Fig Chapter 46 Animal Reproduction

Fig. 46-2

Fig Asexual reproduction Female Sexual reproduction Female Generation 1 Male Generation 2 Generation 3 Generation 4

Fig. 46-4a Both are females; Parthenogenic

Fig. 46-4b Ovary size Hormone level Behavior Estradiol Ovulation Progesterone Time Female Male- like Female Male- like The sexual behavior  the cycle of ovulation

Fig Eggs Fertilization

Fig Giant water bugs: parental protection; few offsprings

Fig Accessory gland Ejaculatory duct Testis Vas deferens Seminal vesicle Penis Ovary Oviduct Spermatheca Vagina Accessory gland (a) Male honeybee (drone) (b) Female honeybee (queen)

Fig Genital pore (Digestive tract) Male organs: Seminal vesicle Sperm duct (vas deferens) Vas efferens Testis Female organs: Uterus Yolk gland Yolk duct Oviduct Ovary Seminal receptacle (Excretory pore) A hermaphrodite 雌雄同體

Fig RESULTS Control; not remated Remated to wild-type males Remated to “no-sperm” males Remated to “no-ejaculate” males Percentage of females lacking sperm in spermatheca Why is sperm usage biased when female fruit flies mate twice?

Fig a (Rectum) Cervix Vagina Vaginal opening Oviduct Ovary Uterus (Urinary bladder) (Pubic bone) Urethra Clitoris Shaft Glans Prepuce Labia minora Labia majora

Fig b Ovaries Oviduct Follicles Corpus luteum Uterine wall Uterus Cervix Endometrium Vagina

Fig b Seminal vesicle (Rectum) Vas deferens Ejaculatory duct Prostate gland Bulbourethral gland Vas deferens Epididymis Testis Scrotum (Urinary bladder) (Urinary duct) (Pubic bone) Erectile tissue Urethra Glans Prepuce Penis

Spermatogenesis

Fig b Epididymis Seminiferous tubule Sertoli cell nucleus Testis Cross section of seminiferous tubule Spermatogonium Primary spermatocyte Secondary spermatocyte Spermatids (two stages) Sperm Lumen of seminiferous tubule

Fig c Primordial germ cell in embryo Mitotic divisions Spermatogonial stem cell Mitotic divisions Spermatogonium Mitotic divisions Primary spermatocyte Meiosis I Secondary spermatocyte Meiosis II Early spermatid Differentiation (Sertoli cells provide nutrients) Sperm 2n2n 2n2n 2n2n n n n n n n n n n n

Fig e Ovary In embryo Primordial germ cell Mitotic divisions Oogonium Mitotic divisions Primary oocyte (present at birth), arrested in prophase of meiosis I First polar body Completion of meiosis I and onset of meiosis II Secondary oocyte, arrested at metaphase of meiosis II Ovulation, sperm entry Completion of meiosis II Second polar body Fertilized egg Primary oocyte within follicle Growing follicle Mature follicle Ruptured follicle Ovulated secondary oocyte Corpus luteum Degenerating corpus luteum 2n2n 2n2n n n n n Oogenesis

Fig f Ovary Primary oocyte within follicle Ruptured follicle Growing follicle Mature follicle Ovulated secondary oocyte Corpus luteum Degenerating corpus luteum

Fig g Primordial germ cell Mitotic divisions Oogonium Mitotic divisions Primary oocyte (present at birth), arrested in prophase of meiosis I Completion of meiosis I and onset of meiosis II Secondary oocyte, arrested at metaphase of meiosis II First polar body Ovulation, sperm entry Completion of meiosis II Second polar body Fertilized egg 2n2n 2n2n n n n n In embryo

Hormone control of the testes

Fig a Control by hypothalamus Inhibited by combination of estradiol and progesterone Stimulated by high levels of estradiol Inhibited by low levels of estradiol Hypothalamus GnRH Anterior pituitary FSH LH Pituitary gonadotropins in blood LH FSH FSH and LH stimulate follicle to grow LH surge triggers ovulation Ovarian cycle Growing follicle Maturing follicle Corpus luteum Degenerating corpus luteum Follicular phase Ovulation Luteal phase (a) (b) (c) Days | | ||| | || – – +

Fig b Ovarian hormones in blood Peak causes LH surge Estradiol level very low Estradiol Progesterone Ovulation Progesterone and estra- diol promote thickening of endometrium Uterine (menstrual) cycle Endometrium | | || | | || Days 15 Menstrual flow phase Proliferative phaseSecretory phase (d) (e) Endometriosis Estrous cycle

Fig Placenta Uterus Umbilical cord Chorionic villus, containing fetal capillaries Maternal blood pools Maternal arteries Maternal veins Maternal portion of placenta Fetal arteriole Fetal venule Umbilical cord Fetal portion of placenta (chorion) Umbilical arteries Umbilical vein

Fig (a) 5 weeks (b) 14 weeks (c) 20 weeks

Fig a (a) 5 weeks

Fig b (b) 14 weeks

Fig c (c) 20 weeks

Fig Estradiol Oxytocin from ovaries Induces oxytocin receptors on uterus from fetus and mother’s posterior pituitary Stimulates uterus to contract Stimulates placenta to make Prostaglandins Stimulate more contractions of uterus Positive feedback + +

Fig Dilation of the cervix Placenta Umbilical cord Uterus Cervix Expulsion: delivery of the infant Uterus Placenta (detaching) Umbilical cord Delivery of the placenta

Fig MaleFemale Method Event Method Production of sperm Production of primary oocytes Vasectomy Combination birth control pill (or injection, patch, or vaginal ring) Sperm transport down male duct system Oocyte development and ovulation Abstinence Condom Coitus interruptus (very high failure rate) Abstinence Sperm deposited in vagina Capture of the oocyte by the oviduct Tubal ligation Female condom Sperm movement through female reproductive tract Transport of oocyte in oviduct Spermicides; diaphragm; cervical cap; progestin alone (as minipill, implant, or injection) Meeting of sperm and oocyte in oviduct Union of sperm and egg Morning-after pill; intrauterine device (IUD) Implantation of blastocyst in endometrium

1. Describe oogenesis and spermatogenesis; describe three major differences between them 2. Explain how the uterine and ovarian cycles are synchronized and describe the functions of the hormones involved You should now be able to: