1. |
|
|
2. |
|
|
3. |
- Klionsky, Daniel J., et al.
(author)
-
Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
-
In: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
-
Research review (peer-reviewed)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.
|
|
4. |
- Hjortswang, H I, et al.
(author)
-
KNOTTED1-like homeobox genes of a gymnosperm, Norway spruce, expressed during somatic embryogenesis
- 2002
-
In: Plant physiology and biochemistry (Paris). - 0981-9428 .- 1873-2690. ; 40:10, s. 837-843
-
Journal article (peer-reviewed)abstract
- Two Norway spruce (Picea abies (L.) Karst.) genes belonging to class I of the KNOTTED1-like homeobox (KNOX) genes, HBK2 and HBK3, were cloned with PCR-based methods. The expression of these and a previously characterised related gene, HBK1, in different organs and during somatic embryogenesis was studied with RTPCR. Transcripts of all three genes were detected in stems, roots and in cone buds, but not in needles. HBK1 and HBK3 are expressed throughout development in a normal cell line with embryogenic potential and in a cell line unable to form somatic embryos. HBK2 is expressed in the normal cell line, but not in the developmentally arrested cell line. This suggests that the HBK2 gene is involved in the somatic embryo development.
|
|
5. |
- Högberg, Karl-Anders, et al.
(author)
-
Critical factors affecting ex vitro performance of somatic embryo plants of Picea abies
- 2001
-
In: Scandinavian Journal of Forest Research. - : Informa UK Limited. - 0282-7581 .- 1651-1891. ; 16:4, s. 295-304
-
Journal article (other academic/artistic)abstract
- The potential to use somatic embryos for large-scale propagation of elite genotypes, for integration into breeding programmes and for connecting breeding and mass propagation, is receiving much attention. However, before the methods are applied it is important that the plants regenerated via somatic embryogenesis grow as expected, i.e. as seedlings or cuttings. Growth of somatic embryo plants is under a cumulative influence of a number of treatments given during the in vitro phase and during the ex vitro establishment phase. The aim of this study was to identify treatments with a negative influence on the subsequent growth of somatic embryo plants of Norway spruce (Picea abies L. Karst.). Based on the results, the time of contact with abscisic acid during somatic embryo maturation and the length of continuous light treatment (CLT) during the first growth period strongly affect the height growth during two successive growth periods. In both cases longer treatments exerted negative effects. Based on these results a new method was set up, which includes: (1) prematuration treatment of the suspension culture in a growth regulator-free medium, by which the maturation step is synchronized and contracted; and (2) a two-phase germination treatment, first on a solidified medium and then in a liquid medium. This treatment avoids extended CLT during the first growth period. Another advantage of the two-phase germination treatment is a better root-system development. Somatic embryo plants produced according to this method can be transferred directly from in vitro conditions to the greenhouse.
|
|