Specimens of the fresh-water planarian Dugesia benazzii, collected in two different localities of the island of Corsica, showed in the first period of laboratory culture (1966-1972) a triploid complement (24 chromosomes) in the somatic cells, a hexaploid complement in the female line and a diploid complement in the male line. New research has now demonstrated the occurrence in the somatic and in both germ lines of metacentric B-chromosomes, varying in number from 1 to 3. The Authors point out that these new chromosomes appeared almost simultaneously in the two different cultures, and in one of them in the three specimens kept isolated for about five years. It is also worthy of notice that this is the first observation of the presence of B-chromosomes in polyploid animals.
Insorgenza di B-cromosomi in individui poliploidi di Dugesia benazzii (triclade paludicolo) allevati in laboratorio
DERI, PAOLO
1977-01-01
Abstract
Specimens of the fresh-water planarian Dugesia benazzii, collected in two different localities of the island of Corsica, showed in the first period of laboratory culture (1966-1972) a triploid complement (24 chromosomes) in the somatic cells, a hexaploid complement in the female line and a diploid complement in the male line. New research has now demonstrated the occurrence in the somatic and in both germ lines of metacentric B-chromosomes, varying in number from 1 to 3. The Authors point out that these new chromosomes appeared almost simultaneously in the two different cultures, and in one of them in the three specimens kept isolated for about five years. It is also worthy of notice that this is the first observation of the presence of B-chromosomes in polyploid animals.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
