| How did you first become interested in biology/science? |
| My family was science-oriented. My older brother, who was interested in math and physics had a great influence in my interest in Science. I must say, however, that as a student, I was equally interested in foreign language and in writing. I keep these interests until now.
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| Who has inspired you most & why? Any important mentors? |
More than a mentor, I became inspired by the discovery of the 8-nucleated oocytes in Ascaphus truei by Herbert Macgregor and Jim Kezer (1970, Chromosoma 29:189-206 ). My former advisor, A.A. Humphries Jr., who returned from a sabbatical leave in H. Magregor’s lab, presented this work in a seminar. Until then, the germinal vesicle (GV) of amphibian oocytes was for me mysterious and of no particular interest, although the study of the oocyte GV was a major subject of his laboratory. During this seminar, I thought that it would be interesting to open up an oocyte and see the 8-nuclei pop up under the microscope. A year or so afterwards I completed the Ph. D. and returned to Ecuador. Here, I decided to study the oocyte characteristics of each frog that was brought to my lab. Additionally I dissected and studied ovaries from museum specimens. All of the many species examined had just a GV, except for Flectonotus pygmaeus, a marsupial frog from Venezuela. I discovered that the oocytes of this frog had between 2000-3000 nuclei per oocyte during the previtellogenic phase. I corresponded with my former doctoral advisor, A. A. Humphries, Jr. and he did not believe my results. He said that the scientific community will not accept something that goes so much against the “dogma”. “Every one knows that oocytes have just one GV”, was his opinion. His critical thinking was important and we published this discovery in 1978. For me it was fascinating to see that multinucleate oocytes occur in several species of marsupial frogs. I wish I had the tools to learn more about this type of oogenesis. I was unable to continue with this work because the marsupial frogs that have multinucleate oocytes are for the most part unavailable. Such frogs live in remote areas, and often in other countries of Latin America. This finding, however, told me that development of the marsupial frogs may be modified in comparison with that of “normal” frogs, such as Xenopus laevis. With the availability of molecular methods, the interest of the scientific community shifted from the study of oogenesis to that of gene expression during development, and I started the study of embryonic development in marsupial frogs.
I need to add that I had already decided to work with the zoology, reproduction and development of the marsupial frogs when I discovered the multinucleated oogenesis
I also need to add that I took a bold decision when I decided to work with the marsupial frogs. In 1972 almost nothing was known of the biology, reproduction and development of these frogs. I decided to do work of good quality and to publish it in international journals. I told myself that my humble contributions will be original and that I had no competion from other and better equipped laboratories. The beauty of the development of the marsupial frogs is fascinating for me.
I also need to add, that by concentrating on the reproduction and development of the marsupial frogs, I became visible to the international community. Most Latin American biologists concentrated in Systematic Biology or in Ecology or in medical or applied fields.
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| What, would you say, is your most transformative work? What was/is your key discovery? |
Transformative work, key discoveries: My first most transformative work is the study of oogenesis in Flectonotus pygmaeus and other marsupial frogs. I explained above the multinucleate oogenesis.
The second most transformative work was the analysis of the reproductive characteristics of the marsupial frog G. riobambae. The eggs develop inside the mother’s pouch and there is a hormonal control of embryonic incubation, by progesterone or a similar hormone of the mother. I did a simple experiment. I took a frog that was not incubating embryos and I introduced plastic beads, with the size of embryos, inside the pouch. The female immediately removed the beads with her toes. I injected progesterone into the abdominal cavity of the female and introduced the beads in the pouch. In this case, the beads were retained for about a week and, moreover, vascularized partitions of pouch tissue enveloped each bead. The ovary has long-lived postovulatory follicles. These follicles may correspond to corpora lutea, I did not check the hormonal characteristics of these follicles. The embryos are kept in the pouch for 4 months, and this is a wonder. There has to be exchanges with the mother. For exchanges with the mother, the embryos are enveloped by vascularized pouch tissue and by an envelope formed by the highly vascularized bell gills. This reproductive pattern resembles the mammals more than the frogs.
The third most transformative work is the characteristics of early development in the marsupial frog Gastrotheca riobambae. Another wonder was the early development of these frogs. In some species the eggs reach one cm in diameter. The question was whether these eggs developed in the same way as X. laevis. For a long time I was unable to understand the process of gastrulation in this frog. Richard Elinson send me a reprint of an article that describes the silver nitrate staining of surface cells in fish (Kageyama, 1980Dev. Growth Differ. 22:659). I adapted the method for G. riobambae and to my surprise I saw a disk of small cells on the surface of a late gastrula. We published this work together (del Pino and Elinson 1983.Nature 306: 589 591).The egg of 3mm in diameter of this frog, not only is larger than that of X. laevis but also it develops very slowly. For example, from start to the end of gastrulation it takes 7 days. This slow development allows the spacing out in time of developmental issues that in X. laevis occur simultaneously, as shown by my study of Brachyury expression (del Pino, 1996).
The 4th most transformative work is more recent. To do experiments with the large eggs of G. riobambae is difficult and the availability of embryos for work is limited. For these reasons, about 10 years ago I decided to explore the development of other frogs. The most likely candidates were the dendrobatids because these frogs reproduce in captivity and a colleague, Dr. Luis Coloma, maintained and studied these frogs. To my surprise, I learned that these frogs have not been studied from the view point of development, although the poisons of their skins are known and although these frogs are kept as pets all over the world. The external appearance of the embryos of the dendrobatid frog Colostethus machalilla is frog-like. The analysis its development, however, is fascinating. First, the eggs of 1.6 mm in diameter are larger than those of X. laevis. Development is slow in comparison with X. laevis, and although the gastrula does not form an embryonic disk as in G. riobambae, small cells accumulate at the blastopore lips. The dorsal convergence and extension is retarded until blastopore closure, as in G. riobambae. We produced a normal table of development for C. machalilla and a description of the features of early development of this frog (del Pino et al 2004. Int. J. Dev. Biol. 48: 663-670). The similarities with the development of G. riobambae, the slow developmental rate of these frogs the small size of these frogs and the ease of their maintenance in the laboratory, for me are promising features for the study of development in dendrobatids.
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| Can you comment on how you think your work has impacted a broader level beyond science? For instance, society, academia as a whole, conservation and/or nature? |
| This is difficult for me to assess
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| How would you define "diversity" within Science? |
| I do not have an answer
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| What is the biggest hurdle you've faced in your career? How did you overcome it? What hurdles do you see researchers facing today? |
It is a difficult question. There were, of course many obstacles such as lack of time to dedicate to research, because my major responsibility was teaching. Another was the lack of adequate laboratory facilities. Another obstacle was the scientific isolation that I faced in Quito. These obstacles, however, were turned into advantages.
First advantage, I had limited time to do research. Therefore I learned to use my time wisely. Second advantage, I had limited laboratory facilities in Quito. I was glad to have a job that allowed the possibility to do what I wanted. I established links of collaboration with other laboratories abroad and visited colleagues to do research at their laboratories. I was not a competitor and therefore my international colleagues have been most generous with me. I have visited the laboratories of my former professor AA. Humphries,Jr. (Emory University), Herbert Macgregor (Univ. of Leicester,UK), Dieter Söll (Yale University, New Haven, Conn), Richard Elinson (then at the University of Toronto), Igor Dawid (NIH, Bethesda), Michael Trendelenburg (DKFZ, Heildelberg, Germany), Joseph Gall (Department of Embryology, Carnegie Institution of Washington), Peter Hausen (Max Planck Institute for Developmental Biology Tübingen,Germany). Third advantage, the scientific isolation that I faced in Quito: I always saw this as a disadvantage until I realized that by having isolation, I was able to develop critical and original thinking. Now, of course with the availability of the Internet and correspondence by email this isolation has disappeared for the most part. I think, however, that it is great to be isolated and concentrated in my research without being disturbed.
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| What advice to you have for young biologists? |
| I have no advice to give except that one has to be true with one self.
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| How have you achieved to reach your science to the general public? |
My work has reached the general public by the following means: Locally, by the interest of journalists that throughout my career have published articles in Ecuadorian newspapers.
Second: I wrote an article for Scientific American in 1989 which was translated into the 10 language editions of this journal and in this way I think that I reached the general informed public worldwide.
Finally: When I was awarded the L’Oreal/UNESCO Prize, my work received worldwide attention from journalists.
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| Can you comment on science worldwide? Research policies, publications, and globalization? |
| Communication between scientists is easier now due to the globalization. Publication will go more and more into electronic forms. I find a great benefit to be able to read abstracts of recent papers. Until now, however, many journals are not free in the Internet, and therefore its access is limited. It will be good to have free access to all of the scientific journals.
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| How do you see technology affecting science? And how do you feel about technology being available for scientists? |
Technology always affects Science. When a new method is developed, it may help the advancement of Biology. For example, when the optics in the Physical Sciences was improved, the microscope was designed. The biologists were able to study cells using the compound microscope. Other examples of the advances in Biology were possible with the invention of the electron microscope and more recently with the molecular biology methods and recombinant technologies.
No one can have all of the technology at his or her disposal. For this reason, the collaboration among scientists is important for the advancement of Science.
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| Any bioethical issues that you may want to comment? |
| I have no comments in this regard
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| Favorite Science Fiction Writer? |
| I do not have time to read Science fiction |
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