Postgenomic histochemistry

In my editorial covering the year 2001, I drew attention to «the torrency of information pouring out of the multiorganizational genome sequence projects into the field of active biological research». On that occasion I also expressed the opinion that this enormous quantity of data coming from genomics and proteomics had to be elaborated by resorting even to new models of cell activity, as for instance, models based on the role of transcripts. The data from this postgenomic biology have to be compared, however, with the qualitative and quantitative data emerging today from the histochemical literature obtained from a variety of models and from the complexity of integrated morphological, submorphological, enzymo- or immunohistochemical in situ biological approaches which are the mainstays of the important refluorishing of the new histochemistry that our Journal has always supported. The objectives of this science are the molecular foundations of the function of the cell organelles, the coordinations among the different organelle activities in a cell, the rhythm of life of different cell populations and their correlation with different tissutal and extratissutal specialisations in humans, mammals, vertebrates, invertebrates and plants and finally bacteria and viruses during development under normal and pathological conditions (see Manfredi Romanini, 2002)

Histochemistry: work in progress

As our subscribers have been notified in a recent letter, this issue of the European Journal of Histochemistry is the last one to be edited and printed by “Luigi Ponzio e figlio editori”: They have generously collaborated with us with the greatest care and professionality for the past twenty years and for that we wish to thank Mr. Luigi Ponzio and his entire staff (in particular, Mr. Luigi Guardamagna) most hearthly. The new publisher Tipografia PIME Editrice has assured us of a strong support in the promotion and the development of the image of the European Journal of Histochemistry in its relations with the media at all levels. While a change in the Publisher may be seen as a merely technical one, it is also the occasion to reflect upon how a Journal such as ours can be enriched. The Journal’s topics touch upon many of the basic issues in biology and, through these, in pathology. Our subjects are humans, as well as all animals and plants, not only looked upon as objects for comparison and taxonomic analysis, but also as models for detailed study.........

Nuclear histochemistry: Its history in fifty volumes

The fiftieth anniversary of the double helix was marked two years ago. The elucidation of the structure of DNA by Watson and Crick can rightfully be considered to be "the" milestone in modern biology because it has conditioned the explosive growth in our understanding of the molecular mechanisms regulating the structural and functional organization of single cells and multicellular organisms...

Facts and paradoxes in current notions of nuclear organization and function

Invisible compartments, identified rather by their activities than by their morphology, seem to operate in the nucleus. These compartments interrelate somehow, including mediation by the nuclear matrix. As our knowledge about the nucleus increases, more paradoxes become evident. We here consider some of them: 1) the well-known C-paradox of Cavalier-Smith, conceming the disproportionate amount of nuclear DNA content in comparison with the amount of DNA potentially able to transcribe; 2) the DNA folding in the chromatin fibre and its superorganization within the nucleus, which seems to be in opposition with the transcribing and self-replicating activities; 3) the elusive role of the DNA sequences with different degrees of repetitivity; and 4) the compartmentalization in the nucleus and how it relates to transcription, processing and transport of transcripts, and to DNA reduplication. We conclude by introducing the concept of species specific, minimal, but essential genome components, ¡.e. the elusive few thousand DNA bases that, in our hypothesis, act as a functional bridge between the nuclear matrix and chromatin

DNA content variability in primates

The DNA content of 58 species of primates out of the approximately 180 described (Chiarelli, 1972), belonging to 29 out of the 54 existing genera is reported. The amount of nuclear DNA was measured microdensitometrically on lymphocytes of peripheral blood submitted to the Feulgen reaction. Genome size was found to range from 4.7 to 10.9 pg (respectively 65% and 150% the value observed in man, considered to be 7.3 pg). Generally speaking, in the group of species studied, no correlation was found between Feulgen-DNAcontent and chromosome number. At any rate, three different situations were revealed: (1) the lemurs of Madagascar, with a fairly low and constant DNAcontent and a highly variable chromosome number; (2) the genus Cercopithecus, showing a quite variable DNAcontent, occasionally related to the chromosome number; (3) the subfamily Papiinae, in which both the chromosome number and the DNAcontent appear exceptionally constant. The hypothesis of a different influence of selective pressure on the two parameters, in relation to different environments, is also discussed. According to this hypothesis, these differences would have led to the development of cytologic conditions which are the reflection of different evolutionary pathways

DNA nuclear content in the cytotaxonomy of Galago senegalensis and Galago crassicaudatus

The DNA nuclear content in lymphocytes of peripheral blood from Galago senegalensis (2 males and 2 females), Galago crassicaudatus (3 males and 2 females) and Perodicticus potto (2 males) was measured by means of the Deeley integrating microdensitometer. The mean of the DNA content does not differ significantly between Galago senegalensis and Galago crassicaudatus specimens, nor does it between the two Galago and Perodicticus potto. This finding lead us to exclude that the difference in the chromosome number between Galago senegalensis (2n = 38) and Galago crassicaudatus (2n = 62) is the result of endoreduplication. In addition, these preliminary findings seems to lend further support to the assumption of a stronger affinity of the Galagidae with the Lorisidae rather than with the Lemuridae

Immunoelectron microscopical distribution of histones H2B and H3 and protamines in the course of mouse spermiogenesis

International audienc

Genome size and constitutive heterochromatin in Hilobates muelleri and Symphalangus syndactylus and in their viable hybrid

Genome size was measured as the amount of Feulgen-stained DN A in six species of the family Hylobatidae and in a hybrid of the gibbon t Hylobates muelleri) and siamang (Symphalangus syndactylus). The family, on the w hole, exhibits a w ider range of genome sizes than pongids: In particular, the siamang has about 15% more DNA than the 44-chromosome Hylobates spe cies of the “lar” group. Quantitative analysis of C-heterochromatin in hybrid metaphases showed that the difference in genome size of the parental species correlates with the amount of C-band-positive material. Hylobatids are the only group of primates in which karyotype diversification has taken place with a massive quantitative change in constitutive heterochromatin

Immunoelectron microscopical distribution of histones H2B and H3 and protamines in the course of mouse spermiogenesis

International audienc

Genome size and C-heterochromatic-DNA in man and the african apes

The genome sizes and the amounts of DNA after C-banding pretreatments (C-heterochromatic DNA) were measured by quantitative cytochemical methods in man and the African apes,Gorilla gorilla andPan troglodytes. As evaluated by flow cytometry on propidium-iodide-stained lymphocytes, gorilla and chimpanzee have genome sizes larger than man. On the basis of the different resistance of metaphase chromosome DNA to the C-banding procedure, two genome compartments were defined, i.e.,C-heterochromatic-DNA andeuchromatic-DNA. The latter proved to be fairly constant in man and the African apes (as well as in two hylobatid species), whereas the variable amounts ofC-heterochromatic-DNA account well for the interspecific differences of genome size among the hominoid species studied so far. During karyotype diversification, quantitative changes (with either gains or losses) ofC-heterochromatic-DNA seem to have taken place independently in the hylobatid and the man/African ape lineages