Cryptic homoelogy analysis in species and hybrids of genus Zea

Cryptic intergenomic pairing of genus Zea was induced by the use of a diluted colchicine solution in order to elucidate the phylogenetic relations and differentiation of the homoeologous genomes. Results indicate that in species and hybrids with 2n = 20, there was chromosome pairing between the homoeologous A and B genomes with a maximum of 5IV, with the exception of Zea diploperennis and their interspecific hybrids where cryptic homoeologous chromosome pairing was not induced. In almost all 2n = 30 hybrids, observed cryptic pairing increased to a maximum of 10III although Z. mays x Z. mays with 2n = 30 did not show significant differences between treated and untreated materials. Pairing was also observed in species and hybrids with 2n = 40, in which a maximum of 10IV was observed, with the exception of Z. mays with 2n = 40 where treated and untreated cells did not differ significantly.This research was supported by the Universidad Nacional de la Plata, Universidad Nacional de Lomas de Zamora and CONICET.Molina, M.; Lopez, C.; Staltari, S.; Chorzempa, S.; Moreno Ferrero, V. (2013). Cryptic homoelogy analysis in species and hybrids of genus Zea. Biologia Plantarum. 57(3):449-456. doi:10.1007/s10535-012-0299-4S449456573Bass, H.W., Riera-Lizarazu, O., Ananiev, E.V.B., Bordolini, S.J., Rines, H.W., Phillips, R.L., Sedat, J.W., Agard, D.A., Cande, Z.W.: Evidence for the coincident initiation of homologous pairing and synapsis during the telomereclustering (bouquet) stage of meiotic prophase. — J. Cell Sci. 113: 1033–1042, 2000.Bozza, C.G., Pawlowsky, W.P.: The cytogenetics of homologous chromosome pairing in meiosis in plants. — Cytogenet. Genet. Res. 120: 313–319, 2008.Chikashige, Y., Haraguchi, T., Hiraoka, Y.: Nuclear envelope attachment is not necessary for telomere function in fission yeast. — Nucleus 1: 481–486, 2010.Dobley, J., Iltis, H.H.: Taxonomy of Zea (Gramineae). I. A subgeneric classification with key to taxa. — Amer. J. Bot. 67: 982–993, 1980.Dover, G.A., Riley, R.: The effect of spindle inhibitors applied before meiosis on meiotic chromosome pairing. — J. Cell. Sci. 12: 143–161, 1973.Driscoll, C.J., Darvey, N.L.: Chromosome pairing: effect of colchicine on an isochromosome. — Science 169: 290–291, 1970.Driscoll, C.J., Darvey, N.L., Barber, H.N.: Effect of colchicine on meiosis of hexaploid wheat. — Nature 216: 687–688, 1967.Feldman, M., Avivi, L.: Genetic control of bivalent pairing in common wheat. The mode of Ph1 action. — In: Brandham, P.E. (ed.) Kew Chromosome Conference III. Pp. 269–279. Royal Botanic Garden, London 1988.Feldman, F., Liu, B., Segal, G., Abbo, S., Levy. A.: Rapid elimination of low copy DNA sequences in polyploidy wheat: a possible mechanism for differentiation of homeologous chromosomes. — Genetics 147: 1381–1387, 1997.Fukunaga, K., Hill, J., Vigoroux, Y., Matsuoka, Y., Sanchez G., J., Liu, K., Bucker, E., Doebley, J.: Genetic diversity and population structure of teosinte. — Genetics 169: 2241–2254, 2005.Furini, A., Jewell, C.: Somatic embryogenesis and plant regeneration of maize/Tripsacum hybrids. — Maydica 40: 205–210, 1995.García, M.D., Molina, M. del C.: Embryo rescue and induction of somatic embryogenesis as a method to overcome seed inviability in Zea mays ssp. mays (2n = 40) × Zea mays ssp. parviglumis crosses. — Biol. Plant. 44: 497–501, 2001.García, M.D., Molina, M. del C., Caso, 0.H.: [Maize (Zea mays ssp. mays) plant regeneration from tissue culture and its applications in maize breeding.] — Rev. Fac. Agron. UNLP 68: 15–25, 1992. [In Spanish]Goluboskaya, I.N., Harper, L.C., Pawlowski, W.P., Schicnes, D.; Cande, W.Z.: The pam1 gene is required for meiotic bouquet formation and efficient homologous synapsis in maize (Zea mays L.). — Genetics 162: 1979–1993, 2002.González, G., Poggio, L.: Karyotype of Zea luxurians and Z. mays subsp. mays using FISH/DAPI, and analysis of meiotic behavior of hybrids. — Genome 54: 26–32, 2011.Harper, L., Golubovskaya, I., Cande, W.Z.: A bouquet of chromosomes. — J. Cell. Sci. 117: 4025–4032, 2004.Iltis, H.H., Benz B.F: Zea nicaraguensis (Poaceae), a new teosinte from Pacific coastal Nicaragua. — Novon 10: 382–390, 2000.Iltis, H.H.; Dobley J.: Taxonomy of Zea (Gramineae). II Subspecific categories in the Zea mays comple× and a generic synopsis. — Amer. J. Bot. 67: 994–1004, 1980.Jackson, R.C.: Polyploidy and diploidy: new perspectives on chromosome pairing and its evolutionary implications. — Amer. J. Bot. 69: 1512–1523, 1982.Jackson, R.C., Murray, B.G.: Colchicine-induced quadrivalent formation in Helianthus: evidence of ancient polyploidy. — Theor. appl. Genet. 64: 219–222, 1983.Jenczewski, E., Alix, K.: From diploids to allopolyploids: the emergence of efficient pairing control genes in plants. — Crit. Rev. Plant Sci. 23: 21–25, 2004.Jenkins, G., Chatterjee, R.: Chromosome structure and pairing preferences in tetraploid rye (Secale cereale). — Genome 37: 784–793, 1994.Molina, M. del C.: Estudios citogenéticos evolutivos del Género Zea. [Cytogenetic Study of Zea Genus Evolution] — PhD Thesis, Polytechnic University of Valencia, Valencia 2011. [In Spanish].Molina, M. del C., Chorzempa, S.E., García, M.D.: Meiotic pairing in the hybrid (Zea mays × Zea diploperennis) × Zea luxurians. — Maize Genet. Coop. Newslett. 79: 5–7, 2005.Molina, M. del C., García, M.D.: Influence of ploidy levels on phenotypic and cytogenetic traits in maize and Zea perennis hybrids. — Cytologia 64: 101–109, 1999.Molina, M. del C., García, M.D.: Meiotic pairing in the interspecific hybrid Zea mays, Z. perennis and Zea diploperennis. — Maize Genet. Coop. Newslett. 74: 42–43, 2000.Molina, M. del C., García, M.D.: Ploidy levels affect phenotype and cytogenetic traits in Zea mays ssp. mays (2n = 20 or 40) and Zea mays ssp. parviglumis hybrids — Cytologia 66: 189–196, 2001.Molina, M. del C., García, M.D., López C.G., Moreno Ferrero, V.: Meiotic pairing in the hybrid (Zea diploperennis × Zea perennis) × Zea mays and its reciprocal. — Hereditas 141: 135–141, 2004.Molina, M. del C., Naranjo, C.A.: Cytogenetic studies in the genus Zea. I. Evidence for five as the basic chromosomes number. — Theor. appl. Genet. 73: 542–550, 1987.Naranjo, C.A., Molina, M. del C., Poggio, L.: [Evidence of a basic number x = 5 in the genus Zea and its importance in studies of the origin of maize] — Acad. Nac. Cs. Ex. Fis. Nat. 5: 75–84, 1989. [In Spanish].Naranjo, C.A., Poggio, L., Molina, M. del C., Bernatene, E.: Increase in multivalent frequency in F1 hybrids of Zea diploperennis × Z. perennis by colchicine treatment. — Hereditas 120: 241–244, 1994.Poggio, L., Molina, M. del C., Naranjo, C.A.: Cytogenetic studies in the genus Zea. 2- colchicine-induced multivalents. — Theor. appl. Genet. 79: 461–464, 1990.Ruiz, C., Sanchez, J.J., Aguilar, S.M.: Potential geographical distribution of teosinte in Mexico: a GISH approach. — Maydica 46: 105–110, 2001.Santos, J.L., Lacadena, J.R., Cermeno, M.C., Orellana, J.: Nucleolar organizer activity in wheat-barley chromosome addition lines. — Heredity 53: 425–429, 1984.Santos, J.L., Orellana, J.: Pairing competition between identical and homologous chromosome in rye and grasshoppers. — Genetics 104: 677–684, 1983.Schnable, J.C., Freeling, M.: Genes identified by visible mutant phenotypes show increased bias toward one of two subgenomes of maize. — PLoS ONE 6–3: e17855. Doi:101371/journal.pone.0017855, 2011.Schnable, J.C., Springer, N.M., Freeling, M.: Differentiation of maize subgenome by genome dominance and both ancient and ongoing gene loss. — PNAS 108: 4069–4074, 2011.Sokal, R.R., Rohlf, Y.: Biometría. — W.H. Freeman and Company, San Francisco 1978.Swanson-Wagner R., Eichten S., Kumari S., Tiffin P., Stein J., Ware D., Springer N.: Pervasive gene content variation and copy number variation in maize and its undomesticated progenitor. — Genome Res., in press, 2012.Swigonová, Z., Lai, J., Ma, J., Ramakrisma, W., Llaca, V., Bennetzen, J., Messing, J.: Close split of sorghum and maize genome progenitors. — Genome Res. 14: 1916–1923, 2004.Wendel, J.: Genome evolution in polyploidy, — Plant mol. Biol. 42: 225–229, 2000.Zickler, D., Kleckner, N.: The leptotene-zygotene transition of meiosis. — Annu. Rev. Genet. 32: 619–697, 1998

Malaria vector research and control in Haiti: a systematic review

BACKGROUND: Haiti has a set a target of eliminating malaria by 2020. However, information on malaria vector research in Haiti is not well known. This paper presents results from a systematic review of the literature on malaria vector research, bionomics and control in Haiti. METHODS: A systematic search of literature published in French, Spanish and English languages was conducted in 2015 using Pubmed (MEDLINE), Google Scholar, EMBASE, JSTOR WHOLIS and Web of Science databases as well other grey literature sources such as USAID, and PAHO. The following search terms were used: malaria, Haiti, Anopheles, and vector control. RESULTS: A total of 132 references were identified with 40 high quality references deemed relevant and included in this review. Six references dealt with mosquito distribution, seven with larval mosquito ecology, 16 with adult mosquito ecology, three with entomological indicators of malaria transmission, eight with insecticide resistance, one with sero-epidemiology and 16 with vector control. In the last 15 years (2000–2015), there have only been four published papers and three-scientific meeting abstracts on entomology for malaria in Haiti. Overall, the general literature on malaria vector research in Haiti is limited and dated. DISCUSSION: Entomological information generated from past studies in Haiti will contribute to the development of strategies to achieve malaria elimination on Hispaniola. However it is of paramount importance that malaria vector research in Haiti is updated to inform decision-making for vector control strategies in support of malaria elimination

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Background: Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. // Methods: We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung's disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. // Findings: We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung's disease) from 264 hospitals (89 in high-income countries, 166 in middle-income countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in low-income countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. // Interpretation: Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between low-income, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Pooled analysis of WHO Surgical Safety Checklist use and mortality after emergency laparotomy

Background The World Health Organization (WHO) Surgical Safety Checklist has fostered safe practice for 10 years, yet its place in emergency surgery has not been assessed on a global scale. The aim of this study was to evaluate reported checklist use in emergency settings and examine the relationship with perioperative mortality in patients who had emergency laparotomy. Methods In two multinational cohort studies, adults undergoing emergency laparotomy were compared with those having elective gastrointestinal surgery. Relationships between reported checklist use and mortality were determined using multivariable logistic regression and bootstrapped simulation. Results Of 12 296 patients included from 76 countries, 4843 underwent emergency laparotomy. After adjusting for patient and disease factors, checklist use before emergency laparotomy was more common in countries with a high Human Development Index (HDI) (2455 of 2741, 89.6 per cent) compared with that in countries with a middle (753 of 1242, 60.6 per cent; odds ratio (OR) 0.17, 95 per cent c.i. 0.14 to 0.21, P <0001) or low (363 of 860, 422 per cent; OR 008, 007 to 010, P <0.001) HDI. Checklist use was less common in elective surgery than for emergency laparotomy in high-HDI countries (risk difference -94 (95 per cent c.i. -11.9 to -6.9) per cent; P <0001), but the relationship was reversed in low-HDI countries (+121 (+7.0 to +173) per cent; P <0001). In multivariable models, checklist use was associated with a lower 30-day perioperative mortality (OR 0.60, 0.50 to 073; P <0.001). The greatest absolute benefit was seen for emergency surgery in low- and middle-HDI countries. Conclusion Checklist use in emergency laparotomy was associated with a significantly lower perioperative mortality rate. Checklist use in low-HDI countries was half that in high-HDI countries.Peer reviewe