Showing papers in "Caryologia in 1967"
TL;DR: It is suggested that the situation found in the resting embryos of the two species reflects a strict control of the sequence of DNA synthesis and mitosis, probably bound to the genetic make-up of the species.
Abstract: SUMMARYThe DNA content of nuclei in the embryo of dry seeds of Pinus pinea and Lactuca sativa was determined by means of a Deeley type cytophotometer. It was found that in the root apex, shoot apex and cotyledon in Pinus and in the root apex and cotyledon in Lactuca all nuclei measured were 2C. Only in the root apex of one embryo (probably an immature seed) of Lactuca were both 2C and 4C nuclei found.The exclusive occurrence of 2C nuclei (G1 stage of the nuclear cycle for cells of meristematic type) in the embryo of Pinus pinea and Lactuca sativa is discussed. It is suggested that the situation found in the resting embryos of the two species reflects a strict control of the sequence of DNA synthesis and mitosis, probably bound to the genetic make-up of the species.
45 citations
TL;DR: The data presented seem to indicate that each of the processes considered is limited by a critical level of water availability.
Abstract: SUMMARYThe relation between cotyledon water content and following processes: i) DNA synthesis in cells of the radicle meristems, ii) mitotic activity in the meristems, iii) accumulation of storage material, has been studied during ripening of seeds in Vicia faba.It has been found that DNA synthesis stops when water content is still 75% of cotyledon fresh weight, while mitotic activity continues as long as water content is higher than 65%. This extended mitotic activity produces a progressive decrease in relative frequency of G2 cells, but not all G2 cells reach the G1 phase at full ripening stage.Accumulation of reserve material is less sensitive to decreased water supply; in fact it lasts as long as water content is higher than 55%.The data presented seem to indicate that each of the processes considered is limited by a critical level of water availability.
37 citations
TL;DR: In this article, the genomic structure of F pratensis, F arundinacea var glaucescens and F mairei was investigated through chromosome pairing in these species and their interspecific hybrids.
Abstract: SUMMARYThe object of the present study was to gain additional information about the genomic structure of F pratensis, F arundinacea var glaucescens, F arundinacea (2 n = 42), F Mairei and to confirm through chromosome pairing in these species and their interspecific hybrids the homologies suggested on karyotypic basis between their chromosome complements Based on two sources of evidence (karyotype and meiosis of F1 progeny) genomic formulae to different species are assigned 1 In the triploid hybrids involving F pratensis X F arundinacea var glaucescens, chromosome pairing at M-I could be represented by a mean of 748I, 548II, 85III In some cells as many as 19 chromosomes were associated (a) This pairing is regarded as allosyndetic though some amount of intergenomic pairing was also observed(b) Considering the karyotypic similarities between the satellited chromosomes of F pratensis and some of those of glaucescens, and also the meiosis of their F1 progeny, the genomic constitution of prate
34 citations
TL;DR: In cases of heterogeneous populations of nuclei, as found for cells of bean root meristems, synthetically active cells can be distinguished from inactive or quiescent cells by means of isotopic labeling.
Abstract: SUMMARY1. Several methods for relating the volumes of individual nuclei to their relative interphase stage have been applied to rapidly proliferating cells of the cortex in root tips of broad bean (Vicia faba). The methods are based upon analysis of the frequency with which particular volume classes appear within a population of nuclei. Presuming random sampling of a particular homogeneous population, it is possible and convenient to relate the volume of an individual nucleus to its age in relative interphase time by using the geometric mean volume and standard deviation of the sampled population to locate a straight line on probability paper. This graph can then be used to estimate the relative interphase time for any given nuclear volume in the population.2. In cases of heterogeneous populations of nuclei, as found for cells of bean root meristems, synthetically active cells can be distinguished from inactive or quiescent cells by means of isotopic labeling. The individual quiescent cells which occur sp...
30 citations
TL;DR: DNA cytophotometry and DNA labelling with 3H-thymidine were used to study the apical cell in lateral root primordia of Marsilea strigosa and in root apices of other species investigated, finding it divides rarely, if at all, whilst mitotic activity is retained by the mass of cells surrounding the apicals.
Abstract: SUMMARYDNA cytophotometry and DNA labelling with 3H-thymidine were used to study the apical cell in lateral root primordia of Marsilea strigosa and in root apices of Marsilea strigosa, Blechnum brasiliense, B. gibbum, Polypodium aureum and Ceratopteris thalictroides.The initial cell of the lateral root in Marsilea makes a series of divisions which lead to a primordium with a tetrahedral apical cell. At different stages of development of the primordium, the apical cell becomes « quiescent »; that is, it divides rarely, if at all, whilst mitotic activity is retained by the mass of cells surrounding the apical. This situation is kept in the apex of adult roots in Marsilea and the other species investigated. Quiescence of the apical cell is due to a permanent, or long-lasting, block in the G2 phase without any interference with further DNA synthesis up to 8–16C intermediate DNA contents. From time to time, the apical cell enters mitosis with either 4C (diploid) or — more rarely — 8C (tetraploid) DNA content. ...
30 citations
TL;DR: Comparative chromosome morphology shows that a uniform pattern prevails throughout the x = 11 species but that of the x= 12 plants is quite distinct and includes three pairs of telocentrics.
Abstract: SUMMARYThe somatic chromosomes of 28 accessions of Crinum have been studies. Ten of these were polyploid (3x, 4x, 6x, 8x) and the remainder diploid. B chromosomes were present in seven plants. Aneusomatic variation does not occur to any significant extent.The common basic number is x = 11 but accessions, based on x = 12 derive from the Accra Plains of Ghana. Comparative chromosome morphology shows that a uniform pattern prevails throughout the x = 11 species but that of the x = 12 plants is quite distinct and includes three pairs of telocentrics. There is every indication that this unique karyotype is closely correlated with the distribution of the species in an area of particular ecological interest.
29 citations
TL;DR: Eccetto R. arvalis, i rimanenti Ranidae presentano 26 cromosomi, suddivisibili in 5 paia di omologhi grandi, con caratteristiche morfologiche assai simili nelle varie specie, e 8 paia oficiali piccoli, with alcune differenze tra R. esculenta e R. ridibunda.
Abstract: RIASSUNTOViene descritto il cariotipo di 6 Ranidae: Rana esculenta, R. ridibunda, R. graeca, R. temporaria, R. arvalis e Mantella aurantiaca.Eccetto R. arvalis, i rimanenti Ranidae presentano 26 cromosomi, suddivisibili in 5 paia di omologhi grandi, con caratteristiche morfologiche assai simili nelle varie specie, e 8 paia di omologhi piccoli, con alcune differenze tra R. esculenta e R. ridibunda da una parte, e R. graeca, R. temporaria e Mantella dall'altra. Il cariotipo di R. arvalis (2 n=24) presenta una coppia di omologhi grandi in piu e due di piccoli in meno rispetto agli altri Ranidae.Attraverso il calcolo di due indici morfometrici delle varie coppie di cromosomi, sono state studiate le relazioni morfologiche fra i cariotipi dei 6 Ranidae. Sembrano essere presenti tre modelli di cariotipi: uno comune a R. esculenta e R. ridibunda; uno comune a R. graeca, R. temporaria e Mantella, il terzo, forse il piu specializzato, alla sola R. arvalis.L'evoluzione del cariotipo delle 6 specie non sempre sembra ...
26 citations
TL;DR: E stata messa in evidenza l'importanza della individuazione di cromosomi « morfologicamente identici » nello studio della cariologia dei Vespertilionidi.
Abstract: RIASSUNTOIn base all'analisi cariometrica, e stato definito il cartogramma di Pipistrellus savii (Bonaparte). Il cariogramma comprende 21 coppie di autosomi ed una coppia di eterocromosomi; delle 21 coppie, tre sono di metacentrici grandi, una di piccoli metacentrici, 15 di acrocentrici, di cui una coppia mostra chiaramente una zona eterocromatica, 2 di cromosomi puntiformi. Il cromosoma X e un metacentrico di medie dimensioni, il cromosoma Y e un acrocentrico piccolo, simile a un cromosoma puntiforme.E stato effettuato inoltre un confronto tra il cariogramma di P. savti e quelli di P. pipistrellus, P. nathusi (Bovey, 1949), Miniopterus schreibersii (Capanna e Civitelli, 1965) e P. kuhli (Capanna e Civitelli, 1966).E stata messa in evidenza l'importanza della individuazione di cromosomi « morfologicamente identici » nello studio della cariologia dei Vespertilionidi.
18 citations
TL;DR: Labelling of the nuclear cycle with 3H-thymidine and the determination of the minimum mitotic cycle by means of colchicine have shown that a 0,4% v/v concentration of ethyl alcohol given to root tips of Allium cepa for two hours induced a mitotic delay of 13 hrs.
Abstract: SUMMARYLabelling of the nuclear cycle with 3H-thymidine and the determination of the minimum mitotic cycle by means of colchicine have shown that a 0,4% v/v concentration of ethyl alcohol given to root tips of Allium cepa for two hours induced a mitotic delay of 13 hrs. The S phase is delayed 6 hrs, and the delay of G, is calculated to be about 7 hrs; G2 and prophase are not aifected by the treatment.
16 citations
TL;DR: In cells cultured in vitro Beryllium exerts a damaging action on all the mitotic phases; in high concentrations (1×10–3M) such action is stronger on lymphocytes than on kidney cells.
Abstract: SUMMARYIn cells cultured in vitro Beryllium exerts a damaging action on all the mitotic phases. In high concentrations (1×10–3M) such action is stronger on lymphocytes than on kidney cells.The mitotic index as well as mitotic morphology is impaired. The abnormalities are mainly stickiness, anaphasic bridges and migration of undivided chromosomes. No action on the achromatic spindle was observed.With the employed technique many chromatids breakages are also obtained; these do not appear to be limited to a particular chromosome or certain chromosome segments.The relationship between the poisonous action of Be++ and alkaline phosphatase are discussed.
14 citations
TL;DR: Im Zygotan bilden sich ebenso wie in den Interphase- and Ruhekernen 3 bis 6 Sammelchromozentren aus, die mit dem Ubergang zum Pachytan regelmassig zu einem einzigen verschmelzen, wahrend sich die euchromatischen Teile der Bivalente parallel anordnen.
Abstract: ZUSAMMENFASSUNGRhinanthus alectorolophus, minor, serotinus und aristatus von Fundorten in Niederosterreich bzw. Tirol besitzen durchwegs im haploiden Chromosomensatz 7 relativ grosse ungleichschenkelige (L-) und 4 kleine gleichschenkelige (K-) Chromosomen. Die ersteren sind zu einem grossen Teil heterochromatisch, die letzteren praktisch rein euchromatisch. Der Formwechsel der K-Chromosomen ist in der Mitose und Meiose gegenuber dem der L-Chromosomen verschoben.Im Zygotan bilden sich ebenso wie in den Interphase- und Ruhekernen 3 bis 6 Sammelchromozentren aus, die mit dem Ubergang zum Pachytan regelmassig zu einem einzigen verschmelzen, wahrend sich die euchromatischen Teile der Bivalente parallel anordnen; es kommt also ein Pachytanbukett zustande.In den beiden hoch endopolyploiden Kernen des chalazalen Endospermhaustoriums liegen die L-Chromosomen stets in Form von 21 Riesenchromosomen vor. Bei allen 4 Arten konnen nicht nur die regularen SAT-Riesenchromosomen, sondern auch andere und wie die Uberprufun...
TL;DR: L'analisi dei caratteri morfologici ha messo in evidenza una riduzione della taglia per la maggiore parte dei mutanti, foglia di forma diversa e generalmente con lamina ristretta, variazioni nel colore e nella morfologia del fiore.
Abstract: RIASSUNTONicotiana tabacum « purpurea » e stata irradiata con raggi gamma (Co60) a tre stadi successivi di sviluppo: gameti, zigoti e proembrioni; l'esposizione totale (1–24 kR) e stata applicata in 16 ore.In alcuni mutanti isolati nelle progenie piante, dai trattamenti suddetti, furono rilevate evidenti modificazioni fenotipiche riguardanti l'abito, l'altezza, l'infiorescenza, la foglia e piu parametri fiorali. L'analisi dei caratteri morfologici ha messo in evidenza una riduzione della taglia per la maggiore parte dei mutanti, foglia di forma diversa e generalmente con lamina ristretta, variazioni nel colore e nella morfologia del fiore che riguardano la lunghezza del tubo corollino, la larghezza della fauce e una situazione exerta o inclusa del pistillo. Le analisi citogenetiche effettuate su apici radicali di piantine mutanti in M6 e sulla metafase prima di ibridi F1 « mutante x test », hanno permesso di accertare: a) la presenza di ponti doppi nelle anafasi mitotiche, che denotano la persistenza di c...
TL;DR: An example of normally occurring coincident endopolyploidy and polyteny is reported from the larval salivary gland nuclei of an unidentified Cecidomyid species (possibly Lestodiplosis pisi).
Abstract: SUMMARYA second example of normally occurring coincident endopolyploidy and polyteny is reported from the larval salivary gland nuclei of an unidentified Cecidomyid species (possibly Lestodiplosis pisi). Two endopolyploid nuclei were found near the anterior end of each salivary gland in « super-giant » cells. These appear to develop from ordinary « diploid » polytene nuclei by progressive splitting.
TL;DR: None of the expected aneuploid or structurally homozygous products of sexual reproduction survive under natural conditions of Nothoscordum fragrans.
Abstract: SUMMARY1. Nothoscordum fragrans has colonised a wide range of habitats and, once introduced, can spread to become a weed.2. In a clone of this species with a heterozygous complement (2 n=19=13L + S) similar to those described by previous investigators, the ovules contained more than one embryo. After fertilisation, an embryo with a suspensor could be identified in some embryo-sacs. Usually, after competition for food reserves, only one seedling from each seed reached maturity, and this was frequently from an adventive nucellar embryo.3. Non-disjunction and lagging of unpaired univalents at meiosis, particularly S chromosomes of the heterotrivalent, result in many aneuploid pollen grains, but about 50% of pollen tubes were capable of reaching the ovule. A weak infertile aneuploid (2n +1 = 20 = 14L + 6S) was raised by artificially separating seedlings produced by one seed.4. None of the expected aneuploid or structurally homozygous products of sexual reproduction survive under natural conditions.5. It was c...
TL;DR: During researches on the ultrastructure of Fungi the author shows that many lomasomes are present in the hyphae of Agaricus campester Fr.
Abstract: SUMMARYDuring researches on the ultrastructure of Fungi the author shows that many lomasomes are present in the hyphae of Agaricus campester Fr. var. bisporus carpophores: however these organelles are not found in Manocha's micrographies of Agaricus campester. The writer can also demonstrate a previously uncharacterized complex of double membranes. It is often located near the hyphal wall, the septa and the cross-wall, rarely in the middle of the hypha. The membranes complex is frequently adjacent and closely related to vesicles and lomasomes.Some hypotheses are proposed on the ontogeny and physiological significance of the described organelles. The author suggests that lomasomes and double membranes complex are closely related in their distribution and ontogeny. Nevertheless it is not possible, at present, to establish a scheme for the behaviour and the relationships of lomasomes and membranes complex. The physiological significance of these organelles is also, at present, unknown: the author suggests th...
TL;DR: A comparison of the chromosomes of these species with those of T. hirtum and T. scabrum showed that the karyotype of each species has distinctive features, but some chromosomes of the species with 2n = 10 are similar in size and shape and may be homologous.
Abstract: SUMMARYThe chromosome number of T. ligusticum was found to be 2n = 12, and that of T. cherleri 2n = 10. A comparison of the chromosomes of these species with those of T. hirtum (2n=10) and T. scabrum (2n = 10) showed that the karyotype of each species has distinctive features, but some chromosomes of the species with 2n = 10 are similar in size and shape and may be homologous.It is unlikely that T. ligusticum is ancestral to the other three species.
TL;DR: Si nota nella matrice continua dei plastidi della spata ancora bianca, l'esistenza di formazioni simili al « corpo opaco » (GEROLA) e al « prolamellar body » (HODGE) e si sottolinea il fatto che non e stata mai riferita la loro presenza contemporanea in plastidio differenziatisi
Abstract: RIASSUNTOViene preso in esame Spathiphyllum wallisii Regel la cui spata presenta la caratteristica di passare dal colore bianco al colore verde ad un dato momento dell'antesi.Con lo scopo di studiare al M.E. i cambiamenti ultrastrutturali a carico dei plastidi, sono prelevati campioni dalla spata bianca, in via di inverdimento e quando e completamente verde.Si nota nella matrice continua dei plastidi della spata ancora bianca, l'esistenza di formazioni simili al « corpo opaco » (GEROLA) e al « prolamellar body » (HODGE) e si sottolinea il fatto che non e stata mai riferita la loro presenza contemporanea in plastidi differenziatisi in condizioni normali. Si osserva inoltre come, con l'inizio dell'inverdimento, « corpo opaco » e « prolamellar body » sembrino prendere contatto, come il « corpo opaco » successivamente si frammenti ed il plastidio assuma gradatamente la struttura lamellare tipica dei cloroplasti, struttura che risulta evidente con i prelievi fatti dalla spata completamente inverdita.Sembra che...
TL;DR: I cromosomi soprannumerari sono presenti in numero variabile da 1 a 3 nei vari individui e nelle cellule dello stesso individuo.
Abstract: RIASSUNTOHo potuto osservare la presenza di cromosomi soprannumerari in alcuni individui di una popolazione di un crostaceo isopode Asellus (Proasellus) coxalis raccolta presso Cittaducale, il cui corredo cromosomico normale e 2 n=12. I cromosomi soprannumerari sono presenti in numero variabile da 1 a 3 nei vari individui e nelle cellule dello stesso individuo. La presenza di due soprannumerari sembra essere la situazione piu stabile.Gli individui con soprannumerari sono stati incrociati con individui normali e hanno dato una discendenza fertile.
TL;DR: The diploid number of Lacerta sicula campestris is 2n = 38 and all the chromosomes are telocentric and morphologically recognizable heterochromosomes are absent.
Abstract: SUMMARYThe diploid number of Lacerta sicula campestris is 2n = 38. All the chromosomes are telocentric and morphologically recognizable heterochromosomes are absent.
TL;DR: The marked chromosome pair has been identified and its behavior, followed through meiosis, suggests that the achromatic zone has an inhibitory action on the formation of chiasmata.
Abstract: In a study of the meiotic chromosomes of Macaca, the mean chiasma frequency has been found to be between 1.9 and 2.1. No instances of translocation or insertions were seen. It is suggested that the Y chromosome pairs with the terminal portion of the short arms of the X chromosome. The marked chromosome pair has been identified and its behavior, followed through meiosis, suggests that the achromatic zone has an inhibitory action on the formation of chiasmata.
TL;DR: Sulla natura dei pigmenti di Orobanche hederae, e stato riferito anche da Baccarini e Melandri al Congresso di Bergamo della Societa Botanica Italiana (ottobre 1966).
Abstract: RIASSUNTONei fusti di Orobanche ramosa e stata accertata, con osservazioni al microscopio elettronico, la presenza di plastidi molto ricchi di amido nella porzione piu giovane e di cromoplasti nelle porzioni piu adulte e nelle squame. Nono sono mai stati osservati cloroplasti neppure ad uno stadio molto primitivo.Nello stesso materiale non e stata rilevata la benche minima quantita di clorofilla ed e stata accertata la incapacita a fissare fotosinteticamente la anidride carbonica.Sulla natura dei pigmenti di Orobanche hederae, e stato riferito anche da Baccarini e Melandri al Congresso di Bergamo della Societa Botanica Italiana (ottobre 1966).
TL;DR: The various abnormalities observed in PMCs and karyotype analysis suggest that this taxon is of possible hybrid origin, borne out by the total absence of fruit setting and the high percentage of pollen sterility observed in these plants.
Abstract: SUMMARYCytology of Iochroma tubulosa Benth has been studied. It showed 12 bivalents in PMC and 24 chromosomes in root tip cells. The various abnormalities observed in PMCs and karyotype analysis suggest that this taxon is of possible hybrid origin. This is also borne out by the total absence of fruit setting and the high percentage of pollen sterility observed in these plants.
TL;DR: Nelle cellule nutrici poliploidi dell'ovario anfigonico a 20′ dall'iniezione di uridina H3 la marcatura e solo nucleare â’ stata attribuita alla sintesi di DNA metabolico.
Abstract: RIASSUNTOE stato effettuato uno studio autoradiografico sull'attivita delle cellule nutrici negli ovari anfigonici e partenogenetici degli Afidi. Gli Afidi sono stati iniettati con timidina e uridine H3, come precursori degli acidi nucleici. L'incorporazione di timidina H3 avviene con le stesse modalita nell'ovario anfigonico e nell'ovario partenogenetico. In quest'ultimo la marcatura delle cellule nutrici diploidi e stata attribuita alla sintesi di DNA metabolico.Nelle cellule nutrici poliploidi dell'ovario anfigonico a 20′ dall'iniezione di uridina H3 la marcatura e solo nucleare. Dopo tempi piu lunghi dall'iniezione interessa anche il citoplasma delle cellule nutrici e quello dell'ovocita.
TL;DR: In bright field microscopy of plant material, the cytoplasm, nucleoli and insoluble polysaccharides are colored magenta by the periodic acid-Schiff reaction, causing an obvious distinction between the poly Saccharide and non-polysaccharide tissue components.
Abstract: SUMMARYIn bright field microscopy of plant material, the cytoplasm, nucleoli and insoluble polysaccharides are colored magenta by the periodic acid-Schiff reaction. Blue-violet light causes an obvious distinction between the polysaccharide and non-polysaccharide tissue components by producing a yellow fluorescence of the cytoplasm and nucleoli, while the polysaccharides appear red.
TL;DR: Le cellule secernenti delle ghiandole salivari di Helix aspersa Muller presentano vari aspetti ultrastrutturali, che possono venir riportate a due soli tipi cellulari funzionalmente diversi: mucociti e zimociti.
Abstract: RIASSUNTOLe cellule secernenti delle ghiandole salivari di Helix aspersa Muller presentano vari aspetti ultrastrutturali. Esse possono pero venir riportate a due soli tipi cellulari funzionalmente diversi: mucociti e zimociti. I condotti escretori di calibro maggiore sono tappezzati da un epitelio ricco di microvilli e di introflessioni della membrana cellulare. Queste ultime emanano dalla regione basale delle cellule, si spingono fino in prossimita della regione apicale e dividono il citoplasma in tanti minuscoli compartimenti, soprattutto occupati da un gran numero di mitocondri. Il quadro ricorda, in complesso, quello di un tipico epitelio bacillare, quale si riscontra, ad esempio, nei tubuli del rene dei Vertebrati.
TL;DR: The presence of glycogen has been put into evidence by electron microscopy with the technique of Hanker, Seaman, Weiss and others (1964) and it has been observed its disappearence with a pretreatment of the cells with diastase solutions at different concentration and for different lenghts of time.
Abstract: SUMMARYIt has been put into evidence by electron microscopy with the technique of Hanker, Seaman, Weiss and others (1964) the presence of glycogen in the cells of Nostoc commune Vaucher and it has been observed its disappearence with a pretreatment of the cells with diastase solutions at different concentration and for different lenghts of time.Glycogen had been already observed in Nostoc commune through the Bauer reaction, PAS, PAS pretreated with diastase and PAS and dimedone (Maugini 1966).
TL;DR: The authors consider that the strong effect of the 3′-adenylic acid upon the nucleus and the chromosomes is probably due to the DNA depolimerization (fact pointed out by the picnosis phenomenon), which contributes to the blocking of the macromolecules synthesis by the deoxyribonucleic acid.
Abstract: The study of the influence of the 3′-adenylic acid on cell division has shown that it has an inhibiting effect. This substance also produces various types of chromosomal aberrations, especially the picnosis phenomenon. By studying the effect of adenine, adenosine and 3′-adenylic acid on the mitotic cycle in Vicia faba, adenine and the 3′-adenylic acid have been found to considerably increase the length of the mitotic cycle. The authors consider that the strong effect of the 3′-adenylic acid upon the nucleus and the chromosomes is probably due to the DNA depolimerization (fact pointed out by the picnosis phenomenon). This also contributes to the blocking of the macromolecules synthesis by the deoxyribonucleic acid.