Abstract
One of the biotypes of the planarian Dugesia benazzii is triploid in the somatic line, hexaploid in the female line owing to a chromosome set doubling, and diploid in the male line due to a haploid set elimination. In a population of this biotype only 50% of the oocytes are hexaploid, the others being triploid as a results of the lack of set doubling; the male line is always diploid. After a long period of laboratory culture most of the individuals became asexual and fissiparous. Almost all the oocytes of the few specimens which have remained sexual showed triploid complement; B-chromosomes also appeared. These events represent the manifestation of a new genetic background which act upon the two germ lines in different ways and moments. These topics are discussed.
Access this chapter
Tax calculation will be finalised at checkout
Purchases are for personal use only
References
Benazzi, M., 1968. Popolazioni di Dugesia benazzii della Sardegna e della Corsica di probabile origine ibrida. Atti Assoc. Genet. Ital. 13: 117–124.
Benazzi, M. amp Giannini, E., 1970. Ricerche su popolazioni della planaria Dugesia benazzii con due tipi di ovociti:analisi statistica delle frequenze e considerazioni di ordine genetico. Riv. Biol. 63: 145–157.
Benazzi Lentati, G., 1966. Amphimixis and pseudogamy in fresh-watertriclads:experimental reconstitution of polyploid pseudogamic biotypes. Chromosoma 20: 1–14.
Benazzi Lentati, G., 1970. Gametogenesis and egg fertilization in planarians. Int. Rev Cytol. 27: 101–179.
Benazzi Lentati, G., 1976. On the relationship between the chromosome set and the sexual differentiation of the neoblasts in planarians. Acta Embryol. Exp., issue 3: 299–317.
Benazzi Lentati, G. & Deri, P., 1977. Insorgenza di B-chromosomi in individui poliploidi di Dugesia benazzii (triclade paludicolo) allevati in laboratorio. Rendic. Acc. Naz. Lincei, Ser. 8, 62: 848–851.
Benazzi Lentati, G. amp Mezzani, V., 1974. Research on the hereditary mechanism of polyploidy in planarians. Rend. Acc. Naz. Lincei Ser. 8, 57: 294–300.
Giannini, E. amp Puccinelli, I., 1969. Ciclo cromosomico ed ovogenesi in popolazioni di Dugesia benazzii con due tipi di ovociti. Atti Soc. Tosc. Sci. Nat. Pisa, Mem., Ser. B, 76: 150–166.
Author information
Authors and Affiliations
Editor information
Rights and permissions
Copyright information
© 1981 Dr W. Junk Publishers, The Hague
About this paper
Cite this paper
Benazzi Lentati, G., Benazzi, M. (1981). Contrasting power of the factors for fission and sexuality in a polyploid planarian. In: Schockaert, E.R., Ball, I.R. (eds) The Biology of the Turbellaria. Developments in Hydrobiology, vol 6. Springer, Dordrecht. https://doi.org/10.1007/978-94-009-8668-8_22
Download citation
DOI: https://doi.org/10.1007/978-94-009-8668-8_22
Publisher Name: Springer, Dordrecht
Print ISBN: 978-94-009-8670-1
Online ISBN: 978-94-009-8668-8
eBook Packages: Springer Book Archive