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BIOL332 > Sex Determination > Flashcards

Sex Determination Flashcards

1
Q

Olympics and Women History

A

1896 – First modern Olympic games

1900 – First women’s events (22 women)
Individuals = Tennis + Golf
Team = Sailing + Croquet + Equestrianism

1928 – Short running events added

1936 – Alpine Skiing + Gymnastics

1991 – Any new sport must have a men’s and women’s division

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2
Q

Caster Semenya Scenerio (What happened to her)

A

She is an elite female athelete competing at the international level

She was raised a gril and indeitifies as a women and hasn’t considered any other possibilities

One of her competators questions whether she was truly biologically female and anaonymoiusly asks offcials to investighate her sex

The group that makes the rules about who can complete is decdinng whetehr you qualify as female and should be able to compete

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3
Q

Who decides who can compete/in what catagory

A
  1. International Association of Athetics Federations (IAAF) – now called World Athetics
  2. International Olympic commitee (IOC)

***Policies made by these givering bodies are tyopically used as models for other organizations – their rules are modeled by other agencies = these agencies make the guidence

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4
Q

When does the development of sex begin

A

Development of sexes begin around 7 weeks in Utereo

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5
Q

Male Development of Sex in Utero

A

The autosomal gene SDRD5A2 codes for an exnymes involoved in porcesses testostrone into DHT –> required for male sex charachteristic develment
- Mutations to SDRD5A2 = unable to processes teststrone = leads to incomplete male development

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6
Q

What is required for male development in Utero

A

The autosomal gene SDRD5A2 codes for an exnymes involoved in porcesses testostrone into DHT – required for male development

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7
Q

Sex Development in Utero

A

Sex is indistiguishable until 7 weeks

Have some cells that turn into a penis or a vagina

Have Indifferent gonads cells – can turn into testes or ovaries (you can;t know what they will turn into until 7 weeks)

Have Indiferent gential cells – turn into penis or vagina

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8
Q

Indiferent genitals Vs. indifefrent gonads

A

Indiferent genitals = Develope into penis or vagine
- Same cells that can direct one way or other

Indifferent Gonads = develope into ovaries or testes

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9
Q

Sex development is…

A

complex

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10
Q

Genes involoved in sex development

A

Involoves sex linked and autosmal genes

Have genes on X that can activate cascade of events from genes that are on autsoomes –> creates cascade that leads to make or female development
- Genes on X that activate cascade of genes on Autosomes
- There are many pathways that form

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11
Q

Three catagories of sex

A
  1. Male
  2. Female
  3. Intersex
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12
Q

Intersex

A

Umbrella term to describe individulas with sex charachteristics (gentials + gonads + Chromsome patterns) that do not fit the typical defintion for male or female bodies

Any deviation from standrd path

Example – Indifferent gential cells go one way and indiffrent gonads go a different way

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13
Q

What can intersex include (what can be affected)

A
  1. Number and types of sex chromsomes
  2. Gonads (overies and testes)
  3. Sex hormone levels
  4. Internal reproductive anatomy (ex. Uterus)
  5. External Genetelia
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14
Q

Gonads

A

Overies + Testes

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15
Q

Sex hormones

A

Testrone + Estrogen

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16
Q

Bimodal vs. Binary sex

A

Sex is Bimodal NOT binary

Have male + female BUT have things in between
- Most people fit into male and demale BUT intersex is not male or female
- How do you define male/fenake

We try and fit somthing into a binary (try and fit sex into a binary) that is not actually a binary (sex is not a binary)

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17
Q

Two main chatagories of intersex varaitions

A
  1. Sex chromsomes anuploidy
  2. DNA variations that affect sexual development
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18
Q

Sex chromsome anuplidies

A
  1. Turner Syndrome (XO)
  2. Klinfelter syndrome (XXY)
  3. XYY Syndrome (XYY)
  4. Triple X Syndrome (XXX)
  5. Moaicism (XX/X, XY/X, XX/XXY)

ALL can lead to intersex

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19
Q

DNA varaitions that affect sexial development

A

Can also lead to intersex

  1. Andrigen Insensitivity syndrome
  2. Congential Adrenal Hyperplasia (CAH)
  3. Other genetic varaitions
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20
Q

Andrigen Insensitivity syndrome

A

Low response to hromones (low response to testrone)
- Body doesn’t repsond to hormones
- Recptors for hormones don’t work

Common cause of XY females (Develope as a female)

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21
Q

Congential Adrenal Hyperplasia (CAH)

A

High production of homrones (high production of testrone)

XX indiviuals with CAH can be:
1. Typical male
2. Combines male and female charachteristics
3. Tyoicaly female

Have a lot of varaition in how individuals develope

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22
Q

XY females

A

Have SRY gene that activates male cahacteristics BUT that genes doesn’t function –> If gene doesn’t function (like if you have a mutation on Y) = won’t develope as a male

These women all develope as women even though XY

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23
Q

SRY gene

A

SRY gene = gene on Y that activates male charchteristics

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24
Q

XX males

A

Occurs because have X and Y chromsomes that don’t normally recombine BUT sometimes they do –> if have recombination that puts the SRY gene on the X chromsome and that recombind X chrosmome with SRy gene goes to gamete then have XX that has SRY gene = have male developmnet

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25
Q

Autosomal mutations

A

There are other autosmal mutations that can redirect paths –> can produce lots of testastone

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26
Q

Thing in her ldies – check to see if added around slide 11

A
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27
Q

How common is intersex

A

Intersex variation as a group are quite common – 1.7% of population

28
Q

Why do we not see intersex as often (intersex invisabikity)

A
  1. People choose not to share personal information – people tend not to talk about it
  2. Many intersex people don’t know they are intersex
29
Q

Why don’t many intersex people know they are intersex

A
  1. No outward signs = don’t even know
    • Might be so minor it is not observed
  2. Surgery preformed during infancey or early childhood
    • Used to be surgery is the sex wasn’t sure
30
Q

Genetic tests + Intersex

A

Genetic tests may reveal unexpected infomration about sex chrosmomes

THIS IS SOO COMMON – so comon that they have a landing page for it – common enough to have a page for it
- “If you are here it may be because your geentic sex from DNA analysis is difefrent than you self-reproted sex. There are many reasons this can happen…”

31
Q

Sex and Gender

A

NOT the same thing

A person’s gender may be difefrent than the sex typically assigned at birth

32
Q

Sex

A

Classifcation of people in male + female + Intersex

Based on physical characteristics including:
1. Chrosmomes
2. Sex hromones
3. Reproduyctive organs

Has genetic compoennt

33
Q

Gender

A

A person’s sense of veing a man or women or both or beother

May or may not have a strong genetic compoennet –> Don’t know if genes play a role in gender (defintley not a single gene – complcated system)

Based on societal ideas of masculinity and femininity

34
Q

History of olympic sex testing

A

1936 – IOC preforms strip searches

1965 – IOC begins chromosomal analysis (Karyotype)

1967 – IOC and IAAF begin Barr Body testing

1992 – IAAF ends chromosome testing

1996 – PCR tests to look for the presnece or absence of teh Y-linked SRY gene
- DNA test to look at the presnece/absence of SRY

1999 – 8 of 3387 females tested positive for SRY gene –> ALL 8 were subject to further testing (Andrigen testing) and all 8 were eventually allowed to compete
AFTER = they stoped sex testing

2000 – teststrone levels used to determine eligibility to combete in women’s events – 10 ng/L limit

35
Q

What can Barr body testing distiguish

A

Barr body testing can destiguish XX from XY BUT not XX from XXY

XX and XXY = both have 1 Barr body

36
Q

Ewa Klobukowska

A

Polish olypic sporinter with genetic mosaicism with soem cells that are XX and some that are XXY –> she became the first athele to fail the gender verification tests due to her “extra chrosome”
- She was stripped of her medals and world records
- Some cells have XX Karyotype and some of XXY karyotpe

AFTER THIS = decided to just look at Barr Bodies

37
Q

Genetic Mosaiscm ex.

A

Some cells = XX and some XXY
- Some cells have XX Karyotype and some of XXY karyotpe

38
Q

Maria Jose Martinez Patino

A

Spanish hurdler – was disquilified after sex verification showed she had XY chrosmomes
- She protested the disqualification based on having Andrgen insensitivity syndrome and was eventually reinstated
- NOW – she is professor and write a lot about the sydnrome and sex testing in sprots

She had XY – had androgen insensitivity syndrome

39
Q

What sex does SRY gene indicate

A

Indivates presence of Y chromosome

40
Q

Caster Semenya and Dutee Chand

A

cater = disqulified from compinatition due to naturally elevated teststrine in 2009
- She begaan taking medicine to lower her testsrine levels

Dutee Chad = disquilified due to naturally elevated testrone level –> BUT she didn;t want to take drugs to lower level
- She fought back –> What is so special about 10 ng/L

They both tested high testrine levels – could take drugs to lower levels to compete

41
Q

Options for female athletes who test high testrone levels

A

IF tested high testrine levels – could take drugs to lower levels to compete

42
Q

Endocrine profiles in 693 elite atheles in post competition setting study

A

They looked at the hormone levels of elite atheltes right after competiton

The IAAF used this data to make an upper limit of testrone level that still allows women to compete

END = They concluded 10 nm/L –> Was at the lwo end of the male testrone range

43
Q

What does this figure show

A

X axis = testrone level

Y axis = Number of althetes

Blue = female

Green = male

Shows the number of atheles in that particular testrone level

Shows where most women are and where most men are BUT note there are some women in the men range and some men in the women range

44
Q

Advice for intersex athletes – if they are not qualified to compete based on testrone levels

A

recommend surgery so you appear more female – told them to get a gonadetcomey

Propose – partial clitordectomy with bilatoral gonadectomy follwoed by a deffered femanizing vaginioplasting and estrogen replrcemnt theraopy

***4 female althese had surgery

45
Q

Health risks of Gonadectomy

A

Requires liftime hormone replacment + get Stereloity + compromise bone and muscle strength + leave people at risk for chronic weakness + depression + sleeo disrtubance + poor libedo + Adverse effects on lipid profiles + diabetes + faturgue + finicial bruden + exlusion from reproductive technologues

46
Q

Legal challenges to 10 ng/L rule

A

2014 – Chand brought legal challegnges gaainst IAAF

2015 – court suspended 10 nm/L limut and ordered IAAF to provide scientific evidence of testrone imporving perfermence

47
Q

BIG question after testrine limit was placed

A

How do we know that testrone level improves preferance

48
Q

IAAF follow up strudy (After tesing hormone levels in altheste)

A

Looking to see how we know that testrone level imporves preformance

TWO questions to be answered:
1. Do naturally occuring elevated testrine levels confer an athletic advantage?

  1. If there is an advantage – what what level of testsrone does that advantage become unfair?

Study = compared prefermane of females woth lowest level and highest levels of testrone

Results: Of 21 events – high levels of testrone show statistically significnat imoporvement in preformance in 5 events

49
Q

What events are there would you put regulations on?

Which events showed significance for higehr testrone levels?

A

400 m

400 m hurdles

800 m

Pole valut

Hammer throw

THESE = have * –> means there is significant difference between low and higehst 1/3 of testrone levels

50
Q

Results of Does testrone imporve prefermance

A

Of 21 events – high levels of testrone show statistically significnat imoporvement in preformance in 5 events

51
Q

Lowest fT tertike vs. Highest fT tertile

A

Lowest = lowest 1/3 of testrone levels

Highest = highets 1/3 of testrone levels

52
Q

Which of the events showed that testrone porvided an advantage

A

400 m Hurdles and non-hrudles

53
Q

Which of the follwoing non-running events showed that testrone provided an advatage

A

Hammer throw and pole vault

54
Q

Result of IAAF study – things that they applied the testrone limit to

A

HERE - they put a limit to testrone level because statistics showed adavantage

400 m hurdles
400 m
800m
1500m (had no significnat advtange)
1 Mile (not even in the study)

ALSO – they lowered the threshold to 5nm/L

55
Q

Controversy over the new rule

A
  1. Marginal Advatage to those with increased testrone
  2. New rule does not apply to the events with the strongest correlated between incerased testosterone and imroved perfermence (Doesn’t include hammer throw and pole vault)
  3. New limit applies to 1500m races even though the stidy did not show imporved performance correlated to eleveated testosterone and included 1 mile even though it was not studies
  4. 5 nm/L is aritrary
56
Q

Critism on IAAF study (Testrone advatge study)

A
  1. Some atheles included were doping – researchers knowingly incldued data from atheete disqualofied for doping
  2. Use of bad data –> some duplicated data + some fabicated/erreneous data – Looked like there was some duplicated data
57
Q

Current regulations

A

5 nm/L limit for XY females for 400m/400m hurdles/800m/1500m/mile

58
Q

Affect of current regulations on Chand and Semenya

A

Chand = can complete – regulations don’t apply to 100m events

Semenya = runs 800m = has options
1. Lower testrone via medication or surgey
2. Participaye in event not in regulation (She did this)
3. Enter only non-international competitions (not covered by rules)
4. Compete in men’s division
5. Possible compete in another third division that doesn’t exist yet

59
Q

Options for XY women who exceed limit

A
  1. Lower testrone via medication or surgey
  2. Participaye in event not in regulation (She did this)
  3. Enter only non-international competitions (not covered by rules)
  4. Compete in men’s division
  5. Possible compete in another third division that doesn’t exist yet
60
Q

State laws for school sports

A

2020 – fairness in women’s sports act (Idaho)

2021 – Other states introduced similar bills (Tenessee + Alabama + Montana + Florida)

2022 – IOC requesting new guidelines

61
Q

Consider the results from physical, genetic, and hormonal sex determination tests
for a female athlete:

Physical characteristics: female genitals fully formed
Genetic test findings: no Barr body present, no SRY gene present
Hormone test findings: Testosterone (T) = 1.2 nmol/L

What is the most likely karyotype of this individual? Keep in mind that a genetic mutation to a particular gene is unlikely to alter the chromosome structure

A

XY

62
Q

Consider the results from physical, genetic, and hormonal sex determination tests
for a female athlete:

Physical characteristics: female genitals fully formed
Genetic test findings: Barr body present in some cells and absent in others, SRY
gene present
Hormone test findings: Testosterone (T) = 3 nmol/L

What is the most likely karyotype of this individual? Keep in mind that a genetic mutation to a particular gene is unlikely to alter the chromosome structure

A

XXY/XY mosaic

63
Q

Consider the results from physical, genetic, and hormonal sex determination tests for a female athlete:

Physical: characteristics: genitals neither typically male nor typically female
Genetic test findings: Barr body present, SRY gene absent
Hormone test findings: Testosterone (T) = 6.3 nmol/L

What is the most likely karyotype of this individual? Keep in mind that a genetic mutation to a particular gene is unlikely to alter the chromosome structure.

A

XX

64
Q

Consider the results from physical, genetic, and hormonal sex determination tests for a female athlete:

Physical characteristics: female genitals fully formed
Genetic test findings: Barr body absent, SRY gene present
Hormone test findings: Testosterone (T) = 25 nmol/L

What is the most likely karyotype of this individual? Keep in mind that a genetic mutation to a particular gene is unlikely to alter the chromosome structure.

A

XY

65
Q

Consider the results from physical, genetic, and hormonal sex determination tests for a female athlete:

Physical characteristics: genitals neither typically male nor typically female
Genetic test findings: Barr body absent, SRY gene present
Hormone test findings: Testosterone (T) = 12 nmol/L

What is the most likely karyotype of this individual? Keep in mind that a genetic mutation to a particular gene is unlikely to alter the chromosome structure.

A

XY

BIOL332 (25 decks)

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