Male parents generally DO NOT Contribute cytoplasm to zygotes
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Transcript of Male parents generally DO NOT Contribute cytoplasm to zygotes
Male parents generally DO NOT
Contribute cytoplasm tozygotes
SO… mitochondria and chloroplasts are MATERNAL CONTRIBUTIONS
Cytokinesis( Cell Division)
- actin microfilaments
and Karyokinesis( Nuclear division, including mitosis)
-tubulin microtubules
Model for organelle divisionFrom Dec 2003 Science
..…without implications for segregation
Maternal effect )NOT Maternal inheritance(
Genetic/genomic imprinting
Maternal imprinting
Paternal imprinting
If neither copy of 15q11 has paternal imprinting, the result is Prader-Willi syndrome )characterised by hypotonia, obesity, and
hypogonadism .)
If neither copy has maternal imprinting, the result is Angelman syndrome )characterised by epilepsy, tremors, and a perpetually smiling facial expression( .
גנטיקה של אוכלוסיותגנטיקה של אוכלוסיות
Formula for allele frequency, based on knowledge of genotypes
A 3 allele case
p = freq of IB = freq B )IBIB( + ½ freq of B )IBi( + ½ freq of AB )IBIA(q = freq of IA … =r = freq of i… =
p + q + r = 1
In 3 allele case, same mathematical treatment
YET:Populations with different genotypes can have the same allele frequency
BUT, if there are random matings, the genotype frequency of offspring is based on solely on the allele freq.
In next generation
Hardy-Weinberg (H-W) Law
&)Chetverikov(
YET, if there are random matings, the genotype frequency of offspring is based on solely on the allele freq.
In this case:
In next generation
Hardy-Weinberg (H-W) Law
Populations NOT in H-W equilibrium
If the processes below do not occur, a population is in Hardy-Weinberg )HW( equilibrium, the following are unchanged:
Allele frequenciesGenotype frequencies
Phenotype frequencies
TEST: if these populations are in H-W equilibrium, then:
If a population is in Hardy-Weinberg equilibrium,
the allele,genotype, and phenotype frequencies will
be stable as long as the HW requirements hold
H-W בשיווי משקל -- הרבה אכלוסיותאז... תיאור של אכלוסיה לפי תדירויות
מתאים )ו'חסכוני'( - של אללים
Genotypefrequencies
2 allele case
Genotypefrequencies
M/M
M/N
N/N
p)M(q)N(
Percent
LocationMMMNNNpq
Iceland31.251.517.300.570.43
Greenland83.515.60.90.920.08
We see HW equilibrium for ‘breeding populations’
We don’t expect HW for, say: the city of New York City Lots of immigration
Not random matings, but many distinct sub-groups
How do HW populations “start” with different allele frequecies? In human populations, often small founder populations:
BUT, MANY human populations are in H-W equilibrium, for example- MN tables we just saw, and:
How do HW populations “start” with different allele frequecies? In human populations, often small founder populations:
Percent
LocationMMMNNNpq
Iceland31.251.517.300.570.43
Greenland83.515.60.90.920.08
If the processes below do not occur, a population is in Hardy-Weinberg )HW( equilibrium, the following are unchanged:
Allele frequenciesGenotype frequencies
Phenotype frequencies
If these processes DOoccur, the populations
change.-Each process can be
studied and quantitated
Selection of allele A: preferential survival
Haplotype
Inbreeding
0.5 X 0.5
Migrationללמוד בבית על
P is the allelic frequency in the donor population And p0 is the original frequency among the recipients
M-migration rate
Source of variation, deviation from HW:migration )M( into a population
OriginallyYamane – not resistance to Gefilte-fish
Poland – 0.42 are resistance to Gefilte-fish
Current- among Yamane 0.046 are resistance
Thus Ptotal 0.046-0 P-P0 is 0.42-0
M= 0.046/0.42=1.095
Inbreeding
Source of variation: deviation from HW:mutations have a slow effect on allele frequency )here, of w.t.(:
Pseudo male - female cross in neurospora
Jan 3 start
Allele names according to phenotype
Wild type
amorph
hypomorph
hypermorph
RR
RR
neomorph
R~
R~R~
R~
NULL
Standard Dominant – Recessive
Haploinsufficiency