Le Mappe dei Cromosomi « Lampbrush » diTriturus(Anfibi Urodeli). I.Triturus Alpestris Apuanus

The Lampbrush Chromosomes ofRana EsculentaL. (Amphibia — Anura)

“…As shown by these characteristics, the spheres on bivalents VIII, X, XI are morphologically similar to those described in Triturus alpestris apuanus by MANCINo and BARSACCHI (1965). Also the structures referred to as spherical bodies by MoRESCALCHI and FILOSA ( 1965 ), are more closely comparable, in their morphology, to the spheres on bivalents VIII, X, XI, rather than to nucleoli.…”

“…Only on chromosomes VI and XII the centromeric regions cannot be established, since two symmetrically located classes are devoid of chiasmata. MANCINO and BARSACCHI 1965;CALLAN 1966;MANCINO and BARSACCHI 1969).…”

Spontaneous aberrations in lampbrush chromosome XI from a specimen of <i>Triturus vulgaris meridionali</i><i>s</i> (Amphibia, Urodela)

“…In the urodele amphibians so far there has been almost no information either of spontaneous or induced chromosomal re arrangements. Cytogenetic research is now at least feasible for species where the individual lampbrush elements of their sets have been mapped (Gall, 1954;Callan and Lloyd, 1960;Mancino and Barsacchi, 1965Lacroix, 1968a;. Gall (1954) was the first to regard a structural repetition of the axis of chromosome VII from Trituras viridescetis as a spontaneous mutation.…”

Experimental Hybridization within the GenusTriturus(Urodela: Salamandridae). II. The Lampbrush Chromosomes of F1Species Hybrids BetweenTriturus Cristatus CarnifexandT. Vulgaris Meridionale

“…The identification of the 2 haploid sets was mainly made possible by the morphological recognition of the specific characters recorded as cytogenetic markers on the parental working maps (CALLAN and LLOYD 1960a;BARSACCHI et al 1970). The size criterion, which is only partly effective even in the case of the lampbrush chromosomes of the pure species (MANCINO and BARSACCHI 1965;BARSACCHI et al 1970), was found to be of limited help in exactly arranging the 2 sets of any hybrid complement, since several elements belonging to both genomes were of similar size and therefore could be interchanged. Nevertheless, the evaluation of the size has proved to be adequate for identifying chromosomes showing apparently similar markers.…”