L14-15 Genome Evolution & Gene Families Flashcards
Syntenic genes
Genes grouped the same way on the chromosomes of 2 or more different species
Synteny block
Chromosomal regions containing homologous genes between two species
Inward translocation
Rearrangement of material within a chromosome
Pericentric inversion
Inversion of the sequence around the middle that includes the centromere
Reciprocal translocation
Rearrangement of material between non-homologous chromosomes (as opposed to between homologous chromosomes, which is recombination)
Translocation may result in either…
Balanced or unbalanced products from meiosis
Unbalanced translocation means material was not…
Swapped equally, chromosomes may have extra or missing pieces
15% of Acute Myelogenous Leukemia have an alteration in karyotype…
Translocation between chromosomes 8 and 21 [t(8;21)]
The mutation seen in 15% of AML cases is known as a…
Dominant negative mutant (because it has negative effects)
Chromosome fusion is when…
Two telocentric chromosomes fuse to make a new chromosome (such as human CH2)
In Robertsonian translocation
Short arms of 2 acrocentric chromosomes are lost, resulting in the fusion of the remaining long arms to form one big chromosome.
Paracentric inversion
An inversion which does not include the centromere
If essential information is on the short arms of chromosomes when Robertsonian translocation occurs…
No phenotype generated
A common chromosome stain used to distinguish between regions depending on the distribution of base pairs
Gimsa
Changes to the genome are the result of…
Mistakes!
Mistakes which result in changes to the genome occur during (3)…
- DNA replication
- DNA Recombination
- DNA Repair
(3 Rs)
Genetic ‘mistakes’ may take the form of (4)…
Base changes
Translocations
Deletions
Insertions
Whole genome duplication events may be advantageous, as the extra set is not vital for function…
Thus are freer to mutate in ways that may confer advantages
The large number of duplicate blocks seen in the genome of S. cerevisiae suggests ? may have occurred recently.
Genome duplication
Duplication may lead to the development of…
2 specialised genes from 1 precursor gene
Homeotic or hox genes are often found…
In clusters
Hox genes code for…
Transcription factors
Hox genes result in…
Segmental identity
Genes that may have arisen from duplication (2)…
Hox genes and globin genes
β-thalassemia
Reduced or absent production of β-globin chains
