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Sohrab?P?Shah David?YM?He Jessica?N?Sawkins Jeffrey?C?Druce Gerald?Quon Drew?Lett Grace?XY?Zheng Tao?Xu BF?Francis?OuelletteEmail author 《BMC bioinformatics》2004,5(1):40
Background
We present Pegasys – a flexible, modular and customizable software system that facilitates the execution and data integration from heterogeneous biological sequence analysis tools. 相似文献3.
Hernández Pérez A E Cerna Chávez JC Delgado Ortiz M Beltrán Beache LM Tapia Vargas YM Ochoa Fuentes 《Phyton》2019,88(1):11-13
Mexico is the main producer, consumer and exporter
of avocado in the world, being Michoacan the main producer state
contributing more than 80% of the national production. There
are phytopathogens that decimate the production causing the
death of the tree. Root samples were collected in avocado trees
that showed the characteristic symptomatology of the disease
known as avocado sadness, the sampling was carried out in four
of the main avocado producing towns, in the state of Michoacan,
Mexico. The isolation consisted in sowing root tissue in Petri
dishes with V8®-PARPH culture medium, subsequently they were
identified morphologically and for species level it was determined
by molecular biology, with the PCR-ITS technique. Pathogenicity
tests were performed in triplicate with avocado seedlings with more
than six leaves. After 24 hours, the inoculated plants expressed
decay in the apical part, after 120 hours the leaves showed yellowing
and after 15 days there was a generalized wilt on the stem and
leaves, re-isolating the phytopathogen Phytopythium vexans.
This study confirms the first report of the oomycete P. vexans
affecting avocado trees in the most important producing region of
the Mexican Republic. 相似文献
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Background
RNA exhibits a variety of structural configurations. Here we consider a structure to be tantamount to the noncrossing Watson-Crick and G-U-base pairings (secondary structure) and additional cross-serial base pairs. These interactions are called pseudoknots and are observed across the whole spectrum of RNA functionalities. In the context of studying natural RNA structures, searching for new ribozymes and designing artificial RNA, it is of interest to find RNA sequences folding into a specific structure and to analyze their induced neutral networks. Since the established inverse folding algorithms, RNAinverse, RNA-SSD as well as INFO-RNA are limited to RNA secondary structures, we present in this paper the inverse folding algorithm Inv which can deal with 3-noncrossing, canonical pseudoknot structures. 相似文献5.
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Caballero-Flores GG Acosta-Navarrete YM Ramírez-Díaz MI Silva-Sánchez J Cervantes C 《FEMS microbiology letters》2012,327(2):148-154
The presence of chromate-resistance genes in enterobacteria was evaluated in a collection of 109 antibiotic-resistant nosocomial isolates from nine major cities in México. Results were compared with the presence of mercury-resistance genes. Susceptibility tests showed that 21% of the isolates were resistant to chromate (Cr(R)), whereas 36% were resistant to mercury (Hg(R)). Cr(R) levels were high in Klebsiella pneumoniae (61%), low in Enterobacter cloacae (12%) and Escherichia coli (4%), and null in Salmonella sp. isolates. Colony hybridization demonstrated that the majority of metal-resistant isolates hybridized with chrA gene (87% of Cr(R) isolates), encoding a CHR transporter homologue, and merA gene (74% of Hg(R) isolates), encoding MerA mercuric reductase, suggesting that most isolates expressed these widespread metal-resistance systems. Southern blot hybridization of Cr(R) isolates showed that plasmids of 80, 85, and 95 kb from K. pneumoniae isolates, and of 100 kb from an E. cloacae isolate, contained chrA-related sequences. These plasmids belonged to IncN or IncP incompatibility groups, and conferred Cr(R), as well as multiple antibiotic resistance, when transferred by conjugation to an E. coli standard strain. These data indicated that Cr(R) genes may be distributed among clinical enterobacteria via conjugative plasmids, probably by coselection with antibiotic-resistant genes. 相似文献
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Spermatogenic cells of the prepuberal mouse: isolation and morphological characterization 总被引:62,自引:6,他引:56
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AR Bellve JC Cavicchia CF Millette DA O'Brien YM Bhatnagar M Dym 《The Journal of cell biology》1977,74(1):68-85
A procedure is described which permits the isolation from the prepuberal mouse testis of highly purified populations of primitive type A spermatogonia, type A spermatogonia, type B spermatogonia, preleptotene primary spermatocytes, leptotene and zygotene primary spermatocytes, pachytene primary spermatocytes and Sertoli cells. The successful isolation of these prepuberal cell types was accomplished by: (a) defining distinctive morphological characteristics of the cells, (b) determining the temporal appearance of spermatogenic cells during prepuberal development, (c) isolating purified seminiferous cords, after dissociation of the testis with collagenase, (d) separating the trypsin-dispersed seminiferous cells by sedimentation velocity at unit gravity, and (e) assessing the identity and purity of the isolated cell types by microscopy. The seminiferous epithelium from day 6 animals contains only primitive type A spermatogonia and Sertoli cells. Type A and type B spermatogonia are present by day 8. At day 10, meiotic prophase is initiated, with the germ cells reaching the early and late pachytene stages by 14 and 18, respectively. Secondary spermatocytes and haploid spermatids appear throughout this developmental period. The purity and optimum day for the recovery of specific cell types are as follows: day 6, Sertoli cells (purity>99 percent) and primitive type A spermatogonia (90 percent); day 8, type A spermatogonia (91 percent) and type B spermatogonia (76 percent); day 18, preleptotene spermatocytes (93 percent), leptotene/zygotene spermatocytes (52 percent), and pachytene spermatocytes (89 percent), leptotene/zygotene spermatocytes (52 percent), and pachytene spermatocytes (89 percent). 相似文献
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