Refer to figure 8.31 (below). Briefly explain, in your own words, the role of al
ID: 176962 • Letter: R
Question
Refer to figure 8.31 (below). Briefly explain, in your own words, the role of alternative splicing of the tra gene in sex determination of Drosophila. (1 x/A ratio determines 2 Sxl transcription Sxl protein directs Tra Alternative Dsx activator-repressor and translation pre-mRNA splicing to produce pre-mRNA splicing in female but not Tra protein in female embryos, ratio. is controlled by Tran in male embryos. not male embryos. protein. 2Xchromosomes Intron A Intron SisA SisA Female embry SisB o Tra gene Tra protein SisB (XIA 1.0) Deadpan Deadpan pre-mRNA Sxl protein Tra-2 protein Female-specific Dsx Tra gene activates female mature mRNA Exon 1 Exon 3 2 autosomes genes and represses male genes. No Sxl activity 1 X chromosome Intron Intron SiSA No Tra protein Tra gene Male embryo SisB Sxl protein pre-mRNA (x/A 0.5) Deadpan Deadpan Male-specific No productive Dsx protein splicing 2 autosomes female genes.Explanation / Answer
Gene Sex-lethal (Sxl) disables in male drosophila. Sxl gene is depend upon X:A [X-sex chromosome and A- autosome] signal, male has X;2A so the Sxl gene does not expressed. Gene tra express when Sxl express by alternative splicing of intron A and B during transcription. Then the RNA from Exon1 and Exon 2 combines to form mRNA of tra gene. That will express into tra protein Gene tra exon 2 will show results in male. The probe will attach here but expression will not occur because tra at exon2 is stopped.
The phase of exon 1 at end is G-A-G. and A-G combines to form splicing acceptor region. The start of exon 2 is A-G-G.
The reading frame is at upstream 19bp because start codon ATG is present at 19th position nucleotide, from starting, 5’ of DNA.