Relationships between specialized cells, capillaries and intermediary cytofibrillary elements. XIIth note. Biological evolution of the respiratory stereotype and subsystem in invertebrates

This note presents the respiratory stereotype and subsystem in invertebrates, developing the previous notes on the emunctory stereotype and subsystem (Xth and XIth notes). As in the previous ones, Cannon's homeostasis conception and Bertlanffy's theory of systems were corroborated with Needham's theory of internal laws and of limits of organizational biological levels, and with the author's theory of biological stereotypes (Marza, Repciuc, Eskenasy, 1962). Four links of the respiratory stereotype (Rsp. Stp.) and subsystem (Rsp. SS) were distinguished. The respiratory subsystem was differentiated when, in triblastic animals, the organizational level of higher worms and of their offsprings was reached. The four links of the Rsp. Stp. are: the Ist link is represented by the oxidoreduction processes of tissue and organ cells; the IInd is the internal conveying link of O2 and CO2; the IIIrd comprises the osmotic surfaces changes and the transport of gases inwards the branchiae or lungs, and later by the water (respectively air)--blood barrier; the IVth link is formed from the structures and mechanisms of rhythmic movements which significantly increase the exchanges at the barrier level. Each link has its specific properties. The gradual evolution of each link and of the vicarious organs of gas exchange is dwelt upon, as well as the interactions between the respiratory subsystem and the other homeostasis subsystems. The theoretical interpretation of the Rsp. Stp. and Rsp. SS evolution also resorted to the theories of stabilizing selection (Schmalhausen, 1949), of canalizing selection (Waddington, 1975 and of disruptive selection (Simpson, 1953; Mayr, 1970).     

Relationships between specialized cells, capillaries and intermediary cytofibrillary elements. XVth note. Biological evolution of the respiratory stereotype and subsystem in aquatic vertebrates

The author continues in aquatic vertebrates the study of the evolution of the respiratory stereotype initiated in the XIIth note of this series and carried out in the light of the systemic conception (Bertalanffy), of Needham's theory of order in nature, and of the theory of biological stereotypes (Marza, Repciuc, Eskenasy). The stability of some characters of the respiratory stereotype inherited by vertebrates from invertebrates is pointed out. The respiratory stereotype in vertebrates gradually passed from the respiration of water-dissolved oxygen through branchiae and skin, to the concomitant uptake of this form and of air oxygen (through buccopharyngeal formations, gaseous bladder or rudimentary lungs in osseous fishes), the double respiration (in Amphibia) and later the air respiration in Reptilia. The five steps of this gradual evolution are described, as well as the conditions of the evolution from crossopterygians to Tetrapoda (amphibians and reptiles).     

Relationships between specialized cells, capillaries and intermediary cyto-fibrillary stroma. Note 6. The capillary stereotype and the factors which influence it.

The human skin and the mammary gland in the woman and the man--all of them ectoblastic-origin tissues, rich in stromal structures and belonging to the IIIrd step of Marza's classification (Vth note) -- were investigated using the method of the microscopic conventional fields. The normal skin (Ist lot), the skin from the vicinity of basaliomatous nodules (II--A), of incipient basaliomatous nodules (II--B), of completely developed (II--C), of the skin during irradiation (II--D) and after irradiation (II--E), as well as the pemphigus skin were studied. In the woman the mammary gland was investigated in the little girl (GMF), in the adult nonpregnant woman (GMA), during the first trimester of pregnancy (GMG), during lactation (GML), during climacterium (GMM), in glandular carcinomas of the adult female (GMAC) and during menopause (GMMC). In the man, the normal gland (GMB) and the hypertrophied one (gynecomastia) (GMBH) were studied.     

Relationships between specialized cells, capillaries, and intermediary cyto-fibrillar elements. Vth note. Organizational steps or levels of these relationships during their biological development.

The developmental analysis of the interrelations between specialized cells, capillaries, and intermediary cyto-fibrillar elements points out the existence of four organizational steps reflecting the gradual increase in complexity and diversity of animal structures and functions. The development of secretory and defence functions produces a dissociation of steps between the increase of the organizational level of the whole animal organism and the autonomy of organizational steps or organs. The steps are not immovable, but under some conditions the possibility of a mutation exists between the IInd and the IIIrd steps.     

Interrelations between specialized cells, capillaries and intermediary cytofibrillar elements. 13. The fibrillar apparatus of the human dermis in some carcinomas of aged people

The changes in the fibrillar apparatus (collagenous, elastic, reticulinic) during the development of some carcinomas in aged people were followed up in 70 fragments of human skin taken from adults and aged people suffering from senile keratosis (typical and with a tendency to malignancy) and skin carcinomas (basal cell and squamous cell carcinomas) and from the apparently healthy skin neighbouring carcinomas. Using the conventional microscopic field method, some previous morphological data were confirmed and new significant ones were reported. The changes were not always similar in intensity and direction in both layers of the dermis for each of the three varieties of fibers investigated. In skin carcinomas developed in aged people with senile keratosis there exists an inverse ratio between the richness of the fibrillar structure and the invasion and dissemination capacity of the tumours.     

The connection between ionophore-mediated Ca-movements and intermediary metabolism in human red cells. I. Relationships between Ca-loading, ATP-consumption and glycolytic flux

Human red cells (RBC) were loaded with moderate amounts of Ca²⁺ by the ionophore A23187. Quantitative relationships between Ca²⁺-loading, ATP consumption and glycolytic flux were established. 1. Ca²⁺-loading is accompanied by ATP depletion. A maximum ATP consumption of approximately 10 mmoles/l RBC/h was estimated. 2. There is a positive correlation between lactate formation and Ca²⁺-loading. This is linear from 1.4 to about 4 mmoles lactate/l RBC/h. 3. Ca²⁺-induced glycolytic stimulation seems not to be mediated by adenine nucleotides. A wide range of energy charges and very different adenine nucleotide patterns were associated with the same stimulation of lactate production. 4. The turnover of the (Ca²⁺-Mg²⁺)-ATPase and its share in the Ca²⁺-stimulated ATP consuming processes were estimated with inhibitors. 1 mM La³⁺ inhibited both Ca²⁺-outward transport and ATP consumption by 80%. The remaining 20% of the ATP consumption was accounted for by the (Na⁺-K⁺)-ATPase. 5. A Ca²⁺ extrusion to ATP consumption molar ratio of 2:1 was found. However, when ATP consumption was due to the breakdown of previously accumulated glycolytic intermediates, the ratio dropped to about 1.     

Relationships between hepatic melanogenesis and respiratory conditions in the newt, Triturus carnifex

The Kupffer cells (melanomacrophages) in the livers of lower vertebrates contain varying quantities of melanin according to the season. Specimens of Triturus carnifex raised for 2 months at 6 degrees C and then transferred to water at 22 degrees C show a rapid increase in the hepatic accumulation of the pigment. The Kupffer cells make up more than one fourth of the liver mass in chlorbutol-anesthetized animals isolated for 6-7 hr in hypoxic water at 18 degrees C (to bring the oxygen content in a 620-mL respiratory chamber from 1.1 ppm to 0.0). Thus, hepatic melanin is synthesized when the newt's oxygen supply is inadequate to meet its metabolic needs; melanogenesis, however, requires the presence of oxygen and does not occur in anesthetized specimens immersed in a totally anoxic fluid such as paraffin oil. The intraperitoneal injection prior to hypoxic treatment of 1 mg/g of body weight of kojic acid (inhibitor of the enzyme tyrosinase which catalyzes melanin synthesis) blocks melanogenesis and doubles oxygen consumption. The combination of hypoxia and tyrosinase inhibition causes permanent damage to essential functions of the nervous system, while hypoxic treatment alone has no irreversible consequences. The genic expression of tyrosinase in hypoxia appears to be a physiological response aimed at prolonging survival time in anaerobiosis by lowering the metabolic level; melanin would be an inert subproduct of this function.     

Relationships between body movements and phase of respiratory cycle in newborns.

To determine the relationships between body movements and phase of the respiratory cycle, we performed polygraphic recordings during daytime sleep in 12 normal newborns: 6 premature infants of 31 to 36 weeks conceptional age and 6 full-term infants of 39-41 weeks conceptional age. Chin and eye movements, movements detected during sighs and body movements not related to sighs were analysed separately. We analysed 1838 chin and body movements with a clearly defined beginning. Data obtained were similar in both premature and full-term infants, without statistically significant differences when active and quiet sleep states were compared. We found that: (a) The 96 movements concomitant with sighs all started during inspiratory diaphragmatic bursts. (b) The 1270 body movements unrelated to sighs started predominantly (78.6% in premature infants, 81.3% in full-term infants) during expiration, after the end of diaphragmatic contraction (P less than 0.002). (c) The 472 chin movements and eye movements occurred randomly with respect to phases of respiration. In conclusion, our data show that central motor command level determines relationships between movement initiation and respiratory phase. They suggest inhibition of trunk and limb movements (under pyramidal control) during diaphragmatic contraction as early as 31 weeks CA. This inhibition is absent during sighs, which involve the inspiratory augmenting reflex, and does not apply to chin and eye movements, which are mediated by cranial nerves.     

Relationships between concentration of hepatic intermediary metabolites and induction of the key glycolytic enzymes in vivo

1. The time-course for the induction of hepatic glucokinase, hexokinase, phosphofructokinase, liver-type and muscle-type pyruvate kinases in reponse to various diets and insulin has been investigated over the first 48h of change in both diabetic and non-diabetic rats. 2. The results are consistent with there being separate regulatory mechanisms for the induction of each of the three key enzymes, that is for glucokinase, phosphofructokinase and liver-type pyruvate kinase. 3. To investigate the possibility that induction of these enzymes is mediated through specific metabolites a full metabolite profile has been determined under conditions identical with those in the induction experiments and the results examined for correlations between metabolite concentrations and enzyme activities. 4. Several such relationships were detected and those between glucokinase activity and the phosphorylation state of the adenine nucleotides and between liver-type pyruvate kinase activity and the concentrations of dihydroxyacetone phosphate and pyruvate are discussed in relation to the concept of inducing metabolites. 5. It is suggested that the induction of glycolytic enzymes by insulin may be secondary to the changes in the concentration of specific hepatic metabolites brought about by the acute effects of the hormone. 6. The details of the metabolite concentrations in the various experimental states have been deposited as Supplementary Publication SUP 50021 at the British Library (Lending Division) (formerly the National Lending Library for Science and Technology), Boston Spa, Yorks. LS23 7BQ, U.K., from whom copies can be obtained on the terms indicated in Biochem. J. (1973), 131, 5.     

Organism size promotes the evolution of specialized cells in multicellular digital organisms

Specialized cells are the essence of complex multicellular life. Fossils allow us to study the modification of specialized, multicellular features such as jaws, scales, and muscular appendages. But it is still unclear what organismal properties contributed to the transition from undifferentiated organisms, which contain only a single cell type, to multicellular organisms with specialized cells. Using digital organisms I studied this transition. My simulations show that the transition to specialized cells happens faster in organism composed of many cells than in organisms composed of few cells. Large organisms suffer less from temporarily unsuccessful evolutionary experiments with individual cells, allowing them to evolve specialized cells via evolutionary trajectories that are unavailable to smaller organisms. This demonstrates that the evolution of simple multicellular organisms which are composed of many functionally identical cells accelerates the evolution of more complex organisms with specialized cells.     

The connection between ionophore-mediated Ca2+-movements and intermediary metabolism in human red cells. I. Relationships between Ca2+-loading,ATP-consumption and glycolytic flux

Human red cells (RBC) were loaded with moderate amounts of Ca²⁺ by the ionophore A23187. Quantitative relationships between Ca²⁺-loading, ATP consumption and glycolytic flux were established. 1. Ca²⁺-loading is accompanied by ATP depletion. A maximum ATP consumption of approximately 10 mmoles/l RBC/h was estimated. 2. There is a positive correlation between lactate formation and Ca²⁺-loading. This is linear from 1.4 to about 4 mmoles lactate/l RBC/h. 3. Ca²⁺-induced glycolytic stimulation seems not to be mediated by adenine nucleotides. A wide range of energy charges and very different adenine nucleotide patterns were associated with the same stimulation of lactate production. 4. The turnover of the (Ca²⁺-Mg²⁺)-ATPase and its share in the Ca²⁺-stimulated ATP consuming processes were estimated with inhibitors. 1 mM La³⁺ inhibited both Ca²⁺-outward transport and ATP consumption by 80%. The remaining 20% of the ATP consumption was accounted for by the (Na⁺-K⁺)-ATPase. 5. A Ca²⁺ extrusion to ATP consumption molar ratio of 2:1 was found. However, when ATP consumption was due to the breakdown of previously accumulated glycolytic intermediates, the ratio dropped to about 1.     

Relationships and evolution of the North African geckos,Geckonia and Tarentola (Reptilia: Gekkonidae), based on mitochondrial and nuclear DNA sequences

Mitochondrial (cytochrome b and 12S rRNA) and nuclear (c-mos) genes, analyzed by a variety of methods, indicate that the distinctive northwest African gecko Geckonia chazaliae is a member of the Tarentola clade, being most closely related to the species of the western Canary and Cape Verde islands. Relationships in Tarentola as a whole are as follows: (T. americana ((T. mauritanica, T. angustimentalis) ((T. deserti, T. boehmei) ((T. b. boettgeri-South (T. b. boettgeri-North (T. b. bischoffi, T. b. hierrensis))) ((T. annularis, T. ephippiata) (Geckonia, T. delalandii, T. gomerensis, Cape Verde species)))))); nearly all nodes have high bootstrap support. Results confirm that T. americana of Cuba and the Bahamas separated at the most basal dichotomy of the phylogeny and give no positive support for the monophyly of the subgenera Tarentola s. str. and Makariogecko. The latter includes Geckonia and the subgenus Sahelogecko. Continental Tarentola appear to have invaded the Sahara desert from its northern edge. They have also colonized groups of Atlantic islands five times: a single invasion of the West Indies and three of the Canary islands, one of which then went on to invade the Cape Verde archipelago. The phylogeny corroborates anatomical evidence that the ground-dwelling Geckonia had a climbing ancestry, something that is paralleled in some southern African terrestrial gekkonids related to Pachydactylus. Distinctive derived features of Geckonia occur in other gekkonids that are ground dwelling in arid habitats and may be functionally related to this environment. The evolution of such features indicates that, although Tarentola is generally very uniform and may have been so for over 10 million years, this is not due to any overwhelming phylogenetic constraint. G. chazaliae should be included in Tarentola, as Tarentola chazaliae.     

Molecular phylogenetics and mitochondrial genomic evolution in the chamaeleonidae (Reptilia,Squamata)

A phylogenetic hypothesis for the lizard family Chamaeleonidae is generated from 1503 aligned base positions (883 parsimony-informative) of mitochondrial DNA for specimens representing 59 species (57 ingroup and two outgroup). Sequences are reported for a genomic segment encoding eight transfer RNAs, NADH dehydrogenase component 2 (ND2), and portions of NADH dehydrogenase component 1 (ND1) and cytochrome c oxidase subunit 1 (COI). Newly reported genomic rearrangements and duplications support the hypothesis that mitochondrial gene order and content are destabilized by phylogenetic loss of a functional origin for light-strand replication between the genes encoding tRNA(Asn) and tRNA(Cys). A novel gene order characterizes all sampled Brookesia except B. nasus. Brookesia nasus, the apparent sister taxon of a clade formed by all other Brookesia, has the ancestral gene order but contains a large tandem duplication. An apparently noncoding 220 base pair insertion between the genes encoding ND2 and tRNA(Trp) is reported for Bradypodion tavetanum. Phylogenetic analysis identifies nine clades whose ancestral lineages diverged early in chamaeleonid evolutionary history: (1) Brookesia (possibly excluding B. nasus), (2) Chamaeleo subgenus Chamaeleo (excluding C. namaquensis), (3) Chamaeleo subgenus Trioceros, (4) viviparous Bradypodion, (5) oviparous Bradypodion, (6) genus Furcifer (except F. balteatus), and (7-9) three distinct clades of Calumma. Chamaeleo namaquensis, Brookesia nasus, Furcifer balteatus, Rhampholeon brevicaudatus, and R. spectrum represent ancient lineages dating to approximately the same time. Multiple independent losses and a possible secondary gain of horns are inferred for Trioceros. Viviparity has at least two separate origins in chameleons, one in Bradypodion and     

Relationships between sorting in the exocytic and endocytic pathways of MDCK cells.

Epithelial cells use both the exocytic and endocytic pathways to generate and maintain the polarized distribution of membrane proteins. This review summarizes current information concerning the general features and functions of the exocytic and endocytic pathways in MDCK cells. We analyse the possible implications of similarities between signals for endocytosis and determinants for basolateral sorting in the TGN. Furthermore, we discuss the fundamental relationships that might also exist in the biochemical basis of membrane traffic in the two pathways.     

Mutator-like elements in Arabidopsis thaliana. Structure, diversity and evolution

While genome-wide surveys of abundance and diversity of mobile elements have been conducted for some class I transposable element families, little is known about the nature of class II transposable elements on this scale. In this report, we present the results from analysis of the sequence and structural diversity of Mutator-like elements (MULEs) in the genome of Arabidopsis thaliana (Columbia). Sequence similarity searches and subsequent characterization suggest that MULEs exhibit extreme structure, sequence, and size heterogeneity. Multiple alignments at the nucleotide and amino acid levels reveal conserved, potentially transposition-related sequence motifs. While many MULEs share common structural features to Mu elements in maize, some groups lack characteristic long terminal inverted repeats. High sequence similarity and phylogenetic analyses based on nucleotide sequence alignments indicate that many of these elements with diverse structural features may remain transpositionally competent and that multiple MULE lineages may have been evolving independently over long time scales. Finally, there is evidence that MULEs are capable of the acquisition of host DNA segments, which may have implications for adaptive evolution, both at the element and host levels.     

Spatial relationship between cardiac mast cells and coronary capillaries in neonatal rats with cardiomegaly.

Density of cardiac mast cells and their localization with respect to coronary capillaries was studied in two experimental situations. First, cardiac hypertrophy produced by aortic constriction in 5-day-old rats was studied. Left ventricular weight increased more than twofold in this experimental situation, while the increases in total capillary length and total number of cardiac mast cells were much smaller, resulting in decreased densities of both tissue components. In the second series of experiments, localization of cardiac mast cells at two distinct portions of coronary capillaries was studied in normal hearts of adult rats. Differential histochemical staining enabled us to distinguish between the portions of capillaries close to arterioles and portions on the venular side. The number of mast cells close to arteriolar portions of coronary capillaries was significantly higher than one would expect in the case of their even distribution along the capillary wall. The relationship between the mast cells and formation of new capillaries is discussed.     

Relationships between the flux of lipid metabolism in vivo and the uncoupling of respiratory control

The influence of dinitrophenol treatment on the balance of lipid metabolism in mouse tissues has been studied by measuring the incorporation in vivo of 3H- and 14C-labelled glycerol. Several significant alterations in the relative utilization of these labels were observed in treated animals, with the greatest influence being evident in liver lipids, and diverse responses occurring in kidney, heart, muscle and adipose tissue. These data establish that dinitrophenol perturbs lipid metabolism in all the major tissues of the animal, and point to the detailed nature of this response in the individual classes of neutral and phospholipids. The implications of individual changes have been discussed in relation to the relative roles of mitochondria and peroxisomes in the regulation of mammalian lipid metabolism.