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PubMed1990

Developmental staging of maize microspores reveals a transition in developing microspore proteins.

A method for the preparation of developmentally staged microspores and young pollen from maize (Zea mays) has been devised. The preparations are of sufficient purity and quantity for biochemical analysis, including the analysis of steady-state protein and RNA populations associated with each stage. A major transition in protein populations occurs during the developmental period that encompasses microspore mitosis, the asymmetric nuclear division producing the vegetative and generative nuclei. Several differences between early and late stage proteins can be detected by one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Two-dimensional gel electrophoresis of proteins reveals that over half of the steady-state proteins differ between the younger and older stages, either quantitative or qualitative. One protein that increases in relative abundance about fourfold is actin. In vitro translation of RNA isolated from staged microspores demonstrates changes in microspore gene expression during the same developmental period.

Journal Article↗

PubMed2004

Microarrays for global expression constructed with a low redundancy set of 27,500 sequenced cDNAs representing an array of developmental stages and physiological conditions of the soybean plant.

BACKGROUND: Microarrays are an important tool with which to examine coordinated gene expression. Soybean (Glycine max) is one of the most economically valuable crop species in the world food supply. In order to accelerate both gene discovery as well as hypothesis-driven research in soybean, global expression resources needed to be developed. The applications of microarray for determining patterns of expression in different tissues or during conditional treatments by dual labeling of the mRNAs are unlimited. In addition, discovery of the molecular basis of traits through examination of naturally occurring variation in hundreds of mutant lines could be enhanced by the construction and use of soybean cDNA microarrays. RESULTS: We report the construction and analysis of a low redundancy 'unigene' set of 27,513 clones that represent a variety of soybean cDNA libraries made from a wide array of source tissue and organ systems, developmental stages, and stress or pathogen-challenged plants. The set was assembled from the 5' sequence data of the cDNA clones using cluster analysis programs. The selected clones were then physically reracked and sequenced at the 3' end. In order to increase gene discovery from immature cotyledon libraries that contain abundant mRNAs representing storage protein gene families, we utilized a high density filter normalization approach to preferentially select more weakly expressed cDNAs. All 27,513 cDNA inserts were amplified by polymerase chain reaction. The amplified products, along with some repetitively spotted control or 'choice' clones, were used to produce three 9,728-element microarrays that have been used to examine tissue specific gene expression and global expression in mutant isolines. CONCLUSIONS: Global expression studies will be greatly aided by the availability of the sequence-validated and low redundancy cDNA sets described in this report. These cDNAs and ESTs represent a wide array of developmental stages and physiological conditions of the soybean plant. We also demonstrate that the quality of the data from the soybean cDNA microarrays is sufficiently reliable to examine isogenic lines that differ with respect to a mutant phenotype and thereby to define a small list of candidate genes potentially encoding or modulated by the mutant phenotype.

Cluster Analysis↗

PubMed1980

Differential expression of minor histocompatibiility antigens on the surface of the mouse oocyte and preimplantation developmental stages.

The expression of specific minor histocompatibility antigens on oocytes and preimplantation developmental stages in the mouse has been examined using immunofluorescence. Multi-specific alloantisera in conjunction with serological adsorption and target cells of the appropriate genotype have been used to how that there is differential expression of minor histocompatibility antigens during early development. Detailed analysis showed that antigen expression can be detected on oocytes and zygotes, but not on two-cell stages. From the eight-cell stage to the blastocyst, reactivity with antibody directed against a single specificity could be detected.

Adsorption↗

PubMedDate not supplied

Different effects of neuroprotectants FK-506 and cyclosporin A on susceptibility to pilocarpine-induced seizures in rats with brain injured at different developmental stages.

Susceptibility of the injured brain to epileptic seizures depends on the developmental stage at which the injury had been inflicted (our previous paper published in Epilepsy Res. 53 (2003) 216-224). The present study was designed to examine whether neuroprotective agents applied following the injury can decrease the seizure susceptibility. In order to solve this problem, the left cerebral hemisphere was mechanically injured in 6- and 30-day-old Wistar rats. Neuroprotectants FK506 or Cyclosporin A (CsA) were injected 20 min and 24h following the injury. On postnatal day 60, all the animals received single i.p. pilocarpine injections to evoke epileptic seizures. During a 6h period following the injection, the animals were observed continuously and pilocarpine-induced symptoms were recorded and rated. The animals were sacrificed 7 days after pilocarpine injection. In rats injured on postnatal days 6 or 30 (P6 or P30, respectively) and injected with FK-506 after the injury, signs of amelioration in the course of epilepsy were observed. Generally, proportions of rats suffering from heavy seizures were lower and/or their survival periods were longer. Following treatment with CsA, proportions of rats displaying heavy seizures were greater. It was accompanied by extremely high mortality (in rats injured on P6) or a longer duration of seizures (in rats injured on P30). The results appear to point to age-dependent differences between the mechanisms of action of the two neuroprotectants.

Aging↗

PubMedDate not supplied

Proteomic analysis of Trypanosoma cruzi developmental stages using isotope-coded affinity tag reagents.

Comparative proteome analysis of developmental stages of the human pathogen Trypanosoma cruzi was carried out by isotope-coded affinity tag technology (ICAT) associated with liquid cromatography-mass spectrometry peptide sequencing (LC-MS/MS). Protein extracts of the protozoan trypomastigote and amastigote stages were labeled with heavy (D8) and light (D0) ICAT reagents and subjected to cation exchange and avidin affinity chromatographies followed by LC-MS/MS analysis. High confidence sequence information and expression levels for 41 T. cruzi polypeptides, including metabolic enzymes, paraflagellar rod components, tubulins, and heat-shock proteins were reported. Twenty-nine proteins displayed similar levels of expression in both forms of the parasite, nine proteins presented higher levels in trypomastigotes, whereas three were more expressed in amastigotes.

Amino Acid Sequence↗

PubMed2006

ChickGCE: a novel germ cell EST database for studying the early developmental stage in chickens.

We established a database to study germ cells during the early developmental stage in the chicken. The ChickGCE database provides integrated expressed sequence tag (EST) data from chicken testis, ovary, embryonic gonads, and primordial germ cells. We gathered data on 10,294 ESTs from approximately 1000 embryonic gonads, and we experimentally determined 10,851 ESTs from primordial germ cells purified from 7955 embryonic gonads by magnetically activated cell sorting. The EST testis and ovary datasets were retrieved from the public database of The Institute for Genomic Research (TIGR). The EST data were clustered and assembled into unique sequences, contigs, and singletons. The ChickGCE database provides functional annotation, identification, and putative embryonic germ-cell-specific novel transcripts based on the Gene Ontology database, as well as statistical analyses of expression patterns and pair-wise comparisons of two types of tissue- and germ-cell-specific alternative splicing events in the chicken. The new database is accessible online and queries can be answered using several search options, including tissue database searches, keywords, clone IDs, expected values, and BLAST search scores.

Animals↗

PubMed1992

Study on the surface morphology of the developmental stages of the liver fluke, Opisthorchis viverrini (Trematoda: Opisthorchiidae).

The external morphology of some developmental stages of the fluke Opisthorchis viverrini (Trematoda: Opisthorchiidae), parasitizing humans in Southeast Asia was studied for the first time using electron microscopy. The surface structure of the egg, as well as the rediae, cercaria, metacercaria, and adult found in naturally infected hosts from Laos are described herein and their morphological characteristics discussed.

Animals↗

PubMed2001

Lipid and protein composition at different developmental stages of Pediculus capitis (Arthropoda, Phthiraptera).

Protein and lipid compositions were studied at different developmental stages of Pediculus capitis De Geer 1778. Phosphatidylcholine was found to be the predominant lipid at all stages and in both sexes. Palmitic and oleic acids were the main fatty acids throughout the 3 stages studied. A marked decline was observed in the total lipid content and triacylglyceride concentration during development, suggesting that their consumption is an energy source. The electrophoretic mobility revealed the predominance of a 320-kDa protein in eggs and adult females, whereas 2 major proteins of 514 and 439 kDa were found in nymphs, as well as in male and female adults. Two very high density lipoprotein fractions were isolated by ultracentrifugation of egg cytosol in a density gradient of NaBr. Both reserve lipoproteins contained phospholipids and triacylglycerols as the predominant lipids and a protein band of around 320 kDa. The structure of this band is likely to be similar to that found in females in a vitellogenic state.

Animals↗

PubMed1993

Light and electron-microscopical observations of the early developmental stages of Theileria sergenti in the gut of Haemaphysalis longicornis.

Morphological characteristics of the early developmental stages of Theileria sergenti in the vector tick were observed by light and electron-microscopies and compared with those of other Theileria species. Just before the repletion of nymphs, various stages of the parasite were observed in gut contents of tick by light microscopy: the spherical intra-erythrocytic stage, the ring-form stage, the spindle-shaped stage and the round-form stage. Electron microscopy revealed that the spherical intra-erythrocytic stages were 1-2 microns in diameter and were marginally located in host erythrocytes. The organisms liberated from host erythrocytes into the tick gut lumen had a large nucleus, an endoplasmic reticulum, electron dense-organelles and a double-walled, mitochondrion-like organelle. In addition ticks had ray-bodies in the gut lumen. These bodies had short protrusions containing 1-3 microtubules and a labyrinthine structure containing highly electron-dense organelles, so they were considered as the developing microgamont of T. sergenti.

Animals↗

PubMed2002

Tegumental ultrastructures of Echinoparyphium recurvatum according to developmental stages.

The present study was performed to observe tegumental ultrastructure of Echinoparyphium recurvatum according to developmental stages. Worms (1, 3, 5 and 15-day old) were recovered from chicks experimentally infected with metacercariae from Radix auricularia coreana. One-day old worms were elongated and ventrally concave, and covered with peg-like tegumental spines except the adjacent areas of the head crown and excretory pore. Type I sensory papillae were distributed on the lip of the oral sucker, and grouped ciliated papillae were around the oral sucker. Peg-like tegumental spines were densely distributed on the anterior surface of the ventral sucker level. The ventral sucker had an aspinous tegument and no sensory papillae. Tegumental spines on the posterior surface of the ventral sucker level were sparsely distributed and disappeared posteriorly. In 3 and 5-day old worms, the tegument around the oral sucker was aspinose and wrinkled concentrically. The ventral sucker had a wrinkled tegument and many bulbous papillae. Type I sensory papillae were distributed between the bulbous papillae. Tegumental spines were spade-shaped with a terminal tip. A total of 45 collar spines including 4 end group ones on both ventral corners was alternately arranged in 2 rows. The 15-day old worms were very stout and their tegumental spines were tongue-shaped without a terminal tip. From the above results, it is confirmed that the surface ultrastructure of E. recurvatum was generally similar to that of other echinostomatid flukes. However, some features, i.e., morphological change of tegumental spines and appearance of sensory papillae on the ventral sucker according to development, and number, shape and arrangement of collar spines, were characteristic, which may be of taxonomic and bioecological significance.

Animals↗

PubMed1999

The cochlear ganglion in human embryos of developmental stages 18 and 19.

The cochlear ganglion was investigated in serially sectioned human embryos at developmental stages 18 and 19 (44-46 postovulatory days). During this period the cochlear ganglion is separated from the vestibular ganglion, and it is adjacent to the cochlear duct. In embryos of investigated stages fibers of the cochlear ganglion enter the nuclei in the brain.

Embryonic and Fetal Development↗

PubMed1991

Cysteine proteinase activity in various developmental stages of Clonorchis sinensis: a comparative analysis.

1. Cysteine proteinase activity in acidic extracts of various developmental stages of Clonorchis sinensis (metacercariae, 1-, 2-, and 3-month old worms) was examined. All the activities were maximum at acidic pH and showed inhibitor susceptibilities similar to the vertebrate cysteine proteinases. 2. Specific activity of cysteine proteinase(s) was highest in metacercariae with either CBZ-phe-arg-AFC or Azocoll as the substrate. The immature and mature worms had similar (but less than metacercariae) levels of activity. 3. A soluble cysteine proteinase with a native molecular weight of approximately 20,000 +/- 1414 was partially purified from 1-, 2-, and 3-month worms. The molecular weight of similar activity in metacercariae was approximately 32,000. 4. Results suggest developmental regulation of cysteine proteinase activity in the life cycle of C. sinensis.

Animals↗

PubMed2001

Variations in chemical mimicry by the ectoparasitic mite Varroa jacobsoni according to the developmental stage of the host honey-bee Apis mellifera.

The ectoparasitic mite Varroa jacobsoni poses a major threat to the survival of European honey-bee populations. Development of effective control methods is therefore much needed. Study of interspecific chemical communication between the parasite and host is a particularly promising avenue of research. Previous study has shown that the cuticular hydrocarbons of the parasite mite Varroa jacobsoni are qualitatively identical to those of its honey-bee host Apis mellifera (Nation J.L., Sanford M.T., Milne K., 1992. Cuticular hydrocarbons from Varroa jacobsoni. Experimental and Applied Acarology 16, 331-344). The purpose of the present study was to compare the cuticular hydrocarbon patterns of the two species at different stages of bee development. Cuticular components were identified by gas chromatography/mass spectrometry. The proportion of each component was calculated at three stages of bee development (larvae, pupa, emerging bee). The degree of chemical mimicry between the parasite and host was evaluated by multivariate analyses using the resulting proportions for each category of individuals. There were four main findings. The first was that the proportions of some components are different at the larval, pupal and imago stage of bee development. Second, Varroa profiles vary depending on the developmental stage of the host. Third, the cuticular profile of adult mites is more similar to that of the stage of the host than that of later and/or earlier stages except for parasites collected from emerging adult bees. Fourth, the degree of mimicry by Varroa is greater during larval and pupal stages than during the emerging adult bee stages. The role of chemical mimicry - although it is not perfect - in enabling parasites to infest bee colonies by the parasite is discussed.

Animals↗

PubMed1998

Early developmental stages of psychopathology study (EDSP): objectives and design.

The primary and secondary objectives of the Early Developmental Stages of Substance Abuse Study (EDSP) are described along with a detailed description of the overall design, special design features and instruments used. The EDSP is a 5-year prospective study with three waves of assessments. Special design features are the linkages with family genetic investigations as well as neuroendocrinological stress tests in high-risk subjects. Overall, 3,021 adolescents and young adults aged 14-24 years are included. The response rate for the baseline investigation was 71%. Diagnostic assessments were made by using a modified lifetime (baseline) and 12-month change version of the WHO-CIDI, adjusted for DSM-IV. Modifications refer to a more detailed quantitative assessment of symptoms and substance use variables as well as the inclusion of questions to assess course of disorders and subthreshold diagnostic conditions.

Adolescent↗

PubMed2000

The Early Developmental Stages of Psychopathology Study (EDSP): a methodological update.

The objectives of the community-based Early Developmental Stages of Psychopathology (EDSP) Study are described along with a detailed account of the overall design, special design features, sample characteristics and instruments used. The EDSP employed a prospective-longitudinal design to study substance use and other mental disorders in a representative population sample of 3,021 subjects aged 14-24 years (birth cohorts 1970-1981) at 'baseline' - the outset of the study. Two follow-up investigations were conducted after the baseline investigation covering an overall period of 3-4 years. Special design features are the linkage with a family supplement (EDSP-FS) as well as neurobiological laboratory studies of high-risk subjects.

Adolescent↗

PubMed1980

Effects of arprinocid on developmental stages of Eimeria tenella.

Restricted medication experiments were done to correlate time of arprinocid medication with developmental stages of the life cycle of Eimeria tenella. By the criterion of histopathology and using a massive inoculum (10(6) sporulated oocysts), 50 ppm was partially active and 70 ppm was fully active against the first asexual generation when medication was delayed until day 1. When medication was delayed until day 2, full activity was demonstrated against the late, first asexual generation. When medication was delayed until day 3, definite but less complete activity was shown against the late, second asexual generation. Using the conventional efficacy parameters and with an inoculum of 5 X 10(4), full activity occurred with 50 ppm when medication was started up to day 2. Essentially full activity was observed with 60 ppm started at day 3. The combined results of the two tests are interpreted to indicate high activity against both the first and second asexual generations. Medication with 70 ppm changed the wall-forming bodies of the macrogamete. They were indistinct and less intensely eosinophilic than controls.

Adenine↗

PubMed2004

Genotoxicant induced DNA damage and repair in early and late developmental stages of the grass shrimp Paleomonetes pugio embryo as measured by the comet assay.

In this study, data are presented which link frequency of DNA strand breaks and repair capability to developmental stage. Stages 4 and 7 embryos of the grass shrimp (Palaemonetes pugio) were exposed to various concentrations of benzo[alpha]pyrene (BalphaP), Cr(VI) and hydrogen peroxide. Following exposure, responses were measured as changes in hatching rates and DNA strand breaks (using the comet assay). The comet assay was modified by treatment of isolated nuclei with endonucleases which cleave DNA at oxidative lesions in DNA prior to electrophoresis. DNA repair was followed by transfer of toxicant exposed embryos to clean water and periodic determination of strand breaks. DNA strand breaks were higher in stage 7 embryos than in stage 4 embryos after exposure to the same concentration of different genotoxicants. However, when samples were treated with endonucleases to measure oxidative lesions, the total amount of DNA damage between stages 4 and 7 were similar. After toxicant exposure and transfer to clean water, DNA strand breaks in stage 7 embryos returned to background levels more rapidly than in stage 4 embryos. Similarly, samples treated with endonucleases during DNA repair studies showed that oxidative lesions were repaired more rapidly in stage 7 than in stage 4. These findings suggest that because of rapid DNA repair in late embryo stages that early embryo stages are more likely to have developmental effects after genotoxicant exposure.

Animals↗

PubMed1995

DNA measurements and ploidy determination of developmental stages in the life cycles of Theileria annulata and T. parva.

The relative DNA levels of different developmental stages of Theileria annulata and T. parva in the cow and the tick were measured by the cytophotometric DNA technique using the fluorochrome Hoechst 33258 as a staining dye. The results revealed that sporozoites, merozoites, gamonts, and gametes were haploid, whereas multinucleated intralymphocytic schizonts were polyploid. No difference was observed between T. parva and T. annulata in these stages. For both Theileria species, the DNA measurements revealed that fusion of gametes occurred in the gut of the final host, thus providing evidence of sexual reproduction. However, differences were observed between the two parasites in the tick. Whereas T. parva zygotes underwent a two-step meiotic division, a comparable reduction division could not be unequivocally detected in T. annulata. Differences could also be detected in the further development of kinetes, indicating that Theileria species are not characterized by only one life cycle, which is specific for this genus.

Animals↗