The estimation of DNA substitution rates requires calibration with the geological events which caused the separation of populations. We used the disintegration of the landbridges between Morocco and Gibraltar as well as the Balearics and Spain at the end of the Messinian event (5.3 myr) in order to calibrate the DNA sequence data of the NADH‐dehydrogenase subunit 1 (ND1) in West Mediterranean Carabus species. The rates of molecular evolution we found are much lower than those reported in the literature and also vary from species to species. Therefore, in insects the calculation of divergence periods using a constant 2% substitution rate per myr is questionable.

Three sympatric forms have been found within the morphospecies Ceroglossus chilensis Esch. through karyotype analysis and characterization of repetitive DNA families. The male chromosome number of these forms is 2n = 28 + XY (form A), 2n = 40 + XY (form B), and 2n = 38 + trivalent (form C). Restriction enzyme analysis of total genomic DNA of form B using EcoRI produces several conspicuous bands corresponding to monomers and dimers of two repetitive DNA families, of about 575 bp and 200 bp respectively; form C has, after total digestion, only one band of 625 bp corresponding to the monomer of a different repetitive DNA family; and form A has no conspicuous band after this treatment. In situ hybridization experiments show that repetitive DNAs are specific for each form and no crossed hybridization is observed. The results suggest that these Ceroglossus forms are actually a complex of sibling species evolving as separate evolutionary and phylogenetic units, whose characterization at the morphological, ecological and geographical levels should be the subject of further investigation.

Journal Article Genetic Control of Chymotrypsin- and Trypsin-Like Enzymes in Carabid Beetles (Coleoptera, Carabidae) Get access S. Braun, S. Braun From the Department of Biology, University of Bremen, Germany, and the Satation de Zoologie Institut National de la Recherche Agronomique, Valbonne, France. Address reprint requests to Sabine Braun, Department of Biology, University of Bremen, Box 330440, D-2800 Bremen 33, Germany. Search for other works by this author on: Oxford Academic PubMed Google Scholar J.-C. Malausa, J.-C. Malausa From the Department of Biology, University of Bremen, Germany, and the Satation de Zoologie Institut National de la Recherche Agronomique, Valbonne, France. Search for other works by this author on: Oxford Academic PubMed Google Scholar D. Mossakowski D. Mossakowski From the Department of Biology, University of Bremen, Germany, and the Satation de Zoologie Institut National de la Recherche Agronomique, Valbonne, France. Search for other works by this author on: Oxford Academic PubMed Google Scholar Journal of Heredity, Volume 82, Issue 2, March 1991, Pages 164–167, https://doi.org/10.1093/oxfordjournals.jhered.a111052 Published: 01 March 1991

We investigated 13 populations of the carabid subgenus Chrysocarabus in the Spanish mountains Sierra de Urbasa and Sierra de Andia. In some areas there were up to 16% hybrids between Carabus lineatus and Carabus splendens. Hybrids are best distinguished as individuals having combinations of morphological characters that are diagnostic for both species. Multivariate discriminant analysis showed a gap between the parental species, but hybrids were either C. lineatus-like or C. splendens-like. Experimentally produced hybrids lie in the same range as natural hybrids. Electrophoretic studies have interpretable results for eight enzymes, but only one sex-linked locus (G-6-pd) was fixed for alternative alleles in the parental species, allowing identification of only female hybrids. Analysis of proteolytic enzymes from the gut revealed one fixed difference for chymotrypsin, but the locus for this enzyme is sex-linked. Trypsin appears polymorphic at several loci and is not useful for identifying hybrids. The geographical range of overlap and hybridization is large when compared with dispersal abilities of C. lineatus and C. splendens. We suggest that the hybrid zone is broken up into a number of subzones defined by differences in habitat structure and related to specific ecological requirements of the parental species. Within each of these zones, theory developed from study of narrow hybrid zones may apply.

In the extra-intestinal fluid of Carabus beetles (Carabidae, Coleoptera) the total proteolytic activity was measured against casein. The trypsin and chymotrypsin-like proteases in the extra-intestinal fluid of the beetles were verified by the esterolysis of TAME and BTEE from 1 hr before to 216 hr (ten days) after feeding. Before feeding, both enzyme activities were high and they decreased very sharply after the beginning of feeding. The inhibition characteristics of various naturally occuring trypsin inhibitors were tested: soybean trypsin inhibitor, lima bean trypsin inhibitor, pancreas kallicrein inhibitor and chicken ovomucoid. Affinity adsorption with soybean trypsin inhibitor combined with isoelectric focusing enabled a comparison of the band pattern of serine-proteases in various species. Most of the tryptic and chymotryptic enzymes are acidic with an isoelectric point (IP) between pH 3 and 6. Proteases with an IP of about pH 7 were found only rarely. The interspecific variability of the serine-proteases in higher than the intraspecific one. In addition to the enzymes typical of Carabus lineatus and Carabus splendens the natural hybrids showed new serine proteases.