(n.) One of the exceedingly minute spores found in certain flowerless plants, as Selaginella and Isoetes, which bear two kinds of spores, one very much smaller than the other. Cf. Macrospore.
Example Sentences:
(1) Finally, the potential of using microinjection for transforming embryogenic microspores has been evaluated.
(2) A study has been made of the systematic fluctuations in the frequency of microspores in these compartments, when plants are grown under rigidly controlled conditions.
(3) Normal stamens exhibited the synthesis of many polypeptides not found in the mutant, from microspore mother cell to the preanthesis stages.
(4) The microspores were purified by centrifugation and washing and cultured in liquid medium on a membrane support.
(5) Rice (Oryza sativa L., 2n=24) anthers containing microspores in the early-uninucleate to first-mitosis stages were induced successfully to develop into plants in vitro through an intermediary step of callus formation.
(6) With both constructs, the appearance of GUS activity in developing anthers was correlated with the onset of microspore mitosis and increased progressively until anthesis (pollen shed).
(7) It is evident that not only do microspores mature at different rates, but that the maturation rate of individual microspores varies during the developmental sequence.
(8) Hoechst 33342, a nuclear stain, alone or in combination with either or both of the other stains, could be used to highlight the nuclear developmental stage of the microspores.
(9) This family is composed of 10 to 15 closely related genes which are expressed in early stages of microspore development.
(10) Blepharoplast formation and function has been investigated by light and electron microscopy in developing microspores of the water fern Marsilea vestita.
(11) Embryogenic microspores continued to increase in size throughout the culture period and fluoresced when stained with fluoresecein diacetate (FDA).
(12) During normal meiosis the distribution of microtubules follows a specific temporal and spatial pattern that reflects the polar nature of microspore formation.
(13) High expression of the transcript is limited to microspores entering and undergoing mitosis.
(14) Farmer's lung, caused by the inhalation of microspores--particularly of the genus, Thermoactinomyces--has been recognised for the past 30-40 years as a condition affecting adult farm workers, especially up to the mid-sixties when undried crops were still threshed indoors.
(15) Above all, the microspore-derived embryo system is recommended to both plant breeders and plant biochemists for the selection and multiplication of plants of superior quality.
(16) A new allele of the maize A1 gene, a gene required for anthocyanin pigment biosynthesis, was identified in a genetic stock exhibiting a high frequency of chromosome breakage at the second microspore mitosis.
(17) The microspores of Marsilea and Pilularia have non-specific esterase activity concentrated in the intine inthe immediate vicinity of the germinal site; that is, above the position of the future male gametangia.
(18) Two anther cDNA libraries were constructed, one from anthers of 1.2-1.8 mm long buds (sporogenesis library) and one from anthers of 1.8-4.0 mm long buds (microspore development library).
(19) The ultrastructure of the mature spermatozoid of Marsilea vestita was studied after its release from the microspore and prior to its penetration of the egg.
(20) With the microblending technique a mean of 9.4 green plants and 0.4 albino plants were regenerated per plated anther while a mean of only 2.8 green and 0.17 albino plants per anther were regenerated from microspores isolated after pestle maceration of the anthers.
Pollen
Definition:
(n.) Fine bran or flour.
(n.) The fecundating dustlike cells of the anthers of flowers. See Flower, and Illust. of Filament.
Example Sentences:
(1) We conclude that the priming effect is not a clinically significant phenomenon during natural pollen exposure in allergic rhinitis patients.
(2) The diagnosis of occupational allergy was based on history, skin prick tests and RAST to the pollen.
(3) Using a large clinic population with adequate controls, significant correlation between ragweed, grass or tree pollen sensitivity and the dates of birth was not obtained.
(4) For pollen asthma, six studies conclude that there were superior results with desensitization than to placebo.
(5) They were placed less than 5 m apart, and estimation of the pollen amount was made on a day-to-day basis during the pollen seasons, and on a weekly basis outside the seasons.
(6) The impact of pollen on the respiratory mucosa was modeled by studying the process by which solutes are eluted from pollen grains.
(7) One part fresh pollen grains is uniformly mixed with nine parts of the solution and left at room temperature for at least 5 hr.
(8) We have developed a reverse-type sandwich ELISA for measurement of IgG (+IgA) antibody to a major allergen of Sugi (Japanese cedar) pollens.
(9) The concentration of these pollens decrease in April, completely diminishing in May.
(10) Six atopic subjects with grass pollen allergy and six nonallergic healthy volunteers were enrolled into this study.
(11) Inhalant allergens as mite house dust, animal danders, pollens, molds and food allergens are considered, now, to be the most sensitizing agents.
(12) Most patients showed several positive skin tests to common allergens particular to grass pollen, house dust and mites (Dermatophagoides pteronyssimus).
(13) The pollen sterility (up to 30% of grains) is due to the abortive spore development.
(14) A pollen-specific cDNA clone, Zmc13, has been isolated from a cDNA library constructed to poly(A) RNA from mature maize pollen.
(15) Sixty patients with seasonal allergic rhinitis due to birch pollen were enrolled in an open, randomized parallel group study.
(16) We have studied some aspects of the atopic syndrome in this population of Southern Italy: frequency of allergic sensitization according to endogenous and extrinsic factors (particularly Parietaria officinalis, a characteristic pollen of the Southern Italian Flora), etc.
(17) It was observed that cocksfoot pollen extract is stable but there appears a slight but significant (P less than 0.05) decay in activity when the extract stored for up to 6 months was compared with a freshly prepared extract.
(18) These are collected in her pollen baskets which she takes back to the nest to feed the young after fertilising the flowers.
(19) It was observed, perhaps for the first time, that feeling worse when there is a high pollen count appears to be associated with the symptom pattern seen in winter SAD patients.
(20) In allergologic out-patient departments of Dubrovnik, Split, Sibenik, Zadar, Pula and Rijeka, 300 patients with pollinosis have been tested by the application of the prick method of group allergens of grass, tree and weed pollen, particularly of Parietariae (pellitory) pollen.