Genetic research with nonhuman primates: serving the needs of mankind Symposium summary and future prospects

The wide array of papers delivered at this symposium, ranging from population genetics to molecular genetics, is convincing evidence that genetic research with nonhuman primates is in full bloom. In fact, progress has been quite remarkable considering that a significant number of pedigreed colonies of nonhuman primates have been available for less than 25 years, which is hardly enough time to raise 3 generations of chimpanzees, 5 generations of baboons or 6 generations of rhesus monkeys. Were it not for these pedigreed colonies, we would not have been privileged to have this assemblage of papers on behavior, social structure, predisposition to disease and management of breeding colonies. It is indeed exciting that preliminary evidence has been obtained for major genes that play a role in susceptibility to dyslipoproteinemias in baboons, and that monoclonal antibodies and DNA markers are helping us to understand cholesterol metabolism. And thanks to computers, we can now rank animals in a colony in terms of their useful genotypes as well as their productivity. One can not help but be impressed with the commonality of humans and nonhuman primates at the structural and functional levels. For example, the major histocompatibility systems and the maternal-fetal relationships are very similar. We heard that this similarity is even more striking at the chromosomal, biochemical and DNA levels. A provocative question yet to be answered is, “what accounts for the obvious differences between humans and nonhuman primates in view of these incredible similarities?” In light of these advances, this symposium was at the cutting edge of primate genetics and the papers published in this issue of Genetica are certain to be hallmarks in the literature.     

Ultraviolet irradiances of various lamps used in animal husbandry

A variety of lamps are used in animal husbandry, but data with respect to ultraviolet irradiances from these lamps, which may be important for alleviating or preventing metabolic bone disease, are generally unavailable. This paper reports irradiances from representative lamps as well as transmission and reflective properties of various materials.     

Structural elements of bactopterin from Pseudomonas carboxydoflava carbon monoxide dehydrogenase

Bactopterin is a novel pterin occurring in bacterial molybdoenzymes as the organic portion of the molybdenum cofactor. Its structure is investigated here. The compound contains a single pterin ring and carries a side chain at carbon atom 6 of the pterin nucleus as indicated by the formation of pterin-6-carboxylic acid upon alkaline permanganate oxidation. Studies with phosphate-cleaving enzymes revealed the presence of two monophosphoric acid monoesters. The affinity of reduced bactopterin for thiol-Sepharose points to the presence of thiol(s) in active bactopterin.     

Calymperes (Musci: Calymperaceae): World ranges,implications for patterns of historical dispersion and speciation,and comments on phylogeny

Refinements in the taxonomy of the genus Calymperes (Musci: Calymperaceae) allow increasingly accurate estimates of the total number of species worldwide and new assessments of world ranges of the species. Instead of the 272 correct names of Calymperes listed in Volume 1 of Index Muscorum, the world total of “good” species now appears to be in the range of 30 to 40, and contrary to the high degree of narrow endemism implied from the compilation of Index Muscorum, many species of Calymperes have broad ranges in the paleo- or neotropics. A few species, including C. afzelii, C. erosum, C. palisotii, C. lonchophyllum, and C. tenerum, are pantropical. World ranges of species of Calymperes are mapped and implications for historical patterns of dispersal and speciation are discussed. Suites of endemic species and species groups in the neotropics differ from those in the paleotropics, demonstrating different ancestries, a long period of geographic separation, and independent evolution in two fundamentally different environments. It is suggested that Calymperes shares close phylogenetic relationship with limbate Syrrhopodon.     

The highly modified membrane of cornified cells in stratified squamous epithelia: A comparison of heterogenous deposits in keratinized and nonkeratinized epithelia

Summary The chemical nature of the thickened plasma membrane of cornified cells in stratified squamous epithelium was investigated in comparison with that in noncornified epithelium. Localizations of transglutaminase, molecular weight 92000 daltons, and detection of epidermal cysteine proteinase inhibitor were effected with a monoclonal antibody and a monospecific rabbit anti-inhibitor immunoglobulin, respectively, directed to the antigens. N-(7-dimethylamino-4-methylcoumarinyl) maleimide was used to demonstrate S-S cross-linking. In all keratinizing epithelia, the enzyme and inhibitor were deposited on membranes of granular cells. S-S bonds were formed in cornification with the appearance of electron-dense material by the inner leaflet. Both enzyme and inhibitors occurred on the corneal epithelium, but S-S linkage and the thickened plasma membrane did not form even at the last stage of maturation. On the other hand, the internal vaginal epithelium in the proestrous stage without keratinization contained the enzyme, but neither inhibitor nor S-S linkage. Both antigens and S-S bonds were detected when keratinization proceeded during estrus. The staining patterns in the epithelium near the vaginal introitus were identical to those in the skin. Cuboidal and simple epithelia exhibited none of those constituents. The findings indicated that heterogenous components contribute to modification of the plasma membrane of cornified cells, but S-S cross-linkages are associated exclusively with formation of the ultrastructurally unique membrane structure. In addition, findings suggested hormonal regulation in the chemical modification of the membrane in estrogen-sensitive internal vaginal epithelium.     

The gene coding for the human T-lymphocyte CD2 antigen is located on chromosome 1p

Summary A cDNA clone encoding the human T lymphocyte sheep erythrocyte receptor [the CD2 (T11) antigen] was used as a probe to define the chromosomal location of the gene. The signal, revealed by hybridisation to Southern blots of genomic DNA from somatic cell hybrids, showed a high degree of concordance for human chromosome 1. In particular, the hybrid F4Sc13C19 which contained the short arm only of human chromosome 1 was positive. The location of the CD2 gene to 1p13 was confirmed by in situ hybridisation.     

Leaf size and inflorescence size may be allometrically related traits

Summary Corner's rules for plant form relate the degree of branching to branch diameter, and branch diameter to leaf or inflorescence size. We report the first interspecific test of these rules for inflorescence size and branch diameter. We derived a simple corollary of Corner's rules; since leaf size and inflorescence size are both correlated to branch thickness, they may be correlated to each other. This corollary holds for Leucadendron and Protea (Proteaceae), and in certain other taxa in the Asteraceae, Bruniaceae and Pinaceae which also have leaves and reproductive structures on the same shoot. For such taxa this implies that selection for aspects of floral display (inflorescence size, pollination type) may also be expressed at the level of leaf size and vice versa. This has implications for many aspects of botany and also points to the importance of the co-ordinating role of plant architecture for aspects of plant form.     

Potency of microwave irradiation during fixation for electron microscopy

Liver, skeletal muscle, peripheral nerves, pancreas, thyroid and adrenal cortex were prepared for electron microscopy employing microwave energy either during prefixation with glutaraldehyde or instead of prefixation. Microwave irradiation in the presence of glutaraldehyde in Na/K-phosphate or Na-cacodylate containing CaCl2 and MgCl2 led to distinct appearance of membranes, mainly plasma membrane, and membranes of SER, Golgi complex and mitochondria in liver, pancreas and muscle. The area of high quality fixation, however, was limited to the periphery of samples. On the other hand, SER was dilated in cells of the adrenal cortex, and RER markedly vacuolated in thyroid follicular cells. Microwave irradiation in the presence of Na/K-phosphate and subsequent osmication resulted in preservation of the ultrastructure in similar quality as was obtained by osmication without previous immersion in glutaraldehyde. However, the preservation of SER and Golgi complex in liver and pancreas, and of mitochondria in muscle was greatly improved. Small myelin sheaths remained intact whereas large ones showed focal disintegration. We consider that enhancement of fixation by microwave energy may greatly improve preservation of membranes in some tissues. Successful fixation depends on the use of glutaraldehyde during microwave irradiation, the type of buffer, the addition of ions to increase stabilization, the exposure time to heat, and on postosmication.     

Factors regulating cladoceran dynamics in a Venezuelan floodplain lake

Five cladoceran zooplankton species in a Venezuelan floodplainlake, Laguna la Orsinera, were analyzed to identify factorscontrolling their dynamics over a period encompassing isolation,inundation by the Orinoco River and drainage. The abundanceof each species increased rapidly to a maximum associated withflooding of the lake by the Orinoco River. We calculated birth,death and population growth rates, and developed a method forestimating uncertainty in these parameters, in order to interpretobserved cladoceran abundance patterns. Rapid increases in populationsizes resulted both from high birth rates associated with decreasingturbidity following inundation and from the hatching of restingeggs. Birth rates remained high throughout the study, but highdeath rates restricted each population to a brief maximum andthen maintained small population sizes throughout the remainderof the study. Our demographic analyses suggest that high mortalityresulted from intense predation by fish and by Chaoborus larvae,rather than from resource limitation, and that this mortalitywas the major factor regulating cladoceran abundance duringinundation and drainage in this tropical floodplain lake.