PROFILE

Profile of Eugenia M. del Pino ugenia del Pino does not con- to . She was not satisfied, how- sider herself a ‘‘real’’ biologist. ever. She wanted to learn more biology She cannot abide dissections or and advanced research techniques. She fieldwork. She chose her Ph.D. struggled with the administrators at research—herE life’s work, as it turned LASPAU. ‘‘I wanted to complete a out—by a process of elimination. ‘‘I Ph.D., something that at the time was didn’t want to work with parasites,’’ she unheard of,’’ she says. ‘‘They said that recalls. ‘‘I didn’t want to work with bac- a master’s degree would suffice for the teria. I didn’t want to do anything in the level of scientific advancement in Ecua- medical profession.’’ Free-living proto- dor. And so I argued and I got every- zoans seemed safe, but her supervisor at thing that needed to be done so they ordered her to collect could allow me to complete a Ph.D.’’ samples from the banks of the Alta- Donald Williams, who had approved maha River. ‘‘I just imagined myself del Pino’s transfer to the master’s pro- having to wear boots, collecting those gram, was a graduate of Emory Univer- things and that was not for me!’’ sity (Atlanta, GA). He advised her to Fortunately for her and for the field apply to Emory because he believed she of developmental biology, another pro- would receive solid biology training fessor was studying frog embryos. there. Also, Emory’s biology department Harmless Xenopus laevis suited del Pi- featured a specialist in free-living proto- no’s taste in experimental animals. After zoa, on which del Pino had written her her Ph.D., she returned to her native Eugenia del Pino master’s thesis. Thus it was that, once Ecuador to apply her research skills to accepted to Emory, she approached her the study of exotic frogs, which are so target professor to ask him about oppor- Peace Corps volunteer Frances Ramirez tunities for studying the life cycle of cili- prolific in Ecuador that she did not have taught microbiology, instilling an ethic of to leave campus to find wild specimens. ates. It soon became apparent that the careful, consistent laboratory work. Both project he had in mind would involve del Pino says she fought to advance at encouraged gifted students to pursue ca- every step of her 35-year career, but her wading in riverside muck to collect spec- reers in science and took a special interest imens. However, fieldwork had always tenacity has paid off. She was named to in del Pino, persuading her to apply for the National Academy of Sciences in been anathema to del Pino. She balked. scholarships for graduate training abroad. Luckily, she met Professor Alan 2006 for the perspective her work has Acosta and Ramirez were delighted Humphries Jr., who was investigating how brought to developmental biology. when the Latin American Scholarship eggs form in X. laevis, the frog equivalent Program of American Universities Exceeding Expectations of Drosophila melanogaster. For her doc- (LASPAU) awarded del Pino a fellow- torate, del Pino joined Humphries’s The Pontifical Catholic University of Ec- ship that paid for her to study at a U.S. laboratory to study the process by which uador [Pontificia Universidad Cato´lica del university, on the condition that she Xenopus eggs are fertilized. She found Ecuador (PUCE), , Ecuador] has return to Ecuador afterward to teach. that how susceptible an egg is to fertiliza- been the setting for most of del Pino’s After a year waiting for the fellowship tion depends on the salt concentration life. ‘‘As a student I was gifted; I could do paperwork to be processed, del Pino and pH of the surrounding medium. If many things,’’ del Pino recalls. ‘‘To choose found out that she had been accepted to salt concentration drops, the outer layers a career path was very difficult for me.’’ Vassar College (Poughkeepsie, NY). of jelly on the egg swell, change structure, She was interested in the German lan- Happy as she was to arrive at Vassar in and block sperm from entering. After she guage and continues to study German 1967, an unpleasant surprise awaited. defended her dissertation in May 1972, it even today. However, when del Pino Vassar considered del Pino’s four years was time to go home. entered PUCE in 1963, the science pro- at PUCE the equivalent of one year at an gram at the School of Education, American institution and had assigned her A Rocky Homecoming established with aid from the Kennedy sophomore status. del Pino could not be- ‘‘Once I accepted a fellowship requiring administration in the United States, was lieve it. ‘‘I went to the dean of studies. I that I return to Ecuador to teach,’’ ex- only one year old. The equipment was said, ‘I think you have a made an error.’’’ plains del Pino, ‘‘it was my moral obliga- brand new, and courses were taught by After careful thought, the dean decided tion to return and try to do my best.’’ imported American professors. Impelled to put del Pino on academic probation However, she did not get the homecoming by curiosity, del Pino enrolled. for a semester. A professor followed her she expected. She wrote to PUCE ahead The aim of the science program was to progress and decided that she was indeed of time, telling them that she was finishing train high school science teachers. Peace graduate student material. Because Vassar her doctorate, in the hope they would Corps volunteers and professors from is primarily an undergraduate college, have a job for her. On her arrival, the PUCE’s sister university, the University of there were only two other students in the head of the science institute informed her St. Louis in Missouri, taught the teachers- master’s program. However, del Pino real- that they could only offer her a position to-be. ‘‘The foreign professors were inspir- ized that the department’s small size was that paid by the hour, she recalls. The ing,’’ del Pino says, ‘‘but in some cases to her advantage: She could benefit from going rate was the equivalent of 25 cents their command of Spanish was somewhat much more attention and support from limited.’’ Two who did speak Spanish had the professors than if she had been at

tremendous influence on the young del a larger university. This is a Profile of a recently elected member of the National Pino. Candida Acosta, a Puerto Rican del Pino finished a master’s degree in Academy of Sciences to accompany the member’s Inaugural affiliated with the University of St. Louis, biology in 1969. According to the terms Article on page 11882 in issue 29 of volume 104. was head of the biology department. And of her fellowship, she needed to return © 2007 by The National Academy of Sciences of the USA

www.pnas.org͞cgi͞doi͞10.1073͞pnas.0709215104 PNAS ͉ October 30, 2007 ͉ vol. 104 ͉ no. 44 ͉ 17249–17251 Downloaded by guest on September 25, 2021 for making thin slices of embryos) and various staining agents. ‘‘I decided that I could enjoy myself, doing whatever I wanted to do in my free time,’’ she says. All she needed was a research subject. Fancy Frogs Fuel a Career ‘‘I decided that I needed to look for an interesting frog,’’ she says. She did not have to travel far. ‘‘I went to the gardens of the university and found two different frogs. And the most strange was the mar- supial frog, which has a pouch and carries the babies inside. The pouch is in the back, like a backpack.’’ Out of the intense competition for reproductive sites in the South American rainforest had evolved over 60 species of these frogs, in which the females double as mobile nests. Their reproduction and development was under- stood only in barest outline. del Pino had found her subject. del Pino and students in her laboratory at PUCE in Quito (credit Micheline Pelletier, L’Oreal). As a natural extension of her gradu- ate work, she examined how marsupial frog eggs are fertilized and how the em- an hour. Furthermore, PUCE would only thought what I was saying was so inter- bryos are maintained in the mother’s allow her to teach the laboratory section esting,’’ she says. ‘‘They didn’t miss a pouch. ‘‘My first idea,’’ she says, ‘‘was, of introductory biology because she had word.’’ At the end of the course, she maybe in the evening, she will go into no teaching experience in Ecuador. ‘‘That gave an exam to assess what the stu- the pool and then the eggs will be re- was pretty discouraging,’’ she says. dents had learned. ‘‘I realized that they freshed with fresh water. Well, take Reluctant to take such an ill-paid, bor- never had cell biology, they had no those eggs from the pouch of the ing job, del Pino sought out the director training whatsoever for what I was mother and place them in fresh water, of the PUCE biology department, Olga teaching. But they were fascinated, and and they die immediately.’’ She found Herrera MacBryde. Herrera was happy to Guayaquil actually offered me a job.’’ In that, unlike Xenopus embryos, marsupial see a talented scientist return to Ecuador. the meantime, however, the administra- frog embryos develop under saline con- ‘‘At that moment,’’ del Pino says, Herrera tors at PUCE had thought things over ditions typically found in the body. ‘‘received a phone call from Guayaquil, and decided to hire del Pino after all. Traditional frogs and marsupial frogs our main port. At the University of ‘‘Now there was a new director of the also differ in how their embryos excrete Guayaquil, they needed someone to come science institute, and he said, ‘I think waste. Free-swimming tadpoles excrete and teach an advanced seminar.’’ Would you are very highly qualified,’’’ del Pino ammonia, which would be toxic if accu- del Pino be interested? says. They offered her a full-time posi- mulated in close quarters. del Pino discov- ‘‘That was really an interesting experi- tion, and she began work in the office of ered that marsupial frog embryos excrete ence,’’ she recalls, ‘‘because after you Olga Herrera, the director of the PUCE urea instead of ammonia. This finding are in these fancy universities in the biology department, who was on vaca- allowed her to devise a urea-based me- States’’ and return, ‘‘you are face to face tion. When the director returned, ‘‘she dium for the in vitro culture of marsupial with what it means to be in a developing announced that her husband had re- frog embryos. Unfortunately, she has country. There were groups at the Uni- ceived a job offer in the United States never been able to fertilize the eggs versity of Guayaquil that used to fight . . . and so this meant that in November artificially. with one another. The day I was starting I became head of the biology depart- Before long, the international re- my seminar, they had taken over the ment!’’ That was November 1972. del search community recognized del Pino building so I couldn’t go in.’’ Pino had defended her doctoral disser- as an expert on marsupial frog develop- The dean of natural sciences at the tation only six months earlier. ‘‘In the ment. Scientific American asked her to University of Guayaquil arranged for del developing world, things change from write a feature article in 1989 (1). Later, Pino to teach the seminar in a house one day to the next,’’ she says. in 2000, she won the L’Oreal/United downtown that served as an administra- The demands of administration and Nations Educational, Scientific and Cul- tive center. ‘‘The room had no window- teaching quickly snowed del Pino under. tural Organization (UNESCO) Award panes,’’ she says. ‘‘I had to teach in the She taught three or four classes for a for Latin American women in science. It evening from seven to nine o’clock, and total of 12 lecture hours a week, along did not hurt that the frogs could only be outside you heard these noises. I asked with the many hours it took her to pre- studied at high altitude: Quito, where what it was, and [was told] those were pare and grade papers. She realized that the frogs evolved, is two miles above sea students shooting one another! When I if she did not keep her research skills level, and after trying experiments in took a bus to go to my uncle’s home, you sharp, she might soon lose all of the the United States and Germany, re- could see the drops of blood on the training that she had acquired during searchers found that the marsupial frog street.’’ her doctorate. Also, she felt that keep- Gastrotheca riobambae refused to repro- She found the civil unrest shocking. ing abreast of research would make her duce overseas. ‘‘This in a way has been ‘‘But on the other hand, never in my life a better teacher. In the PUCE labora- to my advantage,’’ she says, ‘‘because I did I have a group of students that tory, she found a microtome (a machine had no competition.’’

17250 ͉ www.pnas.org͞cgi͞doi͞10.1073͞pnas.0709215104 Mossman Downloaded by guest on September 25, 2021 She has, however, kept strong ties to more than one nucleus. ‘‘He didn’t be- ops. The rest of the gastrula consists of scientists and institutions in the devel- lieve me,’’ del Pino recalls. He said she yolky cells. Before del Pino’s discovery, oped world and takes every opportunity was seeing artifacts. She continued to formation of an embryonic disk was to attend meetings, collaborate, and mail him pictures from Ecuador until he known to occur only in mammals and learn new techniques. To get up to date was persuaded to travel to Quito to see birds. She published her findings in Na- on the newest molecular methods during for himself. He brought the materials to ture (3), accompanied by a full page of her sabbaticals, she visited the laborato- detect the incorporation of tritiated uri- illustrations. She notes in the paper that ries of Michael Trendelenburg at the dine into RNA—a way to verify that the it is remarkable that the early develop- German Cancer Center (Heidelberg, extra nuclei were active. They were. mental stage in various frog species can Germany) and Joe Gall at the Carnegie In fact, del Pino discovered that sev- be so different, even though the end Institution (Baltimore, MD). eral marsupial frog species have result is so similar. multinucleated oocytes. The most dra- del Pino’s Inaugural Article (4)—a Conservation in the Gala´pagos matic occurrence is in the Venezuelan comparative study of development Over the years, many researchers have marsupial frog, Flectonotus pygmaeus, across seven frog species—epitomizes visited Ecuador because of its phenome- whose oocytes contain more than two her research career. Using the 14-hour nal biodiversity. In 1972, the same year thousand nuclei (2). del Pino showed development of Xenopus as a ruler, she that she returned to Ecuador, the that these nuclei provide embryos with and her colleagues observed the events Charles Darwin Foundation for the Ga- a large store of ribosomal RNA and that accompany in fast-, la´pagos Islands tapped her to run a provide multiple copies of genes, which medium-, and slow-developing Ecuador- program that granted fellowships to Ec- most likely allow Flectonotus to develop ian frogs. They show that in the fastest uadorian students to conduct research in quickly. Eventually, all but one of the developers (two species of foam-nesting the Gala´pagos.‘‘In other parts of the nuclei break down, and the cell reab- Engystomops, which take 24 hours to world,’’ she says, ‘‘people would pay sorbs them. In the common Xenopus money to go to the Gala´pagos Islands. frog that del Pino first studied at progress from fertilization to gastrula- This fellowship program is such a privi- Emory, it is known that oocytes have tion), the future backbone and gut elon- lege. Gala´pagosis an important place.’’ just one nucleus with two million copies gate at the same time that cells fold in She had no trouble motivating her stu- of ribosomal DNA in addition to the through the blastopore. However, in sev- dents to go. She also visited the Gala´pa- chromosomes. eral species of dendrobatid ‘‘poison gos regularly to keep tabs on them and Marsupial frogs with multinucleated dart’’ frogs, whose gastrulation takes learn about the variety of wildlife—the oocytes are hard to find, so del Pino four days, by the time the cells fold into frigate birds, the native rats, and the igua- switched to studying the embryonic devel- the blastopore to form the gastrula, only nas. The Darwin Foundation made her opment of frogs with ordinary nuclei. She the future gut has elongated. The future a member of its council, and she became discovered that marsupial frog eggs are backbone develops later. In the marsu- the foundation’s vice president for Ecua- very large, reaching a diameter of one pial frog G. riobambae, gastrulation lasts dor in 1992. The administrative work centimeter in some species. Moreover, the 14 days, and the schedule is even more became a chore, however. The same year gills, called ‘‘bell gills,’’ envelop the em- leisurely: All that is formed by the end she that became vice president, fishermen bryo in a sac closely apposed to the moth- of gastrulation is a small gut cavity. harvesting sea cucumbers for the Japanese er’s pouch. The system resembles the These surprising differences in embry- markets began to protest restrictions on mammalian placenta. Protected in the onic development are accompanied by an fishing in the Gala´pagos coastal waters. mother’s back, the embryos of the marsu- altered schedule of gene expression in They took scientists hostage, and del Pino, pial frogs develop at a very slow pace, like marsupial frogs, which del Pino and col- sitting in Quito, could contribute little to mammalian embryos. leagues detected at the protein level in solve the problem. ‘‘I got this feeling in whole embryos. They conclude that the my stomach—what can you do?’’ she says. Most Unusual Development process of gastrulation in Xenopus appears ‘‘And I decided that that was not for me. In animals, after fertilization the zygote to be so complex because several events The day has only 24 hours, and there are divides until it is a hollow sphere of overlap during the rapid development. other people who can do the lobbying and cells called a blastula. Then the blastula ‘‘You may think that, being in Ecuador, fight for conservation.’’ In the end, she begins to fold in on itself. Cells migrate I am isolated,’’ del Pino says. True, but decided not to run for office again and to across the lips of an opening called the the isolation does give her the time she focus on her research instead. However, blastopore to form specialized inner tis- needs to focus on scientific problems and she maintains interest in the conservation sues that will become organs. This pro- the freedom to explore new methods of of the Gala´pagos’unique environment. cess is termed gastrulation, and the teaching. Additionally, there is no short- embryo at this point is called a gastrula. age of exotic frog species to study in One Egg Cell, Many Nuclei In amphibians, including Xenopus, the Ecuador, every one of which is a new In the years after her return to Ecuador, embryo normally develops from the en- variation on the theme of embryonic de- del Pino kept in touch with her former tire gastrula. However, del Pino found velopment. There is no doubt that del supervisor Alan Humphries, even visit- that this does not happen in marsupial Pino is a ‘‘real’’ biologist, even if she tries frogs. ing his laboratory several times. Back in her very hardest to avoid getting muddy Ecuador, del Pino had observed that, Instead, small cells migrating across feet. when viewed under a microscope, some the blastopore lip form a wide disk from marsupial frog oocytes appeared to have which the embryo subsequently devel- Kaspar Mossman, Science Writer

1. del Pino EM (1989) Sci Am 260:110–118. 3. del Pino EM, Elinson RP (1983) Nature 306:589–592. N, Moya IM, Alarco´n I, Sudou N, Yamamoto S, 2. del Pino EM, Humphries AA (1978) Biol Bull 4. del Pino EM, Venegas-Ferrı´n M, Romero- Taira M (2007) Proc Natl Acad Sci USA 154:198–212. Carvajal A, Montenegro-Larrea P, Sa´enz-Ponce 104:11882–11888.

Mossman PNAS ͉ October 30, 2007 ͉ vol. 104 ͉ no. 44 ͉ 17251 Downloaded by guest on September 25, 2021