Animal Reproduction. Spermatozoa in female tract. # lectures for cumulative test # 03 book

Transcription

1 Animal Reproduction JP Advis DVM, Ph.D. Bartlett Hall, Animal Sciences, Cook, (732) , 21 Course website: rci.rutgers.edu/~advis Material to be covered: About lecture Meetings 01-02: Introduction to Animal Reproduction (2) Meetings 03-04: Reproductive Structures and their Functions (2) Meetings 05-07: The HPG axis and its Liposoluble and Watersoluble Hormones (3) Meetings 08-09: The Neuroendocrine Control of Male and Female Puberty Onset (2) Meetings 10-11: REVIEW AND TEST #1 Meetings 12-17: Female and Male Reproduction and Techniques for their Control (6) Meetings 18-19: REVIEW AND TEST #2 Meetings 20-21: Reproductive Behavior and the Spermatozoa in the Female Tract (2) Meetings 22-23: Embryogenesis, Placentation, Parturition and Lactation (3) Meetings 24-25: Puerperium, Lactation and Reproductive Ageing (2) Meeting 26 Reproductive Pathology and Case Studies (1) Meetings 27-28: REVIEW AND TEST #3 AND TEST #4 slides: There are not intended to be the sole source for studying the course material!!!!!!!!!!!!!!!! Slides are good to review the course material after you have study your course textbook Slides are a good indicator of the relative importance of lecture topics (see slide # per topic) Group slides by titles when using them to review course material. Match lectures and text. Spermatozoa in female tract # lectures for cumulative test # 03 book 20 Reproductive behavior Spermatozoa in female tract: transport, capacitation, fertilization Early embriogenesis and maternal recognition of pregnancy Placentation, the endocrinology of gestation and parturition The puerperium and lactation Reproductive aging and the role of biological clocks in senescence Reproductive pathology: case studies as a tool to study reproductive failure 27 REVIEW material from lecture # 20 through lecture # EXAM # 01 - material from lecture # 01 through lecture # Page 1

2 Events following deposition of spermatozoa in female tract Page 2

3 TRANSPORT Spermatozoa in female tract Leukocyte infiltration helps prevent reproductive tract infections Page 3

4 16% (smooth muscle stimulants) 52% 63% Smooth muscle stimulants increase fertilization rate in rabbits Page 4

5 sub-mucosa mucosa lumen The bovine tube and its components: mucosa, submucosa, muscles, serosa Main components: Ovaries Oviduct Uterus Cervix Vagina External genitalia Specific functions: Gametes Preattachment Sperm transport Early embryogenesis Attachment Cervical mucua Copulatory organ General structure: Serosal layer Muscular layers Submucosal layer Mucosal lining Spermatozoa in female tract Spermatozoa travels through privileged pathways in the cow Page 5

6 PP = privileged path Spermatozoa in female tract Artificial insemination, the most effective male reproductive technique Page 6

7 Cumulative % sperm recovered from vagina Insemination into uterine horns can reduce sperm loss (as recovered from vagina) Cumulative % sperm recovered from vagina Page 7

8 CAPACITATION Spermatozoa in female tract Conceptual version of the main steps in mammalian capacitation Page 8

9 Conceptual overview version of mammalian capacitation Page 9

10 Conceptual version of the main steps in mammalian capacitation Page 10

11 Conceptual version of signal transduction pathways in mammalian capacitation Page 11

12 Schematic representation of the main intracellular signalling pathways that are activated during the process of capacitation and development of hyperactivated motility. Early events during the process of capacitation include cholesterol removal from the membrane, a process which is stimulated by an extracellular cholesterol acceptor (physiologically albumin) and inhibited by glycodelins, entry of calcium (Ca 2+ ) and bicarbonate (HCO 3- ). Another early event is represented by intracellular alkalinization (regulated by membrane potential extracellular ph and zinc), which is involved both in calcium and tyrosine phosphorylation increase occurring later. HCO 3- leads to activation of Sacy and the camp/pka pathway. Autocrine production of reactive oxygen species (ROS), nitric oxide (NO) and PAF has been demonstrated during capacitation. All these pathways converge in an increase of tyrosine phosphorylation of proteins. The increase of intracellular Ca 2+ limits the increase of tyrosine phosphorylation by a poorly defined mechanism that may involve PTP. ras-mek/mapk and PKC activation and serine / threonine phosphorylation of proteins have been shown to occur during capacitation but their role in the process remains to be clearly defined. Pathways involved in development of sperm hyperactivated motility, include entry of Ca2+ through CatSper calcium channels whose role in motility has been recently disclosed in a KO mouse model, and autocrine synthesis of PAF which exert a positive effect. Hyperactivated motility is stimulated by inhibitors of PI3K through increase AKAP tyrosine phosphorylation and AKAP-PKA interaction. CatSper can be also activated by intracellular alkalinization due to the outward transport of protons through Hv1 Voltage-Gated channels. Dotted arrows indicate inhibiting pathways. Interrogation marks indicate lack of definitive proofs of the involvement of a given pathway in the process. Abbreviations: SACY, soluble adenylate cyclase; AKAPs, A-kinase-anchoring proteins; MAPK, mitogen-activated protein kinase; MEK, mitogen-activated protein kinase kinase; NO, nitric oxide; PAF, platelet-activating factor; PDE, Phosphodiesterase; PKA, protein kinase A; PKC, protein kinase C; PI3K, phosphatydil inositol 3 kinase; PTK, protein tyrosine kinase; PTP protein tyrosine phosphatase; Src, cellular homologue of transforming gene of Rous sarcoma virus; reactive oxygen species (ROS). FERTILIZATION Page 12

13 Post - capacitation sequence of events leading to fertilization Page 13

14 1 1 Hyperactive motility Binding to zona pelucida 3 Acrosomal reaction 4 Penetration of zona pelucida 5 Sperm oocyte membrane fusion 6 Sperm engulfed 7 Decondensation of sperm nucleus 8 Formation of male pronucleus Post - capacitation sequence of events leading to fertilization 1 1 Hyperactive motility Binding to zona pelucida 3 Acrosomal reaction Penetration of zona pelucida 5 Sperm oocyte membrane fusion 6 Sperm engulfed Sperm engulfed and decondensation of sperm nucleus 7 Decondensation of sperm nucleus 8 Formation of male pronucleus Page 14

15 Binding and acrosomal reaction Zona binding by sperm and initiation of the acrosomal reaction (stages 2-3) Binding and acrosomal reaction Page 15

16 Spermatozoa in female tract Penetration of zona pelucida and sperm-oocyte membrane fusion Schematic illustration of the acrosomal reaction (stages 4-5) Penetration of zona pelucida and sperm-oocyte membrane fusion Page 16

17 Spermatozoa in female tract Sperm engulfed and decondensation of sperm nucleus before membrane fusion during membrane fusion after membrane fusion Illustration of sperm oocyte fusion (stages 6-7) Sperm engulfed and decondensation of sperm nucleus Page 17

18 Probability of conception when copulation occurred on specific days relative to ovulation in women Spermatozoa in female tract SPECIES FERTILE LIFE (days) Bitch 9-11 Cow Mare 4-5 Woman 5 6 Camelids (camel, llama, alpaca) 4-5 Q9 Duration of fertilizing ability of sperm within the female reproductive tract of various species Page 18

19 Comments on your weekly questions Page 19

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