Difference between revisions of "Kevinmcgee Week 11"
From LMU BioDB 2013
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#**Similar to that in humans that deals with immunity from macrophage | #**Similar to that in humans that deals with immunity from macrophage | ||
==Significant Genetic Findings== | ==Significant Genetic Findings== | ||
| − | + | ===Transcription=== | |
| − | # | + | #L. major genome is organized into 133 clusters of tens to hundreds of protein-coding genes on same DNA strand |
| − | # | + | #Pollycistronic transcription initiates in both directions: |
| − | # | + | #*In divergent strand-switch regions |
| − | # | + | #*terminates within the convergent strand-switch regions |
| − | # | + | #RNAP I, II and III were found in Trytrip |
| − | # | + | #*Very different from other eukaryotes |
| − | # | + | #Not many other homologs of RNAP were found |
| − | # | + | #These findings, along with the polycistronic gene organization, are consistent with posttranscriptional control mechanisms being the primary determinants of Tritryp gene expression |
| − | + | ===RNA Processing=== | |
| − | # | + | #Polyadenylation is determined by trans-splicing of downstream mRNA |
| − | # | + | #Tritryp Poly (A) polymerases |
| − | # | + | #*two distinct ones with different functional roles |
| − | # | + | #**Homologs of CPF are present |
| − | # | + | #**No homologs of CstF are present except for CstF50 |
| − | # | + | #***CstF50 deals with poyadenylation and transcription initiation/termination |
| − | # | + | #***reflects polycistronic transcription |
| − | # | + | #Degredation of mRNA is important in gene expression |
| − | # | + | #*Exonucleases involved in decapping of mRNA were found. |
| − | # | + | # All of these imply reliance on posttranscriptional control of gene expression |
| − | + | ===Translation and co-/postranslational modification=== | |
==Implications== | ==Implications== | ||
Revision as of 05:04, 12 November 2013
trypanosomatid Ecotins chymotrypsin amastins Sphingolipids PG-galactosyltransferases pseudogenes ribonuclease glycoinositol-phospholipids prenylation
Contents |
Leishmania Background
- Leishmania Major is a tropical parasite
- Sepctrum of disease, “Leishmaniases”
- broad term describing a flesh eating virus specific to Leishmania
- 2 million infections in 88 countries annually
- Have adapted to avoid host destruction
- curing is very hard and doesn’t always work
Genome Structure and Content
- 32,816,678 base pairs obtained
- 36 chromosomes
- single continuous sequence generated for each chromosome
- 911 RNA genes
- Organized differently in Tritryp genomes from L. Major
- 8272 protein coding genes
- 663 related families
- Smaller gene families arose from gene duplication
- Larger families have single genes at multiple locations on the gene
Genome Comparison
- Leishmania is compared with other organisms
- Trypanosoma Brucei
- Trypanosoma Cruzi
- Leishmania has many orthologs under in these genomes
- 910 genes not orthologs
- “Leishmania Restricted genes”
- responsible for key metabolic differences
- “Leishmania Restricted genes”
- LmjF33.1740 and LmjF33.1750
- Macrophage migration inhibition factor
- Similar to that in humans that deals with immunity from macrophage
- Macrophage migration inhibition factor
Significant Genetic Findings
Transcription
- L. major genome is organized into 133 clusters of tens to hundreds of protein-coding genes on same DNA strand
- Pollycistronic transcription initiates in both directions:
- In divergent strand-switch regions
- terminates within the convergent strand-switch regions
- RNAP I, II and III were found in Trytrip
- Very different from other eukaryotes
- Not many other homologs of RNAP were found
- These findings, along with the polycistronic gene organization, are consistent with posttranscriptional control mechanisms being the primary determinants of Tritryp gene expression
RNA Processing
- Polyadenylation is determined by trans-splicing of downstream mRNA
- Tritryp Poly (A) polymerases
- two distinct ones with different functional roles
- Homologs of CPF are present
- No homologs of CstF are present except for CstF50
- CstF50 deals with poyadenylation and transcription initiation/termination
- reflects polycistronic transcription
- two distinct ones with different functional roles
- Degredation of mRNA is important in gene expression
- Exonucleases involved in decapping of mRNA were found.
- All of these imply reliance on posttranscriptional control of gene expression
