Somatic hybridizations

The use of protoplasts in studies of stress physiology and biochemistry expands the advantages of cell culture systems discussed in the preceding sections. Additional applications are related to the fusion of protoplasts. Intraspecifie and interspecific protoplast fusion greatly enhance genetic variability of the fused protoplasts (Kumar Cocking, 1987). The resulting somatic hybrids provide cells which can be used for selection of specific traits (e.g. environmental stress tolerance) provided by one or both donor cells and for basic studies on cytoplasmic and nuclear inheritance of desired characteristics. 

Cocking, E.C. (1986). Somatic hybridization implications for agriculture. In Biotechnology in Plant Science, eds. M. Z itland, P. Day A. Hollaender, pp. 101-13. London Academic Press. 

Endo, T., Hamaguchi, H., Eriksson, T. and Yamada, Y. 1991. Alkaloid biosynthesis in somatic hybrids of Duboisia leichhardtii F. Muell., and Nicotiana tabacum L. Planta, 183 505-510. 

Sometimes levels of resistance are not as high in somatic fusion hybrids as in the donor clones, presumably due to a dilution effect in the polyploid hybrids (Cooper-Bland, 1994 Rasmussen et al., 1998 Carputo et al, 2000b McGrath, 2002 Gavrilenko, 2003). On the other hand, somatic hybrids produced from fusions of cultivated potato with the wild species S. nigrum were often more resistant than the resistant wild parent, perhaps due to complementation of resistance genes (Zimnoch-Guzowska, 2003). 

Bidani, A., Nouri-Ellouz, O., Lakhoua, L., Sihachakr, D., Cheniclet, C., Mahjoub, A., Drira, N., Gargouri, B. -R. (2007). Interspeciflc potato somatic hybrids between Solanum berthaultii and Solanum tuberosum L. showed recombinant plastome and improved tolerance to salinity. Plant, Cell, Tissue, and Organ Culture, 91,179-189. 

Fish, N., Karp, A., Jones, M. G. K. (1988). Production of somatic hybrids by electrofusion in Solanum. Theoretical and Applied Genetics, 76,260-266. 

Gavrilenko, T. T., Ramona, Heimbach, U., Thieme, T. (2003). Fertile somatic hybrids of Solanum etuberosum (+) dihaploid Solanum tuberosum and their backcrossing progrenies relationships of genome dosage with tuber development and resistance to potato virus Y. Euphytica 131, 323-332. 

Helgeson, J. R, Rohlman, J. D., Austin, S., Haberlach, G. T, Wielgus, S. M., Ronis, D., Zambolim, L., Tooley, R, McGrath, J. M., James, R. V., Stevenson, W. R. (1998). Somatic hybrids between Solanum bulbo-castanum and potato a new source of resistance to late blight. Theoretical and Applied Genetics, 96, 738-742. 

Lightbourn, G. J., Veilleux, R. E. (2007). Produetion and evaluation of somatic hybrids derived from monoploid potato. American Journal of Potato Research, 84, 425 35. 

McGrath, J. M. W., Christie E.,Haberlach, Geraldine T., Wielgus, SusanM.,Uchytil, ThomasF.,Helgeson, John R (2002). Introgression and stabilization of Env/ma tuber soft rot resistance into potato after somatic hybridization of Solanum tuberosum and S. brevidens. American Journal of Potato Research 79,19-24. 

Przetakiewicz, J., Nadolska-Orczyk, A. N., Kuc, D., Orczyk, W. (2007). Tetraploid somatic hybrids of potato Solanum tuberosum L.) obtained from diploid breeding lines. Cellular and Molecular Biology Letters, 12, 253-267. 

Rasmussen, J. O., Nepeper, J. R, Rasmussen, O. S. (1996). Analysis of somatic hybrids between two sterile dihaploid Solanum tuberosum L. breeding lines. Restoration of fertility and complementation of G. pallida Pa2 and Pa3 resistance. Theoretical and Applied Genetics, 92,403 10. 

Rokka, V. M., Xu, Y. S., Kankila, J., Kuusela, A., Rulli, S., Pehu, E. (1994). Identification of somatic hybrids of dihaploid Solanum tuberosum lines and S. brevidens by species specific RAPD patterns and assessment of disease resistance of the hybrids. Euhpytica, 80,207-217. 

Zimnoch-Guzowska,E. L.,R.,Kryszczuk, A.,Maciejewska,U., Szczerbakowa, A., Wielgat,B. (2003). Resistance to Phytophthora infestans in somatic hybrids of Solanum nigrum L. and diploid potato. Theoretical and Applied Genetics 107, 43 8. 

Kozukue, N., Misoo, S., Yamada, E, Kamijima, O., Friedman, M. (1999). Inheritance of morphological characters and glycoalkaloids in potatoes of somatic hybrids between dihaploid Solanum acaule and tetraploid Solanum tuberosum. J. Agric. Food Chem., 47, 4478 483. 

Cho MS, Yee H, Chan S (2002), Establishment of a human somatic hybrid cell line for recombinant protein production, J. Biomed. Sci. 9 631-638. 

Rhazinilam 3 is an axially chiral phenyl-pyrrole compound which was first isolated from Melodinus australis (F. Muell.) Pierre [53]. It has also been found in other Apocynaceae such as Rhazya stricta Decaisne [54,55], Aspidosperma quebracho-bianco Schlecht. [56,57], Leuconitis eugenifolia A. DC [58,59] and Kopsia singapurensis [60]. More recently, (-)-rhazinilam was isolated from intergeneric somatic hybrid cell cultures of two Apocynaceae, Rauvolfia serpentina Benth. Ex Kurz and Rhazia stricta Decaisne [61]. 

Ehrlich, G., Viegas-Pequignot, E., Ginzberg, D., Sindel, L., Soreq, H., Zakut, H. (1992). Mapping the human acetylcholinesterase gene to chromosome 7q22 by fluorescent in situ hybridization coupled with selective PCR amplification from a somatic hybrid cell panel and chromosome-sorted DNA libraries. Genomics 13 1192-7. 

HKBll Human somatic hybrid Hybrid Recombinant protein production... 

An efficient protoplast plant system has been developed, based on which interspecific hybrids not available by traditional improvement have been produced by a method of somatic hybridization. 

Ravinshankai, G.A. and A.R. Mehtag Genetic manipulation of somatic hybrid plant cells Proc. Natl. Symp. 

Combination of atrazine resistance and cytoplasmic male sterility in rapeseed. Transfer of atrazine resistant chloroplasts from bird s rape (B. oapestris) into oilseed rape has been accomplished by back-crossTng (s this volume). The purpose achieved by somatic cell fusion was to combine the atrazine-resistant chloroplasts carried by a B. napus line with cytoplasmic male sterility (CMS), a mitoohondrlal tralt (l9). The CMS trait was carried by a B. napus line with the cytoplasm of radish (Raphanus sativus). Since both traits, atrazine resistance and CMS, are maternally inherited in sexual crosses, the only way to combine the traits was by protoplast fusion. The desired atrazine-resistant cybrids were identified in a randomly regenerated sample of plants by the presence of the CMS flower morphology and their darker green color at low temperature. Somatic hybrids rather than cybrids were obtained in each clone since no irradiation had been used to facilitate the elimination of one of the parental nuclei. 

Chloroplast transfer into potato. Transfer of atrazine-resistant planum nigrum chloroplasts into S. tuberosum has been attempted by protoplast fusion (20,21 ). In the absence of irradiating the chloroplast donor S. nigrum, only somatic hybrids were obtained... 

There has been no further report on these plants. In any case, the somatic hybrid lines could not be commercially utilized even if they were fertile. Crosses using a potato line as a recurrent pollen parent do not result in an alloplasmlc substitution form of the pollen parent, because potato cultivars cannot be maintained by seed due to their heterozygosity. 

Blair, LA., Cresp, T.M. and MacDermot, J. (1981). Divalent cations increase [ H]-prostacyclin binding to membranes of neuronal somatic hybrid cells. Br. ]. Pharmacol, 73, 691-694... 

Figure 2.5 Trichomes of mint plants (a) and resulting phenotype of a somatic hybridization (b, hybrid) between mint varieties (b, E33, E87 leaves of parent lines used for protoplast fusion, unpublished results E. Baumann, Phytowelt GreenTechnologies GmbH).

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