Download Fish Cell Biology/Genetics Basics

Fish Cell Biology/Genetics
Basics
Dr. Craig Kasper
HCC Brandon
Fig. 01-05
Fig. 01-07
Fig. 01-09
Fig. 01-11
Zebra Fish Larval Development
• We thank Leon Browder & Laurie Iten
(Ed.) Dynamic Development for their
gracious use of material seen in slides 1117.
• We also thank Haffter et al., 1996 and
The Company of Biologists for their
contributions.
Previous Slide Info…
Figure 2. Drawings of zebrafish embryos at 24
hours (A), 48 hours (B,D) and 5 days (C,E) of
development. For clarity, the pigmentation
pattern is omitted from B and C. It is shown
in D and E. Most of the structures that can be
seen in a living embryo with a compound
microscope are labeled. (From Haffter et al.,
1996. Reproduced with permission from The
Company of Biologists.)
Gregor Mendel: Quick Review
• You might look at possible outcomes for your
fish some day. It would be nice to know what to
expect, or how you “got what you got…”
• Punnett Squares and knowledge of basic
genetics will help you determine what traits you
select for maybe in your breeding. (At least until
you spawn several groups.) More on Punnett
Squares shortly…
Introduction
• As always we have several new terms.
• Genotype: genes of the individual. Your
genetic makeup, if you will.
• Phenotype: What you look like, or more
precisely, what physical manifestations are
observed.
• Allele: Alternate forms of a gene which are
located in the same position on a pair of
chromosomes.
• Three paths:
Two results??
• Not really!
• Again, new terms…
• Dominant allele
(capital letter)
• Recessive Allele
(lower case letter)
Fig. 02-01
• Alleles on autosomes
• Basic Mendelian Genetics
and the Punnett Square
• If we “cross multiply,” it
becomes evident that not
all genotypes result in the
same phenotype.
• The example at the left is a
single-trait cross.
• Notice the expected
phenotypic ratio (3:1).
This will become important
later.
• What happens if we
mix it up a bit??
• Same method, different
results.
• Now the phenotypic
ratio is 50:50 (Better odds
than you’d get in Vegas!)
• Okay, Emeril, let’s…
“Kick it up a notch!!”
• Dihybrid crosses
(and beyond) are
handled similarly.
• You must be careful
to transfer all your
alleles though!!
• Once this is done,
figuring out what
you have can be
challenging.