Meiosis News and Research

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Multicellular eukaryotes and single-celled sex cells reproduce by a process called meiosis. In this process, the number of chromosomes in a mother cell is halved to produce gametes, cells that fuse with other cells. This happens in plants, animals, and fungi. German biologist, Oscar Hertwig first discovered meiosis in sea urchin eggs in 1876.

Low levels of dietary folate linked to sperm abnormalities

Healthy men who report lower levels of the nutrient folate in their diets have higher rates of chromosomal abnormalities in their sperm, according to a new study by researchers at the University of California, Berkeley, and the Lawrence Berkeley National Laboratory.

20 Mar 2008

Penn researchers identify first sex chromosome gene involved in meiosis and male infertility

A team of scientists led by University of Pennsylvania veterinary researchers have identified a gene, TEX11, located on the X chromosome, which when disrupted in mice renders the males sterile and reduces female fecundity.

17 Mar 2008

Transgenics sped up

A new method of constructing artificial plant chromosomes from small rings of naturally occurring plant DNA can be used to transport multiple genes at once into embryonic plants where they are expressed, duplicated as plant cells divide, and passed on to the next generation -- a long-term goal for those interested in improving agricultural productivity.

19 Oct 2007

RecA family recombinases repair DNA damages

A biochemistry research team led by Dr. Andrew H.-J. Wang and Dr. Ting-Fang Wang at the Institute of Biological Chemistry, Academia Sinica(IBCAS), has discovered that the RecA family recombinases function as a new type of rotary motor proteins to repair DNA damages.

13 Sep 2007

Discredited Korean embryonic stem cells' true origins revealed

A report from researchers at Children's Hospital Boston and the Harvard Stem Cell Institute sheds new light on a now-discredited Korean embryonic stem cell line, setting the historical record straight and also establishing a much-needed set of standards for characterizing human embryonic stem cells.

3 Aug 2007

Cornell University establishes Center for Reproductive Genomics

Cornell University has established the Center for Reproductive Genomics, which will combine basic research in reproductive sciences on Cornell's Ithaca campus with one of the country's leading fertility clinics at Weill Cornell Medical College (WCMC) in New York City.

10 May 2007

Stranger than science fiction?...Human sperm created from bone marrow

A team of scientists have created primitive human sperm in the laboratory by using bone-marrow tissue from male volunteers.

16 Apr 2007

Human bone marrow has been used to create early-stage sperm cells

For the experiment, Prof Nayernia and his team took bone marrow from male volunteers and isolated the mesenchymal stem cells. These cells have previously been found to grow into other body tissues such as muscle.

15 Apr 2007

Genetic mutation that prevents sperm production found

Up to 15 percent of couples of childbearing age struggle with the heartache of infertility.

11 Apr 2007

Scientists discover function for antisense RNA

Researchers have found that a class of RNA molecules, previously thought to have no function, may in fact protect sex cells from self-destructing. These findings will be published in the November 17 issue of the journal Cell.

20 Nov 2006

Centrosomes may contain ribonucleic acid

Despite more than a century of study, scientists know relatively little about the inner workings of centrosomes - organelles essential to cell division in humans and animals.

7 Jun 2006

New understanding of chromosomal glue

Researchers have a new understanding of the process cells use to ensure that sperm and eggs begin life with exactly one copy of each chromosome - a process that must be exquisitely regulated to prevent problems such as miscarriages and mental retardation.

8 May 2006

Why males produce sperm and females produce eggs

An Australian research team has solved one of biology's most fundamental questions - why males produce sperm and females produce eggs. The finding is a breakthrough that could lead to improved infertility treatment, cancer therapy and pest management.

4 Apr 2006

Protein Mnd2 protects chromosome bonds

The protein Mnd2 inhibits premature separation of chromosomes during the formation of gametes. The now published discovery of this regulatory function may help to understand the origin of some common congenital chromosome defects.

30 Mar 2005

Researchers have uncovered evidence of sexual reproduction in a single-celled organism long thought to reproduce asexually

The finding by John M. Logsdon, Jr., assistant professor in the UI College of Liberal Arts and Sciences Department of Biological Sciences and the Roy J. Carver Center for Comparative Genomics, and colleagues from the UI and Roanoke College (Virginia), provides the first clear evidence that meiosis arose very early in eukaryotic evolution, bringing science one step closer to understanding the mystery of sexual evolution.

26 Jan 2005

Needling chromosomes yields insights into cell division

By impaling individual chromosomes with glass needles one thousandth the diameter of a human hair, a Duke University graduate student has tested their "stickiness" to one another during cell division. Her uncanny surgical skills have added a piece to the large and intricate puzzle of how one cell divides into two -- a process fundamental to all organisms.

23 Dec 2004

Australian platypus research has implications for understanding the evolution of human sex determination

The mystery surrounding sex determination of the unique Australian platypus has yielded a surprising secret: it has 10 sex chromosomes.

25 Oct 2004

Gene responsible for infertility

A paper describing discoveries about the role of a gene that is important in all animals, plants, and fungi is published in the 20 July 2004 issue of the journal Proceedings of the National Academy of Sciences.

23 Jul 2004

Oxidants are responsible for sex in algae

Colonies of the multicellular green alga Volvox carteri exposed to temperatures of 111 degrees Fahrenheit (42.5 degrees Celsius) had twice the amount of free radicals, oxidants that can damage biological structures, as unheated colonies. High levels of oxidants within their cells activated the algae's sex-inducer gene, the researchers report.

11 Jun 2004

New information on genetic shuffling before egg or sperm formation rewrites genetic theory

Key decisions in the genetic shuffling that occurs before eggs or sperm are formed are made earlier than thought, rewriting textbook genetics, according to recent papers from researchers at UC Davis, Harvard University and UC San Diego.

16 Apr 2004