We have written an Excel spreadsheet designed for tetrad data for yeast
genetics. One enters the genotypes of haploid spores into the
spreadsheet and a Macro automatically classifies each tetrad as PD, NPD,
or T for each pair of markers. The data is presented in a table, along
with recombination distances.
When one is performing a cross with multiple markers segregating, it is
often difficult to identify the spores with a particular genotype. The
spreadsheet macro makes this procedure simple. The macro also allows one
to identify tetrads with a particular characteristic (i.e. tetrads that
are NPD for two specific markers).
This spreadsheet requires Excel (version 3.0 or 4.0) for the Macintosh.
The spreadsheet also works with Excel for Windows running on an IBM PC,
but we have not extensively tested it.
The MacTetrad spreadsheet, macro, and an instruction manual are available
over the Internet network via Gopher or FTP:
For Gopher, point Gopher to merlot.welch.jhu.edu
Use the "Search the Titles of All Items in this Gopher Hole" command to
search for "MacTetrad"
For anonymous FTP, log onto the IUBio Archive (Intenet address =
Open up the folder Molbio, and then open up the folder Mac.
The MacTetrad package is also accessible from the Gopher side of the
IUBio Archive, where it is in the IUBio-Software+Data/Molecular
For those without access to the Internet, MacTetrad is available from
either Jonathan Greene or David Stillman. Please send a formatted
Macintosh disk to one of the addresses listed below.
Department of Cellular, Viral and Molecular Biology
University of Utah Medical Center
Salt Lake City, UT 84132
e-mail: stillman at bioscience.utah.edu
Dr. Jon Greene
Schering-Plough Research Institute
Mail Stop K15-4,4700
2015 Galloping Hill Road
Kenilworth, NJ 07033-0539
e-mail: jgreene at phantom.com