2013 kuliah 2 genetika HK mendel (klas indo danInggris) FAPET

Mendelian Genetics
Gregor Mendel is
father of genetics.
recognized as the
Mendel, who was not scientifically
trained, developed his theories in the
1850’s and 1860’s, without any
knowledge of cell biology or the science
of inheritance.
In later years, genes, chromosomes, and DNA were
discovered and people began to understand how and why
Mendel’s theories worked.
Photo courtesy of Wikipedia.
Robert Bakewell
1700s
Gregor Mendel
English Breeder of:
Shire horses
Leicester sheep
Longhorn cattle
basic genetic principles
used pea plants
not well understood
during his life
Used
inbreeding
progeny testing
Mendel, G. 1866. Experiments
on Plant Hybridization.
Transactions of the Brünn
Natural History Society.
 Topic of Discussion :Genetics of Animal
1
2.
3.
4.
5.
6.
Introduction: History and Development of Genetics .
Mendelism :Monohibryd and dihibryd Inheritance,
Exception of Mendelsm : intermedier, linkage ,, sex
limited, sex inlfluenced
Genetic Material I: Chromosome, DNA and Gen ,
Abberation
Multiple Allel
Class Discusion: Proup of 5: Paper and PPT, Presentation.
Topic 1-5.
7.
Class Discusion: Proup of 5: Paper and PPT, Presentation.
Topic 1-5.
8.
MIDTEST
9.
Probability in Genetics Inheritance
10.
Sex Determination , linked and crossing over
11.
Introduction to Genetics Population
12.
Factors influencen in Population
13.
Introduction to Genetics Engineering
14.
Class Discusion: Proup of 5: Paper and PPT, Presentation.
Topic 1-5.
15.
Class Discusion: Proup of 5: Paper and PPT, Presentation.
Topic 1-5.
FINAL TEST
16
Mendel’s experiments dealt with the
relationship between an organism’s genotype
and its phenotype.
Genotype – the genetic composition of an organism.
Phenotype – the observable or measurable characteristics
(called traits) of that organism.
The relationship between phenotype and genotype is
expressed as the following equation:
P=G+E
P = phenotype,
G = genotype, and
E = environment.
To understand Mendel’s principles and
the relationships between phenotype and
genotype, it is necessary to understand what makes
up the genetic material of animals and how this is
transferred from one generation to the next.
1. Nucleolus
5. Rough Endoplasmic Reticulum
9. Mitochondria
2. Nucleus
6. Golgi Aparatus
10. Vacuole
3. Ribosome
7. Cytoskeleton
11. Cytoplasm
4. Vesicle
8. Smooth Endoplasmic Reticulum
12. Lysosome
13. Centrioles
Genetics Vocabulary
• Homozygous- when both alleles of a pair are the
same for a gene
• Homozygouse Dominant- PP
• Homozygous Recessive- pp
• Heterozygous- when the 2 alleles in the pair are
different for a gene
• Heterozygous for flower color: Pp
Fertilization
• Takes place when a sperm cell from a male reaches the egg
cell of a female
• The two haploid cells (the sperm and the egg) unite and form
one complete cell or zygote
• Zygote is diploid, it has a full set of chromosome pairs
• This results in many different combinations of traits in
offspring
Chromosomes
• Occur in pairs in the nucleus of all body cells except the sperm
and ovum
• Each parent contributes to one-half of the pair
• The number of pairs of chromosomes is called the diploid
number
• The diploid number varies species to species but is constant
for each species of animal
Common Livestock Diploid Number
 Cattle 30, Swine 19, Sheep 27, Goat 30, Horse 32,
Donkey 31, Chicken 39, Rabbit 22
MENDELISME
Mendel proposed three principles to describe the transfer of genetic
material from one generation to the next.
• The Principle of Dominance : in a heterozygous organism,
one allele may conceal the presence of another allele.
• The Principle of Segregation: in a heterozygote, two different
alleles segregate from each other during the formation
• The Principle of Independent
Assortment : the alleles
of different genes segregate, or assort, independently of each
other.
Later studies have shown that there are some important
exceptions to Mendel’s Principle of Independent Assortment, but
otherwise, these principles are recognized as the basis of
inheritance.
Dominant and Recessive Genes
• In a heterozygous pair the dominant gene hides the effect
of its allele
• The hidden allele is called a recessive gene
• When working problems involving genetic inheritance the
dominant gene is usually written as a capital letter and the
recessive gene is written as a lowercase letter (PP,pp,pp)
•
•
•
•
•
•
•
•
Black is dominant to red in cattle
White face is dominant to color face in cattle
Black is dominant to brown in horses
Color is dominant to albinism
Rose comb is dominant to single comb (chicken)
Pea comb in chickens is dominant to single comb
Barred feather pattern in chickens is dominant to nonbarred feather—the dominant
gene is also sex-linked
Normal size in cattle is dominant to ―snorter‖ dwarfism
Teories of Inheritance (Conventional)
Ovisma: pemilik sifat keturunan adalah ovum (♀ ),
fungsi jantan menghasilkan cairan untuk perkembangan ovum
Animalkulisma: pada cairan jantan ditemukan hewan2 kecil (Spz),
sbg pembawa sifat keturunan
Preformasi: Loewenhook: (mikroskop)
ada MH kecil dalam spermatozoa atau ada manusia kecil dlm ovum
Epigenesis: Ovum terfertilisasi oleh Spz,
kmd. tumbuh sedikir demi sedikit
Pangenesis (Darwin): dalam sel kelamin ♀ ♂ terdapat tunas 2 tumbuh
menjadi MH baru setelah fertilisasi
Plasma benih (Weisman): Gamet ♀ ♂ dibentuk oleh jar.khusus,
bukan jar. tubuh
Penelitian dan Peneliti Genetika
Mendel:
•From Result of Mendel
•Then, What Is Genetic Factor ?
Genetic Materials ?
W. ROUX (1883): Cromosome
T. Bovery (1902): Gen bagian dari kromosom
Faktor Penentu (Gen/Kromosom) di wariskan lewat GAMET
(pada Anafase Meiosis I saat Separasi Kromosom homolog)
HIPOTESA SUTTON-T. BOVERY
HIPOTESA WS SUTTON-T . BOVERY:
Animal Chromosomes
1.
2.
3.
4.
5.
Gen dibawa oleh kromosom
Satu pasang kromosom asal maternal+paternal
Pemindahan 1 ps kromosom saat meiosis
Sel benih mengandung kombinasi gen jantan dan betina
Kromosom homolog secara genetis berbeda,
sehingga sel benih scr genetis berbeda
6. Tiap kromosome terdiri lebih dari 1 gen,
gen-gen dalam kromosom pindah bersama-sama
TEORI : DOMONANSI-RESESIF
Sifat Tinggi : Dominan (gen T)
Sifat rendah/kerdil: Resesif (gen t)
Parents (P)
TT
Gamet:T
X
tt
Gamet: t
Filial 1 (F1)
Monohibrid: 1 sifat beda
Di hibrid : 2 sifat beda
Tri hibrid : 3 sifat beda
Tt
HIBRIDA
Fenotip: 3:1
Genotip : 1 : 2: 1
tt: homosigot
F2
F2 ?
♂/ ♀
T
t
T
TT
Tt
t
Tt
tt
TT: homosigot
Tt: heterosigot
HK.MENDEL I: Pemisahan Gen se alel
Dominansi penuh dan semi dominant
Semi Dominant:
Bunga pk 4.
Dominansi Penuh
Parents (P)
TT
Gamet:T
(Tinggi)
X
tt
Gamet: t
(rendah)
Merah
X
Putih
Merah Muda
Filial 1 (F1)
Tt
(Tinggi)
Kodominan
RR
x
Merah
Bedanya ???
rr
putih
Rr
Roan/coklat
MONOHIBRID HEWAN
Warna rambut hitam (gen dominan A, pigmentasi melanin)
AA
Hitam
F1
X
Aa
Hitam
1.Resiprok: Kebalikan ♀/
♂ ♂ HH x ♀ hh
Hh
Hasil sama
aa
albino
Pada F2:
Fenotip : 3: 1
Genotip : 1 : 2 : 1
Macam sistim Persilangan
2. Back cross:
3. Test Cross:
F1 dng parent ♂/
♀
F1 dng P resesif
Hasil:
Fenotip/genotip ttt.
Pembuktian F1
homosigot
/heterosigot
Dihidrid pada hewan
x
HH KK
Pada marmot:
•Rambut Hitam (gen H) vs putih (gen h)
Gamet HK
hh kk
Gamet : hk
•Rambut Kasar (gen K) vs rambut halus (gen h)
F1:
F2
Hh Kk x Hh Kk
Gamet
HK
Hk
hK
kk
HK
*
*
*
*
Hk
*
+
*
+
hK
*
*
=
=
kk
*
+
=
O
Rasio fenotip : 9 : 3 : 3 : 1
Perhitungan Matematis (Rumus estimasi)
Juml.
Sifat
beda
Macam Kombi Fenotip Kombi Kombi Genoti
gamet nasi F2 F2
nasi F1 nasi
p F2
F1
homosi
got
n
2n
(2n)2 2n
2n
2n
3n
1
2
4
2
2
2
3
2
4
16
4
4
4
9
3
8
64
8
8
8
27
Macam Gamet:
Kombinasi:
Monohibrid (Aa) : 2 n = 2 1 = 2 = (A/a)
Mono hibrid : (AaxAa)=(21)2 =4 =
(AA,Aa,Aa,aa)
Dihibrid (AaBb) = 2 2 = 4 = (AB, Ab, aB, ab)
Tri hibrid (AaBbCc) 2 = 8 = (ABC, ….., abc)
3
Dihibrid (AaBbxAaBb) = (22)2 = 16
Perkawinan Intermedier
Perkawinan Kodominan
(Dominansi tak sempurna)
(dominansi parsial)
Pd
Pada sapi Shorthorn
Mirabilis jalapa
P mm
P : RR
X MM
putih
Mm
Merah
merah
X
rr
putih
Rr
Mm
X
Rr
Coklat
Merah muda ( pink)
MM
X
1
RR
1
Rr
Mm
Mm
2
Rr
2
mm
1
rr
1
Implementasinya pada ternak:
Jika jumlah gamet (gen)
sama dengan jumlah kromosom
Maka Kombinasinya*
Sapi 2 n = 2 30 kombinasi gamet = 1.07 x 10 9
Kuda 2 n = 2 32 kombinasi gamet = 4.29 x 10 9
Manusia 2 n = 2 23 kombinasi gamet = 8.3 x 10 6
Note : More than a 100 or 1000 gens/ Chromosome
So, What is the conclussion: -
Summary
• Gregor Mendel is considered the father of genetics
• The amount of difference between parents and offspring is
caused by genetics and the environment P= G+ E
• Fertilization occurs when the sperm cell penetrates the egg and
the chromosome pairs are formed again when fertilization takes
place
• Genes control an animals traits
• Some genes are dominant and some are recessive
• Animals may carry two dominant or two recessive genes for a
trait. They are called homozygous pairs
• Animals may also carry a dominant and recessive gene pair.
They are called heterozygous pairs
• Livestock improvement is the result of using
the principles of genetics