The Spo13/Meikin pathway confines the onset of gamete differentiation to meiosis II in yeast

Sexual reproduction requires genome haploidization by the two divisions of meiosis and a differentiation program to generate gametes. Here, we have investigated how sporulation, the yeast equivalent of gamete differentiation, is coordinated with progression through meiosis. Spore differentiation is initiated at metaphase II when a membrane-nucleating structure, called the meiotic plaque, is assembled at the centrosome. While all components of this structure accumulate already at entry into meiosis I, they cannot assemble because centrosomes are occupied by Spc72, the receptor of the gamma-tubulin complex. Spc72 is removed from centrosomes by a pathway that depends on the polo-like kinase Cdc5 and the meiosis-specific kinase Ime2, which is unleashed by the degradation of Spo13/Meikin upon activation of the anaphase-promoting complex at anaphase I. Meiotic plaques are finally assembled upon reactivation of Cdk1 at entry into metaphase II. This unblocking-activation mechanism ensures that only single-copy genomes are packaged into spores and might serve as a paradigm for the regulation of other meiosis II-specific processes

ОСОБЛИВОСТІ ВПРОВАДЖЕННЯ Е-МЕДИЦИНИ В УМОВАХ ДЕРЖАВНО-ПРИВАТНОГО ПАРТНЕРСТВА

It was discussed the possibilities and the reality of the e-medicine challenges through technology of public-private partnership (PPP). It is shown that the use of e-medicine is one of the most important levers of improving the quality of medical care in Ukraine. Taking into account that the computerization of health care is extremely expensive project its rapid implementation is possible for the widest possible PPP. It is believed that mobile medicine is the best example of modern PPP. It is postulated that for the effective control of the quality of medical care it should be created specialized expertise and advisory mechanisms in a specialized system of state control of the new system of electronic health systems with strictly defined principles such as objectivity, complimentarily, law and so on.Рассмотрены возможности и реальность решения задач е-медицины с помощью технологий государственно-частного партнерства (ГЧП). Показано, что применение технологий е-медицины является одним из важнейших рычагов повышения качества оказания медицинской помощи населению Украины. Принимая во внимание, что информатизация здравоохранения является чрезвычайно дорогостоящим проектом, ее быстрая реализация возможна при условии максимально широкого ГЧП. Подчеркивается мысль, что мобильная медицина представляет собой лучший пример современного ГЧП. Постулируется, что для эффективного контроля качества оказания медицинской помощи населению должны быть созданы специализированные экспертные и консультативно-совещательные механизмы в специализированной системе органов государственного контроля новой системы электронного здравоохранения со строго определенными принципами: объективности, комплементарности, законности и тому подобное.Розглянуто можливості та реальність вирішення завдань е-медицини за допомогою технологій державно-приватного партнерства (ДПП). Показано, що застосування технологій е-медицини є одним з найважливіших важелів підвищення якості надання медичної допомоги населенню України. Беручи до уваги, що інформатизація охорони здоров'я є надзвичайно коштовним проектом, її швидка реалізація можлива за умови максимально широкого ДПП. Вважається, що мобільна медицина являє собою найкращий приклад сучасного ДПП. Постулюється, що для ефективного контролю якості надання медичної допомоги населенню мають бути створені спеціалізовані експертні та консультативно-дорадчі механізми в спеціалізованій системі органів державного контролю нової системи електронної системи охорони здоров'я зі строго визначеними принципами: об'єктивності, комплементарності, законності

Deprotection of centromeric cohesin at meiosis II requires APC/C activity but not kinetochore tension

Genome haploidization involves sequential loss of cohesin from chromosome arms and centromeres during two meiotic divisions. At centromeres, cohesin's Rec8 subunit is protected from separase cleavage at meiosis I and then deprotected to allow its cleavage at meiosis II. Protection of centromeric cohesin by shugoshin-PP2A seems evolutionarily conserved. However, deprotection has been proposed to rely on spindle forces separating the Rec8 protector from cohesin at metaphase II in mammalian oocytes and on APC/C-dependent destruction of the protector at anaphase II in yeast. Here, we have activated APC/C in the absence of sister kinetochore biorientation at meiosis II in yeast and mouse oocytes, and find that bipolar spindle forces are dispensable for sister centromere separation in both systems. Furthermore, we show that at least in yeast, protection of Rec8 by shugoshin and inhibition of separase by securin are both required for the stability of centromeric cohesin at metaphase II. Our data imply that related mechanisms preserve the integrity of dyad chromosomes during the short metaphase II of yeast and the prolonged metaphase II arrest of mammalian oocytes

Scientific and practical approaches and principles of guaranteed providing the population of Ukraine with drugs, veterinary medicines, medical and pharmaceutical services from the noopharmaceutical, nooethical and anti-aging perspectives

The article presents theoretical and practical substantiation of the basic methodological principles of strategy and tactics on the harmonization efforts, intentions and balanced interaction in the provision of guaranteed pharmaceutical and medical services on drugs and veterinary preparations sale to the population of Ukraine

Casein Kinase 1 Coordinates Cohesin Cleavage, Gametogenesis, and Exit from M Phase in Meiosis II

Meiosis consists of DNA replication followed by two consecutive nuclear divisions and gametogenesis or spore formation. While meiosis I has been studied extensively, less is known about the regulation of meiosis II. Here we show that Hrr25, the conserved casein kinase 18 of budding yeast, links three mutually independent key processes of meiosis II. First, Hrr25 induces nuclear division by priming centromeric cohesin for cleavage by separase. Hrr25 simultaneously phosphorylates Rec8, the cleavable subunit of cohesin, and removes from centromeres the cohesin protector composed of shugoshin and the phosphatase PP2A. Second, Hrr25 initiates the sporulation program by inducing the synthesis of membranes that engulf the emerging nuclei at anaphase II. Third, Hrr25 mediates exit from meiosis II by activating pathways that trigger the destruction of M-phase-promoting kinases. Thus, Hrr25 synchronizes formation of the single-copy genome with gamete differentiation and termination of meiosis

4Alpha-bromo-5alpha-cholestan-3beta-ol and nor-5alpha-cholestan-3beta-ol derivatives-stereoselective synthesis and hormonal activity in Caenorhabditis elegans

We describe the stereoselective synthesis of 4alpha-bromo-5alpha-cholestan-3beta-ol, 21-nor-5alpha-cholestan-3beta-ol, 27-nor-5alpha-cholestan-3beta-ol and 21,27-bisnor-5alpha-cholestan-3beta-ol. In order to clarify the in vivo metabolism of cholesterol, these compounds have been used for feeding experiments in Caenorhabditis elegans. Our preliminary results provide important insights into the metabolism of cholesterol in worms

Cross-Disciplinarity in Australian Geography: Presidential Address to the Institute of Australian Geographers' Conference, Melbourne, July 2007

The disciplinary space that geographers conceive to be theirs has all been previously possessed, or latterly colonised, by other disciplines. Geographers defend their existence on the basis of their oft-asserted, but never tested, cross-disciplinarity. The journals in which refereed papers were published by members of the Institute of Australian Geographers (IAG) and the papers in Australian Geographical Studies were analysed for the period 1998-2002 to test the hypothesis of cross-disciplinarity in both subject and method. IAG members do strongly tend to publish in more than one disciplinary area, and a large proportion of papers in Australian Geographical Studies are integrative across subdisciplines in geography, with many using more than one methodological approach. However, transgression of the physical geography/human geography divide was sufficiently uncommon to create a statistical break between sets of subdisciplines. Based on the data used in the present paper, Australian geographers can make a case for being members of a vital, integrative discipline, likely to make substantial advances in the hybrid spaces