scholarly journals Proplastid Dna Synthesis at Pachytene in Pollen Mother Cells of Lilium Henryi

1982 ◽  
Vol 56 (1) ◽  
pp. 293-302
Author(s):  
D. R. SMYTH
Keyword(s):  
Dna Synthesis ◽  
Dna Sequences ◽  
Nuclear Dna ◽  
Buoyant Density ◽  
Plastid Dna ◽  
Electron Microscopic ◽  
Pollen Mother Cells ◽  
Specific Hybridization ◽  
Chloroplast Dna Sequences ◽  
Mother Cells

About three-quarters of the DNA synthesis occurring in pachytene pollen mother cells of Lilium henryi takes place in proplastids. Only around 15% can be attributed to mitochondrial labelling and 10% to nuclear DNA synthesis. Label was identified in the proplastid genome by its location in electron microscopic autoradiographs, by its buoyant density (1.698 g/ml), and by its specific hybridization to chloroplast DNA sequences from spinach. Proplastids, while apparently not dividing at pachytene, may be replicating their DNA in readiness for subsequent proliferation in developing microspores. The annealing properties of plastid DNA closely parallel those of labelled pachytene DNA sequences implicated in meiotic exchange events.

scholarly journals Identification of a Natural Hybrid between Castanopsis sclerophylla and Castanopsis tibetana (Fagaceae) Based on Chloroplast and Nuclear DNA Sequences

Forests ◽  
2020 ◽  
Vol 11 (8) ◽  
pp. 873
Author(s):  
Xiaorong Zeng ◽  
Risheng Chen ◽  
Yunxin Bian ◽  
Xinsheng Qin ◽  
Zhuoxin Zhang ◽  
...  
Keyword(s):  
Dna Sequences ◽  
Nuclear Dna ◽  
Genetic Admixture ◽  
Natural Hybrid ◽  
Hybrid Species ◽  
Chloroplast Haplotype ◽  
Flora Of China ◽  
Nuclear Microsatellite ◽  
Chloroplast Dna Sequences ◽  
Genetic Pools

Castanopsis × kuchugouzhui Huang et Y. T. Chang was recorded in Flora Reipublicae Popularis Sinicae (FRPS) as a hybrid species on Yuelushan mountain, but it is treated as a hybrid between Castanopsis sclerophylla (Lindl.) Schott. and Castanopsis tibetana Hance in Flora of China. After a thorough investigation on Yuelushan mountain, we found a population of C. sclerophylla and one individual of C. × kuchugouzhui, but no living individual of C. tibetana. We collected C. × kuchugouzhui, and we sampled 42 individuals of C. sclerophylla from Yuelushan and Xiushui and 43 individuals of C. tibetana from Liangyeshan and Xiushui. We used chloroplast DNA sequences and 29 nuclear microsatellite markers to investigate if C. × kuchugouzhui is a natural hybrid between C. sclerophylla and C. tibetana. The chloroplast haplotype analysis showed that C. × kuchugouzhui shared haplotype H2 with C. sclerophylla on Yuelushan. The STRUCTURE analysis identified two distinct genetic pools that corresponded well to C. sclerophylla and C. tibetana, revealing the genetic admixture of C. × kuchugouzhui. Furthermore, the NewHybrids analysis suggested that C. × kuchugouzhui is an F2 hybrid between C. sclerophylla and C. tibetana. Our results confirm that C. × kuchugouzhui recorded in FRPS is a rare hybrid between C. sclerophylla and C. tibetana.

Ottelia guanyangensis (Hydrocharitaceae), a new species from southwestern China

Phytotaxa ◽  
2018 ◽  
Vol 361 (3) ◽  
pp. 294 ◽  
Author(s):  
ZHI-ZHONG LI ◽  
KUO LIAO ◽  
CHUN-YU ZOU ◽  
YAN LIU ◽  
GUANG-WAN HU ◽  
...  
Keyword(s):  
Phylogenetic Analysis ◽  
New Species ◽  
Dna Sequences ◽  
Internal Transcribed Spacer ◽  
Aquatic Plant ◽  
Nuclear Dna ◽  
Southwestern China ◽  
Molecular Phylogenetic ◽  
Chloroplast Dna Sequences ◽  
A New Species

Ottelia guanyangensis (Hydrocharitaceae), a new species from southwestern China, is described and illustrated. This aquatic plant is a perennial, submersed herb with bisexual flowers and a hexagonal-cylindric fruit. It is related to O. acuminata var. songmingensis and O. balansae but differs from these two taxa by its bisexual flowers, spathe with 2–5 flowers, trinerved leaf with obvious cross veins, and a winged, hexagonal-cylindric fruit. Molecular phylogenetic analysis based on nuclear DNA internal transcribed spacer (ITS) sequences and three chloroplast DNA sequences (rbcL, trnK5’ intron and trnS-trnG) resolves O. guanyangensis as a distinct clade, which further justifies its recognition as a new species.

Preferential mitochondrial and plastid DNA synthesis before multiple cell divisions in Nicotiana tabacum

1992 ◽  
Vol 103 (3) ◽  
pp. 831-837 ◽  
Author(s):  
T. Suzuki ◽  
S. Kawano ◽  
A. Sakai ◽  
M. Fujie ◽  
H. Kuroiwa ◽  
...  
Keyword(s):  
Nicotiana Tabacum ◽  
Stationary Phase ◽  
Dna Synthesis ◽  
Cell Line ◽  
Nuclear Dna ◽  
Root Meristem ◽  
Low Frequency ◽  
Plastid Dna ◽  
Lag Phase ◽  
Quiescent Center

Organelle DNA synthesis in root meristem and cultured cell line BY-2, both derived from Nicotiana tabacum cv. Bright Yellow 2, was examined by immunofluorescence microscopy of Technovit sections with antibody against 5- bromodeoxyuridine (BrdU) and co-fluorescent staining with 4′,6-diamidino-2-phenylindole (DAPI) and quantitative Southern hybridization. In the root meristem, the mitochondrial DNAs (mtDNAs) were synthesized in a specific region near to the quiescent center, where a low frequency of DNA synthesis of cell nuclei was observed. The mitochondrial nuclei (nucleoids) changed morphologically from long ellipsoids with a high frequency of DNA synthesis, in the region just above the quiescent center, to granules with a low frequency of DNA synthesis, as cell distance from the quiescent center increased. Similar patterns were observed in the cultured tobacco cell line (BY-2), in which large amounts of preferential synthesis of DNA of both mitochondria and plastids occurred prior to cell nuclear DNA synthesis just after stationary phase cells were transferred to fresh medium. Granular mitochondria which vigorously synthesized mtDNA were observed in both lag phase and logarithmic growth phase cells. However, long, ellipsoidal mitochondria which showed a low frequency of mtDNA synthesis were observed in stationary phase cells. Morphological changes of plastids were more conspicuous than those of mitochondria. After the medium was renewed, spherical plastids became extremely elongated and string-like, for 24 h, but were divided into small pieces after the third day. Vigorous synthesis of plastid DNA (ptDNA) occurred during this period of plastids elongation.

scholarly journals Plastid DNA fingerprinting of the rare Fritillaria moggridgei (Liliaceae) reveals population differentiation and genetic isolation within the Fritillaria tubiformis complex

Phytotaxa ◽  
2013 ◽  
Vol 91 (1) ◽  
pp. 1 ◽  
Author(s):  
MARCO MUCCIARELLI ◽  
MICHAEL F. FAY
Keyword(s):  
Dna Fingerprinting ◽  
Dna Sequences ◽  
Dna Markers ◽  
Nuclear Dna ◽  
Plastid Dna ◽  
Genetic Isolation ◽  
Analysis Of Molecular Variance ◽  
Molecular Variance ◽  
Matk Gene ◽  
Length Variable

A phylogenetic analysis based on combined DNA sequences of the partial matK gene and the rpl16 intron showed that the rare alpine endemic Fritillaria tubiformis subsp. moggridgei (Liliaceae) and the more widespread F. tubiformis var. burnatii are exclusively related. A genetic study used plastid DNA markers, due to limits imposed by nuclear DNA fingerprinting in species with large genomes, to study variation within and between populations. Five length-variable homopolymer repeats (polyA and polyT) and four regions with one or two insertion/deletions (indels) of different lengths were identified. Of the total of 56 plastid haplotypes obtained, 32 were fixed in the seven populations of subsp. moggridgei and the rest were variable in var. burnatii. Analysis of molecular variance (AMOVA) showed higher genetic variation among rather than within subsp. moggridgei populations. Indel mutations, on the other hand, were fundamental in distinguishing the two taxa.

scholarly journals Molecular systematics of some bifurcate hairy sections in Astragalus L. (Fabaceae) as inferred from nuclear and chloroplast DNA sequences

2016 ◽  
Vol 23 (2) ◽  
pp. 223-235 ◽  
Author(s):  
Reza Sheikhakbari-Mehr ◽  
Ali Asghar Maassoumi ◽  
Shahrokh Kazempour Osaloo
Keyword(s):  
Chloroplast Dna ◽  
Molecular Systematics ◽  
Dna Sequences ◽  
Plastid Dna ◽  
Monophyletic Group ◽  
Monophyletic Clade ◽  
Plant Taxon ◽  
Chloroplast Dna Sequences ◽  
Established Species ◽  
Astragalus Sect

In this study, 38 species belonging to some bifurcate hairy sections of Astragalus L. were analyzed phylogenetically, using nuclear and plastid DNA sequences. Based on our results, Astragalus sect. Dissitiflori DC. with the inclusion of the members of section Erioceras Bunge, formed a monophyletic group. The members of sect. Ornithopodium Bunge and Onobrychoidei DC. were located together within a highly supported monophyletic clade, apart from other sections studied, on the basis of the present molecular data.The positioning of the enigmatic, recently established species, A. juladakensis Maassoumi, within the sect. Dissitiflori was verified. In addition, our results showed that A. pravitzii Podl., which had been already transferred to sect. Ornithopodium, belongs to the section Dissitiflori.Bangladesh J. Plant Taxon. 23(2): 223-235, 2016 (December)

scholarly journals Characterization of cytoplasmic and nuclear genomes in the colorless alga Polytoma. III. Ribosomal RNA cistrons of the nucleus and leucoplast.

1976 ◽  
Vol 69 (2) ◽  
pp. 383-392 ◽  
Author(s):  
C Siu ◽  
K Chiang ◽  
H Swift
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Ribosomal Rna ◽  
Nuclear Dna ◽  
Buoyant Density ◽  
Nuclear Genome ◽  
The Other ◽  
Heterologous Hybridization ◽  
Other Hand ◽  
Specific Hybridization

The colorless alga Polytoma obtusum has been found to possess leucoplasts, and two kinds of ribosomes with sedimentation values of 73S and 79S. The ribosomal RNA (rRNA) of the 73S but not the 79S ribosomes was shown to hybridize with the leucoplast DNA (rho - 1.682 g/ml). Nuclear DNA of Polytoma (rho = 1.711) showed specific hybridization with rRNA from the 79S ribosomes. Saturation hybridization indicated that only one copy of the rRNA cistrons was present per leucoplast genome, with an average buoyant density of rho = 1.700. On the other hand, about 750 copies of the cytoplasmic rRNA cistrons were present per nuclear genome with a density of rho = 1.709. Heterologous hybridization studies with Chlamydomonas reinhardtii rRNAs showed an estimated 80% homology between the two cytoplasmic rRNAs, but only a 50% homology between chloroplast and leucoplast rRNAs of the two species. We conclude that the leucoplasts of Polytoma derive from chloroplasts of a Chlamydomonas-like ancestor, but that the leucoplast rRNA cistrons have diverged in evolution more extensively than the cistrons for cytoplasmic rRNA.

The duration of meiosis in pollen mother cells of wheat, rye and Triticale

1971 ◽  
Vol 178 (1052) ◽  
pp. 259-275 ◽  
Keyword(s):  
Triticum Aestivum ◽  
Dna Synthesis ◽  
Secale Cereale ◽  
Sampling Methods ◽  
Tritiated Thymidine ◽  
Pollen Mother Cells ◽  
Mother Cells

The duration of meiosis and its stages at 20 °C has been determined in wheat ( Triticum aestivum 2 n = 6 x = 42), in rye ( Secale cereale 2 n = 14) and in Triticale (2 n = 8 x = 56) by sampling methods and by timing the intervals between the pre-meiotic DNA synthesis and meiotic stages following the incorporation of tritiated thymidine. The results from all the methods used were in general agreement. Meiosis takes about 24 h in wheat, 21 h in Triticale and about 51 h in rye. The lengths of the meiotic stages relative to that of the division correspond reasonably well in the three forms studied but zygotene and pachytene were much longer in rye than in wheat and Triticale .

Winter and spring changes in the microsporogenous cells of the Scotch pine as revealed by Feulgen photometry and Auramin fluorometry

1977 ◽  
Vol 55 (10) ◽  
pp. 1434-1442 ◽  
Author(s):  
Sirkka Kupila-Ahvenniemi
Keyword(s):  
Dna Synthesis ◽  
Cell Layer ◽  
The Other ◽  
Scotch Pine ◽  
Pollen Mother Cells ◽  
Cell Divisions ◽  
Mother Cells

Sporogenous cells of Scotch pine microsporangia were separated from the other tissues of the strobilus. This made it possible to spread them on slides as a one-cell layer for cytophotometric studies. Feulgen photometry using Schiff s reagent showed that during the overwintering period the DNA level of these cells remained more or less constant. The nuclei in a microsporangium were not fully homogeneous in size and stainability. DNA synthesis occurred in the spring, preceding and overlapping the cell divisions that led to the formation of pollen mother cells. Auramin fluorometry showed that in spite of the steadiness of the DNA quantity, the sporogenous cells were not in a state of complete rest during the winter. Their stainability fluctuated so that it increased during the middle of the winter, reached a peak in February, and then dropped. Higher dye attachment was seen again in the May material. The factor(s) causing the wintertime fluctuation is unknown at the present.

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