Electron-Microscope Observation on the Pollen Development of Male Sterility Wheat Induced by Ethrel

The pollen development of male sterility wheat induced by Ethrel was studied in comparison with that of normal wheat by transmission and scanning electron-microscope. The results obtained are summarized as follows: 1. The primary morphological changes of abortive wheat pollen after treatment with Ethrel took place in the vacuole stage. The materials of cytoplasm were rarefied. All kinds of the cell organelles and vacuoles became degenerated and disorganized. Inside a small number of cell nuclei, chromatin granules coagulated irregularly. The number and the activity of the Ubisch bodices became reduced evidently. 2. In the mature stage, the differences between the treated wheat and normal wheat became even more striking. The normal pollens were spherical in sharp, and full of starch granules. The treated pollen were monstrous. There was a large empty vacuole in every abortive pollen cell, in which the starch granules were smaller and fewer than these in the normal ones. The nuclei and cytoplasm in some of the abortive pollens were degenerated, leaving only the cell walls. 3. Under scanning electron microscope, it was discovered that the normal wheat pollen were spherical or oval. The germinated pores jutted. The round-openings of the pores could be clearly seen. The abortive pollen induced by Ethrel looked like some shrunken balls, and became deformed and were blocked up. 4. On discussion of the mechanism of the Ethrel-induced male sterility in wheat, the authors suggest that special attention should be paid to the changes of the Ubisch bodies and the vacuoles.     

Protein and nuclear changes in pig eggs at fertilization.

The nuclear restructuring that occurs between insemination and full pronuclear formation in pig eggs is accompanied by posttranslational changes to specific egg proteins. Sperm penetration begins in vitro at 3 hr postinsemination (hpi). By 5 hr, decondensing sperm heads and anaphase II plates are observed in 50% of eggs, and, by 8 hpi, both male and female pronuclei have formed. Three consistent changes to the pattern of newly synthesised proteins are triggered in this period; they affect the 46K, 25K, and 22K polypeptides. Changes are also triggered in the 180-200K polypeptides and in the 14K polypeptides, but these are highly variable. The same changes in the prefertilization pattern were observed when prelabelled eggs were used and new protein synthesis was suppressed. The first and most abrupt change involves the apparent catabolic elimination of a group of 46K unphosphorylated polypeptides (pl 7.3-6.4), whose synthesis was greatest before germinal vesicle breakdown but declined slowly in the final phase of maturation, then declined precipitously after activation. Ageing (beyond maturation) also leads to the disappearance of these polypeptides. The progressive disappearance of a set of 25K polypeptides and the concomitant appearance of a dominant 22K polypeptide is the most characteristic fertilization-induced modification to porcine egg proteins. These modifications begin within 1 hr of sperm penetration or activation, are specific to the pig, and involve heavily phosphorylated polypeptides (25K, pl 6.7-6.0) whose synthesis is begun in the early metaphase I stage. Dual ([35S] and [32P]) labelling, protein blocking experiments, and use of alkaline phosphatase suggest that dephosphorylation selectively affects these 25K polypeptides and is mainly or wholly responsible for converting them (completely within 6 hr) to a single, new (22K, pl 7.6) species that is positively charged. The 25K/22K polypeptide modification has a close temporal relationship with the formation of the male and female pronuclei.     

Detecting Minimal Hepatic Encephalopathy in an Endemic Country for Hepatitis B: The Role of Psychometrics and Serum IL-6

Background & Aims

It remains unknown what the prevalence of minimal hepatic encephalopathy is in Taiwan, a highly endemic country for chronic viral hepatitis infection. It is also unclear whether abnormal serum cytokine levels can be indicative of the presence of minimal hepatic encephalopathy. We aimed to standardize the tests of psychometric hepatic encephalopathy score and predictive value of proinflammatory cytokines in minimal hepatic encephalopathy in Taiwan.

Methods

180 healthy subjects and 94 cirrhotic patients without a history of overt hepatic encephalopathy from a tertiary center were invited to participate in this cross-sectional study. Blood sampling for determination of serum levels of interleukin 6 and 18 and tumor necrosis factor-α was performed. Based on the normogram of psychometric hepatic encephalopathy score from healthy volunteers, patients with minimal hepatic encephalopathy were identified from the cirrhotic patients using the criterion of a psychometric hepatic encephalopathy score less than −4.

Results

In the healthy subjects, age and education were predictors of subtests of psychometric hepatic encephalopathy score. Minimal hepatic encephalopathy was identified in 27 (29%) cirrhotic patients. Serum interleukin 6 level (OR = 6.50, 95% CI = 1.64–25.76, P = 0.008) was predictive of the presence of minimal hepatic encephalopathy after multivariate analysis.

Conclusions

The psychometric hepatic encephalopathy score can be a useful tool for detecting patients with minimal hepatic encephalopathy in Taiwan and around one third of cirrhotic outpatients fulfill this diagnosis. A high serum interleukin 6 level is predictive of the presence of minimal hepatic encephalopathy.     

Assessing Mitochondrial DNA Variation and Copy Number in Lymphocytes of ~2,000 Sardinians Using Tailored Sequencing Analysis Tools

DNA sequencing identifies common and rare genetic variants for association studies, but studies typically focus on variants in nuclear DNA and ignore the mitochondrial genome. In fact, analyzing variants in mitochondrial DNA (mtDNA) sequences presents special problems, which we resolve here with a general solution for the analysis of mtDNA in next-generation sequencing studies. The new program package comprises 1) an algorithm designed to identify mtDNA variants (i.e., homoplasmies and heteroplasmies), incorporating sequencing error rates at each base in a likelihood calculation and allowing allele fractions at a variant site to differ across individuals; and 2) an estimation of mtDNA copy number in a cell directly from whole-genome sequencing data. We also apply the methods to DNA sequence from lymphocytes of ~2,000 SardiNIA Project participants. As expected, mothers and offspring share all homoplasmies but a lesser proportion of heteroplasmies. Both homoplasmies and heteroplasmies show 5-fold higher transition/transversion ratios than variants in nuclear DNA. Also, heteroplasmy increases with age, though on average only ~1 heteroplasmy reaches the 4% level between ages 20 and 90. In addition, we find that mtDNA copy number averages ~110 copies/lymphocyte and is ~54% heritable, implying substantial genetic regulation of the level of mtDNA. Copy numbers also decrease modestly but significantly with age, and females on average have significantly more copies than males. The mtDNA copy numbers are significantly associated with waist circumference (p-value = 0.0031) and waist-hip ratio (p-value = 2.4×10^-5), but not with body mass index, indicating an association with central fat distribution. To our knowledge, this is the largest population analysis to date of mtDNA dynamics, revealing the age-imposed increase in heteroplasmy, the relatively high heritability of copy number, and the association of copy number with metabolic traits.     

Comparison of the Morphology Development of Polymer–Fullerene and Polymer–Polymer Solar Cells during Solution‐Shearing Blade Coating

In this work, the detailed morphology studies of polymer poly(3‐hexylthiophene‐2,5‐diyl) (P3HT):fullerene(PCBM) and polymer(P3HT):polymer naphthalene diimide thiophene (PNDIT) solar cell are presented to understand the challenge for getting high performance all‐polymer solar cells. The in situ X‐ray scattering and optical interferometry and ex situ hard and soft X‐ray scattering and imaging techniques are used to characterize the bulk heterojunction (BHJ) ink during drying and in dried state. The crystallization of P3HT polymers in P3HT:PCBM bulk heterojunction shows very different behavior compared to that of P3HT:PNDIT BHJ due to different mobilities of P3HT in the donor:acceptor glass. Supplemented by the ex situ grazing incidence X‐ray diffraction and soft X‐ray scattering, PNDIT has a lower tendency to form a mixed phase with P3HT than PCBM, which may be the key to inhibit the donor polymer crystallization process, thus creating preferred small phase separation between the donor and acceptor polymer.