Emanuele Rodinò

Evolutionary genetics and systematics of the garden dormouse, Eliomys Wagner, 1840. 2‐allozyme diversity and differentiation of chromosomal races

Abstract Genetic differentiation and divergence were analyzed among the circum‐Mediterranean chromosomal forms of the genus Eliomys. Twelve populations from Spain, Italy, Austria, Israel, and Morocco with five different karyotypes (2n = 46, 48, 50, 52, and 54) were investigated by electrophoretic analysis at 41 gene loci. The observed values of genetic variation were within the range generally reported for other rodents; the overall mean heterozygosity for all the populations sampled was 0.06, ranging from 0.01 to 0.12. The mean value of genetic distance between European and Middle East‐North African populations was D=0.248, indicating the presence of two distinct evolutionary lines in the genus Eliomys. Genetic distance between Moroccan (2n = 46) and Israeli (2n = 48) populations was D = 0.136. Values of genetic distance among the European populations were lower and ranged from 0.009 to 0.132, indicating a much more recent origin for the four chromosomal forms (2n = 48, 50, 52, and 54). The taxonomic sta...

Ricerche Elettroforetiche Sulla Variabilita Genetica Di Anguilla Anguilla

Abstract This note refers to a preliminary research intended to verify the possible presence of different populations of eels (Anguilla anguilla L.) in the Mediterranean sea. Eel tissue samples have been analyzed by means of electrophoresis on starch gel. Five enzyme systems present in tissue extracts from glass-eels (elvers) have been studies: MDH I and II, PHI I and II, SHD; four of which are variable and useful as genetic markers. The genetic and molecular interpretations of the complex electrophoretic patterns and the gene frequencies observed on three different samples of elvers from the Tyrrhenian sea are also reported.

The hemoglobins of Anguilla anguilla (L.) ontogenetic variations

Abstract 1. 1. The electrophoretic pattern of the hemoglobin of adult European eels shows two bands. The pattern of the elvers is composed of nine bands, divided into three groups with three bands in each. This pattern undergoes gradual modifications till it changes, after a few months of aquarium rearing, into the two band pattern typical of the adult eels. 2. 2. The ontogenetic variation of the hemoglobin pattern of the eel, a catadromous fish, was postulated by some Authors to be functionally similar to that of an anadromous salmon. Our results do not support this hypothesis, while being in agreement with the habits and physiological requirements of elvers and eels.

Biochemical Polymorphism in Teleosts. The eel problem

Abstract The application of biochemical methods, such as electrophoresis, to the solution of taxonomic problems and to applied population genetics analysis in Teleost fish is discussed and some results obtained by this technique are briefly reviewed. More at length, the eel problem, the different theories on the life history of the Atlantic eels and the hypothesis of the existence of spawning areas in the Mediterranean sea, are also presented. Results obtained by the Authors with the genetic analysis of several eels samples from different localities, seem to confirm the genetic homogeneity of the European eels and the validity of Schmidts classic theory. The possible significance of the high level of genetic variation found in A. anguilla is also discussed in relation to what is known about the peculiar life cycle of this species.

Note on amino acid composition of eel hemoglobin

Abstract All hemoglobin sequences of Osteichthyes determined so far have been limited to the division Euteleostei, while the European eel, Anguilla anguilla (L.), belongs to the division Taeniopaedia; its sequences are thus phylogenetically important. As a preliminary to sequence determination, the amino acid composition of the two hemoglobin components of A. anguilla was determined. As expected, the data were similar to those of the American eel, while more differences were found with respect to the Japanese species.

The hemoglobins of Anguilla anguilla (L.). II: Polypeptide constitution

Abstract 1. 1. The over 300 adult individuals of the European eel, Anguilla anguilla (L.), examined showed the same electrophoretic pattern of the hemoglobins; the 293 juvenile individuals were found to be monomorphic too. 2. 2. The hemoglobin system of the adult individuals includes an acidic (anodic) component and two basic (cathodic) components, a major one and a minor one. 3. 3. Both the acidic component and the major basic component, separated by electrophoresis or by ion-exchange chromatography and analyzed by 8 M urea electrophoresis, were found to be symmetrical heterotetramers. 4. 4. By means of isoelectric focusing a higher multiplicity is obtained, but the polypeptide constitution of the focused fractions is the same we found with the previous methods: the higher multiplicity should depend on associations with the polyampholytes. 5. 5. The molecular weights of the polypeptides have been compared by means of SDS—urea electrophoresis, while the acidic component seems almost normal, in the basic component the β polypeptide were found to be lighter than the α polypeptide. 6. 6. These polypeptides have been attributed to the classes α and β by digestion with carboxypeptidases A and B.

Genetic control of phosphoglucose isomerase (PGI) isozymes in Anguilliformes: Differential tissue expression of the duplicate PGI loci

Abstract The electrophoretic patterns of phosphoglucose isomerase (PGI) in different tissues of 13 species of Anguilliformes, representing 8 families and 2 suborders, have been studied. As in higher teleosts, the overall presence of two PGI loci is confirmed in this order. A substantially uniform tissue pattern of PGI gene expression has been observed among anguilliform species, but differing, to some extent, from that of higher teleosts. These data agree with the generally accepted phylogenesis of Anguilliformes. An exception to this unvaried pattern is observed for Conger conger from the Tyrrhenian Sea: while the PGI-1 expression is always strong in liver, the PGI-1/PGI-2 proportion is quite variable and consistent with a regulatory polymorphism at the PGI-2 locus.