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TEMA 1ACTUALIDAD DE LOS EXPERIMENTOS DE MENDEL

1.- VIGENCIA DE LOS PRINCIPIOS MENDELIANOS

2.- MONOHIBRIDISMO-Principio de la UNIFORMIDAD-Principio de la SEGREGACIÓN

3.- DIHIBRIDISMO

4.- POLIHIBRIDISMO

5.- CONOCIMIENTO DEL GENOTIPO A PARTIR DEL FENOTIPO

-Principio de la COMBINACIÓN INDEPENDIENTE

-Autofecundación-Cruzamiento prueba

6.-CARACTERES MENDELIANOS EN ANIMALES DOMESTICOS

http://www.ncbi.nlm.nih.gov/omimOMIM ® - Online Mendelian Inheritance in Man

Welcome to OMIM ® , Online Mendelian Inheritance in Man ® . OMIM is a comprehensive, authoritative, and timely compendium of human genes and geneticphenotypes. The full-text, referenced overviews in OMIM contain information on allknown mendelian disorders and over 12,000 genes. OMIM focuses on therelationship between phenotype and genotype. It is updated daily, and the entriescontain copious links to other genetics resources.tty

http://omia.angis.org.au/home/OMIA - Online Mendelian Inheritance in Animals

Welcome to OMIA Online Mendelian Inheritance in Animals (OMIA) is a database ofgenes, inherited disorders and traits in 171 animal species (other than human andmouse, which have their own resources)

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75151137268Potenciales modelos caracteres humanos

153770150Caracteres Mendelianos(mutación conocida)

3766119204Caracteresmendelianos

223298408567Total Caracteres

OMIA (Online Mendelian Inheritance in Animals)

RESUMEN

TOTALOTROSCONEJOCABRAPOLLOCABALLOCERDO OVEJAGATOVACADOG

CARACTERES ESTUDIADOS POR MENDEL

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GEN Factor heredado que determina una característica de un organismo

ALELO Formas alternativas de un gen (en individuos diploidescada individuo es portador de dos alelos para cada gen)

Dominante – letra mayúscula (A)Recesivo – letra minúscula (a)

INDIVIDUO HOMOCIGOTOLos dos alelos de un individuo son idénticos (AA o aa)

INDIVIDUO HETEROCIGOTOLos dos alelos de un gen son diferentes (Aa)

GENOTIPO Constitución genética de un individuo, referida a uno o varios genes

FENOTIPO Manifestación externa o aparente del genotipo

EXPERIMENTOSDE MENDEL

GG

X

gg

G g

Gg

Tordo Castaño

ggGg

GgGG

X

Gg

Gametos masculinosG g

Gametos femeninos

G

g

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2,84:1787 largos; 277 cortosTodos largosTallo largo x

corto7

3,14:1651 axiales; 207 terminalesTodas axialesFlores axiales

x terminales6

2,82:1428 verdes; 152 amarillasTodas verdesVainas verdes

x amarillas5

2,95:1882 infladas;

299 contorneadas

Todas infladasVainas infladas x contorneadas4

3,15:1705 púrpura; 224 blancosTodos púrpura

Pétalos púrpura x blancos

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3,01:16022 amarillas; 2001 verdesTodas amarillas

Semillas amarillas x

verdes2

2,96:15474 lisas; 1850 rugosasTodas lisasSemillas lisas x

rugosas1

ProporciónF2F1Fenotipos

parentales

RESULTADOS DE LOS EXPERIMENTOS DE MENDEL

MONOHIBRIDISMO

Cruce entre dos variedades, cada una de las cuales presenta una de las dos formas alternativas del carácter en estudio

Cruce monohíbrido

POSTULADOS DE MENDEL

PRIMERO: PRIMERO: Principio de la UniformidadPrincipio de la Uniformidad

SEGUNDO: Principio de la SegregaciPrincipio de la Segregacióónn

Cuando se cruzan dos líneas homocigóticas, que difieren en un carácter, todos los individuos de la F1 presentan el mismo fenotipo, independientemente de la dirección del cruzamiento y coincidente por el manifestado por alguno de los progenitores

Los miembros de una pareja alélica se separan o segregan cuando el individuo forma los gametos. Por ello, el carácter recesivo enmascarado en la F1 heterocigótica reaparece en la F2 en una proporción de 1/4

Dominante.- Alelo que se manifiesta en la F1Recesivo.- Alelo que queda enmascarado en la F1

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DIHIBRIDISMO

PRINCIPIO DE LA COMBINACIÓN INDEPENDIENTE

En la formación de los gametos, los pares de factores que segregan se transmiten independientemente unos de otros.

La segregación de cualquier par de factores se da independientemente de cualquier otro. Por ello, cada gameto recibe uno de los miembros de cada par de factores.

(9)(3)(3)(1)

DIHIBRIDISMO

verdes

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TRIHIBRIDISMO

POLIHIBRIDISMO…

PREDICCIÓN RESULTADOS CRUZAMIENTOS GENÉTICOS

Cuadro de Punnett:

Diagramas ramificados

Probabilidad:

-Regla de la multiplicación: dos o más sucesos simultáneos (Y)

-Regla de la adición: dos sucesos mutuamente excluyentes (O)

(p + q)n = ― pw qxn!w!x!

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Aa x Aa (aa, animal enfermo)

(p + q)n = ― pw qxn!w!x!

APLICACIÓN BINOMIO NEWTON

probabilidad de tener 3 descendientes enfermos: ¼ x ¼ x ¼ = 1/64

probabilidad de tener 1 enfermo y 2 sanos:

¼ x ¾ x ¾ = 9/64

¾ x ¼ x ¾ = 9/64

¾ x ¾ x ¼ = 9/64

probabilidad de tener 2 enfermos y 3 sanos (5)

9/64 + 9/64 +9/64 = 27/64

p = probabilidad de ser pelirrojo, ¼

q = probabilidad de tener cabello oscuro, ¾

(p +q)5

Aa x Aa (aa, pelirrojo)

APLICACIÓN BINOMIO NEWTON

(p + q)n = ― pw qxn!w!x!

p = probabilidad de ser pelirrojo, ¼

q = probabilidad de tener cabello oscuro, ¾

(p +q)5 = p5 + 5p4q + 10p3q2 + 10p2q3 + 5pq4 + q4

10p2q3 = 10 (1/4)2 (3/4)3 = 270/1024 = 0,26

P = (5!/2!3!) (1/4)2 (3/4)3 = 0,26

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AA (pelo castaño) x aa (albino)

APLICACIÓN MÉTODO DE χ2

AA ( ¼ ) Aa ( ½ ) aa ( ¼ )

Observados 5 9 6

Esperados 20 x ¼ 20 x ½ 20 x ¼

(5) (10) (5)

χ2 = Σ ( O-E)2 / E = (5-5)2/5 + (9-10)2/10 + (6-5)2/5

= 0 + 0,1 + 0,2 = 0,3

gl = 1, 0,3 < 3,841 DIFERENCIA NO SIGNIFICATIVA, DESVIACIONES AL AZAR

F2

CRUCES PARA CONOCER EL GENOTIPO A PARTIR DEL FENOTIPO

AUTOFECUNDACIÓN RETROCRUZAMIENTO

CRUZAMIENTO PRUEBA

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http://omia.angis.org.au/home/

OMIA - Online Mendelian Inheritance in Animals

Welcome to OMIA Online Mendelian Inheritance in Animals (OMIA) is a database of genes, inherited disorders and traits in 171 animal species (other than human and mouse, which have their ownresources)

1172

416

773

2815

255

52

117

593

38

7

21

59

29

8

11

72

40

28

81

188

75

25

79

202

104

24

88

205

75151137268Potenciales modelos caracteres humanos

153770150Caracteres Mendelianos(mutación conocida)

3766119204Caracteresmendelianos

223298408567Total Caracteres

OMNIA (Online Mendelian Inheritance in Animals)

RESUMEN

TOTALOTROSCONEJOCABRAPOLLOCABALLOCERDO OVEJAGATOVACADOG

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204 records foundOMIA 001365 Achromatopsia-3 in Canis lupus familiaris (dog) Gene: CNGB3 OMIA 000018 Afibrinogenaemia in Canis lupus familiaris (dog)OMIA 000030 Alopecia in Canis lupus familiaris (dog)OMIA 000031 Alopecia, colour mutant in Canis lupus familiaris (dog) Gene: MLPH OMIA 000543 Anhidrotic ectodermal dysplasia in Canis lupus familiaris (dog) Gene: EDA OMIA 000078 Ataxia, cerebellar in Canis lupus familiaris (dog) Gene: GRM1 OMIA 000110 Black hair follicle dysplasia in Canis lupus familiaris (dog)OMIA 001564 Bleeding disorder due to P2RY12 defect in Canis lupus familiaris (dog) Gene: P2RY12 OMIA 001295 Blood group system Rh in Canis lupus familiaris (dog)OMIA 001551 Brachycephaly in Canis lupus familiaris (dog)OMIA 000155 C3 deficiency in Canis lupus familiaris (dog) Gene: C3 OMIA 000162 Cardiomyopathy, dilated in Canis lupus familiaris (dog)OMIA 000166 Carpal subluxation in Canis lupus familiaris (dog)OMIA 000168 Cataract in Canis lupus familiaris (dog) Gene: HSF4 OMIA 000177 Cerebellar cortical atrophy in Canis lupus familiaris (dog)OMIA 000187 Chondrodysplasia in Canis lupus familiaris (dog) Gene: FGF4 OMIA 001540 Ciliary dyskinesia, primary in Canis lupus familiaris (dog) Gene: CCDC39 OMIA 000200 Coat colour in Canis lupus familiaris (dog)OMIA 000201 Coat colour, agouti in Canis lupus familiaris (dog) Gene: ASIP OMIA 000202 Coat colour, albinism in Canis lupus familiaris (dog)OMIA 001249 Coat colour, brown in Canis lupus familiaris (dog) Gene: TYRP1 OMIA 001344 Coat colour, cream dilution in Canis lupus familiaris (dog)OMIA 001416 Coat colour, dominant black in Canis lupus familiaris (dog) Gene: CBD103 OMIA 001199 Coat colour, extension in Canis lupus familiaris (dog) Gene: MC1R

EJEMPLO: En el perro hay descritos 204 caracteres con herencia mendeliana

150 records foundOMIA 000248 Neutropenia, cyclic in Canis lupus familiaris (dog) Gene: AP3B1 OMIA 001522 Oculoskeletal dysplasia in Canis lupus familiaris (dog) Gene: COL9A3 OMIA 001523 Oculoskeletal dysplasia, 2 in Canis lupus familiaris (dog) Gene: COL9A2 OMIA 000754 Osteogenesis imperfecta in Canis lupus familiaris (dog)OMIA 001483 Osteogenesis imperfecta_Dachshund in Canis lupus familiaris (dog) Gene: SERPINH1 OMIA 001403 Pancreatitis, hereditary in Canis lupus familiaris (dog) Gene: SPINK1 OMIA 001561 Periodic Fever Syndrome in Canis lupus familiaris (dog) Gene: HAS2 OMIA 000791 Persistent Mullerian duct syndrome in Canis lupus familiaris (dog) Gene: AMHR2 OMIA 000807 Polycystic kidney disease in Canis lupus familiaris (dog)OMIA 000809 Polycythemia in Canis lupus familiaris (dog)OMIA 001292 Polyneuropathy in Canis lupus familiaris (dog) Gene: NDRG1 OMIA 001346 PRA-autosomal dominant in Canis lupus familiaris (dog) Gene: RHO OMIA 000882 PRA-rod-cone dystrophy type 1 in Canis lupus familiaris (dog) Gene: PDE6B OMIA 001260 PRA-rod-cone dystrophy type 2 in Canis lupus familiaris (dog) Genes: RD3, GNB3, CRX, GNAT1, OMIA 001314 PRA-rod-cone dystrophy type 3 in Canis lupus familiaris (dog)OMIA 001575 PRA-rod-cone dystrophy type 4 in Canis lupus familiaris (dog)OMIA 000819 Prekallikrein deficiency in Canis lupus familiaris (dog) Gene: KLKB1 OMIA 001521 Progressive retinal atrophy, Schapendoes in Canis lupus familiaris (dog)OMIA 001572 Progressive retinal atrophy, SLC4A3 in Canis lupus familiaris (dog)OMIA 000831 Progressive retinal atrophy, X-linked in Canis lupus familiaris (dog) Gene: RPGR OMIA 001518 Progressive retinal atrophy, X-linked, 2 in Canis lupus familiaris (dog) Gene: RPGR OMIA 001406 Pyruvate dehydrogenase deficiency in Canis lupus familiaris (dog)OMIA 000844 Pyruvate kinase deficiency of erythrocyte in Canis lupus familiaris (dog) Gene: PKLR OMIA 001335 Renal cystadenocarcinoma and nodular dermatofibrosis in Canis lupus familiaris (dog)OMIA 001135 Renal dysplasia in Canis lupus familiaris (dog)OMIA 001297 Retinal degeneration, early in Canis lupus familiaris (dog) Gene: STK38L OMIA 001222 Retinal pigment epithelial dystrophy in Canis lupus familiaris (dog) Genes: RPE65, CNGA1, SAG OMIA 001413 Retinitis pigmentosa in Canis lupus familiaris (dog) Gene: PDE6A

DE ESOS 204 CARACTERES, EN 150 SE CONOCE LA MUTACIÓN CAUSAL…

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OMIA 001413 : Retinitis pigmentosa in Canis lupus familiaris See the equivalent entry at NCBI

In other species: cow

Single locus: yes

Mode of inheritance: Autosomal Recessive

Considered a defect: yes

Causative mutation known: yes

Species-specific description: Autosomal recessive retinitis pigmentosa

Associated gene:

Symbol Description Species Chr acc Chr name Start Stop Links

PDE6A phosphodiesterase 6A, cGMP-specific, rod, alpha Canis lupus familiarisNC_006586.2 4 62307495 62367392 Homologene, Ensembl

Reference

2009 Tuntivanich, N., Pittler, SJ., Fischer, AJ., Omar, G., Kiupel, M., Weber, AJ., Yao, S., Steibel, JP., Wali Khan, N., Petersen-Jones, S. : Characterization of a canine model of autosomalrecessive retinitis pigmentosa due to a PDE6A mutation. Invest Ophthalmol Vis Sci 50:801-813, 2009. Pubmed reference: 18775863.

Single locus: yes

Mode of inheritance: Autosomal Dominant

Considered a defect: no

Causative mutation known: yes

Species-specific name: Gray; Grey

Species-specific symbol: G

Species-specific description: Horses are born with normal pigmentation, but gradually lose their pigmentation as they age, until, at around 6-8 years old, they become white, while retaining dark skin pigmentation. Included with this phenotype is a relatively high incidence of dermal melanomas, and an associated decrease in life expectancy.

Molecular basis: Pielberg et al. (2008) presented convincing evidence that this classic phenotype is due to a 4.6kb intronicduplication in the gene for syntaxin-17 (STX17). Genetic testing: Since exactly the same mutation is completely associatedwith the grey/gray phenotype in more than 850 horses from numerous breeds (Pielberg et al., 2008), it is very likely that a single DNA test will suffice to detect virtually all occurrences of the grey/gray allele.

9NC_000009.11Homo sapienssyntaxin 17STX17

Chr nameChr accSpeciesDescriptionSymbol

Molecular tests for coat colours in horses. J Anim Breed Genet 126:415-24, 2009. Pubmed reference: 19912415.

CARÁCTER: CAPA TORDA EN LOS CABALLOS

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OMIA 000595-9913 : Leukocyteadhesion deficiency in Bos taurus

In other species: dog , water buffalo

Possible human homologue (MIM number): 116920

Single locus: yes

Mode of inheritance: Autosomal Recessive

Considered a defect: yes

Causative mutation known: yes

Cross-species summary: Affected animals die because of extreme susceptibility to infections, caused by an inabilityof white blood cells (leukocytes) to pass from the blood stream into infected tissue. This inability is due to the lackof a membrane glycoprotein called the leukocyte integrin beta-2 subunit or CD18.

Species-specific name: Bovine leukocyte adhesion deficiency (BLAD)

Species-specific description: In 1992, Shuster et al. showed that this disorder is due to a mis-sense mutation in theCD18 gene.

integrin, beta 2ITGB2DescriptionSymbol

Meydan, H., Yildiz, MA., Agerholm, JS. : Screening for bovine leukocyte adhesion deficiency, deficiency of uridine monophosphate synthase, complex vertebral malformation, bovinecitrullinaemia, and factor XI deficiency in Holstein cows reared in Turkey. Acta Vet Scand 52:56, 2010. Pubmed reference: 20929557

2010

BLAD