The Abnormal Change of Lysine-Rich Histone in the Pollen Mother Cell Nuclei before and after Meiosis

Author(s):  
Xue Guangxing ◽  
Deng Jingyang
Crustaceana ◽  
2016 ◽  
Vol 89 (6-7) ◽  
pp. 669-684
Author(s):  
J. J. Ning ◽  
M. M. Zhang ◽  
Q. Q. Tong ◽  
X. Cao ◽  
D. L. Wang ◽  
...  

To explore the pathogenic mechanism of white spot syndrome virus (WSSV) in crayfish (Cherax quadricarinatus), we analysed activities of the three immune-related enzymes PO, SOD and LSZ in haemolymph tissue ofC. quadricarinatusbefore and after infection, and simultaneously studied the ultrastructural pathology. The results show that WSSV infection affects activities of the three enzymes. After 6-24 h of WSSV infection, the activities of PO, SOD and LSZ increased, but decreased significantly during longer infection times. The enzyme activities in WSSV-infected crayfish were significantly lower than those in controls at 72 h, except for LSZ (). Interestingly, the activities of PO, SOD and LSZ in the group treated with immune-polysaccharides before challenge with WSSV were higher than in the directly infected group, and the immune protection rate reached 51.9%, suggesting that the polysaccharides could improve enzyme activities and enhance antiviral defences of the organism. Ultrastructural pathological changes showed damaged haemolymph tissue, deformed golgiosomes, fuzzy damage in the mitochondrial structures, and nuclear membrane deformation and fracture. High levels of heterochromatin appeared in the nucleus; organoid and chromatin dissolved in dying blood cells, cytoplasm appeared oedematous and cells dissolved. WSSV particles were visible in blood cell nuclei of infected crayfish.


2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Francesco Amadeo ◽  
Gianluca Polvani ◽  
Marco Agrifoglio ◽  
Federica Boschetti ◽  
Maurizio Pesce ◽  
...  

Background: Aldehyde-fixed pericardium is commonly used in valve implant manufacturing. Despite its wide employment, this tissue undergoes chronic rejection that limits implant performance and durability. In this work, we employed a method to engineer a leaflet-like tissue by seeding aortic valve interstitial cells (VIC) into fixative-free decellularized pericardium using a bioreactor based approach. Methods: Following treatment with hypotonic buffer (Tris-HCl) to induce cell lysis, porcine pericardium was incubated with TritonX-100, to remove adipose tissue and then treated with sodium dodecylsulfate to wash cellular debris. DNA was removed by incubation into a DNAse I solution. Pericardium permeability was measured on samples before and after decellularization (pressure from 735 Pa to 2200 Pa). A direct perfusion bioreactor was employed to seed (3days, 3ml/min) porcine VICs (6.5E+5 cell/scaffold) into decellularized pericardium patches (6mm diameters) and perform long-term culture (up to 14 days, 0.03ml/min). Cell seeding efficiency (Day 3) and cell proliferation (Day 7-14) were evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) staining, histological analyses and fluorescence staining for quiescent/activated VIC markers (DAPI, vimentin, α-smooth muscle actin). Results: Permeability tests revealed a significant increase in decellularized samples (1-way ANOVA p < 0.05), thus supporting its use in a direct perfusion bioreactor system. MTT staining revealed homogeneous cell seeding distribution, supported by DAPI staining, showing efficient cellularization through the whole patch volume. Computer-based cell nuclei counting revealed a significant cell increase from day 3 to 7 and 14 ( p <0.05 1-way ANOVA). Immunofluorescence showed a marked reduction of αSMA in cells populating the inner layers. Conclusions: Our data show, for the first time, the capability to seed and culture VICs into a cell/fixative free pericardium with a direct perfusion system. Moreover, the use of pericardium treated with our decellularization procedure and recellularized under dynamic conditions supports a more physiological growth of VIC, as suggested by downregulation of αSMA in the inner pericardium layer.


Forests ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 1598
Author(s):  
Wenju Lu ◽  
Enbo Wang ◽  
Weijuan Zhou ◽  
Yifan Li ◽  
Zhaoji Li ◽  
...  

Dacrydium pectinatum de Laubenfels is a perennial gymnosperm species dominant in tropical montane rain forests. Due to severe damages by excessive deforestation, typhoons, and other external forces, the population of the species has been significantly reduced. Furthermore, its natural regeneration is poor. To better understand the male cone development in D. pectinatum, we examined the morphological and anatomical changes, analyzed the endogenous hormone dynamics, and profiled gene expression. The morpho-histological observations suggest that the development of D. pectinatum male cone can be largely divided into four stages: microspore primordium formation (April to May), microspore sac and pollen mother cell formation (July to November), pollen mother cell division (January), and pollen grain formation (February). The levels of gibberellins (GA), auxin (IAA), abscisic Acid (ABA), cytokinin (CTK), and jasmonic acid (JA) fluctuated during the process of male cone development. The first transcriptome database for a Dacrydium species was generated, revealing >70,000 unigene sequences. Differential expression analyses revealed several floral and hormone biosynthesis and signal transduction genes that could be critical for male cone development. Our study provides new insights on the cone development in D. pectinatum and the foundation for male cone induction with hormones and studies of factors contributing to the species’ low rate of seed germination.


2008 ◽  
Vol 133 (1) ◽  
pp. 107-116 ◽  
Author(s):  
Pablo Bolaños-Villegas ◽  
Shih-Wen Chin ◽  
Fure-Chyi Chen

The development of new cultivars in Doritaenopsis Guillaum. & Lami orchids is often hindered by factors such as low seed count in hybrids. Cytological study may offer the ability to develop new hybrids by revealing cultivars with good chromosome pairing and high pollen viability, which are somewhat difficult to obtain under current breeding programs. Cross pollination, pollen viability, and chromosomal behavior during meiosis were analyzed to reveal the relation between seed fertility and capsule set in Doritaenopsis hybrids. The number of mature capsules harvested and their relative seed content were used as indices of crossing availability. The results of meiosis were evaluated according to pollen viability detected by fluorescein diacetate and quantification of sporad types by acid fuchsin staining. Chromosome number and pairing at meiosis were observed in root tips or in samples of pollen mother cells. A positive relation was found among high seed set, high frequency of viable tetrads, high degree of chromosome pairing, and low frequency of chromosomal aberrations such as inversions and translocations. On the basis of these factors, three types of hybrids could be distinguished. In type one hybrids, chromosomes paired as bivalents, pollen mother cells divided into tetrads, and capsule setting occurred after pollination of pollen acceptors. In type two hybrids, chromosomes remained mainly as univalents that developed into micromeiocytes, pollen mother cell division was disrupted, and seed recovery was low after pollination. Type three hybrids showed chromosomes paired mostly as multivalents, chromosome bridges, pollen mother cell division with massive failure, and little fertility. In Doritaenopsis orchids, high pollen viability and high fertility depends on a high frequency of normal tetrads, and low seed set in cross-pollination is predicted with micronuclei in the end products of meiosis. The occurrence of chromosomal aberrations may suggest a process of genome differentiation that could compromise breeding efforts if not taken into consideration.


2010 ◽  
Vol 36 (10) ◽  
pp. 1777-1785
Author(s):  
Jin-Hua HE ◽  
Xing-An CHENG ◽  
Zhi-Xiong CHEN ◽  
Hai-Bin GUO ◽  
Xiang-Dong LIU ◽  
...  

1986 ◽  
Vol 28 (1) ◽  
pp. 130-137 ◽  
Author(s):  
S. E. Smith ◽  
R. P. Murphy

Fertility (seed production) in alfalfa (Medicago sativa L.) is severely depressed by inbreeding; however, little is known of the factors directly responsible for this depression. Irregularities in meiotic behavior could be partially responsible for the inbreeding depression in fertility observed. This study considered relationships between fertility, inbreeding, and irregularity in microsporogenesis. Fertility declined markedly with inbreeding in the materials examined (S0–S3). Irregularity in microsporogenesis, as measured by the percent irregular quartets, (i.e., quartets with micronuclei, supernumerary microspores, or irregular cytokinesis) increased significantly with inbreeding. Increases in quartet irregularity were associated with increases in the number of univalents per pollen mother cell observed at metaphase I. Considering all materials studied, the percentage of irregular quartets was negatively and significantly correlated with fertility as both a seed and a pollen parent. In more detailed analyses, it was observed that the percent irregular quartets was negatively associated with fertility as a pollen parent only when levels of irregularity were relatively high. No association was observed between the percent irregular quartets and fertility when levels of irregularity were relatively low.Key words: Medicago, microsporogenesis, seed production, breeding, fertility.


1959 ◽  
Vol 34 (1) ◽  
pp. 19-22 ◽  
Author(s):  
Kamla K. Pandey ◽  
Robert D. Henry

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