Lilian Vaughan Morgan (1870-1952): Her Life and Work

Lilian Vaughan Morgan was an important geneticist of the firstpart of the 20th century. She discovered both the attached-Xand closed-X chromosomes as part of her extensive research onthe X chromosome of Drosophila. She received A.B and M.S. degreesin Biology from Bryn Mawr College and became an independentinvestigator in the 1890s at the Marine Biological Laboratory,Woods Hole, Massachusetts. Although her research at the turnof the century was in embryology, she made the successful transitionto genetics. In 1904 she married T. H. Morgan, raised four children,managed the Morgan household, and when the children were grownresumed full time research. She always worked independently,and in her lifetime published 16 single author papers.     

<Emphasis Type="BoldItalic">Regeneration</Emphasis>: Thomas Hunt Morgan’s Window into Development

Early in his career Thomas Hunt Morgan was interested in embryology and dedicated his research to studying organisms that could regenerate. Widely regarded as a regeneration expert, Morgan was invited to deliver a series of lectures on the topic that he developed into a book, Regeneration (1901). In addition to presenting experimental work that he had conducted and supervised, Morgan also synthesized and critiqued a great deal of work by his peers and predecessors. This essay probes into the history of regeneration studies by looking in depth at Regeneration and evaluating Morgan’s contribution. Although famous for his work with fruit fly genetics, studying Regeneration illuminates Morgan’s earlier scientific approach which emphasized the importance of studying a diversity of organisms. Surveying a broad range of regenerative phenomena allowed Morgan to institute a standard scientific terminology that continues to inform regeneration studies today. Most importantly, Morgan argued that regeneration was a fundamental aspect of the growth process and therefore should be accounted for within developmental theory. Establishing important similarities between regeneration and development allowed Morgan to make the case that regeneration could act as a model of development. The nature of the relationship between embryogenesis and regeneration remains an active area of research.     

Photokinesis in the teleost fish Danio malabaricus

Summary Photokinesis as shown by the rapidly moving fish Danio malabaricus was examined in two experiments.In Experiment I, which involved sequences of short periods of light and darkness, the Ss for the most part showed a positive relationship between light intensity and level of activity. This reaction included a well differentiated response to abrupt intensity change, the effect of the transition from darkness to light being marked. Level of activity in both light and dark periods tended to fall; after a certain point, however, it rose again in the light but continued to fall in the darkness.In Experiment II, successive increases in the total area of lighted space available were matched by increases in the total length of time spent there by the Ss. The overall reaction, however, was initially photonegative and became more so as the experiment progressed. The range of most frequent periods of time spent in the lighted area increased gradually, while the length of entries into the shaded area gradually decreased, in the course of the experiment. But for a lighted area the Ss' length of entry was shorter than for the corresponding dark area, the choice of period was more precise, there were fewer longer periods, and the range was less. In the last condition, the Ss divided their time approximately equally between the lighted 7/8 and the shaded 1/8 of the area available. The number of times the Ss crossed from one area to the other almost doubled during the experiment.The author wishes to express his gratitude to Prof. G. Thinès for his help and encouragement. He was supported by a research grant from N. A. T. O., administered through the Science Research Council, London. The findings reported formed part of a study submitted as a doctoral dissertation at the Université de Louvain. The raw data is tabulated in this study and may be consulted at the Institut de Psychologie et des Sciences Pédagogiques. Address after 1 October: Department of Psychology, Bryn Mawr College, Bryn Mawr, Pennsylvania, U.S.A.     

Inbreeding,eugenics, and Helen Dean King (1869–1955)

Helen Dean King’s scientific work focused on inbreeding using experimental data collected from standardized laboratory rats to elucidate problems in human heredity. The meticulous care with which she carried on her inbreeding experiments assured that her results were dependable and her theoretical explanations credible. By using her nearly homozygous rats as desired commodities, she also was granted access to venues and people otherwise unavailable to her as a woman. King’s scientific career was made possible through her life experiences. She earned a doctorate from Bryn Mawr College under Thomas Hunt Morgan and spent a productive career at the Wistar Institute of Anatomy and Biology in Philadelphia where she had access to the experimental subjects which made her career possible. In this paper I examine King’s work on inbreeding, her participation in the debates over eugenics, her position at the Wistar Institute, her status as a woman working with mostly male scientists, and her involvement with popular science.     

Edmund Beecher Wilson, Class of '81

Edmund Beecher Wilson was born in Geneva, Illinois in 1856.He attended Antioch College, the University of Chicago, Yale,and Johns Hopkins (Ph.D. 1881). Most of his professional lifewas spent in the Zoology Department of Columbia University togetherwith his close friend, Thomas Hunt Morgan. They were dominantfigures in developing the Chromosome Theory of Heredity. Wilsonbegan his professional life as a conventional 19th century biologiststudying problems of systematics, morphology, and phylogeny.Soon he became a key figure in the newer experimental disciplinesof embryology, cytology, and heredity. He is remembered todaylargely for his superb synthesis of these three fields in TheCell in Development and Heredity. He died in 1939.     

Haeckel's ABC of evolution and development

One of the central, unresolved controversies in biology concerns the distribution of primitive versus advanced characters at different stages of vertebrate development. This controversy has major implications for evolutionary developmental biology and phylogenetics. Ernst Haeckel addressed the issue with his Biogenetic Law, and his embryo drawings functioned as supporting data. We re-examine Haeckel's work and its significance for modern efforts to develop a rigorous comparative framework for developmental studies. Haeckel's comparative embryology was evolutionary but non-quantitative. It was based on developmental sequences, and treated heterochrony as a sequence change. It is not always clear whether he believed in recapitulation of single characters or entire stages. The Biogenetic Law is supported by several recent studies -- if applied to single characters only. Haeckel's important but overlooked alphabetical analogy of evolution and development is an advance on von Baer. Haeckel recognized the evolutionary diversity in early embryonic stages, in line with modern thinking. He did not necessarily advocate the strict form of recapitulation and terminal addition commonly attributed to him. Haeckel's much-criticized embryo drawings are important as phylogenetic hypotheses, teaching aids, and evidence for evolution. While some criticisms of the drawings are legitimate, others are more tendentious. In opposition to Haeckel and his embryo drawings, Wilhelm His made major advances towards developing a quantitative comparative embryology based on morphometrics. Unfortunately His's work in this area is largely forgotten. Despite his obvious flaws, Haeckel can be seen as the father of a sequence-based phylogenetic embryology.     

Some metabolic aspects of tolerance to bacterial endotoxin

Berry, L. Joe (Bryn Mawr College, Bryn Mawr, Pa.), and Dorothy S. Smythe. Some metabolic aspects of tolerance to bacterial endotoxin. J. Bacteriol. 90:970-977. 1965.-The tolerance to bacterial endotoxins which is produced in mice given a series of daily injections of heat-killed Salmonella typhimurium failed to occur when actinomycin D was administered with the heat-killed cells. Neither ethionine nor 2-thiouracil, when given with endotoxin, altered the development of tolerance. An injection of endotoxin, actinomycin D, or ethionine lowered the activity of the liver enzyme tryptophan pyrrolase more significantly at either 4 or 17 hr postinjection in normal mice than in tolerant mice. Similarly, an injection of either saccharated iron oxide or Thorotrast lowered liver tryptophan pyrrolase activity more extensively in normal than in tolerant animals. Activation of the reticuloendothelial system (RES) of tolerant mice, as determined by an accelerated rate of carbon clearance from the blood, was observed, but this was prevented by the appropriate dose of actinomycin D. Similar results were obtained when saccharated iron oxide, rather than endotoxin, was used to activate the RES, but these animals were not resistant to endotoxin and their tryptophan pyrrolase was normally diminished after an injection of endotoxin. Thus, RES activation may occur without tolerance developing. A more nearly normal level of enzyme activity appears to be characteristic of the tolerant state.     

August Rauber (1841-1917): from the primitive streak to Cellularmechanik

In the early 19th century Karl Ernst von Baer initiated a new research program searching for the mechanisms by which an egg transforms itself into an embryo. August Rauber (1841-1917) took up this challenge. He considered the phylogenetic principle as the right tool to explain the similitude of embryogenetic processes. In extending Baer's approach, he combined comparative embryology and histology in his studies of avian and mammalian embryos. His earlier work demonstrated that the two-layered chick embryo is a modified gastrula and not a "disc" as Wilhelm His had claimed. From the 1880s onwards, he concentrated on the issue of how the development of germ layers is related to tissue differentiation. To address this, he studied the blastopore, epiblast, primitive streak, teratology and the relative importance of nucleus and cytoplasm in heredity. This paper reconstructs some of Rauber's work and concludes that his observations and reflections constituted a new approach combining embryology and histology with "phylogenetic" reasoning.     

Daniel I.C. Wang: a tribute to an inspirational leader and colleague

Daniel I.C. Wang has been an influential leader of the biotechnology industry over the past four decades through his inspirational research activities, the legions of students and other researchers that have studied under him, his development of many research and educational initiatives, both nationally and internationally, and the advice he has given worldwide to companies, research institutions, universities, and governments. He has played an important role in the mentoring and nurturing of junior faculty members, and has been a supportive collaborator in research and teaching. This two-part article provides a brief overview of Danny Wang's many contributions to furthering the global development of biotechnology, with particular emphasis on his recent activities in Asia, and concludes with an account of his research collaborations with the author over the past two decades.     

My perpetual cycle: from student to researcher to teacher to student ..

This contribution stems from the personal experience of the author regarding how he became acquainted with embryology and how he finally entered the field of developmental biology. It reports his feelings as a student of the Histology and Embryology course as it was taught in the late 1970s, and his present efforts in teaching developmental biology to university students. In the Developmental Biology course at Pisa University today, students are taught the tissue, molecular and genetic mechanisms that regulate development of several model systems. Drosophila is introduced at the beginning, because of the great knowledge that it has brought to the unraveling of the molecular aspects of development and because it allows several basic concepts to be introduced, and vertebrate systems follow. Other topics include the classic experiments on amphibian systems, which are explained in the light of recent molecular advances, as well as the genetically more versatile vertebrate systems such as the mouse.     

POSSIBLE SOURCE OF SECONDARY INVADING STAPHYLOCOCCI IN MICE EXPOSED TO ACUTE COLD

Miraglia, Gennaro J. (Bryn Mawr College, Bryn Mawr, Pa.) and L. Joe Berry. Possible source of secondary invading staphylococci in mice exposed to acute cold. J. Bacteriol. 85:345-348. 1963.-In an effort to determine the origin of the staphylococci known to invade the deep tissues (liver, spleen, kidneys, lungs, and heart) of mice exposed continuously to 5 C in individual compartments without bedding, the intestinal tract was freed of these organisms, as judged by absence of growth when fecal suspensions were inoculated into selective media. Substitution of 0.01 n hydrochloric acid for drinking water eliminated staphylococci within a few days, yet the incidence of tissue invasion was unaltered. The coagulase-negative strains normally present in feces and in tissues persisted in tissues even though the intestine was seeded with a coagulase-positive strain by feeding contaminated food. Cultures from the external nares continued unaltered. This suggests that the respiratory tract is a possible origin of the staphylococci found in tissues of the cold-stressed mice.     

The Claude Bernard Distinguished Lecture. In pursuit of meaningful learning

The Bernard Distinguished Lecturers are individuals who have a history of experience and expertise in teaching that impacts multiple levels of health science education. Dr. Joel Michael more than meets these criteria. Joel earned a BS in biology from CalTech and a PhD in physiology from MIT following which he vigorously pursued his fascination with the mammalian central nervous system under continuous National Institutes of Health funding for a 15-yr period. At the same time, he became increasingly involved in teaching physiology, with the computer being his bridge between laboratory science and classroom teaching. Soon after incorporating computers into his laboratory, he began developing computer-based learning resources for his students. Observing students using these resources to solve problems led to an interest in the learning process itself. This in turn led to a research and development program, funded by the Office of Naval Research (ONR), that applied artificial intelligence to develop smart computer tutors. The impact of problem solving on student learning became the defining theme of National Science Foundation (NSF)-supported research in health science education that gradually moved all of Dr. Michael's academic efforts from neurophysiology to physiology education by the early 1980's. More recently, Joel has been instrumental in developing and maintaining the Physiology Education Research Consortium, a group of physiology teachers from around the nation who collaborate on diverse projects designed to enhance learning of the life sciences. In addition to research in education and learning science, Dr. Michael has devoted much of his time to helping physiology teachers adopt modern approaches to helping students learn. He has organized and presented faculty development workshops at many national and international venues. The topics for these workshops have included computer-based education, active learning, problem-based learning, and the use of general models in teaching physiology.     

The sea spider's contribution to T.H. Morgan's (1866-1945) development

Over a century ago, T.H. Morgan helped found The Journal of Experimental Zo?logy, a series devoted to emerging investigations in development and evolution, variation and heredity, adaptation and ecology. T.H. Morgan initially encountered these topics in his graduate research on the ontogeny and phylogeny of the sea spiders. His Ph.D. thesis, written in 1891, reflects in interesting ways the conceptual shifts in evolutionary biology in the late 1800s. Embryology had become a major criterion in using morphological similarity to speculate on phylogenetic relationships. Yet, when Morgan studied the development of sea spiders to draw conclusions about their relatedness, he struggled with the incompleteness of knowledge about the role of inheritance and variation of ontogenetic processes. This can best be seen in his discussions of the properties of conservation during embryonic cleavage, varied development of supposedly homologous appendages, and the evolvability of larval stages. After his dissertation, Morgan never returned to phylogenetic analysis. He had been dissatisfied with the plethora of untestable phylogenetic hypotheses based on comparing complicated embryological phenomenon, and joined an experimental movement in which systems were explicitly chosen and constructed to test hypotheses about developmental processes.     

From eggs to fossils: epigenesis and transformation of species in Pander's biology

Christian Heinrich Pander (1794-1865), a Russian scientist of German culture, is known for his epoch-making work in embryology, as well as for his important contributions to palaeontology. Indeed he viewed embryonic development and the history of the earth as two aspects of one and the same essential phenomenon, namely, a perpetual metamorphosis affecting the living world on different scales. He viewed embryology as a gradual, epigenetic transformation (as opposed to preformation) with an intermediary stage, the formation of simple germ-layers. As early as 1821, he argued more generally that species themselves transform under the influence of certain environmental factors. Pander thus embodies the very close link that existed between the triumph of epigenesis and the expansion of transformist theories in the early 19th century.     

Inhibition of inducible liver enzymes by endotoxin and actinomycin D

Berry, L. Joe (Bryn Mawr College, Bryn Mawr, Pa.), Dorothy S. Smythe, and Louise S. Colwell. Inhibition of inducible liver enzymes by endotoxin and actinomycin D. J. Bacteriol. 92:107-115. 1966.-Bacterial endotoxin at the ld(50) level lowers liver tryptophan pyrrolase in mice, it prevents for 16 to 20 hr the induction of the enzyme by a concurrent injection of cortisone, it lowers significantly but does not prevent substrate induction, and it reduces the enzymatic activity promptly and significantly when administered during the course of hormonal induction. The ld(50) amount of actinomycin D has a similar effect on tryptophan pyrrolase, except that its inhibition of induction by cortisone persists for a longer period of time. Endotoxin in the intact mouse induces tyrosine-alpha-ketoglutarate transaminase almost as well as cortisone, but not in the adrenalectomized animal, a fact that suggests induction of this enzyme is due to release of endogenous adrenal hormones. Actinomycin D, on the other hand, has an effect on this transaminase similar to that on tryptophan pyrrolase. The site of action of endotoxin and actinomycin D would appear to be similar for one of the two enzymes studied and different for the other, a relationship that requires a specificity difficult to imagine for a material as complex as endotoxin.     

ENHANCEMENT OF SALMONELLOSIS AND EMERGENCE OF SECONDARY INFECTION IN MICE EXPOSED TO COLD.

Miraglia, Gennaro J. (Bryn Mawr College, Bryn Mawr, Pa.) and L. Joe Berry. Enhancement of salmonellosis and emergence of secondary infection in mice exposed to cold. J. Bacteriol. 84:1173-1180. 1962.-The ld(50) dose for mice of Salmonella typhimurium, strain RIA, is 4.1 x 10(5) for animals individually housed without bedding and maintained at 25 C. It is 3.8 x 10(3) for animals similarly housed but kept at 5 C. An intravenous injection of 0.1 ml of Proferrin 2 hr prior to infection with RIA lowers the ld(50) to 4.9 x 10(3) and to 4.0 x 10(1) for mice kept, respectively, at 25 and at 5 C. Low environmental temperature and "blockade" of the reticuloendothelial system (RES) lower the resistance of mice to about the same degree, but low temperature and RES impairment together lower resistance as if each were acting independently. No effect of cold could be detected in mice infected with the highly virulent SR-11 strain of S. typhimurium, since all animals died after infection with only a few cells. Mice that were natural carriers of salmonellae, as judged by fecal discharge, were highly resistant to challenge and responded to cold in a manner similar to normal mice infected with RIA. Strain RIA could be isolated from the tissues of infected animals with greater frequency and persisted longer in mice maintained at 5 C than those at 25 C. Staphylococci were isolated from livers of animals that survived salmonella infection for 14 days at 5 C, and the incidence of staphylococci was proportional to the number of salmonellae injected. At 25 C, only a small percentage of mice had staphylococci in tissues and these occurred independent of the infectious dose of salmonellae. These observations were made on normal mice infected with RIA and on carrier mice infected with SR-11.     

Q & A: Till Roenneberg

Till Roenneberg is Professor of Chronobiology at the University of Munich. He studies the circadian clock from its cellular/molecular mechanisms up to the consequences of shift work. He received his education in Munich and London, and worked in the 1980s with Woody Hastings at Harvard. Since then, he has built up the Centre for Chronobiology at the Munich Medical School. For many years, he has coordinated circadian research and education in Germany and in Europe. He is also involved in reforming the University curriculum, incorporating problem-based approaches. He has received international prizes for both his research and his teaching.     

Contribution of late Professor T. C. Tung to the experimental embryology of Amphioxus

Professor T. C. Tung (Fig. 1) was a prominent experimental embryologist in China. He was born in Jin County, Zhejiang Province, China in 1902. After he obtained his Bachelor's degree from the Department of Biology, Fudan University, Shanghai in 1927, he was appointed as a teaching assistant in that department until he moved to Belgium in 1930. He studied as a graduate student in Professors A. Brachet and A. M. Dalcq's laboratory at the Universite Libre de Bruxelles, Belgium and obtained his Doctor of Science degree there in 1934. During that period, he made two short working visits to the Institute of Marine Biology in France and took one training course at Cambridge University (UK). In 1934, he was invited to return to China as a Full Professor to teach at several Chinese universities, (Shandong University in Qingdao, Shandong Province; the National University in Nanjing; and Fudan University in Shanghai). He spent 1 year at Yale University (USA) between 1948 and 1949 as an invited scientist in a joint research project and finally returned to China in 1949. He was Chairman of the Department of Zoology, Shandong University in Qingdao (1949-1952), Vice-President of Shandong University (1952-1960), Director of the Marine Biological Institute, the Chinese Academy of Sciences (CAS) in Qingdao (1949-1958), Director of the Institute of Oceanology (CAS) in Qingdao (1959-1966), Director of the Institute of Zoology (CAS) in Beijing (1960-1962), member of CAS since 1955, Vice-Chairman of the Biological and Geographical Division of CAS (1955-1958), Chairman of the Biological Division of CAS (1959-1979) and Vice-President of CAS in Beijing (1978-1979). In spite of his administrative duties, he spent most of his life conducting bench work in his laboratories at the Institutes of Oceanology and Zoology, CAS, respectively, until he passed away in March 1979. Professor Tung's main research interest was with classic experimental studies on the determination of the egg axis and symmetry planes of fertilized eggs, early differentiation and organizing substances of egg cytoplasm, induction between embryonic cells and cytoplasm in embryogenesis, immunological studies on nuclear transplanted eggs, and cell fusion etc., in several types of animals. He conducted his experiments on a number of invertebrates (ascidians and Amphioxus) and vertebrates (fish and amphibians) by means of very skillful microsurgical operations and the nuclear transplantation method. Among these topics, his studies on the organization and developmental potency of Amphioxus eggs were unique. His important contribution to this research field involved not only establishing a practical method for collecting and using this rare animal for experimental purposes, but also clarifying controversy about the nature and early development of its eggs. He also provided conclusive evidence to determine its evolutionary position between invertebrates and vertebrates. The present article briefly reviews the main results obtained by Professor Tung and his colleagues on Amphioxus. Although their original articles were written both in Chinese and English, many international readers may not even know those original works because they were only published in scientific journals inside China from the 1950s. Comments and discussion on the experimental results of Amphioxus research by Tung's group and those from other earlier authors are also included.     

Acrobat to academic: A sketch of the life and carrer of Frederick E. Samson,Jr.

Fred Samson's carrer began in osteopathy and show business. After service as a medic during World War II, he earned, a doctoral degree in physiology at the University of Chicago and joined the faculty of the University of Kansas in Lawrence in 1952. There he conducted pioneering research on cerebral energy metabolism and axoplasmic transport while inspiring a generation of students in the classroom and lab. During the mid 1960s, he began a fruitful and lasting collaboration with the Neurosciences Research Program and its founder, Francis O. Schmitt. In 1973 he became director of the Ralph Smith Mental Retardation Research Center in Kansas City, where he added metabolic mapping of the brain in relation to seizure activity and drug toxicity to his research accomplishments. He retired in 1989, still pursuing new problems and continuing to inspire colleagues with his enthusiasm for neurochemistry and the joy of science.Special issue dedicated to Dr. Frederick E. Samson.     

Marshall Barber and the century of microinjection: from cloning of bacteria to cloning of everything

A hundred years ago, Dr. Marshall A. Barber proposed a new technique - the microinjection technique. He developed this method initially to clone bacteria and to confirm the germ theory of Koch and Pasteur. Later on, he refined his approach and was able to manipulate nuclei in protozoa and to implant bacteria into plant cells. Continuous improvement and adaptation of this method to new applications dramatically changed experimental embryology and cytology and led to the formation of several new scientific disciplines including animal cloning as one of its latest applications. Interestingly, microinjection originated as a method at the crossroad of bacteriology and plant biology, demonstrating once again the unforeseen impact that basic research in an unrelated field can have on the development of entirely different disciplines.