A Conserved, Mg2+-Dependent Exonuclease Degrades Organelle DNA during Arabidopsis Pollen Development[C][W]

Extrachromosomal DNAs, present in plastids and mitochondria, are present in multiple copies and appear to be degraded in the mature pollen of most angiosperm species. This study, by deciphering a tissue-specific organelle DNA degradation mechanism, identifies the organellar nuclease that degrades these extrachromosomal DNAs during Arabidopsis pollen development

Tissue-specific organelle DNA degradation mediated by DPD1 exonuclease

Organelle DNA in plastids and mitochondria is present in multiple copies and undergoes degradation developmentally. For example, organelle DNA that is detectable cytologically using DNA-fluorescent dye disappears during pollen development. Nevertheless, nucleases involved in this degradation process remain unknown. Our recent study identified the organelle nuclease, DPD1, which has Mg2+-dependent exonuclease activity in vitro. The discovery of DPD1 emerged from Arabidopsis mutant screening and concomitant isolation of dpd1 mutants that retain organelle DNA in mature pollen. DPD1 is conserved only in angiosperms: not in other photosynthetic organisms. Despite these findings, the physiological significance of organelle DNA degradation during pollen development remains unclear because dpd1 exhibits no apparent defects in pollen viability or in the maternal inheritance of organelle DNA. We discuss a possible role of organelle DNA degradation mediated by DPD1, based on a DPD1 expression profile studied using in silico analyses

Development of anaerobic osmotic membrane bioreactor for low-strength wastewater treatment at mesophilic condition

A novel anaerobic osmotic membrane bioreactor (AnOMBR) was developed for treating low strength wastewater. The AnOMBR utilizes a forward osmosis (FO) membrane to retain influent organic waste, which facilitates anaerobic wastewater treatment and energy recovery in the form of methane gas. The feasibility of AnOMBR for treating low-strength wastewater at mesophilic temperature was evaluated and membrane fouling was investigated. Permeate flux declined under the combined effects of both salt accumulation and membrane fouling. Although flux reduction was dominated by the effect of salt accumulation in the reactor, the presence of organic fouling and inorganic scaling could be clearly identified. Bulk pH could be maintained within neutral to slightly alkaline due to the retention of alkalinity by the FO membrane. The AnOMBR shows good and stable removal of soluble chemical oxygen demand (sCOD) and nearly complete removal of total phosphorous. However, only partial removal of total nitrogen and ammonia was observed. The elevated salt environment appeared to have little effect on bioactivity of methanogens, and stable methane production of 0.3 L/g sCOD digested was obtained. (C) 2015 Elsevier B.V. All rights reservedclose2

Cosmeceutical therapy:Engaging the repercussions of uvr photoaging on the skin’s circadian rhythm

Sunlight is an important factor in regulating the central circadian rhythm, including the modulation of our sleep/wake cycles. Sunlight had also been discovered to have a prominent influence on our skin’s circadian rhythm. Overexposure or prolonged exposure to the sun can cause skin photodamage, such as the formation of irregular pigmentation, collagen degradation, DNA damage, and even skin cancer. Hence, this review will be looking into the detrimental effects of sunlight on our skin, not only at the aspect of photoaging but also at its impact on the skin’s circadian rhythm. The growing market trend of natural-product-based cosmeceuticals as also caused us to question their potential to modulate the skin’s circadian rhythm. Questions about how the skin’s circadian rhythm could counteract photodamage and how best to maximize its biopotential will be discussed in this article. These discoveries regarding the skin’s circadian rhythm have opened up a completely new level of understanding of our skin’s molecular mechanism and may very well aid cosmeceutical companies, in the near future, to develop better products that not only suppress photoaging but remain effective and relevant throughout the day

Treatment patterns and outcomes of older patients with mantle cell lymphoma in an Asian population

10.1186/s12885-021-08326-1BMC Cancer21156