Chromosomal inheritance Chapter 13 Genes and Development

Fig. 13.1

Fig. 13.2a Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Parental generation male Parental generation female F 1 progeny all had red eyes

Fig. 13.2b F 2 female progeny had red eyes, only males had white eyes F 1 generation male F 1 generation female Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Fig. 13.2c Parental generation male Testcross F 1 generation female The testcross revealed that white-eyed females are viable. Therefore eye color is linked to the X chromosome and absent from the Y chromosome Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Fig Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Parental generation male Parental generation female F 2 female progeny had red eyes, only males had white eyes F 1 generation male F 1 generation female F 1 progeny all had red eyes Parental generation male Testcross F 1 generation female The testcross revealed that white-eyed females are viable. Therefore eye color is linked to the X chromosome and absent from the Y chromosome

Page 241 Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. X chromosome Y chromosome 2.8 µm © BioPhoto Associates/Photo Researchers, Inc.

Sex determination OrganismSystemFemalesMalesWhy males? Humans (mammals)XX/XYXXXYSRY on Y DrosophilaXX/XYXXXY One X, Y needed for fertility Birds, most reptiles ZW/ZZZWZZTwo Z Some insectsXX/XOXXXOne X Honey beesHaploid/DiploidDiploidHaploidOne set of chromosomes

Fig George III Margaret AnneAndrewEdward Henry AlfonsoJamieGonzalo British Royal House Spanish Royal House HenryAnastasiaAlexis ? Frederick III I II III IV V VI VII Generation AliceAlfredArthurLeopoldBeatriceHelena No hemophilia Juan Irene MauriceLeopold The Royal Hemophilia Pedigree ? ?? ? ? ? Edward Duke of Kent Prince AlbertQueen victoria Louis II Grand Duke of Hesse King Edward VII Victoria German Royal House King George V Duke of Czarina Alexandra Czar Nicholas II Earl of Athlone Princess Alice Queen Eugenie Alfonso King of Spain Prince Henry Viscount Tremation Russian Royal House Prussian Royal House Prince Sigismond WaldemarEarl of Mountbatten King George VI Duke of Windsor Prince Philip Queen Elizabeth II Princess Diana Prince Charles William Hesse No evidence of hemophilia No evidence of hemophilia King Juan Carlos © Bettmann/Corbis Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

Page 243 Barr body attached to the nuclear membrane

Fig Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © Kenneth Mason Nucleus Allele for orange fur is inactivated Allele for black fur is inactivated X chromosome allele for orange fur Inactivated X chromosome becomes Barr body Second gene causes patchy distribution of pigment: white fur = no pigment, orange or black fur = pigment X chromosome allele for black fur Inactivated X chromosome becomes Barr body

Harriet Creighton and Barbara McClintock Maize genetics Evidence for Homologous recombination

Fig Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Parental All parentalRecombinant Meiosis II No recombinant Meiosis II Parent generation F 1 generation Meiosis with Crossing over Meiosis without Crossing over Crossing over during prophase I No crossing over during prophase I

Fig Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. 18% recombinant frequency Cross-fertilization recessive allele (black body) dominant allele (gray body) recessive allele (vestigial wings) dominant allele (normal wings) Parental generation F 1 generation Testcross Testcross male gamete 415 parental wild type (gray body, long wing) 92 recombinant (gray body, vestigial wing) F 1 generation female possible gametes 88 recombinant (black body, long wing) 405 parental mutant type (black body, vestigial wing) = 0.18 total recombinant offspring 18 cM between the two loci Using two-point crosses to map genes

Genetic Mapping The distance between genes is proportional to the frequency of recombination events. recombination recombinant progeny frequency total progeny 1% recombination = 1 map unit (m.u.) 1 map unit = 1 centimorgan (cM) =

Genetic Mapping Multiple crossovers between 2 genes can reduce the perceived genetic distance Progeny resulting from an even number of crossovers look like parental offspring

Fig Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Parental Recombinant A a B b C c ac bA B C Three-point testcrosses

Fig Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Anhidrotic ectodermal dysplasia Albinism–deafness syndrome Fragile-X syndrome Duchenne muscular dystrophy Becker muscular dystrophy Chronic granulomatous disease Retinitis pigmentosa-3 Norrie disease Retinitis pigmentosa-2 Sideroblastic anemia Aarskog–Scott syndrome PGK deficiency hemolytic anemia Agammaglobulinemia Kennedy disease Pelizaeus–Merzbacher disease Alport syndrome Fabry disease Hemophilia A G6PD deficiency: favism Drug-sensitive anemia Chronic hemolytic anemia Manic–depressive illness, X-linked Colorblindness, (several forms) Dyskeratosis congenita TKCR syndrome Adrenoleukodystrophy Adrenomyeloneuropathy Emery–Dreifuss muscular dystrophy Diabetes insipidus, renal Myotubular myopathy, X-linked Hunter syndrome Hemophilia B Lesch–Nyhan syndrome HPRT-related gout Charcot–Marie–Tooth neuropathy Choroideremia Cleft palate, X-linked Spastic paraplegia, X-linked, uncomplicated Deafness with stapes fixation Androgen insensitivity Lowe syndrome PRPS-related gout Incontinentia pigmenti Wiskott–Aldrich syndrome Menkes syndrome Ornithine transcarbamylase deficiency Adrenal hypoplasia Glycerol kinase deficiency Hypophosphatemia Aicardi syndrome Hypomagnesemia, X-linked Ocular albinism Retinoschisis Ichthyosis, X-linked Placental steroid sulfatase deficiency Kallmann syndrome Chondrodysplasia punctata, X-linked recessive Immunodeficiency, X-linked, with hyper IgM Lymphoproliferative syndrome Human X chromosome gene map

Fig Sickle cell anemia

Table 13.2

Normal human karyotypes

Abnormal human karyotype

Fig Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. © Colorado Genetics Laboratory, University of Colorado Denver XY Abnormal human karyotype

What happened here?

Fig Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display Age of Mother Incidence of Down Syndrome per 1000 Live Births Down syndrome increases with the age of the mother

Fig Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Normal male X XXX Y O Nonviable XO Female gametes undergo nondisjunction Triple X syndrome XX XXY Klinefelter syndrome OY Turner syndrome

Fig Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Amniotic fluid Hypodermic syringe Uterus Amniocentesis

Fig Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Cells from the chorion Suction tube Uterus Ultrasound device Chorionic villi Chorionic villi sampling