Genesis of Gametogenesis
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Reference Sheet 1
MALE SEXUAL SYSTEM 8 7 8 OJ 7 .£l"00\.....• ;:; ::>0\~ <Il '"~IQ)I"->. ~cru::>s ~ 6 5 bladder penis prostate gland 4 scrotum seminal vesicle testicle urethra vas deferens FEMALE SEXUAL SYSTEM 2 1 8 " \ 5 ... - ... j 4 labia \ ""\ bladderFallopian"k. "'"f"";".'''¥'&.tube\'WIT / I cervixt r r' \ \ clitorisurethrauterus 7 \ ~~ ;~f4f~ ~:iJ 3 ovaryvagina / ~ 2 / \ \\"- 9 6 adapted from F.L.A.S.H. Reproductive System Reference Sheet 3: GLOSSARY Anus – The opening in the buttocks from which bowel movements come when a person goes to the bathroom. It is part of the digestive system; it gets rid of body wastes. Buttocks – The medical word for a person’s “bottom” or “rear end.” Cervix – The opening of the uterus into the vagina. Circumcision – An operation to remove the foreskin from the penis. Cowper’s Glands – Glands on either side of the urethra that make a discharge which lines the urethra when a man gets an erection, making it less acid-like to protect the sperm. Clitoris – The part of the female genitals that’s full of nerves and becomes erect. It has a glans and a shaft like the penis, but only its glans is on the out side of the body, and it’s much smaller. Discharge – Liquid. Urine and semen are kinds of discharge, but the word is usually used to describe either the normal wetness of the vagina or the abnormal wetness that may come from an infection in the penis or vagina. Duct – Tube, the fallopian tubes may be called oviducts, because they are the path for an ovum. -
THE PHYSIOLOGY and ECOPHYSIOLOGY of EJACULATION Tropical and Subtropical Agroecosystems, Vol
Tropical and Subtropical Agroecosystems E-ISSN: 1870-0462 [email protected] Universidad Autónoma de Yucatán México Lucio, R. A.; Cruz, Y.; Pichardo, A. I.; Fuentes-Morales, M. R.; Fuentes-Farias, A.L.; Molina-Cerón, M. L.; Gutiérrez-Ospina, G. THE PHYSIOLOGY AND ECOPHYSIOLOGY OF EJACULATION Tropical and Subtropical Agroecosystems, vol. 15, núm. 1, 2012, pp. S113-S127 Universidad Autónoma de Yucatán Mérida, Yucatán, México Available in: http://www.redalyc.org/articulo.oa?id=93924484010 How to cite Complete issue Scientific Information System More information about this article Network of Scientific Journals from Latin America, the Caribbean, Spain and Portugal Journal's homepage in redalyc.org Non-profit academic project, developed under the open access initiative Tropical and Subtropical Agroecosystems, 15 (2012) SUP 1: S113 – S127 REVIEW [REVISIÓN] THE PHYSIOLOGY AND ECOPHYSIOLOGY OF EJACULATION [FISIOLOGÍA Y ECOFISIOLOGÍA DE LA EYACULACIÓN] R. A. Lucio1*, Y. Cruz1, A. I. Pichardo2, M. R. Fuentes-Morales1, A.L. Fuentes-Farias3, M. L. Molina-Cerón2 and G. Gutiérrez-Ospina2 1Centro Tlaxcala de Biología de la Conducta, Universidad Autónoma de Tlaxcala, Tlaxcala-Puebla km 1.5 s/n, Loma Xicotencatl, 90062, Tlaxcala, Tlax., México. 2Depto. Biología Celular y Fisiología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510, México, D.F., México. 3Laboratorio de Ecofisiologia Animal, Departamento de Fisiologia, Instituto de Investigaciones sobre los Recursos Naturales, Universidad Michoacana de San Nicolás de Hidalgo, Av. San Juanito Itzicuaro s/n, Colonia Nueva Esperanza 58337, Morelia, Mich., México * Corresponding author ABSTRACT RESUMEN Different studies dealing with ejaculation view this Diferentes estudios enfocados en la eyaculación, process as a part of the male copulatory behavior. -
When Stem Cells Grow Old: Phenotypes and Mechanisms of Stem Cell Aging Michael B
© 2016. Published by The Company of Biologists Ltd | Development (2016) 143, 3-14 doi:10.1242/dev.130633 REVIEW When stem cells grow old: phenotypes and mechanisms of stem cell aging Michael B. Schultz and David A. Sinclair* ABSTRACT Thus, a stark collapse of the hematological system does not occur All multicellular organisms undergo a decline in tissue and organ during normal aging. However, when murine HSCs with long-term + − function as they age. An attractive theory is that a loss in stem cell repopulating ability were isolated by selecting for c-Kit , lineage + number and/or activity over time causes this decline. In accordance (multiple markers), Sca-1 cells (KLS) (Ikuta and Weissman, 1992; with this theory, aging phenotypes have been described for stem cells Spangrude et al., 1988), the number of HSCs was found to steadily of multiple tissues, including those of the hematopoietic system, increase with age (de Haan et al., 1997; Morrison et al., 1996). Only intestine, muscle, brain, skin and germline. Here, we discuss recent when function was measured on a per-cell basis were old advances in our understanding of why adult stem cells age and how immunophenotypic HSCs shown to have a greatly reduced ability this aging impacts diseases and lifespan. With this increased to engraft and properly differentiate in new hosts (Dykstra et al., understanding, it is feasible to design and test interventions that 2011; Liang et al., 2005; Morrison et al., 1996). Furthermore, in delay stem cell aging and improve both health and lifespan. both mice and humans, the proportion of differentiated blood cells arising from just a few HSC clones increases, suggesting that the KEY WORDS: Age-related diseases, Hematopoietic stem cells, number of active, functional HSCs declines with age (Beerman Multicellular organisms et al., 2010; Genovese et al., 2014; Jaiswal et al., 2014). -
Gene Therapy Glossary of Terms
GENE THERAPY GLOSSARY OF TERMS A • Phase 3: A phase of research to describe clinical trials • Allele: one of two or more alternative forms of a gene that that gather more information about a drug’s safety and arise by mutation and are found at the same place on a effectiveness by studying different populations and chromosome. different dosages and by using the drug in combination • Adeno-Associated Virus: A single stranded DNA virus that has with other drugs. These studies typically involve more not been found to cause disease in humans. This type of virus participants.7 is the most frequently used in gene therapy.1 • Phase 4: A phase of research to describe clinical trials • Adenovirus: A member of a family of viruses that can cause occurring after FDA has approved a drug for marketing. infections in the respiratory tract, eye, and gastrointestinal They include post market requirement and commitment tract. studies that are required of or agreed to by the study • Adeno-Associated Virus Vector: Adeno viruses used as sponsor. These trials gather additional information about a vehicles for genes, whose core genetic material has been drug’s safety, efficacy, or optimal use.8 removed and replaced by the FVIII- or FIX-gene • Codon: a sequence of three nucleotides in DNA or RNA • Amino Acids: building block of a protein that gives instructions to add a specific amino acid to an • Antibody: a protein produced by immune cells called B-cells elongating protein in response to a foreign molecule; acts by binding to the • CRISPR: a family of DNA sequences that can be cleaved by molecule and often making it inactive or targeting it for specific enzymes, and therefore serve as a guide to cut out destruction and insert genes. -
Gametogenesis: Spermatogenesis & Oogenesis -Structure of Sperm and Egg Fertilization
Gametogenesis: Spermatogenesis & Oogenesis ‐Structure of Sperm and Egg Fertilization ‐ Definition, Mechanism Early development in Frog ‐ Cleavage, Blas tu la, GtlGastrula, DitiDerivatives of Germ layers Vikasana - CET 2012 y Human reproduction y Brief Account of Fertilization: Implantation, Placenta, Role of Gonadotropins and sex hormones , Menstrual cycle. y Fertility Control: Family Planning Methods- y Infertility Control: Meaning, Causes,Treatment y STD: AIDS , Syphilis and Gonorrhea Vikasana - CET 2012 1.Primary Oocyte is a) Haploid (n) b) Diploid (2n) c) Polyploid d) None of the above Vikasana - CET 2012 2.Secondary Oocyte is a) Haploid (n) b) Diploid (2n) c) Polyploid d) None of the above Vikasana - CET 2012 3.Centrioles of sperm control a) Movement of tail b) Hap lo id numb er of ch romosomes c) Help in fertilization d) None of the above. Vikasana - CET 2012 4.The Fertilization membrane is secreted because a) It checks the entry of more sperms after fertilization b) it checks the entry of antigens in ovum c))p it represents the left out tail of the sperm d) it represen tVikasanas the p - l CETasma 2012 mem brane of the sperm 5.Meiosis I occurs in a) Primary spermatocytes b) Secondary spermatocytes c) Both a and b d) Spermatogonia Vikasana - CET 2012 6.Meiosis II occurs in a) Secondary oocyte b))y Primary oocyte c) Spermatogonia d) Oogonia Vikasana - CET 2012 7.Axial filament of sperm is formed by a) Distal centriole b) Prox ima l centitrio le c) Mitochondria d) DNA Vikasana - CET 2012 8.Polar bodies are formed during a) oogenesis -
The Role of Jelly Coats in Sperm-Egg Encounters, Fertilization Success, and Selection on Egg Size in Broadcast Spawners
vol. 157, no. 6 the american naturalist june 2001 The Role of Jelly Coats in Sperm-Egg Encounters, Fertilization Success, and Selection on Egg Size in Broadcast Spawners Gregory S. Farley* and Don R. Levitan† Department of Biological Science, Florida State University, 1996a, 1998b; Coma and Lasker 1997). The proposed mech- Tallahassee, Florida 32306-1100 anism generating this result is simply that larger egg targets are more likely to be struck by swimming sperm (Rothschild Submitted February 2, 2000; Accepted January 19, 2001 and Swann 1949, 1951; Vogel et al. 1982). This finding has generated the hypothesis that sperm availability can influ- ence the evolutionary trade-off between egg size and num- ber (Levitan 1993, 1996a, 1996b, 1998a, 1998b). However, abstract: Sperm limitation may be an important selective force the idea that fertilization kinetics might influence this trade- influencing gamete traits such as egg size. The relatively inexpensive off has been challenged because of the notion that extra- extracellular structures surrounding many marine invertebrate eggs might serve to enhance collision rates without the added cost of cellular structures or chemoattractants may increase sperm- increasing the egg cell. However, despite decades of research, the egg collisions yet may not represent as great a cost to effects of extracellular structures on fertilization have not been con- fecundity as the trade-off associated with increased egg size clusively documented. Here, using the sea urchin Lytechinus varie- (Podolsky and Strathmann 1996; Styan 1998). These con- gatus, we remove jelly coats from eggs, and we quantify sperm col- tradictory ideas have not been resolved because data de- lisions to eggs with jelly coats, eggs without jelly coats, and inert tailing the influence of extracellular materials on fertilization plastic beads. -
Focus on Stem Cells Germ Cells from Mouse and Human Embryonic Stem Cells
REPRODUCTIONREVIEW Focus on Stem Cells Germ cells from mouse and human embryonic stem cells Behrouz Aflatoonian and Harry Moore Centre for Stem Cell Biology, University of Sheffield, Sheffield S10 2UH, UK Correspondence should be addressed to H Moore; Email: [email protected] Abstract Mammalian gametes are derived from a founder population of primordial germ cells (PGCs) that are determined early in embryogenesis and set aside for unique development. Understanding the mechanisms of PGC determination and differentiation is important for elucidating causes of infertility and how endocrine disrupting chemicals may potentially increase susceptibility to congenital reproductive abnormalities and conditions such as testicular cancer in adulthood (testicular dysgenesis syndrome). Primordial germ cells are closely related to embryonic stem cells (ESCs) and embryonic germ (EG) cells and comparisons between these cell types are providing new information about pluripotency and epigenetic processes. Murine ESCs can differentiate to PGCs, gametes and even blastocysts – recently live mouse pups were born from sperm generated from mESCs. Although investigations are still preliminary, human embryonic stem cells (hESCs) apparently display a similar developmental capacity to generate PGCs and immature gametes. Exactly how such gamete-like cells are generated during stem cell culture remains unclear especially as in vitro conditions are ill-defined. The findings are discussed in relation to the mechanisms of human PGC and gamete development and the biotechnology of hESCs and hEG cells. Reproduction (2006) 132 699–707 Introduction indicate that human embryonic stem cells (hESCs) most likely display a similar developmental capacity (Clark Detailed investigations of the earliest stages of germ cell et al. -
Insights from Male Germ Cell Differentiation
Cell Death & Differentiation (2021) 28:2296–2299 https://doi.org/10.1038/s41418-021-00812-0 COMMENT Natural selection at the cellular level: insights from male germ cell differentiation 1 1 Daniel H. Nguyen ● Diana J. Laird Received: 9 February 2021 / Revised: 20 May 2021 / Accepted: 20 May 2021 / Published online: 2 June 2021 © The Author(s) 2021. This article is published with open access Waddington’s concept of differentiation as an epigenetic The germline is a fascinating context for investigating landscape provides an enduring metaphor visualizing the the consequences of heterogeneity on differentiation and options faced by stem and progenitor cells. However, cell fate. As fetal germ cells establish the gametes, their increasing understanding of cellular heterogeneity poses population dynamics can greatly influence inheritance. The new questions about the identities and behaviors of the cells conflict between diversity and orderly differentiation looms beginning this process. We now recognize a greater diver- centrally over germline development. In mouse embryos, sity of initial states for individual progenitor cells, which germ cells undertake an epic journey, from specification may affect their trajectories and disrupt progress entirely. through sex differentiation, replete with opportunities for 1234567890();,: 1234567890();,: Here, we consider how developmental selection occurs heterogeneity to develop and be assessed. Notably, an when heterogeneity in differentiating progenitors produces excess of germ cells is produced and then pruned by pro- divergent cellular outcomes of survival versus elimination. grammed cell death [5]. This occurs across diverse species Heterogeneity is a fundamental property of biological regardless of sex, suggesting that differential fitness and systems. Individual cell properties like location or cell cycle elimination are critical. -
Fertilization Selection on Egg and Jelly-Coat Size in the Sand Dollar Dendraster Excentricus
Evolution, 55(12), 2001, pp. 2479±2483 FERTILIZATION SELECTION ON EGG AND JELLY-COAT SIZE IN THE SAND DOLLAR DENDRASTER EXCENTRICUS DON R. LEVITAN1,2 AND STACEY D. IRVINE2 1Department of Biological Science, Florida State University, Tallahassee, Florida 32306-1100 2Bam®eld Marine Station, Bam®eld, British Columbia VOR 1B0, Canada Abstract. Organisms with external fertilization are often sperm limited, and in echinoids, larger eggs have a higher probability of fertilization than smaller eggs. This difference is thought to be a result of the more frequent sperm- egg collisions experienced by larger targets. Here we report how two components of egg target size, the egg cell and jelly coat, contributed to fertilization success in a selection experiment. We used a cross-sectional analysis of correlated characters to estimate the selection gradients on egg and jelly-coat size in ®ve replicate male pairs of the sand dollar Dendraster excentricus. Results indicated that eggs with larger cells and jelly coats were preferentially fertilized under sperm limitation in the laboratory. The selection gradients were an average of 922% steeper for egg than for jelly- coat size. The standardized selection gradients for egg and jelly-coat size were similar. Our results suggest that fertilization selection can act on both egg-cell and jelly-coat size but that an increase in egg-cell volume is much more likely to increase fertilization success than an equal change in jelly-coat volume. The strengths of the selection gradients were inversely related to the correlation of egg traits across replicate egg clutches. This result suggests the importance of replication in studies of selection of correlated characters. -
Module 10: Meiosis and Gametogenesis
PEER-LED TEAM LEARNING INTRODUCTORY BIOLOGY MODULE 10: MEIOSIS AND GAMETOGENESIS JOSEPH G. GRISWOLD, PH.D. City College of New York, CUNY (retired) I. Introduction Most cells in our bodies have nuclei with 46 chromosomes organized in 23 homologous pairs. Because there are two chromosomes of each type, the cells are called diploid and 2N = 46. If mothers and fathers each passed 46 chromosomes to their offspring in reproducing, the children in the new generation would have 92 chromosomes apiece. In the following generation it would be 184. Obviously, the increase does not occur; normal people in each generation have the same 2N = 46. To produce a new individual (a zygote, initially) with 46 chromosomes, an egg and sperm each contribute half the total, or 23, when fertilization occurs. Both sperm and eggs, called gametes, develop from body cells in which the full 46 chromosomes are present. These body cells, located in the testes and ovaries, undergo special cell divisions, which reduce the number of chromosomes in half. The special cell divisions, two for each cell, make up a process called meiosis. Cells that have completed meiosis then differentiate to become gametes. The general objective of this laboratory is to learn how meiosis occurs in forming eggs and sperm to carry genetic information from one generation to the next. B. Benchmarks. 1. Demonstrate an understanding of the terminology of cellular genetic structure using diagrams. 2. Demonstrate the process of meiosis by using models or drawing chromosomes on cell outlines. 3. Compare the processes of mitosis and meiosis by: a. drawing diagrams with explanations of the processes, and b. -
Human Germline Genome Editing: Fact Sheet
Human germline genome editing: fact sheet Purpose • To contribute to evidence-informed discussions about human germline genome editing. KEY TAKEAWAYS • Gene editing offers the potential to improve human health in ways not previously possible. • Making changes to human genes that can be passed on to future generations is prohibited in Australia. • Unresolved questions remain on the possible long-term impacts, unintended consequences, and ethical issues associated with introducing heritable changes by editing of the genome of human gametes (sperm and eggs) and embryos. • AusBiotech believes the focus of human gene editing should remain on non-inheritable changes until such time as the scientific evidence, regulatory frameworks and health care models have progressed sufficiently to warrant consideration of any heritable genetic edits. Gene editing Gene editing is the insertion, deletion, or modification of DNA to modify an organism’s specific genetic characteristics. New and evolving gene editing techniques and tools (e.g. CRISPR) allow editing of genes with a level of precision that increases its applications across the health, agricultural, and industrial sectors. These breakthrough techniques potentially offer a range of different options for treating devastating human diseases and delivering environmentally sustainable food production systems that can feed the world’s growing population, which is expected to exceed nine billion by 2050. The current primary application of human gene editing is on non-reproductive cells (‘somatic’ cells) -
INTRODUCTION to REPRODUCTIVE HEALTH and the ENVIRONMENT (Draft for Review)
TRAINING FOR THE HEALTH SECTOR [Date…Place…Event…Sponsor…Organizer] INTRODUCTION TO REPRODUCTIVE HEALTH AND THE ENVIRONMENT (Draft for review) Training Module 1 Children's Environmental Health Public Health and the Environment World Health Organization www.who.int/ceh November 2011 1 <<NOTE TO USER: Please add details of the date, time, place and sponsorship of the meeting for which you are using this presentation in the space indicated.>> <<NOTE TO USER: This is a large set of slides from which the presenter should select the most relevant ones to use in a specific presentation. These slides cover many facets of the issue. Present only those slides that apply most directly to the local situation in the region or country.>> <<NOTE TO USER: This module presents several examples of risk factors that affect reproductive health. You can find more detailed information in other modules of the training package that deal with specific risk factors, such as lead, mercury, pesticides, persistent organic pollutants, endocrine disruptors, occupational exposures; or disease outcomes, such as developmental origins of disease, reproductive effects, neurodevelopmental effects, immune effects, respiratory effects, and others.>> <<NOTE TO USER: For more information on reproductive health, please visit the website of the Department of Reproductive Health and Research at WHO: www.who.int/reproductivehealth/en/>> 1 Reproductive Health and the Environment (Draft for review) LEARNING OBJECTIVES After this presentation individuals should be able to understand, recognize, and know: Basic components of reproductive health Basic hormone and endocrine functions Reproductive physiology Importance of environmental exposures on reproductive health endpoints 2 <<READ SLIDE.>> According to the formal definition by the World Health Organization (WHO), health is more than absence of illness.