C-ski transcripts with and without exon 2 are expressed in skeletal muscle and throughout chick embryogenesis.
Overexpression of v-ski or c-ski cDNAs has a pronounced effect on proliferation, morphological transformation and myogenic differentiation in cells in culture and in transgenic animals. Yet, little is known about expression of the c-ski locus or the relationship between c-ski cDNAs and alternatively spliced c-ski transcripts in chicken tissues, particularly in skeletal muscle or during embryogenesis. We developed a series of probes and oligonucleotide primers specific for the eight coding exons and the long 3' noncoding region found in chicken c-ski mRNAs. The most abundant chicken c-ski mRNAs in a vast array of tissues are 8.5 kb, with additional, but less abundant, mRNAs of 7.5, 6.5 and 4.4 kb. Steady-state levels of c-ski mRNAs, indistinguishable from transcripts in other tissues, accumulate in skeletal muscle from embryonic, newly hatched, and adult chicks. Only exon 2, a small exon of 111 bp, was found to be alternatively spliced in c-ski mRNAs. Transcripts with and without exon 2 appear in all tissues, in somites, and from the earliest stages of chick embryogenesis. Thus, c-ski cDNA sequences, which extend about 4.3 kb, represent either the least abundant form of c-ski mRNAs in tissues or a severely truncated form of the major 8.5 kb transcripts.
Department of Pathology, University of Florida College of Medicine, Gainesville 32610.
H L
HL
Grimes
M R
MR
Ambrose
M M
MM
Goodenow
D000818:Animals; D001483:Base Sequence; D002642:Chick Embryo; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005091:Exons; D008969:Molecular Sequence Data; D009132:Muscles / Q000196:embryology / Q000378:metabolism*; D015345:Oligonucleotide Probes; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D012326:RNA Splicing; D012333:RNA, Messenger / Q000378:metabolism*
D004268:DNA-Binding Proteins; D015345:Oligonucleotide Probes; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger