1
|
Stenshorne I, Syvertsen M, Ramm-Pettersen A, Henning S, Weatherup E, Bjørnstad A, Brüggemann N, Spetalen T, Selmer KK, Koht J. Monogenic developmental and epileptic encephalopathies of infancy and childhood, a population cohort from Norway. Front Pediatr 2022; 10:965282. [PMID: 35979408 PMCID: PMC9376386 DOI: 10.3389/fped.2022.965282] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 07/07/2022] [Indexed: 12/01/2022] Open
Abstract
INTRODUCTION Developmental and epileptic encephalopathies (DEE) is a group of epilepsies where the epileptic activity, seizures and the underlying neurobiology contributes to cognitive and behavioral impairments. Uncovering the causes of DEE is important in order to develop guidelines for treatment and follow-up. The aim of the present study was to describe the clinical picture and to identify genetic causes in a patient cohort with DEE without known etiology, from a Norwegian regional hospital. METHODS Systematic searches of medical records were performed at Drammen Hospital, Vestre Viken Health Trust, to identify patients with epilepsy in the period 1999-2018. Medical records were reviewed to identify patients with DEE of unknown cause. In 2018, patients were also recruited consecutively from treating physicians. All patients underwent thorough clinical evaluation and updated genetic diagnostic analyses. RESULTS Fifty-five of 2,225 patients with epilepsy had DEE of unknown etiology. Disease-causing genetic variants were found in 15/33 (45%) included patients. Three had potentially treatable metabolic disorders (SLC2A1, COQ4 and SLC6A8). Developmental comorbidity was higher in the group with a genetic diagnosis, compared to those who remained undiagnosed. Five novel variants in known genes were found, and the patient phenotypes are described. CONCLUSION The results from this study illustrate the importance of performing updated genetic investigations and/or analyses in patients with DEE of unknown etiology. A genetic cause was identified in 45% of the patients, and three of these patients had potentially treatable conditions where available targeted therapy may improve patient outcome.
Collapse
Affiliation(s)
- Ida Stenshorne
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.,Department of Children and Adolescents, Drammen Hospital, Vestre Viken Health Trust, Drammen, Norway
| | - Marte Syvertsen
- Department of Neurology, Drammen Hospital, Vestre Viken Health Trust, Drammen, Norway
| | - Anette Ramm-Pettersen
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.,Department of Clinical Neurosciences for Children, Oslo University Hospital, Oslo, Norway
| | - Susanne Henning
- Department of Children and Adolescents, Drammen Hospital, Vestre Viken Health Trust, Drammen, Norway
| | - Elisabeth Weatherup
- Department of Children and Adolescents, Drammen Hospital, Vestre Viken Health Trust, Drammen, Norway
| | - Alf Bjørnstad
- Department of Children and Adolescents, Stavanger University Hospital, Stavanger Health Trust, Stavanger, Norway
| | - Natalia Brüggemann
- Department of Children and Adolescents, Drammen Hospital, Vestre Viken Health Trust, Drammen, Norway
| | - Torstein Spetalen
- Department of Neurology, Drammen Hospital, Vestre Viken Health Trust, Drammen, Norway
| | - Kaja K Selmer
- National Center for Epilepsy, Oslo University Hospital, Oslo, Norway.,Division of Clinical Neuroscience, Department of Research and Innovation, Oslo University Hospital, Oslo, Norway
| | - Jeanette Koht
- Department of Neurology, Oslo University Hospital, Oslo, Norway
| |
Collapse
|
2
|
Alston CL, Heidler J, Dibley MG, Kremer LS, Taylor LS, Fratter C, French CE, Glasgow RI, Feichtinger RG, Delon I, Pagnamenta AT, Dolling H, Lemonde H, Aiton N, Bjørnstad A, Henneke L, Gärtner J, Thiele H, Tauchmannova K, Quaghebeur G, Houstek J, Sperl W, Raymond FL, Prokisch H, Mayr JA, McFarland R, Poulton J, Ryan MT, Wittig I, Henneke M, Taylor RW. Bi-allelic Mutations in NDUFA6 Establish Its Role in Early-Onset Isolated Mitochondrial Complex I Deficiency. Am J Hum Genet 2018; 103:592-601. [PMID: 30245030 PMCID: PMC6174280 DOI: 10.1016/j.ajhg.2018.08.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 08/22/2018] [Indexed: 12/04/2022] Open
Abstract
Isolated complex I deficiency is a common biochemical phenotype observed in pediatric mitochondrial disease and often arises as a consequence of pathogenic variants affecting one of the ∼65 genes encoding the complex I structural subunits or assembly factors. Such genetic heterogeneity means that application of next-generation sequencing technologies to undiagnosed cohorts has been a catalyst for genetic diagnosis and gene-disease associations. We describe the clinical and molecular genetic investigations of four unrelated children who presented with neuroradiological findings and/or elevated lactate levels, highly suggestive of an underlying mitochondrial diagnosis. Next-generation sequencing identified bi-allelic variants in NDUFA6, encoding a 15 kDa LYR-motif-containing complex I subunit that forms part of the Q-module. Functional investigations using subjects’ fibroblast cell lines demonstrated complex I assembly defects, which were characterized in detail by mass-spectrometry-based complexome profiling. This confirmed a marked reduction in incorporated NDUFA6 and a concomitant reduction in other Q-module subunits, including NDUFAB1, NDUFA7, and NDUFA12. Lentiviral transduction of subjects’ fibroblasts showed normalization of complex I. These data also support supercomplex formation, whereby the ∼830 kDa complex I intermediate (consisting of the P- and Q-modules) is in complex with assembled complex III and IV holoenzymes despite lacking the N-module. Interestingly, RNA-sequencing data provided evidence that the consensus RefSeq accession number does not correspond to the predominant transcript in clinically relevant tissues, prompting revision of the NDUFA6 RefSeq transcript and highlighting not only the importance of thorough variant interpretation but also the assessment of appropriate transcripts for analysis.
Collapse
|
3
|
Baussant T, Bechmann RK, Taban IC, Larsen BK, Tandberg AH, Bjørnstad A, Torgrimsen S, Naevdal A, Øysaed KB, Jonsson G, Sanni S. Enzymatic and cellular responses in relation to body burden of PAHs in bivalve molluscs: a case study with chronic levels of North Sea and Barents Sea dispersed oil. Mar Pollut Bull 2009; 58:1796-1807. [PMID: 19732912 DOI: 10.1016/j.marpolbul.2009.08.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2009] [Revised: 07/30/2009] [Accepted: 08/03/2009] [Indexed: 05/28/2023]
Abstract
Mytilus edulis and Chlamys islandica were exposed to nominal dispersed crude oil concentrations in the range 0.015-0.25 mg/l for one month. Five biomarkers (enzymatic and cellular responses) were analysed together with bioaccumulation of PAHs at the end of exposure. In both species, PAH tissue residues reflected the exposure concentration measured in the water and lipophilicity determined the bioaccumulation levels. Oil caused biomarker responses in both species but more significant alterations in exposed C. islandica were observed. The relationships between exposure levels and enzymatic responses were apparently complex. The integrated biomarker response related against the exposure levels was U-shaped in both species and no correlation with total PAH body burden was found. For the monitoring of chronic offshore discharges, dose- and time-related events should be evaluated in the selection of biomarkers to apply. From this study, cellular damages appear more fitted than enzymatic responses, transient and more complex to interpret.
Collapse
Affiliation(s)
- T Baussant
- International Research Institute of Stavanger/IRIS-Biomiljø, Mekjarvik 12, 4070 Randaberg, Norway.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
4
|
Abay F, Bjørnstad A, Smale M. Measuring on Farm Diversity and Determinants of Barley Diversity in Tigray, Northern Ethiopia. mejs 2009. [DOI: 10.4314/mejs.v1i2.46048] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
5
|
Lillemo M, Asalf B, Singh RP, Huerta-Espino J, Chen XM, He ZH, Bjørnstad A. The adult plant rust resistance loci Lr34/Yr18 and Lr46/Yr29 are important determinants of partial resistance to powdery mildew in bread wheat line Saar. Theor Appl Genet 2008; 116:1155-66. [PMID: 18347772 DOI: 10.1007/s00122-008-0743-1] [Citation(s) in RCA: 155] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2007] [Accepted: 03/01/2008] [Indexed: 05/18/2023]
Abstract
Powdery mildew, caused by Blumeria graminis f. sp. tritici is a major disease of wheat (Triticum aestivum L.) that can be controlled by resistance breeding. The CIMMYT bread wheat line Saar is known for its good level of partial and race non-specific resistance, and the aim of this study was to map QTLs for resistance to powdery mildew in a population of 113 recombinant inbred lines from a cross between Saar and the susceptible line Avocet. The population was tested over 2 years in field trials at two locations in southeastern Norway and once in Beijing, China. SSR markers were screened for association with powdery mildew resistance in a bulked segregant analysis, and linkage maps were created based on selected SSR markers and supplemented with DArT genotyping. The most important QTLs for powdery mildew resistance derived from Saar were located on chromosomes 7DS and 1BL and corresponded to the adult plant rust resistance loci Lr34/Yr18 and Lr46/Yr29. A major QTL was also located on 4BL with resistance contributed by Avocet. Additional QTLs were detected at 3AS and 5AL in the Norwegian testing environments and at 5BS in Beijing. The population was also tested for leaf rust (caused by Puccinia triticina) and stripe rust (caused by P. striiformis f. sp. tritici) resistance and leaf tip necrosis in Mexico. QTLs for these traits were detected on 7DS and 1BL at the same positions as the QTLs for powdery mildew resistance, and confirmed the presence of Lr34/Yr18 and Lr46/Yr29 in Saar. The powdery mildew resistance gene at the Lr34/Yr18 locus has recently been named Pm38. The powdery mildew resistance gene at the Lr46/Yr29 locus is designated as Pm39.
Collapse
Affiliation(s)
- M Lillemo
- Department of Plant and Environmental Sciences, Norwegian University of Life Sciences, P.O. Box 5003, 1432 As, Norway.
| | | | | | | | | | | | | |
Collapse
|
6
|
Lillemo M, Asalf B, Singh RP, Huerta-Espino J, Chen XM, He ZH, Bjørnstad A. The adult plant rust resistance loci Lr34/Yr18 and Lr46/Yr29 are important determinants of partial resistance to powdery mildew in bread wheat line Saar. Theor Appl Genet 2008. [PMID: 18347772 DOI: 10.1007/s00122‐008‐0743‐1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Subscribe] [Scholar Register] [Indexed: 09/29/2022]
Abstract
Powdery mildew, caused by Blumeria graminis f. sp. tritici is a major disease of wheat (Triticum aestivum L.) that can be controlled by resistance breeding. The CIMMYT bread wheat line Saar is known for its good level of partial and race non-specific resistance, and the aim of this study was to map QTLs for resistance to powdery mildew in a population of 113 recombinant inbred lines from a cross between Saar and the susceptible line Avocet. The population was tested over 2 years in field trials at two locations in southeastern Norway and once in Beijing, China. SSR markers were screened for association with powdery mildew resistance in a bulked segregant analysis, and linkage maps were created based on selected SSR markers and supplemented with DArT genotyping. The most important QTLs for powdery mildew resistance derived from Saar were located on chromosomes 7DS and 1BL and corresponded to the adult plant rust resistance loci Lr34/Yr18 and Lr46/Yr29. A major QTL was also located on 4BL with resistance contributed by Avocet. Additional QTLs were detected at 3AS and 5AL in the Norwegian testing environments and at 5BS in Beijing. The population was also tested for leaf rust (caused by Puccinia triticina) and stripe rust (caused by P. striiformis f. sp. tritici) resistance and leaf tip necrosis in Mexico. QTLs for these traits were detected on 7DS and 1BL at the same positions as the QTLs for powdery mildew resistance, and confirmed the presence of Lr34/Yr18 and Lr46/Yr29 in Saar. The powdery mildew resistance gene at the Lr34/Yr18 locus has recently been named Pm38. The powdery mildew resistance gene at the Lr46/Yr29 locus is designated as Pm39.
Collapse
Affiliation(s)
- M Lillemo
- Department of Plant and Environmental Sciences, Norwegian University of Life Sciences, P.O. Box 5003, 1432 As, Norway.
| | | | | | | | | | | | | |
Collapse
|
7
|
Gomiero A, Pampanin DM, Bjørnstad A, Larsen BK, Provan F, Lyng E, Andersen OK. An ecotoxicoproteomic approach (SELDI-TOF mass spectrometry) to biomarker discovery in crab exposed to pollutants under laboratory conditions. Aquat Toxicol 2006; 78 Suppl 1:S34-41. [PMID: 16631935 DOI: 10.1016/j.aquatox.2006.02.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Ciphergen ProteinChip Technology is a proteomic tool, used for the discovery of new and sensitive biomarkers. This approach was used to evaluate the protein profile of crabs exposed to various pollutants. Two different exposure experiments were performed: spider crabs (Hyas araneus) were exposed for 3 weeks to diallyl phatalate (DAP), bisphenol A (BisA) and polybrominated diphenyl ether (PBDE-47), while shore crabs (Carcinus maeanas) were exposed to crude oil, crude oil spiked with alkylphenols (APs) and 4-nonylphenol (NP). Gender and species-related protein pattern alterations were observed and compared to controls. Results showed different responses to pollutants by the two species. Major disruption in protein peak expression was observed in samples exposed to mixtures of pollutants, i.e. oil spiked with APs. Compared to shore crab, spider crab species showed a lower degree of response in terms of number of altered protein peaks following exposure. In general, female individuals of both species showed a larger number of significantly altered proteins compared to males. Data analysis by non-metric multi-dimensional scaling (MDS) was performed. Bi-dimesional-MDS plots revealed a good separation of groups for both spider and shore crabs. In some cases, a good discrimination can also be observed between the two genders within each treatment. Results highlight the potential of crabs as sentinel organisms for the aquatic environment. The results indicate that SELDI-ToF technology is a powerful tool to discover protein expression signatures for different pollutants and sex dependent responses.
Collapse
Affiliation(s)
- A Gomiero
- IRIS-International Research Institute of Stavanger, Mekjarvik 12, N-4070 Randaberg, Norway
| | | | | | | | | | | | | |
Collapse
|
8
|
Bjørnstad A, Larsen BK, Skadsheim A, Jones MB, Andersen OK. The potential of ecotoxicoproteomics in environmental monitoring: biomarker profiling in mussel plasma using ProteinChip array technology. J Toxicol Environ Health A 2006; 69:77-96. [PMID: 16291563 DOI: 10.1080/15287390500259277] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
New global technologies, allowing simultaneous analysis of thousands of genes, proteins, and metabolites (so-called "omics" technologies), are being adopted rapidly by industry, academia, and regulatory agencies. This study evaluated the potential of proteomics in ecotoxicological research (i.e., ecotoxicoproteomics). Filter-feeding mussels (Mytilus edulis) were exposed continuously for 3 wk to oil, or oil spiked with alkylphenols and extra polycyclic aromatic hydrocarbons. The influence of chronic exposure on mussel plasma protein expression was investigated utilizing ProteinChip array technology in combination with surface-enhanced laser desorption/ionization time-of-flight mass spectrometry (SELDI TOF MS). Results indicated that exposure to spiked oil had a more significant effect on protein expression in mussels than oil alone. In total, 83 mass peaks (intact or modified proteins/peptides) were significantly altered by spiked oil, while 49 were altered by oil. In exposed organisms, the majority of peaks were upregulated compared to controls (i.e., 69% in oil and 71% in spiked oil). Some peaks (32 in total) were affected by both treatments; however, the degree of response was higher in the spiked oil group for 25 of the 32 commonly affected features. Additionally, certain peaks revealed exposure- or gender-specific responses. Multivariate analysis with regression tree-based methods detected protein patterns associated with exposure that correctly classified masked samples with 90-95% accuracy. Similarly, 92% of females and 85% of males were correctly classified (independent of exposure). Results indicate that proteomics have the potential to make a valuable contribution to environmental monitoring and risk assessment.
Collapse
|
9
|
Bjørnstad A, Grønnerød S, Mac Key J, Tekauz A, Crossa J, Martens H. Resistance to barley scald (Rhynchosporium secalis) in the Ethiopian donor lines ‘Steudelli’ and ‘Jet’, analyzed by partial least squares regression and interval mapping. Hereditas 2004; 141:166-79. [PMID: 15660977 DOI: 10.1111/j.1601-5223.2004.01817.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
The resistance of barley (Hordeum vulgare L.) to Rhynchosporium secalis (scald) has been investigated in two crosses between the susceptible cv. 'Ingrid' and two resistant Ethiopian landraces, 'Steudelli' and 'Jet'. Doubled haploids were inoculated in replicated tests using two isolates of R. secalis, '4004' and 'WRS1872'. Expression of resistance differed widely between replicated tests. AFLP, SSR and RFLP markers were used to develop chromosome maps. Results have been analysed using partial least squares regression (PLSR) and interval mapping. In PLSR the major covariance structures or 'latent variables' between X (markers) and Y (isolates, tests) are modelled as principal components and their optimal number determined by cross-validation. In 'Steudelli' two QTL were detected, one on each of chromosomes 3H and 7H, in 4 out of 5 tests, while in 'Jet' only one (different) allele at the 3H locus was found. The validated R(2) varied between 11.0% and 64.9% in the replicated tests with '4004'.With isolate 'WRS1872' the 7H locus and another 3H locus were detected. By interval mapping the QTL detected were less stable and generally gave lower R(2) values than PLSR. PLSR does not depend on maps, but interval mapping based on values predicted by PLSR had R(2) around 90%. It is suggested that PLSR may be a useful tool in QTL analysis.
Collapse
Affiliation(s)
- A Bjørnstad
- Agricultural University of Norway, Department of Plant and Environmental Sciences, NO-1432 As, Norway.
| | | | | | | | | | | |
Collapse
|
10
|
Bjørnstad A, Patil V, Tekauz A, Marøy AG, Skinnes H, Jensen A, Magnus H, Mackey J. Resistance to Scald (Rhynchosporium secalis) in Barley (Hordeum vulgare) Studied by Near-Isogenic Lines: I. Markers and Differential Isolates. Phytopathology 2002; 92:710-720. [PMID: 18943266 DOI: 10.1094/phyto.2002.92.7.710] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
ABSTRACT Near-isogenic lines (NILs) with resistance for scald in seventh generation backcross with 'Ingrid' as recurrent parent (RP) were tested with seven differential isolates of Rhynchosporium secalis in Norway and Canada. NILs of 'Turk', 'Brier', 'CI 8162', 'La Mesita', 'Hispont', 'Atlas 46', 'Modoc', 'Hudson', 'Abyssinian', 'Steudelli', and 'CI 2222' also were evaluated for field reactions. The genetic characterization of the NILs (degree of isogeneity with Ingrid) and with each other was carried out. The molecular marker pattern shows that the backcrossing program has resulted in from 86.3 to 100% RP genome in the NILs, depending on the marker system. On an average, 96% RP genome was found in the NILs. There were certain consistent (pairwise) differences between the NILs and RP on chromosomes 3H and 7H. Both chromosomes are known to contain loci conferring resistance to R. secalis, indicating successful introgression from the donors into the NILs. Approximately two-thirds of the observed RP-NIL polymorphisms were linked to the assumed resistance in the NIL. Based on the marker and phenotypic analyses of the NILs, suggestions for a more appropriate and updated terminology of genes for resistance to R. secalis in barley are made. The proposed changes in nomenclature also indicate the differentials that are available as NILs and those lacking.
Collapse
|
11
|
Bjørnstad A, Skjeldal OH. [Ischemic stroke in children--a diagnostic challenge]. Tidsskr Nor Laegeforen 2001; 121:1826-8. [PMID: 11464690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
Abstract
BACKGROUND, MATERIAL AND METHODS Ischaemic cerebral infarctions are relatively uncommon in childhood, and the aetiologies seen in this age group are different from those commonly seen in adults. This study presents clinical findings, investigation results and outcome in a five-year material collected between 1994 and 1999 in our department. It includes 22 children with ischaemic strokes aged three months to 13 year at the first or only stroke episode. RESULTS The symptoms caused by ischaemic strokes in this age group vary and are often combined. Motor symptoms dominate, and we found hemiplegia, facial palsy, visual disturbances and reduced consciousness, listed according to decreasing occurrence. Infections and cardiac diseases or procedures were the most common aetiologies, both occurring with 22%. Other groups were autoimmune diseases (14%), malignancies (5%) and dissection of the a. carotis after trauma (5%). None of the patients in this material died as a result of the ischaemic stroke; 27% recovered completely. 41% had light sequela, 18% moderate sequela, and 14% ended up severely disabled. 18% had recurrent stroke episodes. INTERPRETATION Appropriate examination after stroke in childhood is of great importance, since some of the aetiologies are associated with recurrence risk. Based on our clinical experiences and literature studies, we suggest a plan for diagnostic evaluation and treatment strategies for children who undergo an acute cerebral vascular disease.
Collapse
|
12
|
Opsahl-Ferstad HG, Bjørnstad A, Rognli OA. Influence of medium and cold pretreatment on androgenetic response in Lolium perenne L. Plant Cell Rep 1994; 13:594-600. [PMID: 24196228 DOI: 10.1007/bf00234518] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/1993] [Revised: 01/20/1994] [Indexed: 06/02/2023]
Abstract
Genotypes of Lolium perenne L. with different androgenetic responses were used to test effects of induction medium composition. The media tested were potato II (pII), 190-2, and modified Linsmaier and Skoog media, LS-1, LS-2, and LS-3. The effect of different gelling agents, activated charcoal in a 'double layer' design, and casein hydrolysate were also studied. From 36,696 anthers, 25,906 embryo-like structures, 1,959 albino and 173 green plants were generated. Significant differences were found between media, genotypes and medium-genotype interactions studied. All three media commonly used, pII, 190-2, and LS-3, were equivalent in production of green plants. Cold pretreatment of the anthers (4°C) significantly increased the number of embryo-like structures, the number and proportion of albino plants produced, but not the production of green plants.
Collapse
Affiliation(s)
- H G Opsahl-Ferstad
- Department of Biotechnological Sciences, Agricultural University of Norway, POB 5040, N-1432, Ås, Norway
| | | | | |
Collapse
|