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1

generally paternal alleles want offspring to be what?

big

2

generally maternal alleles want offspring to be what

equal size and manageable

3

how was it shown that both maternal and paternal genes are essential for embryo development

gynogenetic diploid were inviable and androgenetic diploids were inviable

4

as even the XX individuals did not survive what could the authors conclude

that inviability was not caused by the sex chromosomes

5

imprinting is essential for normal development in mammals T/F

T

6

Imprinting is important for development of what animals

development of long lived animals with placenta

7

what is a classic example of an imprinted gene

IGF-II

8

what is IGF-II

insulin like growth factor II gene

9

what kind of imprinting does IGF-II go under

maternal imprinting

10

if IGF-II is knocked out what size mice

small mice

11

when the IGF-II mutation is transmitted through which germline does it result in heterozygous progeny that are growth deficient

male

12

- When the disrupted IGF-2 gene is transmitted maternally, the heterozygous off-spring are

phenotypically normal

13

how was it concluded that inheritance of Igf-2 and phenotpye was not a dosage effect

Homozyous mutants are indistinguishable in appearance from growth-deficient heterozygous siblings

14

in mice the paternal and maternal members of some autosomal gene pairs are functionally...

non equivalent

15

- Only the paternal allele of IGF-2 is expressed in embryos, while the maternal allele is silent

T

16

what is maternal imprinting

allele of a particular gene inherited from mother is transcriptionally silent (not expressed
direct observation of phenotype is governed by paternal allele

17

what is paternal imprinting

allele of a particular gene inherited from father is transcriptionally silent
direct observation of the phenotype is governed by maternal allele

18

usually in diploid species, if a defective copy of a gene is inherited there is a second functioning copy from the other parent that can compensate for this loss. what is this not true for

imprinted genes

19

in imprinted genes - Even though there are two copies of the gene, as only one copy is expressed, mutations affecting this copy will result in disease. T/F

T

20

- Situations that result in both copies of a gene being silenced will also lead to expression of the disease. this is known as ...

uniparental disomy (UPD)

21

- An imprinted region of the human genome that contains Ifg2 (the human homologue of IGF-II mouse gene) causes a paternally inherited disease called what

Beckwith-Weidemann syndrome

22

what is beckwith weidemann syndrome?

pediatric overgrowth disorder involving a predisposition to tumour development

23

1. mutation in dad germline results in hypermethylation of IC1
2. daughter now has active copy of IGFR2 from dad. the maternal copy is silenced
3. has child that has active copies from both parents so has BWS

T

24

what is prader willi syndrome characterised by

obesity, behaviour and cognitive problems. deficiencies in sexual development

25

in the gene that causes preader willi and angelmans which copy of the gene normally gets expressed and which is normally silenced

dad -expressed
mums - silent

26

what happens in prader willi syndrome

paternal gene doesnt get expressed so no forms of the gene are expressed

27

how is the paternal gene not expressed in prader willi

deletion of PW genes
maternal UPD (silent)
mutation in imprinting centre leading to methylation of paternal gene
epimutation - wrong methylation (not erased from mother)
translocation to move the genes away from imprinting centre

28

which gene causes angelmans syndrome and where is it usually expressed

UBE3A - only expressed on maternal

29

paternal mutations in chromsome 15 lead to what

prader willi

30

maternal mutations in chromosome 15 leads to what

angelmans