Greetings Friends!
We have updated our MacTetrad 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 macro also marks and counts exceptional
tetrads. The data are 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).
Two new features in MacTetrad6.9:
1. A macro was created to search for exceptional tetrads (non 2:2
segregation). The tetrads are marked and counted such that the number of
each type of exceptional tetrad is tabulated at the bottom of the spreadsheet.
These tetrads are then excluded from recombination distance
mapping.
2. When searching for tetrads with a particular genotype, one can use the
"Pull Tetrads" command to put the desired strains into a new spreadsheet.
MacTetrad 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 on the IBM platform.
For Mac Users: The MacTetrad Package was compressed with Stuffit Deluxe
into a self-extracting archive, and this was then binhexed.
The package is called MacTetrad69.hqx.
For PC Users: The MacTetrad Package was compressed with PKZIP.
The package is called MCTTRD69.ZIP.
The MacTetrad macro, examples, 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
FTP.Bio.Indiana.Edu). Open up the folder Molbio, and then open up the
folder Mac. (The PC version is in the folder molbio/IBMPC).
The MacTetrad package is also accessible from the Gopher side of the IUBio
Archive, where it is in the IUBio-Software+Data/Molecular Biology/Mac
folder. (The PC version is in the IBMPC folder, instead of the Mac folder.)
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.
Happy Dissecting!
David Stillman
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. Jonathan Greene
Schering-Plough Research Institute
Mail Stop K15-4,4700
2015 Galloping Hill Road
Kenilworth, NJ 07033-0539
e-mail: jgreene at phantom.com
