How can genetics benefit aquaculture? I Flashcards
the nucleus of a cell (where all of the genetical information is held)
what is contained in the nucleus? (three important parts)
Chromatin
- contains DNA
- formed into chromosomes
Nucleolus
-Manufactures ribosomes
Nuclear envelope
-Allows the nucleus to control entry and exit of molecules
what happens to chromosomes during cell division?
Just before cell division (and after DNA synthesis), the chromatin condenses further into individual metaphase chromosomes
Describe the DNA structure
- DNA consists of two long polymers of simple units called nucleotides.
- DNA backbone made of sugars and phosphate groups joined by ester bonds.
- Two strands run in opposite directions to each other and are therefore anti-parallel.
- Attached to each sugar is one of four types of molecules called bases.
How much (in percent) of genomes is producing protein?
about 2%
how are genes separated in the genome?
A gene is separated in the genome by coding (EXON) and noncoding (INTRON) regions
How are genes expressed?
Stretches of DNA that code for genes are copied into the related nucleic acid RNA (Transcription).
Messenger RNA (mRNA) for the gene produced used for protein production (Translation).
How does temperature influence genes?
it influences the growth ratre
What is the outcome of gene expression?
Gene information is used in the synthesis of a functional gene product, often proteins.
Gene is switched on or off:
- mRNA increases/decreases
- Proteins increase/decrease
-
Levels of gene expression relate to involvement of gene in a particular process.
What does CPR stand for?
In vitro catalysed DNA replication
How do you measure mRNA levels
Polymerase Chain Reaction (PCR)
Technique that permits the analysis of a short DNA (or RNA) sequence in samples containing only minute quantities of DNA or RNA.
PCR is used to reproduce (amplify) selected sections of DNA or RNA for analysis.
PCR is highly efficient so that untold numbers of copies can be made of the DNA.
Uses the same molecules that nature uses for copying DNA
what is PCR complementary to?
-Complementary to a defined sequence on each of the two DNA strands.
how are DNA primers made?
-Primers are extended by a DNA polymerase so that a copy is made of the designated sequence.
Describe the required conditions for PCR
Strands then separate, primers bind and extension of this region occurs again.
-Allows exponential amplification.
-
PCR cycle consists of three distinct steps, carried out at different temperatures:
1) Denaturation of double stranded DNA (dsDNA).
94 0C separates strands of target DNA
2) Annealing of primers.
50-60 0C
3) Extension of the primers by Taq DNA polymerase.
720C (Polymerase from Thermus aquaticus)
name fours samples of fish whos genes have been sequenced
what are the three main aquaculture species in NZ?
- King Salmon (Oncorhynchus tshawytscha)
- Greenshelled muscle (Perna canaliculus)
- Pacific Oyster (Crassostrea gigas)
What four factors are an interconnection of fish physiology?
