Additional behavioral experiments suggest that dunce knockdown in the mushroom body neurons impairs memory without significantly affecting acquisition. We also characterized one high hit, sickie, to show that RNAi knockdown of this gene enhances memory through effects in dopaminergic neurons without apparent effects on acquisition. These studies further our understanding of two genes involved in memory formation, provide a valuable list of genes that impair memory that may be important for understanding the neurophysiology of memory or neurodevelopmental disorders, and offer a new resource of memory suppressor genes that will aid in understanding restraint mechanisms employed by the brain to optimize resources. 相似文献