HOU, GUI-CHUAN*, JEFFREY P. HILL, LAURENS H. JR. SMITH, and BECKY A. NIELD. Department of Biological Sciences, Idaho State University, Pocatello, ID83209-8007. - Molecular genetic studies of root development in fern Ceratopteris richardii.
Root heteroblastic development during early sporophyte ontogeny and
the developmental anatomy of the fifth root were characterized in
previous investigations of the homosporous fern Ceratopteris
richardii. Here we report preliminary results of a molecular
genetic study of root development in C. richardii. Total mRNA
was extracted from gametophytes, sporophylls, and roots of the
species. Reverse transcription-polymerase chain reaction (RT-PCR) was
employed to copy cDNAs from the original RNA populations. The
differential display-polymerase chain reaction (DD-PCR) technique was
used to identify putative root specific cDNAs. Six root specific
subclones were recovered from a display of 6 primer combinations.
Northern analysis of the first subclone (designated as RSG1)
has confirmed that it is specifically expressed in roots of C.
richardii. Efforts are in progress to characterize the full-length
sequence of RSG1 and determine its expression pattern in situ.
Key words: Ceratopteris richardii, root development, root specific gene