| 1. |
|
|
| 2. |
- Klionsky, Daniel J., et al.
(författare)
-
Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
-
Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
-
Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
|
|
| 3. |
- Dubbaka Venu, Pradeep Reddy, 1982-, et al.
(författare)
-
Oocyte-specific deletion of Pten causes premature activation of the primordial follicle pool
- 2008
-
Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 319:5863, s. 611-613
-
Tidskriftsartikel (refereegranskat)abstract
- In the mammalian ovary, progressive activation of primordial follicles from the dormant pool serves as the source of fertilizable ova. Menopause, or the end of female reproductive life, occurs when the primordial follicle pool is exhausted. However, the molecular mechanisms underlying follicle activation are poorly understood. We provide genetic evidence that in mice lacking PTEN (phosphatase and tensin homolog deleted on chromosome 10) in oocytes, a major negative regulator of phosphatidylinositol 3-kinase (PI3K), the entire primordial follicle pool becomes activated. Subsequently, all primordial follicles become depleted in early adulthood, causing premature ovarian failure (POF). Our results show that the mammalian oocyte serves as the headquarters of programming of follicle activation and that the oocyte PTEN-PI3K pathway governs follicle activation through control of initiation of oocyte growth.
|
|
| 4. |
- Rajareddy, Singareddy, et al.
(författare)
-
p27kip1 (cyclin-dependent kinase inhibitor 1B) controls ovarian development by suppressing follicle endowment and activation and promoting follicle atresia in mice
- 2007
-
Ingår i: Molecular Endocrinology. - : The Endocrine Society. - 0888-8809 .- 1944-9917. ; 21:9, s. 2189-2202
-
Tidskriftsartikel (refereegranskat)abstract
- In humans, the molecular mechanisms underlying ovarian follicle endowment and activation, which are closely related to the control of female reproduction, occurrence of menopause, and related diseases such as premature ovarian failure, are poorly understood. In the current study, we provide several lines of genetic evidence that the cyclin-dependent kinase (Cdk) inhibitor 1B (commonly known as p27kip1 or p27) controls ovarian development in mice by suppressing follicle endowment and activation, and by promoting follicle death. In p27-deficient (p27−/−) mice, postnatal follicle assembly was accelerated, and the number of endowed follicles was doubled as compared with p27+/+ mice. Moreover, in p27−/− ovaries the primordial follicle pool was prematurely activated once it was endowed, and at the same time the massive follicular death that occurs before sexual maturity was rescued by loss of p27. In early adulthood, however, the overactivated follicular pool in p27−/− ovaries was largely depleted, causing premature ovarian failure. Furthermore, we have extensively studied the molecular mechanisms underlying the above-mentioned phenotypes seen in p27−/− ovaries and have found that p27 controls follicular development by several distinct mechanisms at different stages of development of the ovary. For example, p27 controls oocyte growth by suppressing the functions of Cdk2/Cdc2-cyclin A/E1 in oocytes that are arrested at the diplotene stage of meiosis I. This function of p27 is distinct from its well-known role as a suppressor of cell cycle progression. In addition, we have found that p27 activates the caspase-9-caspase-3-caspase-7-poly (ADP-ribose) polymeraseapoptotic cascade by inhibiting Cdk2/Cdc2-cyclin A/B1 kinase activities in follicles, thereby inducing follicle atresia. Our results suggest that the p27 gene is important in determining mammalian ovarian development. This study therefore provides insight into ovary-borne genetic aberrations that cause defects in folliculogenesis and infertility in humans.
|
|
| 5. |
- Chen, Wenbo, et al.
(författare)
-
The draft genome of whitefly Bemisia tabaci MEAM1, a global crop pest, provides novel insights into virus transmission, host adaptation, and insecticide resistance
- 2016
-
Ingår i: BMC Biology. - : Springer Science and Business Media LLC. - 1741-7007. ; 14:1
-
Tidskriftsartikel (refereegranskat)abstract
- Background: The whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is among the 100 worst invasive species in the world. As one of the most important crop pests and virus vectors, B. tabaci causes substantial crop losses and poses a serious threat to global food security. Results: We report the 615-Mb high-quality genome sequence of B. tabaci Middle East-Asia Minor 1 (MEAM1), the first genome sequence in the Aleyrodidae family, which contains 15,664 protein-coding genes. The B. tabaci genome is highly divergent from other sequenced hemipteran genomes, sharing no detectable synteny. A number of known detoxification gene families, including cytochrome P450s and UDP-glucuronosyltransferases, are significantly expanded in B. tabaci. Other expanded gene families, including cathepsins, large clusters of tandemly duplicated B. tabaci-specific genes, and phosphatidylethanolamine-binding proteins (PEBPs), were found to be associated with virus acquisition and transmission and/or insecticide resistance, likely contributing to the global invasiveness and efficient virus transmission capacity of B. tabaci. The presence of 142 horizontally transferred genes from bacteria or fungi in the B. tabaci genome, including genes encoding hopanoid/sterol synthesis and xenobiotic detoxification enzymes that are not present in other insects, offers novel insights into the unique biological adaptations of this insect such as polyphagy and insecticide resistance. Interestingly, two adjacent bacterial pantothenate biosynthesis genes, panB and panC, have been co-transferred into B. tabaci and fused into a single gene that has acquired introns during its evolution. Conclusions: The B. tabaci genome contains numerous genetic novelties, including expansions in gene families associated with insecticide resistance, detoxification and virus transmission, as well as numerous horizontally transferred genes from bacteria and fungi. We believe these novelties likely have shaped B. tabaci as a highly invasive polyphagous crop pest and efficient vector of plant viruses. The genome serves as a reference for resolving the B. tabaci cryptic species complex, understanding fundamental biological novelties, and providing valuable genetic information to assist the development of novel strategies for controlling whiteflies and the viruses they transmit.
|
|
| 6. |
- Liao, Hong, et al.
(författare)
-
Genome-wide identification of resistance genes and response mechanism analysis of key gene knockout strain to catechol in Saccharomyces cerevisiae
- 2024
-
Ingår i: FRONTIERS IN MICROBIOLOGY. - 1664-302X. ; 15
-
Tidskriftsartikel (refereegranskat)abstract
- Engineering Saccharomyces cerevisiae for biodegradation and transformation of industrial toxic substances such as catechol (CA) has received widespread attention, but the low tolerance of S. cerevisiae to CA has limited its development. The exploration and modification of genes or pathways related to CA tolerance in S. cerevisiae is an effective way to further improve the utilization efficiency of CA. This study identified 36 genes associated with CA tolerance in S. cerevisiae through genome-wide identification and bioinformatics analysis and the ERG6 knockout strain (ERG6 Delta) is the most sensitive to CA. Based on the omics analysis of ERG6 Delta under CA stress, it was found that ERG6 knockout affects pathways such as intrinsic component of membrane and pentose phosphate pathway. In addition, the study revealed that 29 genes related to the cell wall-membrane system were up-regulated by more than twice, NADPH and NADP(+) were increased by 2.48 and 4.41 times respectively, and spermidine and spermine were increased by 2.85 and 2.14 times, respectively, in ERG6 Delta. Overall, the response of cell wall-membrane system, the accumulation of spermidine and NADPH, as well as the increased levels of metabolites in pentose phosphate pathway are important findings in improving the CA resistance. This study provides a theoretical basis for improving the tolerance of strains to CA and reducing the damage caused by CA to the ecological environment and human health.
|
|
| 7. |
- Zhou, Jie, et al.
(författare)
-
Simultaneously enhancing the strength and plasticity of Ti-based bulk metallic glass composites via microalloying with Ta
- 2019
-
Ingår i: Materials Research Letters. - : TAYLOR & FRANCIS INC. - 2166-3831. ; 8:1, s. 23-30
-
Tidskriftsartikel (refereegranskat)abstract
- Characteristics of deformation-induced transformation under loading dictate the mechanical performance of TRIP (transformation-induced plasticity)-reinforced bulk metallic glass composites (BMGCs), which have shown great potential as engineering materials. Here, we report that the addition of 0.3 at.% Ta in the Ti45Cu41Ni9Zr5 alloy could induce the formation of uniform glassy composite structure with B2-(Ti,Zr)(Ni,Cu) precipitates. More interestingly, nanosized A2-(Ti,Zr)(Ni,Cu) particles also formed inside B2 grains which effectively impede rapid propagation of martensite plates and lead to the formation of multi-oriented martensites, eventually homogenizing the involved plastic flow during deformation-induced transformation. Consequently, high fracture strength (similar to 3000 MPa), large plasticity (similar to 25%) and pronounced work-hardening ability were achieved. [GRAPHICS] IMPACT STATEMENT Microalloying of Ta not only homogenizes the B2 distribution, but also facilitates formation of multi-orientated martensites during deformation, resulting in simultaneously enhanced strength and plasticity of a Be-free Ti-based BMGC.
|
|
