0000000001091544

AUTHOR

Maria B. Rasotto

showing 2 related works from this author

The chromosomes of 16 molluscan species

1982

Abstract Chromosome numbers were determined for two species of Placophora, eleven species of Gastropoda, one species of Pelecypoda and two species of Cephalopoda. No heterotypic or supernumerary chromosome resulted from the analysis of meiotic and, when possible, of mitotic chromosomes. For this reason no positive evidence emerges for the presence of differentiated sex chromosome pairs. Data available seem to indicate that evolution within the Mollusca phylum has been accompanied by a decrease in both chromosome number and DNA content (according to Hinegardner, 1974), if we consider subclasses, orders and families (apart from the subclass Prosobranchia). On the contrary the primitive class …

Chromosome 17 (human)B chromosomeChromosome 4Chromosome 16Chromosome 3Chromosome 18ZoologyAnimal Science and ZoologyBiologySmall supernumerary marker chromosomeChromosome 12Bolletino di zoologia
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Spermatocyte Chromosomes in Some Species of the Family Aplysiidae (Gastropoda, Opisthobranchia)

1982

SUMMARYCounting spermatocyte bivalents, we have determined the haploid number n = 16 for Aplysia depilans and A. punctata, and n = 17 for A. limacina. We have confirmed n = 17 for Bursatella leachii. Male diakinetic bivalents are probably chiasmatic in all the species examined. The orders Nudibranchia and Notaspidea, possessing haploid values of 13 and 12 chromosomes respectively, seem to be more evolved than the other orders of the sub-class Opisthobranchia.

biologyAplysia depilansBotanyGastropodaGeneticsOpisthobranchiaAplysiidaeLimacinaBursatella leachiiPloidyGeneral Agricultural and Biological Sciencesbiology.organism_classificationNotaspideaCaryologia
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