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UNSW Embryology

Week 1 - Meiosis

© Dr Mark Hill (2011)

Acknowledgements

Introduction

The first week of human development begins with fertilization of the egg (oocyte) by sperm forming the zygote. Both the oocyte and sperm have to have half the DNA (haploid) to forn the zygote (diploid). This is achieved by a special form of cell division that only occurs in species that undergo sexual reproduction, meiosis.

Meiosis differs from mitosis in that the cells produced have recombuned their DNA and only contain half the normal cell's DNA content and recomThese notes also cover events before fertilization formation of both the egg and sperm, gametogenesis. Cell division can occur in 2 forms, mitosis and meiosis. Mitosis can occur in all cells, while meiosis only occurs during the formation of the sex gametes.

Initially, there is a halving of choromosomal content in the gametes, which is restored by fertilization, allowing genetic recombination to occur. This is then followed by a series of cell divisions without cytoplasmic growth.

I have also included in the Week 1 notes information about male sex determination and X inactivation, which are not really specific to the first week of development.

Page Links: Introduction | Some Recent Findings | Meiosis Overview | Differences in Mammalian Meioses | Polar Bodies | Comparison of Meiosis/Mitosis | Abnormalities | References | Glossary

Related Pages: Cell division | Mitosis | Gamete Formation | Oogenesis | Spermatogenesis |

Some Recent Findings

Akiyama T, Nagata M, Aoki F. Inadequate histone deacetylation during oocyte meiosis causes aneuploidy and embryo death in mice. Proc Natl Acad Sci U S A. 2006 May 9;103(19):7339-44.

"It was recently reported that histones are globally deacetylated in mammalian oocytes during meiosis but not mitosis. ... The high incidence of aneuploidy in the embryos of older females may be due to inadequate meiotic histone deacetylation."

Wang Q, Yin S, Ai JS, Liang CG, Hou Y, Chen DY, Schatten H, Sun QY. Histone deacetylation is required for orderly meiosis. Cell Cycle. 2006 Apr;5(7):766-74.

"The results showed that subcellular translocation, expression level and phosphorylated modification of histone deacetylase 1 were temporally regulated and likely to coparticipate in the establishment of histone acetylation profiles in oocyte meiosis."

Meiosis Overview

There are several full versions of this content as a lecture available online from UNSW Cell Biology website Medicine- Society and Health , Science- Cell Biology

Differences in Mammalian Meioses

Female Oogenesis

Male Spermatogenesis

Polar Bodies

In female gametogenesis only a single (1) haploid egg is produced from meiosis. In male gametogenesis four (4) haploid sperm are produced from meiosis.

So what happens to all the extra DNA in producing this single egg?

In Meiosis 1 the "extra" DNA is excluded to the periphery as a 1st polar body, which encloses the extra DNA.

In Meiosis 2 the "extra" DNA is once again excluded as a 2nd polar body. The first polar body may also under go meiosis 2 producing a 3rd polar body.

These polar bodies are not gametes. These polar bodies appear to have no other function than to dispose of the extra DNA.

Comparison of Meiosis/Mitosis

After DNA replication 2 nuclear (and cell) divisions required to produce haploid gametes Each diploid cell in meiosis produces 4 haploid cells Each diploid cell mitosis produces 2 diploid cells only one pair of homologous chromosomes is shown

Abnormalities

Meiotic Nondisjunction

Occurs when homologues fail to separate during meiotic division I or II

Down Syndrome Caused by an extra copy of chromosome 21.

Genome Modifications

chromosomal translocations

Philadelphia chromosome

Chronic myelogenous leukemia

Piece of Chr9 exchanged with Chr22

Generates truncated abl

Overstimulates cell production

Glossary

A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z | Numbers | Old Glossary

References

Links: Journals | Online Textbooks | Search Textbooks | Reviews | Articles | 1999 Refs | Search PubMed | Glossary

Journals

Online Textbooks

Molecular Biology of the Cell Alberts, Bruce; Johnson, Alexander; Lewis, Julian; Raff, Martin; Roberts, Keith; Walter, Peter New York and London: Garland Science; c2002 Meiosis

Developmental Biology Gilbert, Scott F. Sunderland (MA): Sinauer Associates, Inc.; c2000Meiosis

Molecular Cell Biology Lodish, Harvey; Berk, Arnold; Zipursky, S. Lawrence; Matsudaira, Paul; Baltimore, David; Darnell, James E. New York: W. H. Freeman & Co.; c1999 Meiosis Figure

Search NLM Online Textbooks meiosis Molecular Biology of the Cell | The Cell- A molecular Approach

Reviews

Burgoyne PS, Mahadevaiah SK, Turner JM. The consequences of asynapsis for mammalian meiosis. Nat Rev Genet. 2009 Mar;10(3):207-16. Review. PMID: 19188923

Location, location, location! Monotremes provide unique insights into the evolution of sex chromosome silencing in mammals. Daish T, Grützner F. DNA Cell Biol. 2009 Feb;28(2):91-100. Review. PMID: 19196046

Maternal origin of the human aneuploidies. Are homolog synapsis and recombination to blame? Notes (learned) from the underbelly. Garcia-Cruz R, Roig I, Caldés MG. Genome Dyn. 2009;5:128-36. Review. PMID: 18948712

Articles

Nongenomic steroid-triggered oocyte maturation: Of mice and frogs. Deng J, Carbajal L, Evaul K, Rasar M, Jamnongjit M, Hammes SR. Steroids. 2009 Jul;74(7):595-601. Epub 2008 Nov 24. PMID: 19071151

Kit ligand promotes first polar body extrusion of mouse preovulatory oocytes. Ye Y, Kawamura K, Sasaki M, Kawamura N, Groenen P, Gelpke MD, Rauch R, Hsueh AJ, Tanaka T. Reprod Biol Endocrinol. 2009 Apr 3;7(1):26. [Epub ahead of print] PMID: 19341483

Search Mar 2009 "meiosis" 17,749 reference articles of which 1,873 were reviews.

Search PubMed: term = meiosis

Old References

Molecular Biology of the Cell- References

These are a list of references retrieved in a 2000 search of PubMed.(More? meiosis)

26 citations found

Zhan XL, et al.           [See Related Articles]

Essential functions of protein tyrosine phosphatases ptp2 and ptp3 and rim11 tyrosine phosphorylation in saccharomyces cerevisiae meiosis and sporulation.
Mol Biol Cell. 2000 Feb;11(2):663-76.
[MEDLINE record in process]
PMID: 10679022; UI: 20143586.
Hicks JL, et al.           [See Related Articles]
Class VI unconventional myosin is required for spermatogenesis in Drosophila.
Mol Biol Cell. 1999 Dec;10(12):4341-53.
PMID: 10588662; UI: 20056109.
Sohaskey ML, et al.           [See Related Articles]
Distinct, constitutively active MAPK phosphatases function in Xenopus oocytes: implications for p42 MAPK regulation In vivo.
Mol Biol Cell. 1999 Nov;10(11):3729-43.
PMID: 10564268; UI: 20032171.
Grether ME, et al.           [See Related Articles]
Genetic and biochemical characterization of the yeast spo12 protein.
Mol Biol Cell. 1999 Nov;10(11):3689-703.
PMID: 10564265; UI: 20032168.
Culp PA, et al.           [See Related Articles]
c-mos and cdc2 cooperate in the translational activation of fibroblast growth factor receptor-1 during Xenopus oocyte maturation.
Mol Biol Cell. 1999 Nov;10(11):3567-81.
PMID: 10564256; UI: 20032159.
Gavin AC, et al.           [See Related Articles]
A p90(rsk) mutant constitutively interacting with MAP kinase uncouples MAP kinase from p34(cdc2)/cyclin B activation in Xenopus oocytes.
Mol Biol Cell. 1999 Sep;10(9):2971-86.
PMID: 10473640; UI: 99402804.
Fowler TJ, et al.           [See Related Articles]
Multiple sex pheromones and receptors of a mushroom-producing fungus elicit mating in yeast.
Mol Biol Cell. 1999 Aug;10(8):2559-72.
PMID: 10436012; UI: 99365150.
Alsheimer M, et al.           [See Related Articles]
Architecture of the nuclear periphery of rat pachytene spermatocytes: distribution of nuclear envelope proteins in relation to synaptonemal complex attachment sites.
Mol Biol Cell. 1999 Apr;10(4):1235-45.
PMID: 10198069; UI: 99214008.
Hartsuiker E, et al.           [See Related Articles]
The role of topoisomerase II in meiotic chromosome condensation and segregation in Schizosaccharomyces pombe.
Mol Biol Cell. 1998 Oct;9(10):2739-50.
PMID: 9763441; UI: 98437181.
Simerly C, et al.           [See Related Articles]
Differential expression and functions of cortical myosin IIA and IIB isotypes during meiotic maturation, fertilization, and mitosis in mouse oocytes and embryos.
Mol Biol Cell. 1998 Sep;9(9):2509-25.
PMID: 9725909; UI: 98395051.
Rudge SA, et al.           [See Related Articles]
ADP-Ribosylation factors do not activate yeast phospholipase Ds but are required for sporulation.
Mol Biol Cell. 1998 Aug;9(8):2025-36.
PMID: 9693364; UI: 98359829.
Högstrand K, et al.           [See Related Articles]
Gene Conversion of Major Histocompatibility Complex Genes in the Mouse Spermatogenesis is a Premeiotic Event.
Mol Biol Cell. 1997 Dec 1;8(12):2511-7.
[Record as supplied by publisher]
PMID: 9398672.
Marko JF, et al.           [See Related Articles]
Polymer models of meiotic and mitotic chromosomes.
Mol Biol Cell. 1997 Nov;8(11):2217-31.
PMID: 9362064; UI: 98028157.
Tarsounas M, et al.           [See Related Articles]
Protein-protein interactions in the synaptonemal complex.
Mol Biol Cell. 1997 Aug;8(8):1405-14.
PMID: 9285814; UI: 97431777.
Elfring LK, et al.           [See Related Articles]
Drosophila PLUTONIUM protein is a specialized cell cycle regulator required at the onset of embryogenesis.
Mol Biol Cell. 1997 Apr;8(4):583-93.
PMID: 9247640; UI: 97390805.
Ochs RL, et al.           [See Related Articles]
cDNA cloning and characterization of a novel nucleolar protein.
Mol Biol Cell. 1996 Jul;7(7):1015-24.
PMID: 8862517; UI: 97015880.
Sperry AO, et al.           [See Related Articles]
Kinesin-related proteins in the mammalian testes: candidate motors for meiosis and morphogenesis.
Mol Biol Cell. 1996 Feb;7(2):289-305.
PMID: 8688559; UI: 96228687.
Smith MG, et al.           [See Related Articles]
Organelle-cytoskeletal interactions: actin mutations inhibit meiosis-dependent mitochondrial rearrangement in the budding yeast Saccharomyces cerevisiae.
Mol Biol Cell. 1995 Oct;6(10):1381-96.
PMID: 8573793; UI: 96117051.
Li J, et al.           [See Related Articles]
Requirement for phosphorylation of cyclin B1 for Xenopus oocyte maturation.
Mol Biol Cell. 1995 Sep;6(9):1111-24.
PMID: 8534910; UI: 96079260.
Richler C, et al.           [See Related Articles]
Splicing components are excluded from the transcriptionally inactive XY body in male meiotic nuclei.
Mol Biol Cell. 1994 Dec;5(12):1341-52.
PMID: 7696714; UI: 95210752.
Taagepera S, et al.           [See Related Articles]
The MPM-2 antibody inhibits mitogen-activated protein kinase activity by binding to an epitope containing phosphothreonine-183.
Mol Biol Cell. 1994 Nov;5(11):1243-51.
PMID: 7532473; UI: 95170120.
Brown AJ, et al.           [See Related Articles]
Expression and activity of p40MO15, the catalytic subunit of cdk-activating kinase, during Xenopus oogenesis and embryogenesis.
Mol Biol Cell. 1994 Aug;5(8):921-32.
PMID: 7803859; UI: 95102156.
Pickham KM, et al.           [See Related Articles]
Mutants at Ser277 of Xenopus cdc2 protein kinase induce oocyte maturation in the absence of the positive regulatory phosphorylation site Thr161.
Mol Biol Cell. 1994 May;5(5):587-96.
PMID: 7919539; UI: 95003216.
Galas S, et al.           [See Related Articles]
A nuclear factor required for specific translation of cyclin B may control the timing of first meiotic cleavage in starfish oocytes.
Mol Biol Cell. 1993 Dec;4(12):1295-306.
PMID: 7513215; UI: 94220786.
Stith BJ, et al.           [See Related Articles]
Inositol 1,4,5-trisphosphate mass changes from fertilization through first cleavage in Xenopus laevis.
Mol Biol Cell. 1993 Apr;4(4):435-43.
PMID: 8507898; UI: 93283738.
Lee MS, et al.           [See Related Articles]
cdc25+ encodes a protein phosphatase that dephosphorylates p34cdc2.
Mol Biol Cell. 1992 Jan;3(1):73-84.
PMID: 1312880; UI: 92199341.

Quick Links

Week 1 Pages:

Introduction | Abnormalities | Gamete formation | Cell division | Fertilization | Zygote | Blastocyst | Male sex determination| X inactivation | References | Text only page | WWW Links |

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