THE Howard Hughes Medical Institute (HHMI) presents the seventh volume of Research 
in Progress, a series begun in 1986 to describe the research activities of the Institute. 
Early in 1992 the scientists associated with HHMI at that time were asked to provide 
statements in nontechnical terms of their past accomplishments, current work, and plans for 
the future, in order to provide a concise but informative picture of the Institute's research 
in progress. You will read their personal essays in the pages that follow. We are pleased that 
this annual publication has come to be a useful source of information for scientists and 
nonscientists interested in biomedical research, as well as for the members of the HHMI family. 
The Institute also publishes as a companion volume the formal Annual Scientific Report. 
This is the official archival record of the research of each HHMI laboratory and includes 
yearly bibliographies as well as descriptions of other HHMI scientific activities. A general 
Annual Report of the Howard Hughes Medical Institute describes the various programs for 
a lay audience and gives a summary of the Institute's financial data. With the recent 
publication of From Egg to Adult, which describes the exciting process of biological 
development, the Institute has expanded its series of reports on subjects of current scientific 
interest written for a general audience. This booklet joins the widely acclaimed Finding the 
Critical Shapes and Blazing a Genetic Trail that have been in great demand by a broad 
spectrum of readers, especially teachers who have used these reports in classrooms across 
this country and abroad. 
In recognition of the fact that the boundaries of biomedical science are not constrained by 
national borders, the Institute launched its International Research Scholars Program in the 
spring of 1991- This is a limited and experimental program with the purpose of providing 
research support in selected countries for promising scientists whose careers are in a 
developing phase but who have already made significant contributions to biomedical 
research. The international program is separate from the Institute's ongoing medical research 
program, described in the first section of this volume, in which scientists join HHMI as full- 
time employee-investigators and are supported through the Institute's operation as a Medical 
Research Organization (MRO). The Scholars do not join the HHMI staff, but instead each 
receives research support through a grant. 
For the initial awards in this program, selected scientists in the countries that are our 
immediate neighbors, Canada and Mexico, were invited to compete. Twenty-four outstanding 
investigators received five-year awards (14 from Canada and 10 from Mexico). You will read 
their descriptions of the research in their laboratories in the second section of this volume. 
For awards in 1993, the Institute has turned to scientists in the United Kingdom, Australia, 
and New Zealand. Those selected for grant support will be announced in late 1992, and their 
work will be included in the next volume of Research in Progress. 
The Institute has a large grants program that complements its MRO activities. In addition to 
the International Research Scholars initiative, the grants program supports education in the 
biomedical and related sciences at the precollege, college undergraduate, graduate, and 
postdoctoral levels. New in 1992 were grants awarded to certain science museums, science 
and technology centers, children's museums, and natural history museums to assist in 
education and outreach programs for elementary school children and their families. The 
Institute's annual publication Grants for Science Education details these initiatives. 
A very important event for HHMI occurred in the spring of 1991, when construction began 
on the buildings that will become our new headquarters and conference center complex in 
Chevy Chase, Maryland. At this writing, the construction is entering its final phases, and the 
attractiveness of the buildings of this large facility and how they fit into the gentle hills and 
valleys of the lovely site are exceeding our original expectations. We expect to occupy the 
buildings in early 1993- The facility provides the administrative focus for the Institute's 222 
investigators (as of July 1, 1992) whose laboratories are located at 53 institutions across 
this country. 
We invite you to share the excitement of the research of the HHMI investigators whose 
work forms the core of the Institute's activities and of the studies of our International 
