Bio 37 - Reproductive Technology.pdf

Aim: How is biological sex determined? Do Now: Should we continue to have male and female categories in sports? Why or why not? Success Criteria: I can describe which parts of the human reproductive system are involved in sex determination and development. SRY gene: (sex-determining re...

Aim: How is biological sex determined? Do Now: Should we continue to have male and female categories in sports? Why or why not? Success Criteria: I can describe which parts of the human reproductive system are involved in sex determination and development. SRY gene: (sex-determining region of the Y chromosome) hormones steer development male Heterogametic: XY males Homogametic: XX females SRY codes for a transcription factor that promotes development of male characteristics Remember: 5-alpha reductase deficiency - “guevedoces” prevents SRY from being expressed Sex Ratio: proportion of males to females in a population (1.000 would be equal males and females) Countries by sex ratio 2021 - StatisticsTimes.com Congenital Adrenal Hyperplasia (CAH) affects: ● Cortisol ● Mineralocorticoids ● Androgens, such as testosterone Caused by a mutation in CYP21A2 which causes a lack of the enzyme known as 21-hydroxylase 46 XX DSD Congenital Adrenal Hyperplasia (CAH) is most common 95% CYP11B1 - causes 11β-hydroxylase deficiency 5% An early intervention could be favorable for anatomic resolution, a better development of gender identity, and better future reproductive health. 46 XY DSD DSD: Differences in Sex Development There are a TON of genes involved in the formation of sex organs What constitutes cheating in the olympics? Mariya Sergeyevna Savinova Born 46XX Injected testosterone and Oxandrolone for years including during her 2012 800m Gold Medal winning race Is this cheating? Pedro Spajari Has Kleinfelter’s Syndrome (XXY) Was allowed to take hormone replacement testosterone and compete as a male Is this cheating? Caster Semenya Born DSD 46XY Forced to take hormones to reduce her natural testosterone levels to below 5 nmol/L Normal Female Range: 0.12 to 1.79 nmol/L Normal Male Range: 7.7 to 29.4 nmol/L Is this cheating? Aim: How can we differentiate between sex-influenced and sex-limited inheritance? Do Now: Pair/Share: Do you think parents should choose a sex for their infants at birth if they have a DSD? Why or why not? Sex hormone replacement is needed to induce pubertal development. Testosterone is used in the treatment of patients with testosterone deficiency (46XY DSD). Different forms of testosterone (topical and intramuscular) are available and treatment will vary depending on what is best for the patient. A short course of testosterone can be given during infancy to induce penile growth prior to surgical correction. For 46XY DSD patients with functioning Sertoli cells, HCG can be used to stimulate testicular production. Estrogen is used in the treatment of those reared female. Estrogen is available as an oral tablet or transdermal patch. Estrogen doses should be initiated at the lowest dose possible and slowly increased to a maximum of 0.625 mg/day of conjugated estrogen to allow for gradual breast development. Progesterone supplementation with estrogen is recommended in patients with a uterus. Success Criteria: I can.. Know the sequence of sex determination from conception to determination of genetic sex, then gonadal sex, then phenotypic sex. Understand and describe dosage compensation, and the difference between sex-influenced and sex-limited inheritance. Genetic Sex: Determined by XX (female) or XY (male) at conception Gonadic Sex: undifferentiated genital ridge forms testes or ovaries - begins at 6 weeks Phenotypic Sex: Begins at 8 weeks external and internal structures begin and continue to develop until birth at week 40 “Female” genes suppress “male” genes - sometimes this doesn’t go to plan ovotestis: organ with features of an ovary and testis Dosage compensation: is the process by which organisms equalize the expression of genes between members of different biological sexes. X-chromosome dampening (XCD): humans turn down transcription Imprinted X-chromosome inactivation (XCI): X chromosome is turned off X-inactive specific transcript (Xist) is a long non-coding RNA Sex-Influenced Female Dominant Inheritance The trait is dominant in females while at the same time it is recessive in males. variation in the MATN3 gene on chromosome 2p24 Heberden’s nodes: a form of osteoarthritis - found in 50% of females and 25% of males Sex-Influenced Male Dominant Inheritance The trait is dominant in men while at the same time it is recessive in women. Male Pattern Baldness autosomal locus on 3q26 Males only need one copy to express the trait - females need two copies Sex Limited Inheritance Only males can have prostate cancer and only females can have ovarian cancer, although both males and females can carry the genes for these conditions. HPCX on chromosome Xq27-q28 The genes for the trait can be carried and transmitted by the opposite sex although it is NOT displayed in that sex because of anatomical or physiological differences. Summary: Sex Influenced Traits are dominant in one sex and recessive in the other Sex limited traits can’t exist in the opposite sex because they do not have the organs Sex linked traits are carried and transmitted by the X or Y chromosome Success Criteria: I can.. Know the sequence of sex determination from conception to determination of genetic sex, then gonadal sex, then phenotypic sex. Understand and describe dosage compensation, and the difference between sex-influenced and sex-limited inheritance. Aim: What are some of the causes of infertility in humans? Do Now: Pair/Share: Read the scenario. “Glenn and Gillian” Discuss at your tables, your answer, choose one person from your group to share your answer and explanation. Each table will share. Success Criteria: I can… define and describe male and female fertility and infertility test describe various assisted reproductive technologies utilized as childbearing options Infertility: is the inability to conceive a child after a year of frequent intercourse without the use of contraceptives. 1 in 5 women ages 15-49 are unable to get pregnant Impaired fecundity: inability to carry pregnancy to term 1 in 4 women ages 15-49 have difficulty carrying pregnancies to term What can cause male infertility? Azoospermia : 2% of males do not make any sperm cells Oligospermia : males produce fewer than the 20-200 million sperm cells per mL. Can be caused by: - Hormonal imbalance - Excess IgA antibodies - Vericose veins in scrotum What can cause male infertility? Globozoospermia : sperm lack an acrosome, so they cannot penetrate an egg Point mutation in SPATA16 on chromosome 3 Females can carry the mutation but are unaffected (sex-limited inheritance) What can cause female infertility? How can we test for infertility? Sperm can be tested for motility and number Y chromosomes on sperm can be examined - AZF gene affects sperm formation Female is later examined for functioning organs Assisted Reproductive Technologies (ART) Intrauterine insemination (IUI): a doctor places donated sperm into a woman’s cervix or uterus. Has been used in humans since 1790 Costs about $865 per cycle Aim: What are some reproductive technologies and how do they aid in pregnancy? Do Now: Pair/Share: Do you think it should be a crime to inseminate a woman without her knowing who the sperm belongs to? Is the circumstance different if it’s a random donor vs. her husband? https://www.nbcbayarea.com/investigations/doctor-sperm-donor-cases-fertility/314 8093/#:~:text=She%20has%20since%20tracked%2038,more%20people%20take %20DNA%20tests . Success Criteria: I can… describe various assisted reproductive technologies utilized as childbearing options. Discuss pre-implantation technologies and potential therapies Do you think it should be a crime to inseminate a woman without her knowing who the sperm belongs to? Is the circumstance different if it’s a random donor vs. her husband? Assisted Reproductive Technologies (ART) In vitro fertilization (IVF): which means “fertilization in glass” Egg and sperm are joined in a petri dish and the embryo is implanted Sir Robert Geoffrey Edwards is awarded the Nobel Prize in 2010 for developing IVF 8 million babies born using IVF Costs about $10,000-20,000 per round What do we do with the extra embryos? Assisted Reproductive Technologies (ART) If you could choose to have a baby guaranteed with no genetic diseases, would you? Why or why not? If you could choose the sex of your baby, would you? Why or why not? If you could choose the physical characteristics of your baby (eye color, hair color, weight etc) would you? Why or why not? Preimplantation genetic diagnosis (PGD): detects genetic and chromosomal abnormalities before pregnancy starts. Some countries (ie: UK, Italy, France) have laws against using this except to prevent disease Gestational Surrogate : provides the uterus to the couple who underwent IVF - has no genetic relationship with the embryo Genetic Surrogate: provides oocyte and is pregnant - half of the genetic information is from this donor Pair/Share: Why do you think New York and Michigan have outlawed gestational surrogacy? $27,162.80 mean compensation for a gestational surrogate IPs paid well over $100,000 Aim: How can we examine ethical issues around reproduction? Do Now: Pair/Share: Why do you think New York and Michigan have outlawed gestational surrogacy? Pair/Share: Why do you think New York and Michigan have outlawed gestational surrogacy? $27,162.80 mean compensation for a gestational surrogate IPs paid well over $100,000 Eugenics: “good genes” Eugenics is the scientifically inaccurate theory that humans can be improved through selective breeding of populations. Buck v. Bell (1927) Ruled 8 to 1 that compulsory sterilization did not violate the 14th amendment “Three generations of imbeciles are enough” Reproduction Scenarios: For the given scenario at your table, come prepared with one argument for and one argument against the answer the to the question at the end of your scenario. Choose your presenters and make sure all voices are heard in your group. You will present both the pro/con of your scenario and brief synopsis in 8 minutes. Scenario #1 - Deaf Baby Should the doctor implant a deaf embryo rather than a hearing one, so that the couple have a deaf baby? Scenario #2 - Drug Addicted Mothers Should physicians turn over these test results to the authorities? Scenario #3 - Stolen Sperm Do the unusual circumstances of this case justify ordering Joan to undergo an abortion? Aim: To what extent should we allow reproductive technologies be allowed to be used? Do Now: Should there be laws passed regulating the use of reproductive technologies? If so, which ones? Scenario #4 : Murdered Parents Assuming both Beatrice and Thelma would be excellent parents, who has a better claim to the child? Scenario #5: Sterilization Should Dr. Moreau be allowed to go ahead with the surgery? Scenario #6: If scientists are able to develop the technology to clone humans, and one of these women is still willing to bring the clone to term, would it be ethical to fulfill the wishes of Dr. No and his followers? Respond to the following quote: “ "I not only think that we will tamper with Mother Nature, I think Mother wants us to." Willard Gaylin Would you want to know the date that you would die at birth? Why or why not? Do you agree with Anton and Marie’s decision to genetically engineer their second child? https://video.vice.com/en_us/video/unnatural-selection/582b52c2f487fd700408bfe 2 Compare and Contrast the science fiction version of this scene (1997) to the News version (2016) Is it worth the time, money and effort to send someone to medical school if they’re going to die at age 30? Where do we draw the line? What do you need to be able to do for Tuesday’s exam? 1. Reproductive Technologies a. Be able to describe which parts of the human reproductive system are involved in sex determination and development. b. Know the sequence of sex determination from conception to determination of genetic sex, then gonadal sex, then phenotypic sex. c. Understand and describe dosage compensation, and the difference between sex-influenced and sex-limited inheritance. d. Be able to define and describe male and female fertility and infertility test e. Be able to describe various assisted reproductive technologies utilized as childbearing options. f. Discuss pre-implantation technologies and potential therapies