This article may require cleanup to meet Wikipedia's quality standards. The specific problem is: the egg cell of plants is very rarely called an ovum; the material about it needs to be separated. Please help improve this article if you can; the talk page may contain suggestions. (April 2012)

Ovum
A human ovum with corona radiata surrounding it

An ovum (plural ova, from the Latin word ovum meaning egg or egg cell) is a haploid female reproductive cell or gamete. Both animals and embryophytes have ova. The term ovule is used for the young ovum of an animal, as well as the plant structure that carries the female gametophyte and egg cell and develops into a seed after fertilization. In lower plants and algae, the ovum is also often called oosphere.

Ova production[link]

In higher animals, ova are produced by female gonads (sexual glands) called ovaries and all of them are present at birth in mammals and mature via oogenesis.

Human and mammal ova[link]

A sperm cell fusing with an ovum

The process of fertilizing an ovum (Top to bottom)

In the viviparous animals (which include humans and all other placental mammals), the ovum is fertilized inside the female body and the embryo then develops inside the uterus, receiving nutrition directly from the mother.

The human ova grow from primitive germ cells that are embedded in the substance of the ovaries. Each of them divides repeatedly to give rise to several smaller cells, the oogonia. The oogonia then develop via meiosis into the ova, the primary oocytes, and the polar bodies.^[1]

The ovum is one of the largest cells in the human body, typically visible to the naked eye without the aid of a microscope or other magnification device. The human ovum measures approximately 0.12 mm in diameter.^[2]

Protist and plant ova[link]

In protists, fungi and many plants, such as bryophytes, ferns, and gymnosperms, ova are produced inside archegonia. Since the archegonium is a haploid structure, egg cells are produced via mitosis. The typical bryophyte archegonium consists of a long neck with a wider base containing the egg cell. Upon maturation, the neck opens to allow sperm cells to swim into the archegonium and fertilize the egg. The resulting zygote then gives rise to an embryo, which will grow out of the archegonium as a young sporophyte.

In the flowering plants, the female gametophyte, which usually gives rise to the archegonium, has been reduced to just eight cells referred to as the embryo sac inside the ovule. The gametophyte cell closest to the micropyle opening of the embryo sac develops into the egg cell. Upon pollination, a pollen tube delivers sperm into the embryo sac and one sperm nucleus fuses with the egg nucleus. The resulting zygote develops into an embryo inside the ovule. The ovule in turn develops into a seed and in many cases the plant ovary develops into a fruit to facilitate the dispersal of the seeds. Upon germination, the embryo grows into a seedling.

Gene expression pattern determined by histochemical GUS assays in Physcomitrella patens. The Polycomb gene FIE is expressed (blue) in unfertilised egg cells of the moss Physcomitrella patens (right) and expression ceases after fertilisation in the developing diploid sporophyte (left). In situ GUS staining of two female sex organs (archegonia) of a transgenic plant expressing a translational fusion of FIE-uidA under control of the native FIE promoter

In the moss Physcomitrella patens, the Polycomb protein FIE is expressed in the unfertilised egg cell (Figure, right) as the blue colour after GUS staining reveals. Soon after fertilisation the FIE gene is inactivated (the blue colour is no longer visible, left) in the young embryo. ^[3]

Ooplasm[link]

Ooplasm (also: oöplasm) is the yolk of the ovum, a cell substance at its center, which contains its nucleus, named the germinal vesicle, and the nucleolus, called the germinal spot.^[4]

The ooplasm consists of the cytoplasm of the ordinary animal cell with its spongioplasm and hyaloplasm, often called the formative yolk; and the nutritive yolk or deutoplasm, made of rounded granules of fatty and albuminoid substances imbedded in the cytoplasm.^[4]

Mammalian ova contain only a tiny amount of the nutritive yolk, for nourishing the embryo in the early stages of its development only. In contrast, bird eggs contain enough to supply the chick with nutriment throughout the whole period of incubation.^[4]

Ova development in oviparous animals[link]

In the oviparous animals (all birds, most fishes, amphibians and reptiles) the ova develop protective layers and pass through the oviduct to the outside of the body. They are fertilized by male sperm either inside the female body (as in birds), or outside (as in many fishes). After fertilization, an embryo develops, nourished by nutrients contained in the egg. It then hatches from the egg, outside the mother's body. See egg (biology) for a discussion of eggs of oviparous animals.

The egg cell's cytoplasm and mitochondria (and chloroplasts in plants) are the sole means the egg is able to reproduce by mitosis and eventually form a blastocyst after fertilization.

Ovoviviparity[link]

There is an intermediate form, the ovoviviparous animals: the embryo develops within and is nourished by an egg as in the oviparous case, but then it hatches inside the mother's body shortly before birth, or just after the egg leaves the mother's body. Some fish, reptiles and many invertebrates use this technique.

See also[link]

• Egg (biology)
• Fertilization
• Insemination
• Menstrual cycle
• Ovulation
• Pollination
• Pregnancy
• Polar body

External links[link]

• The Ovarian Kaleidoscope Database description of 1800 genes involved in ovarian functions

References[link]

This biographical article needs additional citations for verification. Please help by adding reliable sources. Contentious material about living persons that is unsourced or poorly sourced must be removed immediately, especially if potentially libelous or harmful. (March 2009)

Ian Pooley (born Ian Pinnekamp in 1973) is a German-born record producer and DJ. While incorporating samples of various musical genres, Pooley's creations are usually classified as house or tech house with Brazilian influence.

Career[link]

Pooley's music career began in 1993.^[1] After a long stretch with V2 Records in which Pooley released several very successful^{[citation needed]} albums (Meridian and Since Then) Pooley left V2 and started his own record company, Pooled Music, in 2003.^[1]

Ian Pooley has also cited on various albums (Brazilution 5.3 and Souvenirs being two) that he had an audible 'click' when listening to Brazilian music at a night club.^{[citation needed]} As such, a lot of his music has a noticeable Brazilian flavor to it. He has incorporated artists like Rosanna and Zelia and veteran musician Marcos Valle in some of his works.

In addition to original works, Pooley has remixed artists such as Deee-Lite, The Cardigans, Daft Punk, Carl Cox and Bob Sinclar.^[2]

Discography[link]

Albums[link]

• 1993 The Latest Adventures of Kool Killer, as Space Cube
• 1995 Relations
• 1996 The Times
• 1998 Meridian
• 1999 The Allnighter/Calypso
• 2000 Since Then
• 2002 The IP Series
• 2004 Souvenirs
• 2005 A Subterranean Soundtrack
• 2008 In Other Words

Singles[link]

Ian Pooley

• 1993 "Limited Edition"
• 1994 "Pulse Code EP", as Ian Pooley & Alec Empire (with Alec Empire)
• 1994 "Roller Skate Disco"
• 1994 "Twin Gods EP"
• 1995 "Twin Gods Vol. 2"
• 1995 "Celtic Cross EP"
• 1995 "Celtic Cross Remixes"
• 1995 "My Anthem"
• 1995 "Today"
• 1996 "Chord Memory"
• 1996 "Two Space Cowboys on a [Bad] Trip to Texas", as Ian Pooley & The Jaguar (with Alec Empire)
• 1996 "What's Your Number"
• 1997 "Calypso EP"
• 1997 "Gimme Sound"
• 1997 "Higgledy Piggedly"
• 1998 "Followed"
• 1998 "Loopduelle"
• 1998 "Rock Da Discoteque EP"
• 1998 "What's Your Number" (re-release)
• 1999 "Coldwait"
• 2000 "900 Degrees"
• 2000 "Coração Tambor" (with Rosanna & Zélia)
• 2000 "The Allnighter EP"
• 2001 "Balmes (A Better Life)" (with Esthero)
• 2002 "Traffic"
• 2002 "The Fly Shuffle"
• 2002 "Niteflite"
• 2002 "Missing You"
• 2002 "Ready to Flow"
• 2002 "Piha", as Ian Pooley & Magik J (with Magik J)
• 2003 "Here We Go!"
• 2003 "Heke", as Ian Pooley & Magik J (with Magik J)
• 2004 "Searchin'"
• 2004 "Heaven" (with Jade and Danni'elle)
• 2005 "Samo Iluzija"
• 2006 "Higgledy Piggedly 2006"
• 2006 "Celtic Cross 2006"
• 2007 "All Nite"

Ides

• 1994 "Sweet & Sour EP"
• 1996 "Plastered EP"
• 1996 "Elastic EP"
• 1998 "Limer"
• 2005 "Right in the Night EP"

Space Cube

All are collaborations with DJ Tonka

• 1991 "Space Cube EP"
• 1991 "Sub Audible"
• 1992 "Kool Killer EP"
• 1992 "Kool Killer Vol. 2"
• 1993 "Kool Killer Vol. 3"
• 1993 "Kool Killer Mixes EP"
• 1993 "Unreleased Project EP"
• 1993 "The Latest Adventures of Kool Killer EP"
• 1994 "Dschungelfieber"
• 1994 "Inbound/Outbound"
• 1995 "Kommerz Killer/Big Bam Bam"
• 1997 "Unreleased Space Cube Tracks"

T'N'I

All are collaborations with DJ Tonka

• 1991 "Low Mass EP"
• 1991 "Trip Men"
• 1991 "Do You Still Care" (with Marie Pullins)
• 1992 "Beam EP"
• 1993 "Depart EP"
• 1993 "Dream Team EP"
• 1993 "I Want To Be Free"
• 1994 "Mad Situation/Be Straight"

Other aliases

• 1991 "Emperor/Daylight", as Outrage (with DJ Tonka)
• 1993 "The Modular", as The Modulor
• 1996 "Next to Nowhere", as Ansicht
• 1996 "Skippin' EP", as John Skipper Trax
• 1996 "Roll With It!", as The Low Frequency Band
• 1996 "Ice Fractions 1", as Silvershower
• 1996 "Ice Fractions 2", as Silvershower
• 1997 "Enlite EP", as Bluelite
• 1999 "Enlite Juice", as Bluelite
• 1999 "Valle Valle!", as Pinnchiky"
• 2001 "Viewing a Decade EP", as Quiet Daze
• 2002 "Skippin' EP", as John Skipper Trax (re-release)

References[link]

External links[link]

• Official website
• Ian Pooley discography at Discogs

This article on a house musician is a stub. You can help Wikipedia by expanding it. v t e