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Morfogénesis in vitro de dioon merolae de Luca, Sabato & Vázquez-Torres (zamiaceae, cycadales) a partir de megagametofitos y embriones cigóticos
Cabrera Hilerio,Sandra Luz; Chávez ávila,Victor Manuel; Sandoval Zapotitla,Estela; Litz,Richard E; Cruz Sosa,Francisco;
Interciencia , 2008,
Abstract: organogenic cultures were induced from zygotic embryo and megagametophyte explants of the chiapas state (méxico) endangered cycad species, dioon merolae. the litz induction medium consisted of b5 major salts, ms medium minor salts and the organics glutamine (400mg·l-1), arginine (100mg·l-1), asparagines (100mg·l-1), sucrose (60g·l-1), gellan gum (4g), and supplemented with 0, 0.45, 2.26, 4.52 and 9.05μm 2,4-dichlorophenoxyacetic acid (2,4-d) and 0, 2.32, 4.60, 9.30, 13.90μm kinetin (k), arranged as a 5′5 factorial in a randomized block design. cultures were maintained in darkness at 25°c, and callus was subcultured onto fresh medium at 4 week intervals. callus initiation occurred on a wide range of plant growth regulators (pgr) combinations from megagametophyte explants. in comparison, callus initiation from explanted zygotic embryos occurred on few pgr combinations. adventitious shoot induction occurred from callus on formulations with k and 2,4-d. through the histological analysis of longitudinal sections of zygotic embryos were detected apical meristematic cells of the shoot and root and in megagametophytes the formation of elements similar to tracheids and coralloid roots. this technique has a great potential for preservation of the highly endangered cycads.
The ceremonial use of the threatened espada a cycad (Dioon merolae, Zamiaceae) by a community of the central depression of Chiapas, Mexico  [cached]
Miguel A. Pérez Farrera,Andrew P. Vovides
Boletín de la Sociedad Botánica de México , 2006,
Abstract: Dioon merolae De Luca, Sabato et Vázq.Torres, una especie de cícada de Chiapas conocida localmente como espada a, juega un papel importante durante la festividad de la Santa Cruz del 3 de mayo entre la comunidad de Suchiapa de la Depresión Central del estado de Chiapas. Aparentemente ésta es una tradición nativa chiapaneca de origen prehispánico que se sincretizó con la religión católica durante la época colonial. Sus hojas se usan para adornar altares cada mayo durante esta festividad religiosa Católica. Las cícadas no parecen sufrir da o alguno por la poda anual de las hojas, pero la amenaza actual a las poblaciones y a esta tradición milenaria viene de activistas de otras tradiciones religiosas que provocan incendios al hábitat de la cícada durante el período del estiaje antes de la cosecha de las hojas.
Gene Targeting in the Red Alga Cyanidioschyzon merolae: Single- and Multi-Copy Insertion Using Authentic and Chimeric Selection Markers  [PDF]
Takayuki Fujiwara, Mio Ohnuma, Masaki Yoshida, Tsuneyoshi Kuroiwa, Tatsuya Hirano
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0073608
Abstract: The unicellular red alga Cyanidioschyzon merolae is an emerging model organism for studying organelle division and inheritance: the cell is composed of an extremely simple set of organelles (one nucleus, one mitochondrion and one chloroplast), and their genomes are completely sequenced. Although a fruitful set of cytological and biochemical methods have now been developed, gene targeting techniques remain to be fully established in this organism. Thus far, only a single selection marker, URACm-Gs, has been available that complements the uracil-auxotrophic mutant M4. URACm-Gs, a chimeric URA5.3 gene of C. merolae and the related alga Galdieria sulphuraria, was originally designed to avoid gene conversion of the mutated URA5.3 allele in the parental strain M4. Although an early example of targeted gene disruption by homologous recombination was reported using this marker, the genome structure of the resultant transformants had never been fully characterized. In the current study, we showed that the use of the chimeric URACm-Gs selection marker caused multicopy insertion at high frequencies, accompanied by undesired recombination events at the targeted loci. The copy number of the inserted fragments was variable among the transformants, resulting in high yet uneven levels of transgene expression. In striking contrast, when the authentic URA5.3 gene (URACm-Cm) was used as a selection marker, efficient single-copy insertion was observed at the targeted locus. Thus, we have successfully established a highly reliable and reproducible method for gene targeting in C. merolae. Our method will be applicable to a number of genetic manipulations in this organism, including targeted gene disruption, replacement and tagging.
A 100%-complete sequence reveals unusually simple genomic features in the hot-spring red alga Cyanidioschyzon merolae
Hisayoshi Nozaki, Hiroyoshi Takano, Osami Misumi, Kimihiro Terasawa, Motomichi Matsuzaki, Shinichiro Maruyama, Keiji Nishida, Fumi Yagisawa, Yamato Yoshida, Takayuki Fujiwara, Susumu Takio, Katsunori Tamura, Sung Chung, Soichi Nakamura, Haruko Kuroiwa, Kan Tanaka, Naoki Sato, Tsuneyoshi Kuroiwa
BMC Biology , 2007, DOI: 10.1186/1741-7007-5-28
Abstract: Our present complete sequence consists of 16546747 nucleotides covering 100% of the 20 linear chromosomes from telomere to telomere, representing the simple and unique chromosomal structures of the eukaryotic cell. We have unambiguously established that the C. merolae genome contains the smallest known histone-gene cluster, a unique telomeric repeat for all chromosomal ends, and an extremely low number of transposons.By virtue of these attributes and others that we had discovered previously, C. merolae appears to have the simplest nuclear genome of the non-symbiotic eukaryotes. These unusually simple genomic features in the 100% complete genome sequence of C. merolae are extremely useful for further studies of eukaryotic cells.The biological sciences have been embracing a new paradigm as a result of accruing genome information [1-13]. However, all previously reported eukaryotic nuclear genome sequences have been incomplete, especially in highly repeated units and chromosomal ends. Because repetitive DNA is essential to genome function [14], and may contribute to the diversity of isoforms [15] and the evolution of life [16], complete chromosomal structures are fundamental for understanding eukaryotic cells.Our recently published nuclear-genome sequence of the ultra-small, hot-spring red alga, Cyanidioschyzon merolae 10D, revealed some unique features, such as very few introns, only three copies of ribosomal (r)DNA, and a small total number of genes [9,10]. However, because uncertainties remained regarding the features of certain important repeated elements, such as histone-gene clusters and telomeres [9], this sequence, like all previous eukaryotic nuclear-genome sequences, was incomplete. Given the functional significance of such elements [14], it was obviously desirable to complete the sequence and resolve all ambiguities before attempting to summarize all of the unique features of the C. merolae genome. Therefore, we aimed to complete all previous gaps and sequenc
Venation and Anatomy of Pinnae in Stanger iacea(Cycadales)
托叶铁科(苏铁目)羽片脉序和羽片解剖学研究

XIE Zhong-yu,TANG Yuan-jiang,LIU Nian,WU Qi-gen,LIAO Jing-ping,
谢中誉
,唐源江,刘念,吴七根,廖景平

热带亚热带植物学报 , 2002,
Abstract: Pinna venation pattern and pinna anatomy of two species, S tangeria eriopus and Bowenia serrulata, represent atives of the two genera in Stangeriaceae were studied in this paper. The two sp ecies (genera) are similar in stomatal character and in the absence of accessory transfusion tissue, but they are very different in stomatal distribution, pinna venation pattern and pinna marginal shape, presence or absence of mucilage cana l, differentiation of palisade and spongy parenchyma, characteristics of girder parenchyma and epidermal anticlinal wall. Pinna venation and pinna anatomy of St angeriaceae are compared with those of Cycadaceae and Zamiaceae. Stevenson's cla ssification (1992) with two subfamilies and the treatment of Stangeriaceae as a transitional evolutionary position between Cycadaceae and Zamiaceae is supported by present study.
Réquiem para un cóndor ciego: Juan Lavalle según la visión estetizada de la dupla Sabato-Falú
Mamani,Ariel;
Prohistoria , 2006,
Abstract: this article inquires about the strategies suggested by ernesto sabato for the diffusion of his point of view about argentinean history and in special, general juan lavalle’s life. the author, in his will of participating in the intellectual and political field, essayed to diverse forms of participation in its re-interpretation of past. his piece of work entitled romance de la muerte de juan lavalle has been written in collaboration with native music composer eduardo falú. my intention is to remark some of the quarrels which took place in the field of "memories" in the purpose of analyze the construction of the differents discourses about past from non traditional historical enclosures
El tratamiento con progesterona previene las alteraciones motoras inducidas por la intoxicación con semillas de cícada (Dioon spinulosum) en la rata macho  [cached]
E Rivadeneyra-Domínguez,M Saavedra,JF Rodríguez-Landa
Revista de Toxicología , 2009,
Abstract: El consumo crónico de semillas de cícadas ha sido asociado con enfermedades neurodegenerativas, las cuales predominan en el género masculino. En México, las semillas de cícada (Dioon spinulosum) son usadas como sustituto de maíz y a nivel experimental producen un déficit motor; probablemente causado por sus componentes neurotóxicos. En este sentido, la progesterona ejerce efectos neuroprotectores contra traumatismo cerebral, hipoxia, así como la muerte neuronal inducida por colchicina en el SNC; por lo que podría prevenir los efectos neurotóxicos producidos por el consumo crónico de semillas de Dioon spinulosum en ratas, una posibilidad explorada en el presente estudio. Se emplearon 32 ratas macho de la cepa Wistar distribuidas en cuatro grupos: a) un grupo control recibió 1 ml de agua purificada(v.o.) y 0,2 ml de aceite de maíz (s.c.); b) un grupo cícada recibió 5 g/kg de la semilla de cícada (v.o.) y 0,2 ml de aceite de maíz (s.c.); c)un grupo más recibió 1 ml de agua purificada (v.o.) y 3 mg/kg de progesterona (s.c.); y d) el último grupo recibió semilla de cícada y progesterona. Los tratamientos fueron administrados diariamentedurante 40 días y el efecto fue evaluado en las pruebas de actividad locomotora y nado forzado a los 20, 30 y 40 días de tratamiento. El grupo cícada redujo el número de cuadros cruzados en la prueba de actividad locomotora. En la prueba de nado forzado, los animales tratados con la semilla de cícada fueron los únicos que presentaron la conducta de giro, un efecto que fue prevenido por el tratamientoprevio con progesterona. La administración de vehículo y progesterona no produjo per se la conducta de giro. En conclusión, la progesterona previene las alteraciones motoras inducidas por el consumo crónico de semillas de cícada en ratas forzadas a nadar.
Réquiem para un cóndor ciego: Juan Lavalle según la visión estetizada de la dupla Sabato-Falú
Ariel Mamani
Prohistoria , 2006,
Abstract: Este artículo indaga las estrategias desplegadas por Ernesto Sabato para la difusión de su particular visión de la historia argentina, especialmente de la controvertida figura del general Juan Lavalle. El deseo de terciar en el campo intelectual y político lo llevó a ensayar diversas formas de participación en los combates por la reinterpretación del pasado. Romance de la Muerte de Juan Lavalle, obra poético-musical realizada en colaboración con el músico folclórico Eduardo Falú, es abordada con la intención de analizar la construcción de discursos acerca del pasado desde ámbitos historiográficos no tradicionales This article inquires about the strategies suggested by Ernesto Sabato for the diffusion of his point of view about argentinean history and in special, general Juan Lavalle’s life. The author, in his will of participating in the intellectual and political field, essayed to diverse forms of participation in its re-interpretation of past. His piece of work entitled Romance de la Muerte de Juan Lavalle has been written in collaboration with native music composer Eduardo Falú. My intention is to remark some of the quarrels which took place in the field of "memories" in the purpose of analyze the construction of the differents discourses about past from non traditional historical enclosures
Systematic implications of pinna venation and pinna anatomy in Zamiaceae
泽米科植物羽片脉序和解剖学及其系统学意义

Abstract,
唐源江
,刘念,廖景平,谢中誉,吴七根,陈家瑞

植物分类学报 , 2004,
Abstract: Pinna venation and pinna anatomy were examined in ten species of six genera of Zamiaceae (Cycadales), which represent all four tribes. Pinna venation consists of dichotomous parallel veins without a midrib. The vein endings connect to each other in different forms in Dioon spinulosum, Encephalartos friderici_guilielmii and Macrozamia moorei, while they are never connected and reach the pinna margin in Lepidozamia peroffskyana, Ceratozamia mexicana var. robusta, C. hildae, Zamia muricata, Z. debilis, Z. furfuracea and Z. floridana, and gradually fade out in L. peroffskyana, C. mexicana var. robusta, and C. hildae. In transverse section, pinna generally consists of an adaxial epidermis and an abaxial epidermis, hypodermal sclerenchyma and mesophyll which may be differentiated into distinct adaxial and abaxial palisade regions, or adaxial palisade only, or entirely spongy tissue. However, typical spongy parenchyma and transfusion tissue are absent from this family. Mucilage canals are opposite the vascular bundles in D. spinulosum, or alternate with vascular bundles in E. friderici_guilielmii, L. peroffskyana and M. moorei. Girder sclerenchyma is connected with the abaxial epidermis only in C. mexicana var. robusta and C. hildae, but with both adaxial and abaxial epidermis in Z. muricata, Z. debilis, Z. furfuracea and Z. floridana. Pinna venation and anatomy support Stevenson's classification of Zamiaceae into two subfamilies.
Systematic implications of pinna venation and pinna anatomy in Zamiaceae
泽米科植物羽片脉序和解剖学及其系统学意义

TANG Yuan-Jiang,LIU Nian,LIAO Jing-Ping,XIE Zhong-Yu,
唐源江
,刘念,廖景平,谢中誉,吴七根,陈家瑞

中国科学院研究生院学报 , 2004,
Abstract: Pinna venation and pinna anatomy were examined in ten species of six genera of Zamiaceae (Cycadales), which represent all four tribes. Pinna venation consists of dichotomous parallel veins without a midrib. The vein endings connect to each other in different forms in Dioon spinulosum, Encephalartos friderici-guilielmii and Macrozamia moorei, while they are never connected and reach the pinna margin in Lepidozamia peroffskyana, Ceratozamia mexicana var. robusta, C. hildae, Zamia muricata, Z. debilis, Z. furfuracea and Z. floridana, and gradually fade out in L. peroffskyana, C. mexicana var. robusta, and C. hildae. In transverse section, pinna generally consists of an adaxial epidermis and an abaxial epidermis, hypodermal sclerenchyma and mesophyll which may be differentiated into distinct adaxial and abaxial palisade regions, or adaxial palisade only, or entirely spongy tissue. However, typical spongy parenchyma and transfusion tissue are absent from this family. Mucilage canals are opposite the vascular bundles in D. spinulosum, or alternate with vascular bundles in E. friderici-guilielmii, L. peroffskyana and M. moorei. Girder sclerenchyma is connected with the abaxial epidermis only in C. mexicana var. robusta and C. hildae, but with both adaxial and abaxial epidermis in Z. muricata, Z. debilis, Z. furfuracea and Z. floridana. Pinna venation and anatomy support Stevenson's classification of Zamiaceae into two subfamilies.
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