Interaction Between The MEC1-Dependent DNA Synthesis Checkpoint And G1 Cyclin Function In Saccharomyces Cerevisiae

The completion of DNA synthesis in yeast is monitored by a checkpoint that requires MEC1 and RAD53. Here we show that deletion of the Saccharomyces cerevisiae G1 cyclins CLN1 and CLN2 suppressed the essential requirement for MEC1 function. Wild-type levels of CLN1 and CLN2, or overexpression of CLN1, CLN2, or CLB5, but not CLN3, killed mec1 strains. We identified RNR1, which encodes a subunit of ribonucleotide reductase, as a high-copy suppressor of the lethality of mec1 GAL1-CLN1. Northern analysis demonstrated that RNR1 expression is reduced by CLN1 or CLN2 overexpression. Because limiting RNR1 expression would be expected to decrease dNTP pools, CLN1 and CLN2 may cause lethality in mec1 strains by causing initiation of DNA replication with inadequate dNTPs. In contrast to mec1 mutants, MEC1 strains with low dNTPs would be able to delay S phase and thereby remain viable. We propose that the essential function for MEC1 may be the same as its checkpoint function during hydroxyurea treatment, namely, to slow S phase when nucleotides are limiting. In a cln1 cln2 background, a prolonged period of expression of genes turned on at the G1-S border, such as RNR1, has been observed. Thus deletion of CLN1 and CLN2 could function similarly to overexpression of RNR1 in suppressing mec1 lethality

Pengembangan Industri Pengolahan Kayu Sebagai Upaya Pengembangan Ekonomi Lokal (Studi Pada Desa Sukorejo, Kecamatan Bojonegoro, Kabupaten Bojonegoro)

: Development of Wood Processing Industry as a Local Economic Development Efforts (Study at Sukorejo, Kecamatan Bojonegoro, Kabupaten Bojonegoro). Wood processing industry center is quite commonly found in Bojonegoro, one of the place is located in Sukorejo Village. It is stated in the “Rencana Pembangunan Jangka Menengah Daerah” (RPJMD) 2013-2018 Bojonegoro, related to the development of potential industrial sectors, one of them is the wood processing industry. This study aims to describe and identify Development of Wood Processing Industry as a Local Economic Development Efforts in Sukorejo Village. This type of research is descriptive with qualitative approach belongs to Miles, Hubberman and Saldana. The result of the development has been successful. But the work program is still needed in order to training and coaching the craftsmen. And also, it takes more intensive communication to the craftsmen from the stakeholder

Mutations In RAD27 Define A Potential Link Between G₁ Cyclins And DNA Replication

The yeast Saccharomyces cerevisiae has three G1 cyclin (CLN) genes with overlapping functions. To analyze the functions of the various CLN genes, we examined mutations that result in lethality in conjunction with loss of cln1 and cln2. We have isolated alleles of RAD27/ERC11/YKL510, the yeast homolog of the gene encoding flap endonuclease 1, FEN-1.cln1 cln2 rad27/erc11 cells arrest in S phase; this cell cycle arrest is suppressed by the expression of CLN1 or CLN2 but not by that of CLN3 or the hyperactive CLN3-2. rad27/erc11 mutants are also defective in DNA damage repair, as determined by their increased sensitivity to a DNA-damaging agent, increased mitotic recombination rates, and increased spontaneous mutation rates. Unlike the block in cell cycle progression, these phenotypes are not suppressed by CLN1 or CLN2. CLN1 and CLN2 may activate an RAD27/ERC11-independent pathway specific for DNA synthesis that CLN3 is incapable of activating. Alternatively, CLN1 and CLN2 may be capable of overriding a checkpoint response which otherwise causes cln1 cln2 rad27/erc11 cells to arrest. These results imply that CLN1 and CLN2 have a role in the regulation of DNA replication. Consistent with this, GAL-CLN1 expression in checkpoint-deficient, mec1-1 mutant cells results in both cell death and increased chromosome loss among survivors, suggesting that CLN1 overexpression either activates defective DNA replication or leads to insensitivity to DNA damage

Roles Of Hof1p, Bni1p, Bnr1p, And Myo1p In Cytokinesis In Saccharomyces Cerevisiae

Cytokinesis in Saccharomyces cerevisiae occurs by the concerted action of the actomyosin system and septum formation. Here we report on the roles of HOF1,BNI1, and BNR1 in cytokinesis, focusing on Hof1p. Deletion of HOF1 causes a temperature-sensitive defect in septum formation. A Hof1p ring forms on the mother side of the bud neck in G2/M, followed by the formation of a daughter-side ring. Around telophase, Hof1p is phosphorylated and the double rings merge into a single ring that contracts slightly and may colocalize with the actomyosin structure. Upon septum formation, Hof1p splits into two rings, disappearing upon cell separation. Hof1p localization is dependent on septins but not Myo1p. Synthetic lethality suggests that Bni1p and Myo1p belong to one functional pathway, whereas Hof1p and Bnr1p belong to another. These results suggest that Hof1p may function as an adapter linking the primary septum synthesis machinery to the actomyosin system. The formation of the actomyosin ring is not affected by bni1Δ, hof1Δ, orbnr1Δ. However, Myo1p contraction is affected bybni1Δ but not by hof1Δ orbnr1Δ. In bni1Δ cells that lack the actomyosin contraction, septum formation is often slow and asymmetric, suggesting that actomyosin contraction may provide directionality for efficient septum formation

Ethical Challenges of the Industry: Are Graduates Prepared?

Hospitality graduates often enter their first jobs unaware of the difficult ethical dilemmas they will face. By having ethics teaching in a curriculum, the authors of this article believe that the perceptions of ethics of senior hospitality students at Northern Arizona University were comparable to those of operating industry managers

Peranan Kepemimpinan Camat dalam Implementasi Program Nasional Pemberdayaan Masyarakat (PNPM) Mandiri di Kecamatan Pasan Kabupaten Minahasa Tenggara

The chief of a district as district leader is either one perpetrators of PNPM Mandiri in thedistrict as a founder execution PNPM Mandiri to the villages in the district area. That iswhy the role district leadership on the implementation PNPM Mandiri in the district to bevery important and to determine. In connection with that's thing then this researchintended to answer the question how the role of district leadership on the implementationPNPM Mandiri in the Pasan District Southeast Minahasa Regency.Based on literature review then the role of district leadership on the implementationPNPM Mandiri viewed from three activity the chief of a district as a founder executionPNPM Mandiri in the district are the role to socialize program with build and direct theperpetrators PNPM Mandiri in the district and village; the role of coordinate plan andexecution a program PNPM Mandiri in the villages; and the role to control execution aprogram PNPM Mandiri in the villages.This research used qualitative method. Data source/informant take from theperpetrators unsure PNPM Mandiri in the district level and in the village level, are 14peoples. Data collection used interview technique. Whereas data analyze used techniquequalitative analyze interactive mode by Miles and Hubernan.The result of the research to showed : (1) the chief of a district's role to socialize aprogram with build and direct the perpetrators PNPM Mandiri in the district level andvillages in the Pasan District area can be performed effectively; (2) the chief of a district'srole to coordinate plan and execution a program PNPM Mandiri in the villages in thePasan District area can be performed effectively; (3) the chief of a district's role to controlexecution a program PNPM Mandiri in the villages in the Pasan District area can beperformed effectively.Based on the result of that research deduced role of the chief of a district'sleadership on the implementation PNPM Mandiri in the district already can be realized byeffective in the Pasan District Southeast Minahasa.Based on the result of this research then suggested that the chief of a district'sleadership on the implementation PNPM Mandiri in the Pasan District still needs to beimproved so it becomes more effective

Immobile Myosin-II Plays A Scaffolding Role During Cytokinesis In Budding Yeast

Core components of cytokinesis are conserved from yeast to human, but how these components are assembled into a robust machine that drives cytokinesis remains poorly understood. In this paper, we show by fluorescence recovery after photobleaching analysis that Myo1, the sole myosin-II in budding yeast, was mobile at the division site before anaphase and became immobilized shortly before cytokinesis. This immobility was independent of actin filaments or the motor domain of Myo1 but required a small region in the Myo1 tail that is thought to be involved in higher-order assembly. As expected, proteins involved in actin ring assembly (tropomyosin and formin) and membrane trafficking (myosin-V and exocyst) were dynamic during cytokinesis. Strikingly, proteins involved in septum formation (the chitin synthase Chs2) and/or its coordination with the actomyosin ring (essential light chain, IQGAP, F-BAR, etc.) displayed Myo1-dependent immobility during cytokinesis, suggesting that Myo1 plays a scaffolding role in the assembly of a cytokinesis machine

Active Learning Outside The Classroom: Implementation And Outcomes Of Peer-Led Team-Learning Workshops In Introductory Biology

Study group meetings (SGMs) are voluntary-attendance peer-led team-learning workshops that supplement introductory biology lectures at a selective liberal arts college. While supporting all students’ engagement with lecture material, specific aims are to improve the success of underrepresented minority (URM) students and those with weaker backgrounds in biology. Peer leaders with experience in biology courses and training in science pedagogy facilitate work on faculty-generated challenge problems. During the eight semesters assessed in this study, URM students and those with less preparation attended SGMs with equal or greater frequency than their counterparts. Most agreed that SGMs enhanced their comprehension of biology and ability to articulate solutions. The historical grade gap between URM and non-URM students narrowed slightly in Biology 2, but not in other biology and science, technology, engineering, and mathematics courses. Nonetheless, URM students taking introductory biology after program implementation have graduated with biology majors or minors at the same rates as non-URM students, and have enrolled in postcollege degree programs at equal or greater rates. These results suggest that improved performance as measured by science grade point average may not be necessary to improve the persistence of students from underrepresented groups as life sciences majors

Trehalose Is A Chemical Attractant In The Establishment Of Coral Symbiosis

Coral reefs have evolved with a crucial symbiosis between photosynthetic dinoflagellates (genus Symbiodinium) and their cnidarian hosts (Scleractinians). Most coral larvae take up Symbiodinium from their environment; however, the earliest steps in this process have been elusive. Here we demonstrate that the disaccharide trehalose may be an important signal from the symbiont to potential larval hosts. Symbiodinium freshly isolated from Fungia scutaria corals constantly released trehalose (but not sucrose, maltose or glucose) into seawater, and released glycerol only in the presence of coral tissue. Spawning Fungia adults increased symbiont number in their immediate area by excreting pellets of Symbiodinium, and when these naturally discharged Symbiodinium were cultured, they also released trehalose. In Y-maze experiments, coral larvae demonstrated chemoattractant and feeding behaviors only towards a chamber with trehalose or glycerol. Concomitantly, coral larvae and adult tissue, but not symbionts, had significant trehalase enzymatic activities, suggesting the capacity to utilize trehalose. Trehalase activity was developmentally regulated in F. scutaria larvae, rising as the time for symbiont uptake occurs. Consistent with the enzymatic assays, gene finding demonstrated the presence of a trehalase enzyme in the genome of a related coral, Acropora digitifera, and a likely trehalase in the transcriptome of F. scutaria. Taken together, these data suggest that adult F. scutaria seed the reef with Symbiodinium during spawning and the exuded Symbiodinium release trehalose into the environment, which acts as a chemoattractant for F. scutaria larvae and as an initiator of feeding behavior- the first stages toward establishing the coral-Symbiodinium relationship. Because trehalose is a fixed carbon compound, this cue would accurately demonstrate to the cnidarian larvae the photosynthetic ability of the potential symbiont in the ambient environment. To our knowledge, this is the first report of a chemical cue attracting the motile coral larvae to the symbiont